NGF Antagonists for Medical Use

Information

  • Patent Application
  • 20220169740
  • Publication Number
    20220169740
  • Date Filed
    March 20, 2020
    4 years ago
  • Date Published
    June 02, 2022
    2 years ago
Abstract
Provided are various embodiments relating to TrkA ECD polypeptides from companion animal species that bind to NGF. Such polypeptides can be used in methods to treat NGF-induced condition related to chronic pain and/or inflammatory pain in companion animals, such as canines, felines, and equines.
Description
FIELD

This present disclosure relates to polypeptides comprising an extracellular domain of TrkA from a companion animal species that bind to NGF. This present disclosure also relates to methods of using the polypeptides, for example, for treating NGF-induced conditions or reducing NGF signaling activity in cells, for instance in companion animals, such as canines, felines, and equines.


BACKGROUND

Nerve growth factor (NGF) is a neurotrophic factor with broad effect on regulation of growth, maintenance, proliferation, and survival of certain neurons. NGF has also been linked to chronic and inflammatory pain. NGF binds to two classes of receptors: the tropomyosine receptor kinase A (TrkA) and low affinity NGF receptor. When NGF, a dimer, binds to TrkA extracellular domains, it causes the dimerization of the receptor, activating the downstream kinase activity. TrkA extracellular domains may be useful to antagonize NGF activity, reduce free NGF, and/or diminishing clinical signs and symptoms associated with NGF-related pain.


Companion species animals, such as cats, dogs, and horses, suffer from many conditions similar to human conditions, including chronic and inflammatory pain. There remains a need, therefore, for methods and species specific compounds that can be used specifically to bind companion animal NGF for treating NGF-induced conditions and for reducing NGF signaling activity.


SUMMARY

Embodiment 1. A contiguous polypeptide comprising at least one extracellular domain of a TrkA polypeptide (TrkA ECD polypeptide) from a companion animal species and a fusion partner.


Embodiment 2. The contiguous polypeptide of embodiment 1, wherein the contiguous polypeptide binds to an NGF polypeptide with a dissociation constant (Kd) of less than 5×10−6M, less than 1×10−6M, less than 5×10−7 M, less than 1×10−7 M, less than 5×10−8 M, less than 1×10−8 M, less than 5×10−9 M, less than 1×10−9 M, less than 5×10−10 M, less than 1×10−10 M, less than 5×10−11 M, less than 1×10−11 M, less than 5×10−12 M, or less than 1×10−12 M, as measured by biolayer interferometry.


Embodiment 3. The contiguous polypeptide of embodiment 2, wherein the NGF polypeptide is a human NGF polypeptide, a canine NGF polypeptide, a feline NGF polypeptide, or an equine polypeptide.


Embodiment 4. The contiguous polypeptide of any one of the preceding embodiments, wherein the contiguous polypeptide reduces NGF signaling in the companion animal species.


Embodiment 5. The contiguous polypeptide of any one of the preceding embodiments, wherein the companion animal species is canine, feline, or equine.


Embodiment 6. The contiguous polypeptide of any one of the preceding embodiments, wherein the amino acid sequence of the TrkA ECD polypeptide is at least 90% identical, at least 91% identical, at least 92% identical, at least 93% identical, at least 94% identical, at least 95% identical, at least 96% identical, at least 97% identical, at least 98% identical, or at least 99% identical to the amino acid sequence of SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, or SEQ ID NO: 15.


Embodiment 7. The contiguous polypeptide of any one of the preceding embodiments, wherein the TrkA ECD polypeptide comprises:


a) a cysteine at a position corresponding to position 7 and position 89 of SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 12, SEQ ID NO: 13, or SEQ ID NO: 14; or


b) a cysteine at a position corresponding to position 5 and position 87 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15.


Embodiment 8. The contiguous polypeptide of any one of the preceding embodiments, wherein the TrkA ECD polypeptide comprises:


a) a cysteine at position 7 and position 89 of SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 12, SEQ ID NO: 13, or SEQ ID NO: 14; or


b) a cysteine at position 5 and position 87 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15.


Embodiment 9. The contiguous polypeptide of any one of the preceding embodiments, wherein the TrkA ECD polypeptide comprises at least one N-linked glycosylation site not present in the corresponding wild-type TrkA ECD polypeptide, wherein the N-linked glycosylation site comprises the sequence asparagine-xaa-serine or asparagine-xaa-threonine, wherein xaa is any amino acid except proline, and wherein one N-linked glycosylation site does not overlap with another N-linked glycosylation site.


Embodiment 10. The contiguous polypeptide of any one of the preceding embodiments, wherein the TrkA ECD comprises at least one N-linked glycosylation site at one or more position(s) selected from:


a) amino acid positions 6-8, 31-33, 84-86, 85-87, 86-88, 88-90, 90-92, 92-94, and/or 94-96 of SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 13, or SEQ ID NO: 14; or


b) amino acid positions 4-6, 29-31, 82-84, 83-85, 84-86, 86-88, 89-90, 90-92, and/or 92-94 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15.


Embodiment 11. The contiguous polypeptide of any one of the preceding embodiments, wherein the TrkA ECD polypeptide comprises:


a) an amino acid other than proline at an amino acid position corresponding to position 30 and/or position 85 of SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 13, or SEQ ID NO: 14; and/or


b) an amino acid other than proline at an amino acid position corresponding to position 28 or position 83 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15.


Embodiment 12. The contiguous polypeptide of any one of the preceding embodiments, wherein the TrkA ECD polypeptide comprises:


a) a valine, a glutamic acid, an alanine, or an isoleucine at an amino acid position corresponding to position 30 and/or position 85 of SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 13, or SEQ ID NO: 14; and/or


b) a valine, a glutamic acid, an alanine, or an isoleucine at an amino acid position corresponding to position 28 or position 83 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15.


Embodiment 13. The contiguous polypeptide of any one of the preceding embodiments, wherein the TrkA ECD polypeptide comprises one or more amino acid modifications listed in Table A:












Amino acid substitutions for N-linked glycosylation sites










Based on canine TrkA ECD
Based on canine TrkA



v2 or v3 sequence
ECD v4 sequence



(SEQ ID NOs: 3 or 4)
(SEQ ID NO: 5)







N6S8
N4S6



N6T8
N4T6



*X30N31S33
*X28N29S31



*X30N31T33
*X28N29T31



*X85
*X83



*X85T86
*X83T84



N85S87
N83S85



N85T87
N83T85



*X85N86S88
*X83N84S86



*X85N86T88
*X83N84T86



N88S90
N86S88



N88T90
N86T88



N90S92
N88S90



N90T92
N88T90



N92S94
N90S92



N92T94
N90T92



N94S96
N92S94



N94T96
N92T94,







wherein *X indicates any amino acid except proline (such as E, V, A, or I);






Table B:












Amino acid substitutions for N-linked glycosylation sites










Based on feline TrkA ECD
Based on feline TrkA



v2 or v3 sequence
ECD v4 sequence



(SEQ ID NOs: 8 or 9)
(SEQ ID NO: 10)







N6S8
N4S6



N6T8
N4T6



*X30N31S33
*X28N29S31



*X30N31T33
*X28N29T31



*X85
*X83



*X85T86
*X83T84



N85S87
N83S85



N85T87
N83T85



*X85N86S88
*X83N84S86



*X85N86T88
*X83N84T86



N88S90
N86S88



N88T90
N86T88



N90
N88



N90T92
N88T90



N92S94
N90S92



N92T94
N90T92



N94S96
N92S94



N94T96
N92T94,







wherein *X indicates any amino acid except proline (such as E, V, A, or I);






Table C:












Amino acid substitutions for N-linked glycosylation sites










Based on equine TrkA ECD
Based on equine TrkA



v2 or v3 sequence
ECD v4 sequence



(SEQ ID NOs: 13 or 14)
(SEQ ID NOs: 15)







N6S8
N4S6



N6T8
N4T6



*X30N31S33
*X28N29S31



*X30N31T33
*X28N29T31



*X85S86
*X83S84



*X85T86
*X83T84



N85S87
N83S85



N85T87
N83T85



*X85N86S88
*X83N84S86



*X85N86T88
*X83N84T86



N88
N86



N88T90
N86T88



N90
N88



N90T92
N88T90



N92S94
N90S92



N92T94
N90T92



N94S96
N92S94



N94T96
N92T94,







wherein *X indicates any amino acid except proline (such as E, V, A, or I).







Embodiment 14. The contiguous polypeptide of any one of the preceding embodiments, wherein the TrkA ECD polypeptide comprises an amino acid sequence selected from SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32, and SEQ ID NO: 33.


Embodiment 15. The contiguous polypeptide of any one of the preceding embodiments, wherein the contiguous polypeptide comprises a linker.


Embodiment 16. The contiguous polypeptide of embodiment 15, wherein the linker comprises an amino acid sequence selected from G, GG, GGG, S, SS, SSS, GS, GSGS (SEQ ID NO: 143), GSGSGS (SEQ ID NO: 144), GGS, GGSGGS (SEQ ID NO: 145), GGSGGSGGS (SEQ ID NO: 146), GGGS (SEQ ID NO: 147), GGGSGGGS (SEQ ID NO: 148), GGGSGGGSGGGS (SEQ ID NO: 149), GSS, GSSGSS (SEQ ID NO: 150), GSSGSSGSS (SEQ ID NO: 151), GGSS (SEQ ID NO: 152), GGSSGGSS (SEQ ID NO: 153), GGSSGGSSGGS (SEQ ID NO: 154), SGGSGGS (SEQ ID NO: 155), and SGGGSGGGS (SEQ ID NO: 156).


Embodiment 17. The contiguous polypeptide of any one of the preceding embodiments, wherein the fusion partner is selected from an Fc polypeptide, albumin, and an albumin binding fragment.


Embodiment 18. The contiguous polypeptide of any one of preceding embodiments, wherein the fusion partner is a Fc polypeptide comprising (a) a wild-type or a variant canine IgG-A, IgG-B, IgG-C, or IgG-D polypeptide; (b) a wild-type or a variant feline IgG1a, IgG1b, or IgG2 polypeptide; or (c) a wild-type or a variant equine IgG1, IgG2, IgG3, IgG4, IgG5, IgG6, or IgG7 polypeptide.


Embodiment 19. The contiguous polypeptide of any one of the preceding embodiments comprising:





TrkA ECD 1-L1-Fc;  formula (I):





Fc-L1-TrkA ECD 1;  formula (II):





TrkA ECD 1-L1-Fc-L2-TrkA ECD 2;  formula (III):





TrkA ECD 1-L1-TrkA ECD 2-L2-Fc;  formula (IV): or





Fc-L1-TrkA ECD 1-L2-TrkA ECD 2,  formula (V):


wherein TrkA ECD 1 is a first TrkA ECD polypeptide, TrkA ECD 2 is a second TrkA ECD polypeptide, L1 and L2 are optional linkers, and Fc is a wild type or variant IgG Fc polypeptide of a companion animal species.


Embodiment 20. The contiguous polypeptide of embodiment 19, wherein TrkA ECD 1 and TrkA ECD 2 are the same polypeptide.


Embodiment 21. The contiguous polypeptide of embodiment 19, wherein TrkA ECD 1 and TrkA ECD 2 are different polypeptides.


Embodiment 22. The contiguous polypeptide of any one of the preceding embodiments, wherein the fusion partner or Fc is a variant Fc polypeptide comprising:


a) at least one amino acid modification relative to a wild-type IgG Fc polypeptide of a companion animal species, wherein the variant IgG Fc polypeptide has increased binding affinity to Protein A relative to the wild-type IgG Fc polypeptide;


b) at least one amino acid modification relative to a wild-type IgG Fc polypeptide of a companion animal species, wherein the variant IgG Fc polypeptide has reduced binding affinity to C1q relative to the wild-type IgG Fc polypeptide;


c) at least one amino acid modification relative to a wild-type IgG Fc polypeptide of a companion animal species, wherein the variant IgG Fc polypeptide has reduced binding affinity to CD16 relative to the wild-type IgG Fc polypeptide;


d) a hinge region comprising at least one amino acid modification to relative to a wild-type feline or equine IgG Fc polypeptide;


e) at least one amino acid substitution relative to a wild-type feline IgG Fc polypeptide, wherein the at least one amino acid substitution is a cysteine, and wherein the variant IgG Fc polypeptide is capable of forming at least one additional inter-chain disulfide linkage relative to the wild-type feline IgG Fc polypeptide; and/or


f) at least one amino acid substitution relative to a wild-type IgG Fc polypeptide derived from a companion animal species, wherein the variant Fc polypeptide is capable of binding to neonatal Fc receptor (FcRn) with an increased affinity relative to the wild-type Fc polypeptide.


Embodiment 23. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide that binds to C1q and/or CD16 with a dissociation constant (Kd) of greater than 5×10−6M, greater than 1×10−5 M, greater than 5×10−5 M, greater than 1×10−4M, greater than 5×10−4M, or greater than 1×10−3 M, as measured by biolayer interferometry.


Embodiment 24. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide binds to Protein A with a dissociation constant (Kd) of less than 5×10−6M, less than 1×10−6M, less than 5×10−7 M, less than 1×10−7 M, less than 5×10−8M, less than 1×10−8M, less than 5×10−9M, less than 1×10−9M, less than 5×10−10 M, less than 1×10−10 M, less than 5×10−11M, less than 1×10−11 M, less than 5×10−12 M, or less than 1×10−12 M, as measured by biolayer interferometry.


Embodiment 25. The contiguous polypeptide of any one of the preceding claims, comprising a variant IgG Fc polypeptide that binds to FcRn with an affinity greater than the wild-type IgG Fc polypeptide, as measured by biolayer interferometry, surface plasmon resonance, or any protein-protein interaction tool at a pH in the range of from about 5.0 to about 6.5, such as at a pH of about 5.0, a pH of about 5.2, a pH of about 5.5, a pH of about 6.0, a pH of about 6.2, or a pH of about 6.5.


Embodiment 26. The contiguous polypeptide of any one of the preceding claims, comprising a variant IgG Fc polypeptide that binds to FcRn with a dissociation constant (Kd) of less than 5×10−6M, less than 1×10−6M, less than 5×10−7 M, less than 1×10−7 M, less than 5×10−8 M, less than 1×10−8M, less than 5×10−9M, less than 1×10−9M, less than 5×10−10 M, less than 1×10−10 M, less than 5×10−11M, less than 1×10−11M, less than 5×10−12M, or less than 1×10−12M, as measured by biolayer interferometry, surface plasmon resonance, or any protein-protein interaction tool at a pH in the range of from about 5.0 to about 6.5, such as at a pH of about 5.0, a pH of about 5.5, a pH of about 6.0, or a pH of about 6.5.


Embodiment 27. The contiguous polypeptide of any one of the preceding claims, comprising a variant IgG Fc polypeptide that binds to FcRn with an increased affinity relative to the wild-type Fc polypeptide and wherein the contiguous polypeptide has increased serum half-life relative to a contiguous polypeptide comprising a wild-type Fc polypeptide.


Embodiment 28. The contiguous polypeptide of any one of the preceding embodiments, wherein the wild-type IgG Fc polypeptide is:


a) a canine IgG-A Fc, IgG-B Fc, IgG-C Fc, or IgG-D Fc;


b) an equine IgG1 Fc, IgG2 Fc, IgG3 Fc, IgG4 Fc, IgG5 Fc, IgG6 Fc, or IgG7 Fc; or c) a feline IgG1a Fc, IgG1b Fc, or IgG2 Fc.


Embodiment 29. The contiguous polypeptide of any one of the preceding embodiments, wherein the wild-type IgG Fc polypeptide comprises the amino acid sequence of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 72, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, or SEQ ID NO: 90.


Embodiment 30. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising:


a) at least one amino acid substitution relative to a wild-type feline IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 16 of SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, or SEQ ID NO: 90;


b) at least one amino acid substitution relative to a wild-type equine IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 3 of SEQ ID NO: 72; and/or


c) at least one amino acid substitution relative to a wild-type equine IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 20 of SEQ ID NO: 72.


Embodiment 31. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising:


a) at least one amino acid substitution relative to a wild-type feline IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises an amino acid substitution at position 16 of SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, or SEQ ID NO: 90;


b) at least one amino acid substitution relative to a wild-type equine IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises an amino acid substitution at position 3 of SEQ ID NO: 72; and/or


c) at least one amino acid substitution relative to a wild-type equine IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises an amino acid substitution at position 20 of SEQ ID NO: 72.


Embodiment 32. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising:


a) at least one amino acid substitution relative to a wild-type feline IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises a proline at a position corresponding to position 16 or at position 16 of SEQ ID NO: SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, or SEQ ID NO: 90;


b) at least one amino acid substitution relative to a wild-type equine IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises a serine at a position corresponding to position 3 or at position 3 of SEQ ID NO: 72; and/or


c) at least one amino acid substitution relative to a wild-type equine IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises a proline at a position corresponding to position 20 or at position 20 of SEQ ID NO: 72.


Embodiment 33. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising a hinge region or a portion of a hinge region from an IgG Fc polypeptide of a different isotype.


Embodiment 34. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising a hinge region or a portion of a hinge region from a wild-type feline IgG-1 Fc polypeptide or from a wild-type equine IgG1 Fc polypeptide.


Embodiment 35. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising a cysteine at a position corresponding to position 8, position 9, position 10, position 11, position 12, position 13, position 14, position 15, or position 16 of SEQ ID NO: 90.


Embodiment 36. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising a cysteine at a position corresponding to position 14 of SEQ ID NO: 90.


Embodiment 37. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising a cysteine at position 14 of SEQ ID NO: 90.


Embodiment 38. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising:


a) an amino acid substitution at a position corresponding to position 21 of SEQ ID NO: 34, an amino acid substitution at a position corresponding to position 23 of SEQ ID NO: 34, an amino acid substitution at a position corresponding to position 25 of SEQ ID NO: 34, an amino acid substitution at a position corresponding to position 80 of SEQ ID NO: 34, an amino acid substitution at a position corresponding to position 205 of SEQ ID NO: 34, and/or an amino acid substitution at a position corresponding to position 207 of SEQ ID NO: 34;


b) an amino acid substitution at a position corresponding to position 21 of SEQ ID NO: 37, an amino acid substitution at a position corresponding to position 23 of SEQ ID NO: 37, and/or an amino acid substitution at a position corresponding to position 24 of SEQ ID NO: 37;


c) an amino acid substitution at a position corresponding to position 21 of SEQ ID NO: 39, an amino acid substitution at a position corresponding to position 23 of SEQ ID NO: 39, an amino acid substitution at a position corresponding to position 25 of SEQ ID NO: 39, an amino acid substitution at a position corresponding to position 80 of SEQ ID NO: 39, and/or an amino acid substitution at a position corresponding to position 207 of SEQ ID NO: 39;


d) an amino acid substitution at a position corresponding to position 15 of SEQ ID NO: 71, and/or an amino acid substitution at a position corresponding to position 203 of SEQ ID NO: 71;


e) an amino acid substitution at a position corresponding to position 199 of SEQ ID NO: 75, and/or an amino acid substitution at a position corresponding to position 200 of SEQ ID NO: 75; and/or


f) an amino acid substitution at a position corresponding to position 199 of SEQ ID NO: 76, an amino acid substitution at a position corresponding to position 200 of SEQ ID NO: 76, an amino acid substitution at a position corresponding to position 201 of SEQ ID NO: 76, and/or an amino acid substitution at a position corresponding to position 202 of SEQ ID NO: 76.


Embodiment 39. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising:


a) an amino acid substitution at position 21 of SEQ ID NO: 34, an amino acid substitution at position 23 of SEQ ID NO: 34, an amino acid substitution at position 25 of SEQ ID NO: 34, an amino acid substitution at position 80 of SEQ ID NO: 34, an amino acid substitution at position 205 of SEQ ID NO: 34, and/or an amino acid substitution at position 207 of SEQ ID NO: 34;


b) an amino acid substitution at position 21 of SEQ ID NO: 37, an amino acid substitution at position 23 of SEQ ID NO: 37, and/or an amino acid substitution at position 24 of SEQ ID NO: 37;


c) an amino acid substitution at position 21 of SEQ ID NO: 39, an amino acid substitution at position 23 of SEQ ID NO: 39, an amino acid substitution at position 25 of SEQ ID NO: 39, an amino acid substitution at position 80 of SEQ ID NO: 39, and/or an amino acid substitution at position 207 of SEQ ID NO: 39;


d) an amino acid substitution at position 15 of SEQ ID NO: 71, and/or an amino acid substitution at position 203 of SEQ ID NO: 71;


e) an amino acid substitution at position 199 of SEQ ID NO: 75, and/or an amino acid substitution at position 200 of SEQ ID NO: 75; and/or


f) an amino acid substitution at position 199 of SEQ ID NO: 76, an amino acid substitution at position 200 of SEQ ID NO: 76, an amino acid substitution at position 201 of SEQ ID NO: 76, and/or an amino acid substitution at position 202 of SEQ ID NO: 76.


Embodiment 40. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising:


a) a threonine at a position corresponding to position 21 of SEQ ID NO: 34, a leucine at a position corresponding to position 23 of SEQ ID NO: 34, an alanine at a position corresponding to position 25 of SEQ ID NO: 34, a glycine at a position corresponding to position 80 of SEQ ID NO: 34, an alanine at a position corresponding to position 205 of SEQ ID NO: 34, and/or a histidine at a position corresponding to position 207 of SEQ ID NO: 34;


b) a threonine at a position corresponding to position 21 of SEQ ID NO: 37, a leucine at a position corresponding to position 23 of SEQ ID NO: 37, and/or an isoleucine at a position corresponding to position 24 of SEQ ID NO: 37;


c) a threonine at a position corresponding to position 21 of SEQ ID NO: 39, a leucine at a position corresponding to position 23 of SEQ ID NO: 39, an alanine at a position corresponding to position 25 of SEQ ID NO: 39, a glycine at a position corresponding to position 80 of SEQ ID NO: 39, and/or a histidine at a position corresponding to position 207 of SEQ ID NO: 39;


d) a threonine or a valine at a position corresponding to position 15 of SEQ ID NO: 71, and/or a tyrosine or a valine at a position corresponding to position 203 of SEQ ID NO: 71;


e) a leucine at a position corresponding to position 199 of SEQ ID NO: 75, and/or a histidine at a position corresponding to position 200 of SEQ ID NO: 75; and/or


f) a leucine at a position corresponding to position 199 of SEQ ID NO: 76, a histidine at a position corresponding to position 200 of SEQ ID NO: 76, an asparagine at a position corresponding to position 201 of SEQ ID NO: 76, and/or a histidine at a position corresponding to position 202 of SEQ ID NO: 76.


Embodiment 41. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising:


a) a threonine at position 21 of SEQ ID NO: 34, a leucine at position 23 of SEQ ID NO: 34, an alanine at position 25 of SEQ ID NO: 34, a glycine at position 80 of SEQ ID NO: 34, an alanine at position 205 of SEQ ID NO: 34, and/or a histidine at position 207 of SEQ ID NO: 34;


b) a threonine at position 21 of SEQ ID NO: 37, a leucine at position 23 of SEQ ID NO: 37, and/or an isoleucine at position 24 of SEQ ID NO: 37;


c) a threonine at a position 21 of SEQ ID NO: 39, a leucine at position 23 of SEQ ID NO: 39, an alanine at position 25 of SEQ ID NO: 39, a glycine at position 80 of SEQ ID NO: 39, and/or a histidine at position 207 of SEQ ID NO: 39;


d) a threonine or a valine at position 15 of SEQ ID NO: 71, and/or a tyrosine or a valine at position 203 of SEQ ID NO: 71;


e) a leucine at position 199 of SEQ ID NO: 75, and/or a histidine at position 200 of SEQ ID NO: 75; and/or


f) a leucine at position 199 of SEQ ID NO: 76, a histidine at position 200 of SEQ ID NO: 76, an asparagine at position 201 of SEQ ID NO: 76, and/or a histidine at position 202 of SEQ ID NO: 76.


Embodiment 42. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising:


a) an amino acid substitution at a position corresponding to position 93 of SEQ ID NO: 35, or an amino acid substitution at a position corresponding to position 93 of SEQ ID NO: 37;


b) an amino acid substitution at a position corresponding to position 87 of SEQ ID NO: 70, an amino acid substitution at a position corresponding to position 87 of SEQ ID NO: 73, an amino acid substitution at a position corresponding to position 87 of SEQ ID NO: 74, or an amino acid substitution at a position corresponding to position 87 of SEQ ID NO: 77; or


c) an amino acid substitution at a position corresponding to position 198 of SEQ ID NO: 86, an amino acid substitution at a position corresponding to position 198 of SEQ ID NO: 87, an amino acid substitution at a position corresponding to position 198 of SEQ ID NO: 88, or an amino acid substitution at a position corresponding to position 198 of SEQ ID NO: 89.


Embodiment 43. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising:


a) an amino acid substitution at position 93 of SEQ ID NO: 35, or an amino acid substitution at position 93 of SEQ ID NO: 37;


b) an amino acid substitution at position 87 of SEQ ID NO: 70, an amino acid substitution at position 87 of SEQ ID NO: 73, an amino acid substitution at position 87 of SEQ ID NO: 74, or an amino acid substitution at position 87 of SEQ ID NO: 77; or


c) an amino acid substitution at position 198 of SEQ ID NO: 86, an amino acid substitution at position 198 of SEQ ID NO: 87, an amino acid substitution at position 198 of SEQ ID NO: 88, or an amino acid substitution at position 198 of SEQ ID NO: 89.


Embodiment 44. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising:


a) an arginine at a position corresponding to position 93 of SEQ ID NO: 35, or an arginine at a position corresponding to position 93 of SEQ ID NO: 37;


b) a serine at a position corresponding to position 87 of SEQ ID NO: 70, a serine substitution at a position corresponding to position 87 of SEQ ID NO: 73, a serine at a position corresponding to position 87 of SEQ ID NO: 74, or a serine at a position corresponding to position 87 of SEQ ID NO: 77; or


c) an alanine at a position corresponding to position 198 of SEQ ID NO: 86, an alanine at a position corresponding to position 198 of SEQ ID NO: 87, an alanine at a position corresponding to position 198 of SEQ ID NO: 88, or an alanine at a position corresponding to position 198 of SEQ ID NO: 89.


Embodiment 45. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising:


a) an arginine at position 93 of SEQ ID NO: 35, or an arginine at position 93 of SEQ ID NO: 37;


b) a serine at position 87 of SEQ ID NO: 70, a serine at position 87 of SEQ ID NO: 73, a serine at position 87 of SEQ ID NO: 74, or a serine at position 87 of SEQ ID NO: 77; or


c) an alanine at position 198 of SEQ ID NO: 86, an alanine at position 198 of SEQ ID NO: 87, an alanine at position 198 of SEQ ID NO: 88, or alanine at position 198 of SEQ ID NO: 89.


Embodiment 46. The contiguous polypeptide of any one of the preceding embodiments, comprising a variant IgG Fc polypeptide comprising:


a) a tyrosine or a phenylalanine at a position corresponding to position 23 of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;


b) a tyrosine at a position corresponding to position 82 of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;


c) a tyrosine at a position corresponding to position 82 and a histidine at a position corresponding to position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;


d) a tyrosine at a position corresponding to position 82 and a tyrosine at a position corresponding to position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;


e) a tyrosine at a position corresponding to position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;


f) a tyrosine at a position corresponding to position 82 and a histidine at a position corresponding to position 208 of SEQ ID NO: 34 or SEQ ID NO: 39;


g) a tyrosine at a position corresponding to position 82 and a tyrosine at a position corresponding to position 208 of SEQ ID NO: 34 or SEQ ID NO: 39; or


h) a tyrosine at a position corresponding to position 208 of SEQ ID NO: 34 or SEQ ID NO: 39.


Embodiment 47. The contiguous polypeptide of any one of the preceding embodiments, comprising a variant IgG Fc polypeptide comprising:


a) a tyrosine or a phenylalanine at position 23 of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;


b) a tyrosine at position 82 of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;


c) a tyrosine at position 82 and a histidine at position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;


d) a tyrosine at position 82 and a tyrosine at position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;


e) a tyrosine at position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;


f) a tyrosine at position 82 and a histidine at position 208 of SEQ ID NO: 34 or SEQ ID NO: 39;


g) a tyrosine at position 82 and a tyrosine at position 208 of SEQ ID NO: 34 or SEQ ID NO: 39; or


h) a tyrosine at position 208 of SEQ ID NO: 34 or SEQ ID NO: 39.


Embodiment 48. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising an amino acid sequence having at least 90% identity, at least 91% identity, at least 92% identity, at least 93% identity, at least 94% identity, at least 95% identity, at least 96% identity, at least 97% identity, at least 98% identity, or at least 99% identity to the amino acid sequence of SEQ ID NO: 40, SEQ ID NO: 41, SEQ ID NO: 42, SEQ ID NO: 43, SEQ ID NO: 44, SEQ ID NO: 45, SEQ ID NO: 46, SEQ ID NO: 47, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 50, SEQ ID NO: 51, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54, SEQ ID NO: 55, SEQ ID NO: 56, SEQ ID NO: 57, SEQ ID NO: 58, SEQ ID NO: 59, SEQ ID NO: 60, SEQ ID NO: 61, SEQ ID NO: 62, SEQ ID NO: 63, SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68, SEQ ID NO: 69, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99, SEQ ID NO: 100, SEQ ID NO: 101, SEQ ID NO: 102, SEQ ID NO: 103, SEQ ID NO: 104, SEQ ID NO: 105, SEQ ID NO: 106, SEQ ID NO: 107, SEQ ID NO: 108, SEQ ID NO: 109, SEQ ID NO: 197, SEQ ID NO: 198, SEQ ID NO: 199, SEQ ID NO: 200, SEQ ID NO: 201, SEQ ID NO: 202, SEQ ID NO: 203, SEQ ID NO: 204, SEQ ID NO: 205, SEQ ID NO: 206, SEQ ID NO: 207, SEQ ID NO: 208, SEQ ID NO: 209, and/or SEQ ID NO: 210.


Embodiment 49. The contiguous polypeptide of any one the preceding embodiments, comprising a variant IgG Fc polypeptide comprising an amino acid sequence of SEQ ID NO: 40, SEQ ID NO: 41, SEQ ID NO: 42, SEQ ID NO: 43, SEQ ID NO: 44, SEQ ID NO: 45, SEQ ID NO: 46, SEQ ID NO: 47, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 50, SEQ ID NO: 51, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54, SEQ ID NO: 55, SEQ ID NO: 56, SEQ ID NO: 57, SEQ ID NO: 58, SEQ ID NO: 59, SEQ ID NO: 60, SEQ ID NO: 61, SEQ ID NO: 62, SEQ ID NO: 63, SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68, SEQ ID NO: 69, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99, SEQ ID NO: 100, SEQ ID NO: 101, SEQ ID NO: 102, SEQ ID NO: 103, SEQ ID NO: 104, SEQ ID NO: 105, SEQ ID NO: 106, SEQ ID NO: 107, SEQ ID NO: 108, SEQ ID NO: 109, SEQ ID NO: 197, SEQ ID NO: 198, SEQ ID NO: 199, SEQ ID NO: 200, SEQ ID NO: 201, SEQ ID NO: 202, SEQ ID NO: 203, SEQ ID NO: 204, SEQ ID NO: 205, SEQ ID NO: 206, SEQ ID NO: 207, SEQ ID NO: 208, SEQ ID NO: 209, and/or SEQ ID NO: 210.


Embodiment 50. The contiguous polypeptide of any one of the preceding embodiments further comprising at least one extracellular domain of an NGFR polypeptide (NGFR ECD polypeptide).


Embodiment 51. The contiguous polypeptide of any one of the preceding embodiments further comprising at least one NGFR ECD polypeptide comprising the amino acid sequence of SEQ ID NO: 135, SEQ ID NO: 137, and/or SEQ ID NO: 139.


Embodiment 52. The contiguous polypeptide of any one of the preceding embodiments comprising the amino acid sequence of SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21, SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO: 110, SEQ ID NO: 111, SEQ ID NO: 112, SEQ ID NO: 113, SEQ ID NO: 114, SEQ ID NO: 115, SEQ ID NO: 116, SEQ ID NO: 117, SEQ ID NO: 118, SEQ ID NO: 119, SEQ ID NO: 120, SEQ ID NO: 121, SEQ ID NO: 122, SEQ ID NO: 123, SEQ ID NO: 124, SEQ ID NO: 125, SEQ ID NO: 126, SEQ ID NO: 127, SEQ ID NO: 128, SEQ ID NO: 129, SEQ ID NO: 130, SEQ ID NO: 131, SEQ ID NO: 132, SEQ ID NO: 133, SEQ ID NO: 140, SEQ ID NO: 141, SEQ ID NO: 142, SEQ ID NO: 159, SEQ ID NO: 160, SEQ ID NO: 161, SEQ ID NO: 162, SEQ ID NO: 163, SEQ ID NO: 164, SEQ ID NO: 165, SEQ ID NO: 166, SEQ ID NO: 167, SEQ ID NO: 168, SEQ ID NO: 169, SEQ ID NO: 170, SEQ ID NO: 171, SEQ ID NO: 172, SEQ ID NO: 173, SEQ ID NO: 174, SEQ ID NO: 175, SEQ ID NO: 176, SEQ ID NO: 177, SEQ ID NO: 178, SEQ ID NO: 179, SEQ ID NO: 180, SEQ ID NO: 181, SEQ ID NO: 182, SEQ ID NO: 183, SEQ ID NO: 184, SEQ ID NO: 185, SEQ ID NO: 186, SEQ ID NO: 187, SEQ ID NO: 188, SEQ ID NO: 189, SEQ ID NO: 190, SEQ ID NO: 191, SEQ ID NO: 192, SEQ ID NO: 193, SEQ ID NO: 194, SEQ ID NO: 211, SEQ ID NO: 212, SEQ ID NO: 213, SEQ ID NO: 214, SEQ ID NO: 215, SEQ ID NO: 216, SEQ ID NO: 217, SEQ ID NO: 218, SEQ ID NO: 219, SEQ ID NO: 220, SEQ ID NO: 221, SEQ ID NO: 222, SEQ ID NO: 223, SEQ ID NO: 224, SEQ ID NO: 225, SEQ ID NO: 226, SEQ ID NO: 227, SEQ ID NO: 228, SEQ ID NO: 229, SEQ ID NO: 230, SEQ ID NO: 231, SEQ ID NO: 232, SEQ ID NO: 233, SEQ ID NO: 234, SEQ ID NO: 235, SEQ ID NO: 236, SEQ ID NO: 237, SEQ ID NO: 238, SEQ ID NO: 239, SEQ ID NO: 240, SEQ ID NO: 241, SEQ ID NO: 242, SEQ ID NO: 243, SEQ ID NO: 244, SEQ ID NO: 245, or SEQ ID NO: 246.


Embodiment 53. A contiguous polypeptide comprising the amino acid sequence of SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21, SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO: 110, SEQ ID NO: 111, SEQ ID NO: 112, SEQ ID NO: 113, SEQ ID NO: 114, SEQ ID NO: 115, SEQ ID NO: 116, SEQ ID NO: 117, SEQ ID NO: 118, SEQ ID NO: 119, SEQ ID NO: 120, SEQ ID NO: 121, SEQ ID NO: 122, SEQ ID NO: 123, SEQ ID NO: 124, SEQ ID NO: 125, SEQ ID NO: 126, SEQ ID NO: 127, SEQ ID NO: 128, SEQ ID NO: 129, SEQ ID NO: 130, SEQ ID NO: 131, SEQ ID NO: 132, SEQ ID NO: 133, SEQ ID NO: 140, SEQ ID NO: 141, SEQ ID NO: 142, SEQ ID NO: 159, SEQ ID NO: 160, SEQ ID NO: 161, SEQ ID NO: 162, SEQ ID NO: 163, SEQ ID NO: 164, SEQ ID NO: 165, SEQ ID NO: 166, SEQ ID NO: 167, SEQ ID NO: 168, SEQ ID NO: 169, SEQ ID NO: 170, SEQ ID NO: 171, SEQ ID NO: 172, SEQ ID NO: 173, SEQ ID NO: 174, SEQ ID NO: 175, SEQ ID NO: 176, SEQ ID NO: 177, SEQ ID NO: 178, SEQ ID NO: 179, SEQ ID NO: 180, SEQ ID NO: 181, SEQ ID NO: 182, SEQ ID NO: 183, SEQ ID NO: 184, SEQ ID NO: 185, SEQ ID NO: 186, SEQ ID NO: 187, SEQ ID NO: 188, SEQ ID NO: 189, SEQ ID NO: 190, SEQ ID NO: 191, SEQ ID NO: 192, SEQ ID NO: 193, SEQ ID NO: 194, SEQ ID NO: 211, SEQ ID NO: 212, SEQ ID NO: 213, SEQ ID NO: 214, SEQ ID NO: 215, SEQ ID NO: 216, SEQ ID NO: 217, SEQ ID NO: 218, SEQ ID NO: 219, SEQ ID NO: 220, SEQ ID NO: 221, SEQ ID NO: 222, SEQ ID NO: 223, SEQ ID NO: 224, SEQ ID NO: 225, SEQ ID NO: 226, SEQ ID NO: 227, SEQ ID NO: 228, SEQ ID NO: 229, SEQ ID NO: 230, SEQ ID NO: 231, SEQ ID NO: 232, SEQ ID NO: 233, SEQ ID NO: 234, SEQ ID NO: 235, SEQ ID NO: 236, SEQ ID NO: 237, SEQ ID NO: 238, SEQ ID NO: 239, SEQ ID NO: 240, SEQ ID NO: 241, SEQ ID NO: 242, SEQ ID NO: 243, SEQ ID NO: 244, SEQ ID NO: 245, or SEQ ID NO: 246.


Embodiment 54. The contiguous polypeptide of any one of the preceding embodiments, wherein the Trk A ECD polypeptide is glycosylated.


Embodiment 55. The contiguous polypeptide of any one of the preceding embodiments, wherein the Trk A ECD polypeptide comprises at least one glycan moiety.


Embodiment 56. The contiguous polypeptide of any one of the preceding embodiments, wherein the Trk A ECD polypeptide is PEGylated.


Embodiment 57. The contiguous polypeptide of any one of the preceding embodiments, wherein the Trk A ECD polypeptide is PEGylated at a glycan, at a primary amine, and/or the N-terminal alpha-amine.


Embodiment 58. An isolated nucleic acid encoding the contiguous polypeptide of any one of the preceding embodiments.


Embodiment 59. A host cell comprising the nucleic acid of embodiment 58.


Embodiment 60. A method of producing a polypeptide comprising culturing the host cell of embodiment 59 and isolating the contiguous polypeptide.


Embodiment 61. A pharmaceutical composition comprising the contiguous polypeptide of any one of embodiments 1 to 57 and a pharmaceutically acceptable carrier.


Embodiment 62. The pharmaceutical composition of embodiment 61, wherein the pharmaceutical acceptable carrier comprises from about 5 to about 50 mM sodium citrate; from about 5 to about 50 mM histidine; or from about 5 to about 50 mM sodium acetate.


Embodiment 63. The pharmaceutical composition of embodiment 61 or embodiment 62, wherein the pharmaceutical composition has a pH of from 5 to 6.


Embodiment 64. A method of treating a companion animal species having an NGF-induced condition, the method comprising administering to the companion animal species a therapeutically effective amount of the contiguous polypeptide of any one of embodiments 1 to 52 or the pharmaceutical composition of any one of embodiments 61 to 63.


Embodiment 65. A method of treating a companion animal species having pain, the method comprising administering to the companion animal species a therapeutically effective amount of the contiguous polypeptide of any one of embodiments 1 to 57 or the pharmaceutical composition of any one of embodiments 61 to 63.


Embodiment 66. The method of embodiment 64 or embodiment 65, wherein the companion animal species is canine, feline, or equine.


Embodiment 67. The method of any one of embodiments 64 to 66, wherein the NGF-induced condition or the pain is chronic pain, acute pain, and/or inflammatory pain.


Embodiment 68. The method of any one of embodiments 64 to 67, wherein the NGF-induced condition or the pain is osteoarthrititic pain, back pain, cancer pain, and/or a neuropathic pain.


Embodiment 69. The method of any one of embodiments 64 to 68, wherein the NGF-induced condition or the pain is pain associated with a surgery, a broken or fractured bone, dental work, a burn, a cut, and/or labor.


Embodiment 70. The method of any one of embodiments 64 to 69, wherein the contiguous polypeptide or the pharmaceutical composition is administered parenterally.


Embodiment 71. The method of any one of embodiments 64 to 70, wherein the contiguous polypeptide or the pharmaceutical composition is administered by an intramuscular route, an intraperitoneal route, an intracerebrospinal route, a subcutaneous route, an intra-arterial route, an intrasynovial route, an intrathecal route, or an inhalation route.


Embodiment 72. The method of any one of embodiments 64 to 71, wherein the method further comprises administering an NGF kinase inhibitor, a PI3K inhibitor, a ras inhibitor, a CGRP inhibitor, a TNF inhibitor, an IL17 inhibitor, an EGFR inhibitor, and/or a Phospholipase C pathway inhibitor.


Embodiment 73. The method of any one of embodiments 64 to 72, wherein the method further comprises administering one or more pain therapy drugs, such as a corticosteroid, a non-steroidal anti-inflammatory drug (NSAID), a cyclooxygenase inhibitor, an opioid, and/or a cannabinoid.


Embodiment 74. A method of reducing NGF signaling activity in a cell, the method comprising exposing the cell to the contiguous polypeptide of any one of embodiments 1 to 57 or the pharmaceutical composition of any one of embodiments 61 to 63 under conditions permissive for binding of the contiguous polypeptide to NGF.


Embodiment 75. The method of embodiment 74, wherein the cell is exposed to the contiguous polypeptide or the pharmaceutical composition ex vivo.


Embodiment 76. The method of embodiment 74, wherein the cell is exposed to the contiguous polypeptide or the pharmaceutical composition in vivo.


Embodiment 77. The method of any one of embodiments 74 to 76, wherein the cell is a canine cell, a feline cell, or an equine cell.


Embodiment 78. A method for detecting NGF in a sample from a companion animal species comprising contacting the sample with the contiguous polypeptide of any one of embodiments 1 to 57 or the pharmaceutical composition of any one of embodiments 61 to 63 under conditions permissive for binding of the contiguous polypeptide to NGF, and detecting whether a complex is formed between the polypeptide and NGF in the sample.


Embodiment 79. The method of embodiment 78, wherein the sample is a biological sample obtained from a canine, a feline, or an equine.





BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 shows a sensorgram comparing the affinity of canine and feline TrkA ECD v2 and v3 IgG-Fc fusion proteins to NGF. Irrelevant canine or feline IgG-Fc fusion proteins were used as a negative control.



FIG. 2 shows a sensorgram comparing the affinities of equine TrkA ECD v2 and v3 IgG-Fc fusion proteins to NGF. An irrelevant equine IgG-Fc fusion protein was used as a negative control.



FIG. 3 is a graph showing that an exemplary equine TrkA ECD-IgG Fc polypeptide (SEQ ID NO: 22) neutralizes NGF activity in a TF1 cell-proliferation assay performed as described in Example 4. An irrelevant monoclonal antibody was used as a negative control.



FIG. 4 is a graph showing the concentration of NGF in synovial membrane following administration of canine TrkA-Fc polypeptide (1 mg/kg and 20 mg/kg) in a rat MIA-induced osteoarthritis model.



FIG. 5 shows a Biacore sensorgram of various concentrations of canine FcRn (12.5, 25, 50, 100, and 200 nM) binding to wild-type canine IgG-B Fc polypeptide.



FIG. 6 shows a Biacore sensorgram of various concentrations of canine FcRn (12.5, 25, 50, 100, and 200 nM) binding to variant canine IgG-B Fc polypeptide L(23)Y.



FIG. 7 shows a Biacore sensorgram of various concentrations of canine FcRn (12.5, 25, 50, 100, and 200 nM) binding to variant canine IgG-B Fc polypeptide L(23)F.



FIG. 8 shows a Biacore sensorgram of various concentrations of canine FcRn (12.5, 25, 50, 100, and 200 nM) binding to variant canine IgG-B Fc polypeptide L(23)M.



FIG. 9 shows a Biacore sensorgram of various concentrations of canine FcRn (12.5, 25, 50, 100, and 200 nM) binding to variant canine IgG-B Fc polypeptide YTE.



FIG. 10 is a OctetRed sensorgram of chimeric variant canine IgG-A Fc F00 antibody (A) and IgG-D Fc F00 antibody (B) binding to canine FcRn compared to that of chimeric variant canine IgG-A Fc without the Phe mutation (C) and IgG-D Fc without the Phe mutation (D).



FIG. 11 shows the serum pharmacokinetics profiles for chimeric variant canine IgG-A F00 antibody (“IgG-A F00”; n=2) and chimeric variant canine IgG-A without the Phe mutation (“IgG-A”; n=2) after subcutaneous administration to rats at 2 mg/kg.



FIG. 12 is a OctetRed sensorgram of chimeric antibodies with variant canine IgG-B Fcs (0Y0, 0YH, 0YY, or 00Y) binding to canine FcRn compared to that of chimeric antibody with a wild-type canine IgG-B.



FIG. 13 is a chart showing percent antibody normalized over time resulting from the in vivo pharmacokinetic study in dog as described in Example 19.





DESCRIPTION OF THE SEQUENCES

Table 1 provides a listing of certain sequences referenced herein.












Description of the Sequences









SEQ ID




NO:
SEQUENCE
DESCRIPTION












1
MLRGGRLGQRGGHGRAAGPGSLLAWLVLASAGAAPCPDVCCP
Canine TrkA



HGPSGLRCTRAGALQSLHRLPGVENLTELYIDNQEHLQHLDA
NCBI Reference



VHLKGLGMLRDLTIVKSGLRSVAPDAFHFTPRLRRLNLSFNA
Sequence:



LESLSWKTVQGLPLQELVLSGNPLHCSCALHWLLRWEEEGLG
XP_022276948.1



GVRGQRLQCPGQGPLALLSNASCGVPVLKVQMPNASVEVGDD




VLLQCQVEGRGLERAGWILPEVEELATVTPSGDLPSLGLILA




NVTSDLNRKNVTCWAENDVGRAEVSVQVNVSFPASVQLHEAV




ELHHWCIPFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPV




ANETVRHGCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAF




MDNPFEFNPEDPIPVSFSPVDTNSTSGDPVEKKGQTPFGVSV




AVGLAVFACLFLSTLFLALNKCGRRNKFGGNRAVVLAPEDGL




AMSLHFMTLGGSSLSPTEGKGSGLQGHIIENPQYFSDACVHH




IKRQDIVLKWELGEGAFGKVFLAECHNLLPEQDKMLVAVKAL




KEVSESARQDFQREAQLLTMLQHQHIVRFFGVCTEGRPLLMV




FEYMRHGDLNRFLRSHGPDAKLLAGGEDVAPGPLGLGQLLAV




ASQVAAGMVYLAGLHFVHRDLATRNCLVGQGLVVKIGDFGMS




RDIYSTDYYRVGGRTMLPIRWMPPESILYRKFTTESDVWSFG




VVLWEIFTYGKQPWYQLSNTEAIECITQGRELERPRACPPEV




YAIMRGCWQREPQQRHSIKDVHARLQALAQAPPVYLDVLG






2
MLRGGRLGQRGGHGRAAGPGSLLAWLVLASAGAAPCPDVCCP
Exemplary canine TrkA



HGPSGLRCTRAGALQSLHRLPGVENLTELYIDNQEHLQHLDA
ECD (v1)



VHLKGLGMLRDLTIVKSGLRSVAPDAFHFTPRLRRLNLSFNA




LESLSWKTVQGLPLQELVLSGNPLHCSCALHWLLRWEEEGLG




GVRGQRLQCPGQGPLALLSNASCGVPVLKVQMPNASVEVGDD




VLLQCQVEGRGLERAGWILPEVEELATVTPSGDLPSLGLILA




NVTSDLNRKNVTCWAENDVGRAEVSVQVNVSFPASVQLHEAV




ELHHWCIPFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPV




ANETVRHGCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAF




MDNPFEFNPEDPIPVSFSPVDTNSTSGDPVEKKGQTPFG






3
VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN
Exemplary canine TrkA



ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN
ECD (v2)



PSGRAAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGD






4
VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN
Exemplary canine TrkA



ETSFIFTEFLEPVANETVRHGCLRLNQP
ECD (v3)



THVNNGNYTLLAANPSGRAAAFVMAAFMDNP






5
FPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET
Exemplary canine TrkA



SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAANPS
ECD (v4)



GRAAAFVMAAFMDNP






6
MLRGGRGPRGGHGRAAGPGSLLAWLMLASAGAAPCADVCCPH
Feline TrkA



GPSGLRCTRAGALESLRRLPGAENLTELYIENQERLRHLEPS
NCBI Reference



DLRGLGELRGLTIVKSGLRFVAPDVFHFTPRLSRLNLSFNAL
Sequence:



ESLSWKTVQGLSLQELVLSGNPLRCSCALHWLLRWEEEGLGG
XP_023103311.1



VRAQRLQCPGQGPLALLSNASCGVPVLKVQTPNASVNVGDDV




LLQCQVEGRGLEQAGWILTELEESATVTQSGALPSLGLTLAN




VTSDLNRKNVTCWAENDVGRAEVSVQVNVSFPASVQLHAAVE




LHHWCIPFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPAA




NETVRHGCLRLNQPTHVNNGNYTLLAANPSGRAAASVLAAFM




DNPFEFNPEDPIPVSFSPVDSNSTSGDPVEKKDETPFGVSVA




VGLAVFACLLLSAFFLVLNKCGRRNKFGINRTAVLAPEDGLA




MSLHFMTLGGSSLSPTEGKGSGLQGHIIENPQYFSDACVHHI




KRRDIVLKWELGEGAFGKVFLAECYNLLPEQDKMLVAVKALK




EVSESARQDFQREAQLLTVLQHQHIVRFFGVCTEGRPLLMVF




EYMRHGDLNRFLRSHGPDAKLLAGREDVAPGPLGLSQLLAVA




SQVAAGMVYLAGLHFVHRDLATRNCLVGQGLVVKIGDFGMSR




DIYSTDYYRVGGRTMLPIRWMPPESILYRKFTTESDVWSFGV




VLWEIFTYGKQPWYQLSNTEAIECITQGRELERPRACPPEVY




AIMRGCWQREPQQRHSIKEVHARLQALAQAPPVYLDVLG






7
MLRGGRGPRGGHGRAAGPGSLLAWLMLASAGAAPCADVCCPH
Exemplary feline TrkA



GPSGLRCTRAGALESLRRLPGAENLTELYIENQERLRHLEPS
ECD (v1)



DLRGLGELRGLTIVKSGLRFVAPDVFHFTPRLSRLNLSFNAL




ESLSWKTVQGLSLQELVLSGNPLRCSCALHWLLRWEEEGLGG




VRAQRLQCPGQGPLALLSNASCGVPVLKVQTPNASVNVGDDV




LLQCQVEGRGLEQAGWILTELEESATVTQSGALPSLGLTLAN




VTSDLNRKNVTCWAENDVGRAEVSVQVNVSFPASVQLHAAVE




LHHWCIPFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPAA




NETVRHGCLRLNQPTHVNNGNYTLLAANPSGRAAASVLAAFM




DNPFEFNPEDPIPVSFSPVDSNSTSGDPVEKKDETPFG






8
VSFPASVQLHAAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN
Exemplary feline TrkA



ETSFIFTEFLEPAANETVRHGCLRLNQPTHVNNGNYTLLAAN
ECD (v2)



PSGRAAASVLAAFMDNPFEFNPEDPIPVSFSPVDSNSTSGD






9
VSFPASVQLHAAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN
Exemplary feline TrkA



ETSFIFTEFLEPAANETVRHGCLRLNQP
ECD (v3)



THVNNGNYTLLAANPSGRAAASVLAAFMDNP






10
FPASVQLHAAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET
Exemplary feline TrkA



SFIFTEFLEPAANETVRHGCLRLNQPTHVNNGNYTLLAANPS
ECD (v4)



GRAAASVLAAFMDNP






11
MLRGGRRGQLGWHGRATGPGSLLAWLMLASAGAAPCPDACCP
Equine TrkA



HGPSGLRCTQPGALDSLRHLPGAENLTELYIENQQNLQRLER
NCBI Reference



NDLRGLGELRNLTIVKSGLHFVAPDAFHFTPRLSRLNLSFNA
Sequence:



LKSLSWKTVQGLSLQQLVLLGNPLDCSCALRWLQRWEEEGLG
XP_023496742.1



GVREQKLQCHQQGPLALMSNTNCGVPLLKVQVPNASVDVGDN




VWLQCQVEGQGLEQAGWILTELEESATVMQSGGLPSLGLTLA




NVTSDLNRKNVTCWAENDVGRAEVSVQVNVSFPASVHLQTAV




EQHHWCIPFSVDGQPAPTLRWLFNGSVLNETSFIFTEFLESA




ANETMRHGCLRLNQPTHVNNGNYTLLATNPYGQDSASVMVAF




MDNPFEFNPEDPIPVSFSPVDTNSTSRDPVEKKDETHFGVSV




AVGLAVFACLFLSTLFLVLNKCGRRNKFGINRPAVLAPEDGL




AMSLHFMTLGGSSLSPTEGKGSGLQGHIIENPQYFSDACVHH




IKRRDIVLKWELGEGAFGKVFLAECHNLLPEQDKMLVAVKAL




KEVSESARQDFQREAELLTMLQHQHIVRFFGVCTEGRPLLMV




FEYMRHGDLNRFLRSHGPDAKLLAGGEDVAPGPLGLGQLLAV




ASQVAAGMVYLAGLHFVHRDLATRNCLVGQGLVVKIGDFGMS




RDIYSTDYYRVGGRTMLPIRWMPPESILYRKFTTESDVWSFG




VVLWEIFTYGKQPWYQLSNTEAIECITQGRELERPRACPPEV




YAIMRGCWQREPQQRHSIKDVHARLQALVQAPPVYLDVLG






12
MLRGGRRGQLGWHGRATGPGSLLAWLMLASAGAAPCPDACCP
Exemplary equine TrkA



HGPSGLRCTQPGALDSLRHLPGAENLTELYIENQQNLQRLER
ECD (v1)



NDLRGLGELRNLTIVKSGLHFVAPDAFHFTPRLSRLNLSFNA




LKSLSWKTVQGLSLQQLVLLGNPLDCSCALRWLQRWEEEGLG




GVREQKLQCHQQGPLALMSNTNCGVPLLKVQVPNASVDVGDN




VWLQCQVEGQGLEQAGWILTELEESATVMQSGGLPSLGLTLA




NVTSDLNRKNVTCWAENDVGRAEVSVQVNVSFPASVHLQTAV




EQHHWCIPFSVDGQPAPTLRWLFNGSVLNETSFIFTEFLESA




ANETMRHGCLRLNQPTHVNNGNYTLLATNPYGQDSASVMVAF




MDNPFEFNPEDPIPVSFSPVDTNSTSRDPVEKKDETHFG






13
VSFPASVHLQTAVEQHHWCIPFSVDGQPAPTLRWLFNGSVLN
Exemplary equine TrkA



ETSFIFTEFLESAANETMRHGCLRLNQPTHVNNGNYTLLATN
ECD (v2)



PYGQDSASVMVAFMDNPFEFNPEDPIPVSFSPVDTNSTSRD






14
VSFPASVHLQTAVEQHHWCIPFSVDGQPAPTLRWLFNGSVLN
Exemplary equine TrkA



ETSFIFTEFLESAANETMRHGCLRLNQPTHVNNGNYTLLATN
ECD (v3)



PYGQDSASVMVAFMDNP






15
FPASVHLQTAVEQHHWCIPFSVDGQPAPTLRWLFNGSVLNET
Exemplary equine TrkA



SFIFTEFLESAANETMRHGCLRLNQPTHVNNGNYTLLATNPY
ECD (v4)



GQDSASVMVAFMDNP






16

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v2-wildtype




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNPFEF

canine IgG-B Fc with




NPEDPIPVSFSPVDTNSTSGD
SGGGSGGGSRPPDCPKCPAPE

signal sequence



MLGGPSVFIFPPKPKDTLLTARTPEVTCVVVDLDPEDPEVQI
Protein A+



SWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGK
C1q+



QFTCKVNNKALPSPIERTISKARGQAHQPSVYVLPPSREELS
CD16+



KNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLD




EDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESL




SHSPGK






159

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v2-wildtype




PSGRAAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGD
S

canine IgG-B Fc




GGGSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDILLIAR

Protein A+



TPEVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFN
C1q+



GTYRVVSVLPIGHQDWLKGKQFTCKVNNKALPSPIERTISKA
CD16+



RGQAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEW




QSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGD




TFICAVMHEALHNHYTQESLSHSPGK






17

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-wildtype




GCLRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNP
SGG

canine IgG-B Fc with




GSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLLIARTP

signal sequence



EVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGT
Protein A+



YRVVSVLPIGHQDWLKGKQFTCKVNNKALPSPIERTISKARG
C1q+



QAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQS
CD16+



NGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTF




ICAVMHEALHNHYTQESLSHSPGK






160

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3-wildtype




PSGRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGG

canine IgG-B Fc



PSVFIFPPKPKDTLLIARTPEVTCVVVDLDPEDPEVQISWFV
Protein A+



DGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTC
C1q+



KVNNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTV
CD16+



SLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGS




YFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSP




GK






18

MDMRVPAQLLGLLLLWLRGARC
FPASVQLHEAVELHHWCIPF

Exemplary canine TrkA




SVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRHGC

ECD v4-wildtype




LRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNP
SGGGS

canine IgG-B Fc with




GGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLLIARTPEV

signal sequence



TCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGTYR
Protein A+



VVSVLPIGHQDWLKGKQFTCKVNNKALPSPIERTISKARGQA
Protein+



HQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG
C1q+



QQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTFIC
CD16+



AVMHEALHNHYTQESLSHSPGK






161

FPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET

Exemplary canine TrkA




SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAANPS

ECD v4-wildtype




GRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGGPS

canine IgG-B Fc



VFIFPPKPKDTLLIARTPEVTCVVVDLDPEDPEVQISWFVDG
Protein A+



KQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTCKV
C1q+



NNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSL
CD16+



TCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYF




LYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSPGK






19

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHAAVELHHWCI

Exemplary feline TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPAANETVRH

ECD v2-wildtype




GCLRLNQPTHVNNGNYTLLAANPSGRAAASVLAAFMDNPFEF

feline IgG2 Fc with




NPEDPIPVSFSPVDSNSTSGD
SGGGSGGGSPKTASTIESKTG

signal sequence Protein



EGPKCPVPEIPGAPSVFIFPPKPKDTLSISRTPEVTCLVVDL
A+



GPDDSNVQITWFVDNTEMHTAKTRPREEQFNSTYRVVSVLPI
C1q-



LHQDWLKGKEFKCKVNSKSLPSAMERTISKAKGQPHEPQVYV
CD16-



LPPTQEELSENKVSVTCLIKGFHPPDIAVEWEITGQPEPENN




YQTTPPQLDSDGTYFLYSRLSVDRSHWQRGNTYTCSVSHEAL




HSHHTQKSLTQSPGK






162

VSFPASVQLHAAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary feline TrkA




ETSFIFTEFLEPAANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v2-wildtype




PSGRAAASVLAAFMDNPFEFNPEDPIPVSFSPVDSNSTSGD
S

feline IgG2 Fc




GGGSGGGSPKTASTIESKTGEGPKCPVPEIPGAPSVFIFPPK

Protein A+



PKDTLSISRTPEVTCLVVDLGPDDSNVQITWFVDNTEMHTAK
C1q-



TRPREEQFNSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPS
CD16-



AMERTISKAKGQPHEPQVYVLPPTQEELSENKVSVTCLIKGF




HPPDIAVEWEITGQPEPENNYQTTPPQLDSDGTYFLYSRLSV




DRSHWQRGNTYTCSVSHEALHSHHTQKSLTQSPGK






20

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHAAVELHHWCI

Exemplary feline TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPAANETVRH

ECD v3-wildtype




GCLRLNQPTHVNNGNYILLAANPSGRAAASVLAAFMDNP
SGG

feline IgG2 Fc with




GSGGGSPKTASTIESKTGEGPKCPVPEIPGAPSVFIFPPKPK

signal sequence



DTLSISRTPEVTCLVVDLGPDDSNVQITWFVDNTEMHTAKTR
Protein A+



PREEQFNSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSAM
C1q-



ERTISKAKGQPHEPQVYVLPPTQEELSENKVSVICLIKGFHP
CD16-



PDIAVEWEITGQPEPENNYQTTPPQLDSDGTYFLYSRLSVDR




SHWQRGNTYTCSVSHEALHSHHTQKSLTQSPGK






163

VSFPASVQLHAAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary feline TrkA




ETSFIFTEFLEPAANETVRHGCLRLNQPTHVNNGNYILLAAN

ECD v3-wildtype




PSGRAAASVLAAFMDNP
SGGGSGGGSPKTASTIESKTGEGPK

feline IgG2 Fc



CPVPEIPGAPSVFIFPPKPKDTLSISRTPEVTCLVVDLGPDD
Protein A+



SNVQITWFVDNTEMHTAKTRPREEQFNSTYRVVSVLPILHQD
C1q-



WLKGKEFKCKVNSKSLPSAMERTISKAKGQPHEPQVYVLPPT
CD16-



QEELSENKVSVTCLIKGFHPPDIAVEWEITGQPEPENNYQTT




PPQLDSDGTYFLYSRLSVDRSHWQRGNTYTCSVSHEALHSHH




TQKSLIQSPGK






21


MDMRVPAQLLGLLLLWLRGARCFPASVQLHAAVELHHWCIPF


Exemplary feline TrkA




SVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPAANETVRHGC

ECD v4-wildtype




LRLNQPTHVNNGNYILLAANPSGRAAASVLAAFMDNP
SGGGS

feline IgG2 Fc with




GGGSPKTASTIESKTGEGPKCPVPEIPGAPSVFIFPPKPKDT

signal sequence Protein



LSISRTPEVTCLVVDLGPDDSNVQITWFVDNTEMHTAKTRPR
A+



EEQFNSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSAMER
C1q-



TISKAKGQPHEPQVYVLPPTQEELSENKVSVTCLIKGFHPPD
CD16-



IAVEWEITGQPEPENNYQTTPPQLDSDGTYFLYSRLSVDRSH




WQRGNTYTCSVSHEALHSHHTQKSLTQSPGK






164

FPASVQLHAAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET

Exemplary feline TrkA




SFIFTEFLEPAANETVRHGCLRLNQPTHVNNGNYILLAANPS

ECD v4-wildtype




GRAAASVLAAFMDNP
SGGGSGGGSPKTASTIESKTGEGPKCP

feline IgG2 Fc



VPEIPGAPSVFIFPPKPKDTLSISRTPEVTCLVVDLGPDDSN
Protein A+



VQITWFVDNTEMHTAKTRPREEQFNSTYRVVSVLPILHQDWL
C1q-



KGKEFKCKVNSKSLPSAMERTISKAKGQPHEPQVYVLPPTQE
CD16-



ELSENKVSVTCLIKGFHPPDIAVEWEITGQPEPENNYQTTPP




QLDSDGTYFLYSRLSVDRSHWQRGNTYTCSVSHEALHSHHTQ




KSLIQSPGK






22

METDTLLLWVLLLWVPGSTG
VSFPASVHLQTAVEQHHWCIPF

Exemplary equine TrkA




SVDGQPAPTLRWLFNGSVLNETSFIFTEFLESAANETMRHGC

ECD v2-variant equine




LRLNQPTHVNNGNYILLATNPYGQDSASVMVAFMDNPFEFNP

IgG2 Fc with signal




EDPIPVSFSPVDTNSTSRDPPCVLSAEGVIPIPSVPKPQCPP

sequence



YTHSKFLGGPSVFIFPPNPKDTLMISRTPVVTCVVVNLSDQY
Protein A+



PDVQFSWYVDNTEVHSAITKQREAQFNSTYRVVSVLPIQHQD
C1q-



WLSGKEFKCSVTNVGVPQPISRAISRGKGPSRVPQVYVLPPH
CD16-



PDELAKSKVSVICLVKDFYPPDISVEWQSNRWPELEGKYSTT




PAQLDGDGSYFLYSKLSLETSRWQQVESFTCAVMHEALHNHY




TKTDISESLGK






165

VSFPASVHLQTAVEQHHWCIPFSVDGQPAPTLRWLFNGSVLN

Exemplary equine TrkA




ETSFIFTEFLESAANETMRHGCLRLNQPTHVNNGNYILLATN

ECD v2-variant equine




PYGQDSASVMVAFMDNPFEFNPEDPIPVSFSPVDTNSTSRDP

IgG2 Fc



PCVLSAEGVIPIPSVPKPQCPPYTHSKFLGGPSVFIFPPNPK
Protein A+



DTLMISRTPVVTCVVVNLSDQYPDVQFSWYVDNTEVHSAITK
C1q-



QREAQFNSTYRVVSVLPIQHQDWLSGKEFKCSVTNVGVPQPI
CD16-



SRAISRGKGPSRVPQVYVLPPHPDELAKSKVSVTCLVKDFYP




PDISVEWQSNRWPELEGKYSTTPAQLDGDGSYFLYSKLSLET




SRWQQVESFICAVMHEALHNHYTKTDISESLGK






23


METDTLLLWVLLLWVPGSTGVSFPASVHLQTAVEQHHWCIPF


Exemplary equine TrkA




SVDGQPAPTLRWLFNGSVLNETSFIFTEFLESAANETMRHGC

ECD v3-variant equine




LRLNQPTHVNNGNYILLATNPYGQDSASVMVAFMDNPPPCVL

IgG2 Fc with signal



SAEGVIPIPSVPKPQCPPYTHSKFLGGPSVFIFPPNPKDTLM
sequence



ISRTPVVTCVVVNLSDQYPDVQFSWYVDNTEVHSAITKQREA
Protein A+



QFNSTYRVVSVLPIQHQDWLSGKEFKCSVTNVGVPQPISRAI
C1q-



SRGKGPSRVPQVYVLPPHPDELAKSKVSVTCLVKDFYPPDIS
CD16-



VEWQSNRWPELEGKYSTTPAQLDGDGSYFLYSKLSLETSRWQ




QVESFTCAVMHEALHNHYTKTDISESLGK






166

VSFPASVHLQTAVEQHHWCIPFSVDGQPAPTLRWLFNGSVLN

Exemplary equine TrkA




ETSFIFTEFLESAANETMRHGCLRLNQPTHVNNGNYILLATN

ECD v3-variant equine




PYGQDSASVMVAFMDNPPPCVLSAEGVIPIPSVPKPQCPPYT

IgG2 Fc



HSKFLGGPSVFIFPPNPKDTLMISRTPVVTCVVVNLSDQYPD
Protein A+



VQFSWYVDNTEVHSAITKQREAQFNSTYRVVSVLPIQHQDWL
C1q-



SGKEFKCSVTNVGVPQPISRAISRGKGPSRVPQVYVLPPHPD
CD16-



ELAKSKVSVTCLVKDFYPPDISVEWQSNRWPELEGKYSTIPA




QLDGDGSYFLYSKLSLETSRWQQVESFTCAVMHEALHNHYTK




TDISESLGK






24


METDTLLLWVLLLWVPGSTGFPASVHLQTAVEQHHWCIPFSV


Exemplary equine TrkA




DGQPAPTLRWLFNGSVLNETSFIFTEFLESAANETMRHGCLR

ECD v4-variant equine




LNQPTHVNNGNYTLLATNPYGQDSASVMVAFMDNPPPCVLSA

IgG2 Fc with signal



EGVIPIPSVPKPQCPPYTHSKFLGGPSVFIFPPNPKDTLMIS
sequence



RTPVVTCVVVNLSDQYPDVQFSWYVDNTEVHSAITKQREAQF
Protein A+



NSTYRVVSVLPIQHQDWLSGKEFKCSVTNVGVPQPISRAISR
C1q-



GKGPSRVPQVYVLPPHPDELAKSKVSVTCLVKDFYPPDISVE
CD16-



WQSNRWPELEGKYSTTPAQLDGDGSYFLYSKLSLETSRWQQV




ESFTCAVMHEALHNHYTKTDISESLGK






167

FPASVHLQTAVEQHHWCIPFSVDGQPAPTLRWLFNGSVLNET

Exemplary equine TrkA




SFIFTEFLESAANETMRHGCLRLNQPTHVNNGNYILLATNPY

ECD v4-variant equine




GQDSASVMVAFMDNPPPCVLSAEGVIPIPSVPKPQCPPYTHS

IgG2 Fc



KFLGGPSVFIFPPNPKDTLMISRTPVVTCVVVNLSDQYPDVQ
Protein A+



FSWYVDNTEVHSAITKQREAQFNSTYRVVSVLPIQHQDWLSG
C1q-



KEFKCSVTNVGVPQPISRAISRGKGPSRVPQVYVLPPHPDEL
CD16-



AKSKVSVTCLVKDFYPPDISVEWQSNRWPELEGKYSTTPAQL




DGDGSYFLYSKLSLETSRWQQVESFTCAVMHEALHNHYTKTD




ISESLGK






25
VSFPASCQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN
Exemplary canine TrkA



ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYILLAAN
ECD (v2)



PSGRCAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGD
Extra disulfide





26
VSFPASCQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN
Exemplary canine TrkA



ETSFIFTEFLEPVANETVRHGCLRLNQP
ECD (v3)



THVNNGNYILLAANPSGRCAAFVMAAFMDNP
Extra disulfide





27
FPASCQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET
Exemplary canine TrkA



SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYILLAANPS
ECD (v4)



GRCAAFVMAAFMDNP
Extra disulfide





28
VSFPASCQLHAAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN
Exemplary feline TrkA



ETSFIFTEFLEPAANETVRHGCLRLNQPTHVNNGNYILLAAN
ECD (v2)



PSGRCAASVLAAFMDNPFEFNPEDPIPVSFSPVDSNSTSGD
Extra disulfide





29
VSFPASCQLHAAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN
Exemplary feline TrkA



ETSFIFTEFLEPAANETVRHGCLRLNQP
ECD (v3)



THVNNGNYILLAANPSGRCAASVLAAFMDNP
Extra disulfide





30
FPASCQLHAAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET
Exemplary feline TrkA



SFIFTEFLEPAANETVRHGCLRLNQPTHVNNGNYTLLAANPS
ECD (v4)



GRCAASVLAAFMDNP
Extra disulfide





31
VSFPASCHLQTAVEQHHWCIPFSVDGQPAPTLRWLFNGSVLN
Exemplary equine TrkA



ETSFIFTEFLESAANETMRHGCLRLNQPTHVNNGNYTLLATN
ECD (v2)



PYGQCSASVMVAFMDNPFEFNPEDPIPVSFSPVDTNSTSRD
Extra disulfide





32
VSFPASCHLQTAVEQHHWCIPFSVDGQPAPTLRWLFNGSVLN
Exemplary equine TrkA



ETSFIFTEFLESAANETMRHGCLRLNQPTHVNNGNYTLLATN
ECD (v3)



PYGQCSASVMVAFMDNP
Extra disulfide





33
FPASCHLQTAVEQHHWCIPFSVDGQPAPTLRWLFNGSVLNET
Exemplary equine TrkA



SFIFTEFLESAANETMRHGCLRLNQPTHVNNGNYTLLATNPY
EC (v4)



GQCSASVMVAFMDNP
Extra disulfide





34
PVPEPLGGPSVLIFPPKPKDILRITRTPEVTCVVLDLGREDP
Exemplary wild-type



EVQISWFVDGKEVHTAKTQSREQQFNGTYRVVSVLPIEHQDW
canine IgG-A Fc



LTGKEFKCRVNHIDLPSPIERTISKARGRAHKPSVYVLPPSP
Protein A-



KELSSSDTVSITCLIKDFYPPDIDVEWQSNGQQEPERKHRMT
C1q-



PPQLDEDGSYFLYSKLSVDKSRWQQGDPFTCAVMHETLQNHY
CD16-



TDLSLSHSPGK






35
PAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDPEDP
Exemplary wild-type



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCKVNNKALPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16+



QESLSHSPGK






36
PKRENGRVPRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLLI
Exemplary wild-type



ARTPEVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQ
canine IgG-B Fc with



FNGTYRVVSVLPIGHQDWLKGKQFTCKVNNKALPSPIERTIS
hinge



KARGQAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDV
Protein A+



EWQSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQR
C1q+



GDTFICAVMHEALHNHYTQESLSHSPGK
CD16+





37
PGCGLLGGPSVFIFPPKPKDILVTARTPTVTCVVVDLDPENP
Exemplary wild-type



EVQISWFVDSKQVQTANTQPREEQSNGTYRVVSVLPIGHQDW
canine IgG-C Fc



LSGKQFKCKVNNKALPSPIEEIISKTPGQAHQPNVYVLPPSR
Protein A-



DEMSKNTVTLTCLVKDFFPPEIDVEWQSNGQQEPESKYRMTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16+



QISLSHSPGK






38
AKECECKCNCNNCPCPGCGLLGGPSVFIFPPKPKDILVTART
Exemplary wild-type



PTVTCVVVDLDPENPEVQISWFVDSKQVQTANTQPREEQSNG
canine IgG-C Fc with



TYRVVSVLPIGHQDWLSGKQFKCKVNNKALPSPIEEIISKTP
hinge



GQAHQPNVYVLPPSRDEMSKNTVTLTCLVKDFFPPEIDVEWQ
Protein A-



SNGQQEPESKYRMTPPQLDEDGSYFLYSKLSVDKSRWQRGDT
C1q+



FICAVMHEALHNHYTQISLSHSPGK
CD16+





39
PVPESLGGPSVFIFPPKPKDILRITRTPEITCVVLDLGREDP
Exemplary wild-type



EVQISWFVDGKEVHTAKTQPREQQFNSTYRVVSVLPIEHQDW
canine IgG-D Fc



LTGKEFKCRVNHIGLPSPIERTISKARGQAHQPSVYVLPPSP
Protein A-



KELSSSDTVTLTCLIKDFFPPEIDVEWQSNGQPEPESKYHTT
C1q-



APQLDEDGSYFLYSKLSVDKSRWQQGDTFTCAVMHEALQNHY
CD16-



TDLSLSHSPGK






40
PVPEPLGGPSVLIFPPKPKDTLLIARTPEVTCVVLDLGREDP
Exemplary variant



EVQISWFVDGKEVHTAKTQSREQQFNGTYRVVSVLPIGHQDW
canine IgG-A Fc



LTGKEFKCRVNHIDLPSPIERTISKARGRAHKPSVYVLPPSP
C1q-



KELSSSDTVSITCLIKDFYPPDIDVEWQSNGQQEPERKHRMT
CD16-



PPQLDEDGSYFLYSKLSVDKSRWQQGDPFTCAVMHEALHNHY
Protein A+



TDLSLSHSPGK
I(21)T




R(23)L




T(25)A




E(80)G




T(205)A




Q(207)H





41
PGCGLLGGPSVFIFPPKPKDTLLIARTPTVTCVVVDLDPENP
Exemplary variant



EVQISWFVDSKQVQTANTQPREEQSNGTYRVVSVLPIGHQDW
canine IgG-C Fc



LSGKQFKCKVNNKALPSPIEEIISKTPGQAHQPNVYVLPPSR
C1q+



DEMSKNTVTLTCLVKDFFPPEIDVEWQSNGQQEPESKYRMTP
Protein A+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
I(21)T



QISLSHSPGK
V(23)L




T(24)I





42
PVPESLGGPSVFIFPPKPKDTLLIARTPEITCVVLDLGREDP
Exemplary variant



EVQISWFVDGKEVHTAKTQPREQQFNSTYRVVSVLPIGHQDW
canine IgG-D Fc



LTGKEFKCRVNHIGLPSPIERTISKARGQAHQPSVYVLPPSP
C1q-



KELSSSDTVTLTCLIKDFFPPEIDVEWQSNGQPEPESKYHTT
CD16-



APQLDEDGSYFLYSKLSVDKSRWQQGDTFTCAVMHEALHNHY
Protein A+



TDLSLSHSPGK
I(21)T




R(23)L




T(25)A




E(80)G




Q(207)H





43
PVPEPLGGPSVLIFPPKPKDTLRITRIPEVTCVVLDLGREDP
Exemplary variant



EVQISWFVDGKEVHTAKTQSREQQFNGTYRVVSVLPIEHQDW
canine IgG-A Fc



LTGKEFKCRVNHIDLPSPIERTISKARGRAHKPSVYVLPPSP
C1q-



KELSSSDTVSITCLIKDFYPPDIDVEWQSNGQQEPERKHRMT
CD16-



PPQLDEDGSYFLYSKLSVDKSRWQQGDPFTCAVMHETLHNHY
Protein A+



TDLSLSHSPGK
I(21)T




Q(207)H





44
PGCGLLGGPSVFIFPPKPKDTLVTARTPTVTCVVVDLDPENP
Exemplary variant



EVQISWFVDSKQVQTANTQPREEQSNGTYRVVSVLPIGHQDW
canine IgG-C Fc



LSGKQFKCKVNNKALPSPIEEIISKTPGQAHQPNVYVLPPSR
C1q+



DEMSKNTVTLICLVKDFFPPEIDVEWQSNGQQEPESKYRMTP
Protein A+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
I(21)T



QISLSHSPGK






45
PVPESLGGPSVFIFPPKPKDTLRITRTPEITCVVLDLGREDP
Exemplary variant



EVQISWFVDGKEVHTAKTQPREQQFNSTYRVVSVLPIEHQDW
canine IgG-D Fc



LTGKEFKCRVNHIGLPSPIERTISKARGQAHQPSVYVLPPSP
C1q-



KELSSSDTVTLTCLIKDFFPPEIDVEWQSNGQPEPESKYHTT
Protein A+



APQLDEDGSYFLYSKLSVDKSRWQQGDTFTCAVMHEALHNHY
I(21)T



TDLSLSHSPGK
Q(207)H





46
PAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDPEDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCRVNNKALPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q-



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
K(93)R



QESLSHSPGK






47
PGCGLLGGPSVFIFPPKPKDILVTARTPTVTCVVVDLDPENP
Exemplary variant



EVQISWFVDSKQVQTANTQPREEQSNGTYRVVSVLPIGHQDW
canine IgG-C Fc



LSGKQFKCRVNNKALPSPIEEIISKTPGQAHQPNVYVLPPSR
Protein A-



DEMSKNTVTLTCLVKDFFPPEIDVEWQSNGQQEPESKYRMTP
C1q-



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16+



QISLSHSPGK
K(93)R





48
PAPEPLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDPEDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCKVNNKALPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QESLSHSPGK
M(5)P





49
PAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDREDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCKVNNKALPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QESLSHSPGK
P(39)R





50
PAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLGPEDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCKVNNKALPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QESLSHSPGK
D(38)G





51
PAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLGREDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCKVNNKALPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QESLSHSPGK
D(38)G




P(39)R





52
PAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDPEDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCKVNNIALPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QESLSHSPGK
K(97)I





53
PAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDPEDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCKVNNKGLPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QESLSHSPGK
A(98)G





54
PAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLGPEDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCKVNNIGLPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QESLSHSPGK
D(38)G




K(97)I




A(98)G





55
PAPEPLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDREDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCKVNNKALPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QESLSHSPGK
M(5)P




P(39)R





56
PGCGPLGGPSVFIFPPKPKDILVTARTPTVTCVVVDLDPENP
Exemplary variant



EVQISWFVDSKQVQTANTQPREEQSNGTYRVVSVLPIGHQDW
canine IgG-C Fc



LSGKQFKCKVNNKALPSPIEEIISKTPGQAHQPNVYVLPPSR
Protein A-



DEMSKNTVTLTCLVKDFFPPEIDVEWQSNGQQEPESKYRMTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QISLSHSPGK
L(5)P





57
PGCGLLGGPSVFIFPPKPKDILVTARTPTVTCVVVDLDRENP
Exemplary variant



EVQISWFVDSKQVQTANTQPREEQSNGTYRVVSVLPIGHQDW
canine IgG-C Fc



LSGKQFKCKVNNKALPSPIEEIISKTPGQAHQPNVYVLPPSR
Protein A-



DEMSKNTVTLTCLVKDFFPPEIDVEWQSNGQQEPESKYRMTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QISLSHSPGK
P(39)R





58
PGCGLLGGPSVFIFPPKPKDILVTARTPTVTCVVVDLGPENP
Exemplary variant



EVQISWFVDSKQVQTANTQPREEQSNGTYRVVSVLPIGHQDW
canine IgG-C Fc



LSGKQFKCKVNNKALPSPIEEIISKTPGQAHQPNVYVLPPSR
Protein A-



DEMSKNTVTLTCLVKDFFPPEIDVEWQSNGQQEPESKYRMTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QISLSHSPGK
D(38)G





59
PGCGLLGGPSVFIFPPKPKDILVTARTPTVTCVVVDLDPENP
Exemplary variant



EVQISWFVDSKQVQTANTQPREEQSNGTYRVVSVLPIGHQDW
canine IgG-C Fc



LSGKQFKCKVNNIALPSPIEEIISKTPGQAHQPNVYVLPPSR
Protein A-



DEMSKNTVTLTCLVKDFFPPEIDVEWQSNGQQEPESKYRMTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QISLSHSPGK
K(97)I





60
PGCGLLGGPSVFIFPPKPKDILVTARTPTVTCVVVDLDPENP
Exemplary variant



EVQISWFVDSKQVQTANTQPREEQSNGTYRVVSVLPIGHQDW
canine IgG-C Fc



LSGKQFKCKVNNKGLPSPIEEIISKTPGQAHQPNVYVLPPSR
Protein A-



DEMSKNTVTLTCLVKDFFPPEIDVEWQSNGQQEPESKYRMTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QISLSHSPGK
A(98)G





61
PGCGPLGGPSVFIFPPKPKDILVTARTPTVTCVVVDLDRENP
Exemplary variant



EVQISWFVDSKQVQTANTQPREEQSNGTYRVVSVLPIGHQDW
canine IgG-C Fc



LSGKQFKCKVNNKALPSPIEEIISKTPGQAHQPNVYVLPPSR
Protein A-



DEMSKNTVTLTCLVKDFFPPEIDVEWQSNGQQEPESKYRMTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QISLSHSPGK
L(5)P




P(39)R





62
PGCGLLGGPSVFIFPPKPKDILVTARTPTVTCVVVDLGPENP
Exemplary variant



EVQISWFVDSKQVQTANTQPREEQSNGTYRVVSVLPIGHQDW
canine IgG-C Fc



LSGKQFKCKVNNIGLPSPIEEIISKTPGQAHQPNVYVLPPSR
Protein A-



DEMSKNTVTLTCLVKDFFPPEIDVEWQSNGQQEPESKYRMTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QISLSHSPGK
D(38)G




K(97)I




A(98)G





63
PGCGLLGGPSVFIFPPKPKDTLLIARTPTVTCVVVDLDPENP
Exemplary variant



EVQISWFVDSKQVQTANTQPREEQSNGTYRVVSVLPIGHQDW
canine IgG-C Fc



LSGKQFKCRVNNKALPSPIEEIISKTPGQAHQPNVYVLPPSR
C1q-



DEMSKNTVTLTCLVKDFFPPEIDVEWQSNGQQEPESKYRMTP
K(93)R



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
Protein A+



QISLSHSPGK
I(21)T




V(23)L




T(24)I





64
PAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDPEDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCRVNNIGLPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q-



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QESLSHSPGK
K(93)R




K(97)I




A(98)G





65
PAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLGPEDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCRVNNIGLPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q-



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QESLSHSPGK
D(38)G




K(93)R




K(97)I




A(98)G





66
PAPEPLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDREDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCRVNNKALPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q-



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QESLSHSPGK
M(5)P




P(39)R




K(93)R





67
PAPEPLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLGREDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCRVNNKALPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q-



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QESLSHSPGK
M(5)P




D(38)G




P(39)R




K(93)R





68
PGCGLLGGPSVFIFPPKPKDILVTARTPTVTCVVVDLGPENP
Exemplary variant



EVQISWFVDSKQVQTANTQPREEQSNGTYRVVSVLPIGHQDW
canine IgG-C Fc



LSGKQFKCRVNNIGLPSPIEEIISKTPGQAHQPNVYVLPPSR
Protein A-



DEMSKNTVTLTCLVKDFFPPEIDVEWQSNGQQEPESKYRMTP
C1q-



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QISLSHSPGK
D(38)G




K(93)R




K(97)I




A(98)G





69
PGCGPLGGPSVFIFPPKPKDILVTARTPTVTCVVVDLDRENP
Exemplary variant



EVQISWFVDSKQVQTANTQPREEQSNGTYRVVSVLPIGHQDW
canine IgG-C Fc



LSGKQFKCRVNNKALPSPIEEIISKTPGQAHQPNVYVLPPSR
Protein A-



DEMSKNTVTLTCLVKDFFPPEIDVEWQSNGQQEPESKYRMTP
C1q-



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16-



QISLSHSPGK
M(5)P




P(39)R




K(93)R





70
GGPSVFLFPPNPKDTLMITRTPEVTCVVVDVSQENPDVKFNW
Exemplary wild-type



YMDGVEVRTATTRPKEEQFNSTYRVVSVLRIQHQDWLSGKEF
equine IgG1 Fc



KCKVNNQALPQPIERTITKTKGRSQEPQVYVLAPHPDESKKS
Protein A+



KVSVTCLVKDFYPPEINIEWQSNGQPELETKYSTTQAQQDSD
C1q+



GSYFLYSKLSVDRNRWQQGTTFTCGVMHEALHNHYTQKNVSK




NPGK






71
GGPSVFIFPPNPKDALMISRTPVVTCVVVNLSDQYPDVQFSW
Exemplary wild-type



YVDNTEVHSAITKQREAQFNSTYRVVSVLPIQHQDWLSGKEF
equine IgG2 Fc



KCSVTNVGVPQPISRAISRGKGPSRVPQVYVLPPHPDELAKS
Protein A-



KVSVTCLVKDFYPPDISVEWQSNRWPELEGKYSTTPAQLDGD
C1q-



GSYFLYSKLSLETSRWQQVESFTCAVMHEALHNHFIKTDISE




SLGK






72

PPCVLSAEGVIPIPSVPKPQCPPYTHSKFLGGPSVFIFPPNP

Exemplary wild-type



KDALMISRTPVVTCVVVNLSDQYPDVQFSWYVDNTEVHSAIT
equine IgG2 Fc with



KQREAQFNSTYRVVSVLPIQHQDWLSGKEFKCSVTNVGVPQP
hinge



ISRAISRGKGPSRVPQVYVLPPHPDELAKSKVSVTCLVKDFY
Protein A-



PPDISVEWQSNRWPELEGKYSTTPAQLDGDGSYFLYSKLSLE
C1q-



TSRWQQVESFTCAVMHEALHNHFTKTDISESLGK






73
GGPSVFIFPPKPKDVLMITRMPEVTCLVVDVSHDSSDVLFTW
Exemplary wild-type



YVDGTEVKTAKTMPNEEQNNSTYRVVSVLRIQHQDWLNGKKF
equine IgG3 Fc



KCKVNNQALPAPVERTISKATGQTRVPQVYVLAPHPDELSKN
Protein A+



KVSVTCLVKDFYPPDITVEWQSNEHPEPEGKYRTTEAQKDSD
C1q+



GSYFLYSKLTVEKDRWQQGTTFTCVVMHEALHNHVMQKNISK




NPGK






74
VGPSVFIFPPKPKDVLMISRTPTVTCVVVDVGHDFPDVQFNW
Exemplary wild-type



YVDGVETHTATTEPKQEQFNSTYRVVSVLPIQHKDWLSGKEF
equine IgG4 Fc



KCKVNNKALPAPVERTISAPTGQPREPQVYVLAPHRDELSKN
Protein A+



KVSVTCLVKDFYPPDIDIEWKSNGQPEPETKYSTTPAQLDSD
C1q+



GSYFLYSKLTVETNRWQQGTTFTCAVMHEALHNHYTEKSVSK




SPGK






75
GGPSVFIFPPKPKDVLMISRKPEVTCVVVDLGHDDPDVQFTW
Exemplary wild-type



FVDGVETHTATTEPKEEQFNSTYRVVSVLPIQHQDWLSGKEF
equine IgG5 Fc



KCSVTSKALPAPVERTISKAKGQLRVPQVYVLAPHPDELAKN
Protein A-



TVSVTCLVKDFYPPEIDVEWQSNEHPEPEGKYSTTPAQLNSD
C1q-



GSYFLYSKLSVETSRWKQGESFTCGVMHEAVENHYTQKNVSH




SPGK






76
GRPSVFIFPPNPKDTLMISRTPEVTCVVVDVSQENPDVKFNW
Exemplary wild-type



YVDGVEAHTATTKAKEKQDNSTYRVVSVLPIQHQDWRRGKEF
equine IgG6 Fc



KCKVNNRALPAPVERTITKAKGELQDPQVYILAPHPDEVTKN
Protein A-



TVSVTCLVKDFYPPDINVEWQSNEEPEPEVKYSTTPAQLDGD
C1q-



GSYFLYSKLTVETDRWEQGESFTCVVMHEAIRHTYRQKSITN




FPGK






77
VGPSVFIFPPKPKDVLMISRTPTVTCVVVDVGHDFPDVQFNW
Exemplary wild-type



YVDGVETHTATTEPKQEQNNSTYRVVSILAIQHKDWLSGKEF
equine IgG7 Fc



KCKVNNQALPAPVQKTISKPTGQPREPQVYVLAPHPDELSKN
Protein A+



KVSVTCLVKDFYPPDIDIEWKSNGQPEPETKYSTTPAQLDGD
C1q



GSYFLYSKLTVETNRWQQGTTFTCAVMHEALHNHYTEKSVSK




SPGK






78
GGPSVFIFPPNPKDALMISRTPVVTCVVVNLSDQYPDVQFSW
Exemplary variant



YVDNTEVHSAITKQREAQFNSTYRVVSVLPIQHQDWLSGKEF
equine IgG2 Fc



KCSVTNVGVPQPISRAISRGKGPSRVPQVYVLPPHPDELAKS
C1q-



KVSVTCLVKDFYPPDISVEWQSNRWPELEGKYSTTPAQLDGD
Protein A+



GSYFLYSKLSLETSRWQQGESFTCAVMHEALHNHYTKTDISE
F(203)Y



SLGK






79
GGPSVFIFPPNPKDTLMISRTPVVTCVVVNLSDQYPDVQFSW
Exemplary variant



YVDNTEVHSAITKQREAQFNSTYRVVSVLPIQHQDWLSGKEF
equine IgG2 Fc



KCSVTNVGVPQPISRAISRGKGPSRVPQVYVLPPHPDELAKS
C1q-



KVSVTCLVKDFYPPDISVEWQSNRWPELEGKYSTTPAQLDGD
Protein A+



GSYFLYSKLSLETSRWQQVESFTCAVMHEALHNHYTKTDISE
A(15)T



SLGK
F(203)Y





80
GGPSVFIFPPKPKDVLMISRKPEVTCVVVDLGHDDPDVQFTW
Exemplary variant



FVDGVETHTATTEPKEEQFNSTYRVVSVLPIQHQDWLSGKEF
equine IgG5 Fc



KCSVTSKALPAPVERTISKAKGQLRVPQVYVLAPHPDELAKN
C1q-



TVSVTCLVKDFYPPEIDVEWQSNEHPEPEGKYSTTPAQLNSD
Protein A+



GSYFLYSKLSVETSRWKQGESFTCGVMHEALHNHYTQKNVSH
V(199)L



SPGK
E(200)H





81
GRPSVFIFPPNPKDTLMISRTPEVTCVVVDVSQENPDVKFNW
Exemplary variant



YVDGVEAHTATTKAKEKQDNSTYRVVSVLPIQHQDWRRGKEF
equine IgG6 Fc



KCKVNNRALPAPVERTITKAKGELQDPQVYILAPHPDEVTKN
C1q-



TVSVTCLVKDFYPPDINVEWQSNEEPEPEVKYSTTPAQLDGD
Protein A+



GSYFLYSKLTVETDRWEQGESFTCVVMHEALHNHYRQKSITN
I(199)L



FPGK
R(200)H




H(201)N




T(202)H





82
GGPSVFLFPPNPKDTLMITRIPEVTCVVVDVSQENPDVKFNW
Exemplary variant



YMDGVEVRTATTRPKEEQFNSTYRVVSVLRIQHQDWLSGKEF
equine IgG1 Fc



KCSVNNQALPQPIERTITKTKGRSQEPQVYVLAPHPDESKKS
Protein A+



KVSVTCLVKDFYPPEINIEWQSNGQPELETKYSTTQAQQDSD
C1q-



GSYFLYSKLSVDRNRWQQGTTFTCGVMHEALHNHYTQKNVSK
K(87)S



NPGK






83
GGPSVFIFPPKPKDVLMITRMPEVTCLVVDVSHDSSDVLFTW
Exemplary variant



YVDGTEVKTAKTMPNEEQNNSTYRVVSVLRIQHQDWLNGKKF
equine IgG3 Fc



KCSVNNQALPAPVERTISKATGQTRVPQVYVLAPHPDELSKN
Protein A+



KVSVTCLVKDFYPPDITVEWQSNEHPEPEGKYRTTEAQKDSD
C1q-



GSYFLYSKLTVEKDRWQQGTTFTCVVMHEALHNHVMQKNISK
K(87)S



NPGK






84
VGPSVFIFPPKPKDVLMISRTPTVTCVVVDVGHDFPDVQFNW
Exemplary variant



YVDGVETHTATTEPKQEQFNSTYRVVSVLPIQHKDWLSGKEF
equine IgG4 Fc



KCSVNNKALPAPVERTISAPTGQPREPQVYVLAPHRDELSKN
Protein A+



KVSVTCLVKDFYPPDIDIEWKSNGQPEPETKYSITPAQLDSD
C1q-



GSYFLYSKLTVETNRWQQGTTFTCAVMHEALHNHYTEKSVSK
K(87)S



SPGK






85
VGPSVFIFPPKPKDVLMISRTPTVTCVVVDVGHDFPDVQFNW
Exemplary variant



YVDGVETHTATTEPKQEQNNSTYRVVSILAIQHKDWLSGKEF
equine IgG7 Fc



KCSVNNQALPAPVQKTISKPTGQPREPQVYVLAPHPDELSKN
Protein A+



KVSVTCLVKDFYPPDIDIEWKSNGQPEPETKYSITPAQLDGD
C1q-



GSYFLYSKLTVETNRWQQGTTFTCAVMHEALHNHYTEKSVSK
K(87)S



SPGK






86
RKTDHPPGPKTGEGPKCPPPEMLGGPSIFIFPPKPKDTLSIS
Exemplary wild-type



RTPEVTCLVVDLGPDDSDVQITWFVDNIQVYTAKTSPREEQF
feline IgG1a Fc



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSPIERTISK
Protein A+



AKGQPHEPQVYVLPPAQEELSENKVSVTCLIKSFHPPDIAVE
C1q+



WEITGQPEPENNYRTTPPQLDSDGTYFVYSKLSVDRSHWQRG




NTYTCSVSHEALHSHHTQKSLTQSPGK






87
RKTDHPPGPKPCDCPKCPPPEMLGGPSIFIFPPKPKDTLSIS
Exemplary wild-type



RTPEVTCLVVDLGPDDSDVQITWFVDNIQVYTAKTSPREEQF
feline IgG1a Fc



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSPIERTISK
Protein A+



AKGQPHEPQVYVLPPAQEELSENKVSVTCLIKSFHPPDIAVE
C1q+



WEITGQPEPENNYRTTPPQLDSDGTYFVYSKLSVDRSHWQRG




NTYTCSVSHEALHSHHTQKSLTQSPGK






88
RKTDHPPGPKTGEGPKCPPPEMLGGPSIFIFPPKPKDTLSIS
Exemplary wild-type



RTPEVTCLVVDLGPDDSDVQITWFVDNIQVYTAKTSPREEQF
feline IgG1b Fc



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSPIERTISK
Protein A+



DKGQPHEPQVYVLPPAQEELSENKVSVTCLIEGFYPSDIAVE
C1q+



WEITGQPEPENNYRTTPPQLDSDGTYFLYSRLSVDRSRWQRG




NTYTCSVSHEALHSHHTQKSLTQSPGK






89
RKTDHPPGPKPCDCPKCPPPEMLGGPSIFIFPPKPKDTLSIS
Exemplary wild-type



RTPEVTCLVVDLGPDDSDVQITWFVDNIQVYTAKTSPREEQF
feline IgG1b Fc



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSPIERTISK
Protein A+



DKGQPHEPQVYVLPPAQEELSENKVSVTCLIEGFYPSDIAVE
C1q+



WEITGQPEPENNYRTIPPQLDSDGTYFLYSRLSVDRSRWQRG




NTYTCSVSHEALHSHHTQKSLTQSPGK






90
PKTASTIESKTGEGPKCPVPEIPGAPSVFIFPPKPKDTLSIS
Exemplary wild-type



RTPEVTCLVVDLGPDDSNVQITWFVDNTEMHTAKTRPREEQF
feline IgG2 Fc



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSAMERTISK
Protein A+



AKGQPHEPQVYVLPPTQEELSENKVSVTCLIKGFHPPDIAVE
C1q-



WEITGQPEPENNYQTTPPQLDSDGTYFLYSRLSVDRSHWQRG




NTYTCSVSHEALHSHHTQKSLTQSPGK






91
RKTDHPPGPKPCDCPKCPPPEMLGGPSIFIFPPKPKDTLSIS
Exemplary variant feline



RTPEVTCLVVDLGPDDSDVQITWFVDNIQVYTAKTSPREEQF
IgG1a Fc



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSPIERTISK
Protein A+



AKGQPHEPQVYVLPPAQEELSENKVSVTCLIKSFHPPDIAVE
C1q-



WEITGQPEPENNYRTIPPQLDSDGTYFVYSKLSVDRSHWQRG
P(198)A



NTYTCSVSHEALHSHHTQKSLTQSPGK






92
RKTDHPPGPKTGEGPKCPPPEMLGGPSIFIFPPKPKDTLSIS
Exemplary variant feline



RTPEVTCLVVDLGPDDSDVQITWFVDNIQVYTAKTSPREEQF
IgG1a Fc



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSPIERTISK
Protein A+



AKGQPHEPQVYVLPPAQEELSENKVSVTCLIKSFHPPDIAVE
C1q-



WEITGQPEPENNYRTIPPQLDSDGTYFVYSKLSVDRSHWQRG
P(198)A



NTYTCSVSHEALHSHHTQKSLTQSPGK






93
RKTDHPPGPKPCDCPKCPPPEMLGGPSIFIFPPKPKDTLSIS
Exemplary variant feline



RTPEVTCLVVDLGPDDSDVQITWFVDNIQVYTAKTSPREEQF
IgG1b Fc



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSPIERTISK
Protein A+



DKGQPHEPQVYVLPPAQEELSENKVSVTCLIEGFYPSDIAVE
C1q-



WEITGQPEPENNYRTIPPQLDSDGTYFLYSRLSVDRSRWQRG
P(198)A



NTYTCSVSHEALHSHHTQKSLTQSPGK






94
RKTDHPPGPKTGEGPKCPPPEMLGGPSIFIFPPKPKDTLSIS
Exemplary variant feline



RTPEVTCLVVDLGPDDSDVQITWFVDNIQVYTAKTSPREEQF
IgG1b Fc



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSPIERTISK
Protein A+



DKGQPHEPQVYVLPPAQEELSENKVSVTCLIEGFYPSDIAVE
C1q-



WEITGQPEPENNYRTIPPQLDSDGTYFLYSRLSVDRSRWQRG
P(198)A



NTYTCSVSHEALHSHHTQKSLTQSPGK






95
PKTASTIESKTGECPKCPVPEIPGAPSVFIFPPKPKDTLSIS
Exemplary variant feline



RTPEVTCLVVDLGPDDSNVQITWFVDNTEMHTAKTRPREEQF
IgG2 Fc



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSAMERTISK
Hinge Cys



AKGQPHEPQVYVLPPTQEELSENKVSVTCLIKGFHPPDIAVE
G(14)C



WEITGQPEPENNYQTTPPQLDSDGTYFLYSRLSVDRSHWQRG




NTYTCSVSHEALHSHHTQKSLTQSPGK






96
RKTDHPPGPKTGEGPPCPPPEMLGGPSIFIFPPKPKDTLSIS
Exemplary variant feline



RTPEVTCLVVDLGPDDSDVQITWFVDNIQVYTAKTSPREEQF
IgG1a Fc with modified



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSPIERTISK
hinge



AKGQPHEPQVYVLPPAQEELSENKVSVTCLIKSFHPPDIAVE
K(16)P



WEITGQPEPENNYRTIPPQLDSDGTYFVYSKLSVDRSHWQRG




NTYTCSVSHEALHSHHTQKSLTQSPGK






97
RKTDHPPGPKPCDCPPCPPPEMLGGPSIFIFPPKPKDTLSIS
Exemplary variant feline



RTPEVTCLVVDLGPDDSDVQITWFVDNIQVYTAKTSPREEQF
IgG1a Fc with modified



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSPIERTISK
hinge



AKGQPHEPQVYVLPPAQEELSENKVSVTCLIKSFHPPDIAVE
K(16)P



WEITGQPEPENNYRTTPPQLDSDGTYFVYSKLSVDRSHWQRG




NTYTCSVSHEALHSHHTQKSLTQSPGK






98
RKTDHPPGPKTGEGPPCPPPEMLGGPSIFIFPPKPKDTLSIS
Exemplary variant feline



RTPEVTCLVVDLGPDDSDVQITWFVDNIQVYTAKTSPREEQF
IgG1b Fc with modified



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSPIERTISK
hinge



DKGQPHEPQVYVLPPAQEELSENKVSVTCLIEGFYPSDIAVE
K(16)P



WEITGQPEPENNYRTTPPQLDSDGTYFLYSRLSVDRSRWQRG




NTYTCSVSHEALHSHHTQKSLTQSPGK






99
RKTDHPPGPKPCDCPPCPPPEMLGGPSIFIFPPKPKDTLSIS
Exemplary variant feline



RTPEVTCLVVDLGPDDSDVQITWFVDNIQVYTAKTSPREEQF
IgG1b Fc with modified



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSPIERTISK
hinge



DKGQPHEPQVYVLPPAQEELSENKVSVTCLIEGFYPSDIAVE
K(16)P



WEITGQPEPENNYRTTPPQLDSDGTYFLYSRLSVDRSRWQRG




NTYTCSVSHEALHSHHTQKSLTQSPGK






100
PKTASTIESKTGEGPPCPVPEIPGAPSVFIFPPKPKDTLSIS
Exemplary variant feline



RTPEVTCLVVDLGPDDSNVQITWFVDNTEMHTAKTRPREEQF
IgG2 Fc with modified



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSAMERTISK
hinge



AKGQPHEPQVYVLPPTQEELSENKVSVTCLIKGFHPPDIAVE
K(16)P



WEITGQPEPENNYQTTPPQLDSDGTYFLYSRLSVDRSHWQRG




NTYTCSVSHEALHSHHTQKSLTQSPGK






101

PPCVLSAEGVIPIPSVPKPPCPPYTHSKFLGGPSVFIFPPNP

Exemplary variant



KDALMISRTPVVTCVVVNLSDQYPDVQFSWYVDNTEVHSAIT
equine IgG2 Fc with



KQREAQFNSTYRVVSVLPIQHQDWLSGKEFKCSVTNVGVPQP
modified hinge



ISRAISRGKGPSRVPQVYVLPPHPDELAKSKVSVTCLVKDFY
Protein A-



PPDISVEWQSNRWPELEGKYSTTPAQLDGDGSYFLYSKLSLE
C1q-



TSRWQQVESFTCAVMHEALHNHFTKTDISESLGK
Q(20)P





102

PPSVLSAEGVIPIPSVPKPQCPPYTHSKFLGGPSVFIFPPNP

Exemplary variant



KDALMISRTPVVTCVVVNLSDQYPDVQFSWYVDNTEVHSAIT
equine IgG2 Fc with



KQREAQFNSTYRVVSVLPIQHQDWLSGKEFKCSVTNVGVPQP
modified hinge



ISRAISRGKGPSRVPQVYVLPPHPDELAKSKVSVTCLVKDFY
Protein A-



PPDISVEWQSNRWPELEGKYSTTPAQLDGDGSYFLYSKLSLE
C1q-



TSRWQQVESFTCAVMHEALHNHFTKTDISESLGK
C(3)S





103

PPSVLSAEGVIPIPSVPKPPCPPYTHSKFLGGPSVFIFPPNP

Exemplary variant



KDALMISRTPVVTCVVVNLSDQYPDVQFSWYVDNTEVHSAIT
equine IgG2 Fc with



KQREAQFNSTYRVVSVLPIQHQDWLSGKEFKCSVTNVGVPQP
modified hinge



ISRAISRGKGPSRVPQVYVLPPHPDELAKSKVSVTCLVKDFY
Protein A-



PPDISVEWQSNRWPELEGKYSTTPAQLDGDGSYFLYSKLSLE
C1q-



TSRWQQVESFTCAVMHEALHNHFTKTDISESLGK
C(3)S




Q(20)P





104

PPCVLSAEGVIPIPSVPKPQCPPYTHSKFLGGPSVFIFPPNP

Exemplary variant



KDTLMISRTPVVTCVVVNLSDQYPDVQFSWYVDNTEVHSAIT
equine IgG2 Fc with



KQREAQFNSTYRVVSVLPIQHQDWLSGKEFKCSVTNVGVPQP
hinge



ISRAISRGKGPSRVPQVYVLPPHPDELAKSKVSVTCLVKDFY
Protein A+



PPDISVEWQSNRWPELEGKYSTTPAQLDGDGSYFLYSKLSLE
C1q-



TSRWQQVESFTCAVMHEALHNHYTKTDISESLGK
A(45)T




F(233)Y





105

PPCVLSAEGVIPIPSVPKPPCPPYTHSKFLGGPSVFIFPPNP

Exemplary variant



KDTLMISRTPVVTCVVVNLSDQYPDVQFSWYVDNTEVHSAIT
equine IgG2 Fc with



KQREAQFNSTYRVVSVLPIQHQDWLSGKEFKCSVTNVGVPQP
modified hinge



ISRAISRGKGPSRVPQVYVLPPHPDELAKSKVSVTCLVKDFY
Protein A+



PPDISVEWQSNRWPELEGKYSTTPAQLDGDGSYFLYSKLSLE
C1q-



TSRWQQVESFTCAVMHEALHNHYTKTDISESLGK
Q(20)P




A(45)T




F(233)Y





106

PPSVLSAEGVIPIPSVPKPPCPPYTHSKFLGGPSVFIFPPNP

Exemplary variant



KDTLMISRTPVVTCVVVNLSDQYPDVQFSWYVDNTEVHSAIT
equine IgG2 Fc with



KQREAQFNSTYRVVSVLPIQHQDWLSGKEFKCSVTNVGVPQP
modified hinge



ISRAISRGKGPSRVPQVYVLPPHPDELAKSKVSVTCLVKDFY
Protein A+



PPDISVEWQSNRWPELEGKYSTTPAQLDGDGSYFLYSKLSLE
C1q-



TSRWQQVESFTCAVMHEALHNHYTKTDISESLGK
C(3)S




Q(20)P




A(45)T




F(233)Y





107

RKTDHPPGPKPCDCPKCPPPEMLGGPSVFIFPPKPKDTLSIS

Exemplary variant feline



RTPEVTCLVVDLGPDDSNVQITWFVDNTEMHTAKTRPREEQF
IgG2 Fc with feline



NSTYRVVSVLPILHQDWLKGKEFKCKVNSKSLPSAMERTISK
IgG1 hinge



AKGQPHEPQVYVLPPTQEELSENKVSVTCLIKGFHPPDIAVE




WEITGQPEPENNYQTTPPQLDSDGTYFLYSRLSVDRSHWQRG




NTYTCSVSHEALHSHHTQKSLTQSPGK






108


DMSKCPKCPAPELL
GGPSVFIFPPNPKDALMISRTPVVTCVV

Exemplary variant



VNLSDQYPDVQFSWYVDNTEVHSAITKQREAQFNSTYRVVSV
equine Fc IgG2 (with



LPIQHQDWLSGKEFKCSVTNVGVPQPISRAISRGKGPSRVPQ
equine IgG1 hinge)



VYVLPPHPDELAKSKVSVTCLVKDFYPPDISVEWQSNRWPEL
Protein A-



EGKYSTTPAQLDGDGSYFLYSKLSLETSRWQQVESFTCAVMH
C1q-



EALHNHFTKTDISESLGK






109


DMSKCPKCPAPELL
GGPSVFIFPPNPKDTLMISRTPVVTCVV

Exemplary variant



VNLSDQYPDVQFSWYVDNTEVHSAITKQREAQFNSTYRVVSV
equine IgG2 Fc (with



LPIQHQDWLSGKEFKCSVTNVGVPQPISRAISRGKGPSRVPQ
equine IgG1 hinge)



VYVLPPHPDELAKSKVSVTCLVKDFYPPDISVEWQSNRWPEL
C1q-



EGKYSTTPAQLDGDGSYFLYSKLSLETSRWQQVESFTCAVMH
Protein A+



EALHNHYTKTDISESLGK
A(29)T




F(217)Y





110

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v2-variant canine




GCLRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNPFEF

IgG-B Fc with signal




NPEDPIPVSFSPVDTNSTSGD
SGGGSGGGSRPPDCPKCPAPE

sequence





P
LGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDREDPEVQI

Protein A+



SWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGK
C1q-



QFTCRVNNKALPSPIERTISKARGQAHQPSVYVLPPSREELS
CD16-



KNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLD




EDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESL




SHSPGK






168

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v2-variant canine




PSGRAAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGD
S

IgG-B Fc




GGGSGGGSRPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLIAR

Protein A+



TPEVTCVVVDLDREDPEVQISWFVDGKQMQTAKTQPREEQFN
C1q-



GTYRVVSVLPIGHQDWLKGKQFTCRVNNKALPSPIERTISKA
CD16-



RGQAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEW




QSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGD




TFICAVMHEALHNHYTQESLSHSPGK






111

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary Canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGG

IgG-B Fc with signal




GSGGGSRPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLIARTP

sequence



EVTCVVVDLDREDPEVQISWFVDGKQMQTAKTQPREEQFNGT
Protein A+



YRVVSVLPIGHQDWLKGKQFTCRVNNKALPSPIERTISKARG
C1q-



QAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQS
CD16-



NGQQEPESKYRTIPPQLDEDGSYFLYSKLSVDKSRWQRGDTF




ICAVMHEALHNHYTQESLSHSPGK






169

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3-variant canine




PSGRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEPLGG

IgG-B Fc



PSVFIFPPKPKDILLIARTPEVTCVVVDLDREDPEVQISWFV
Protein A+



DGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTC
C1q-





R
VNNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTV

CD16-



SLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTIPPQLDEDGS




YFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSP




GK






112

MDMRVPAQLLGLLLLWLRGARC
FPASVQLHEAVELHHWCIPF

Exemplary canine TrkA




SVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRHGC

ECD v4-variant canine




LRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGGGS

IgG-B Fc with signal




GGGSRPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLIARTPEV

sequence



TCVVVDLDREDPEVQISWFVDGKQMQTAKTQPREEQFNGTYR
Protein A+



VVSVLPIGHQDWLKGKQFTCRVNNKALPSPIERTISKARGQA
C1q-



HQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG
CD16-



QQEPESKYRTIPPQLDEDGSYFLYSKLSVDKSRWQRGDTFIC




AVMHEALHNHYTQESLSHSPGK






170

FPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET

Exemplary canine TrkA




SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAANPS

ECD v4-variant canine




GRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEPLGGPS

IgG-B Fc



VFIFPPKPKDILLIARTPEVTCVVVDLDREDPEVQISWFVDG
Protein A+



KQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTCRV
C1q-



NNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSL
CD16-



TCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYF




LYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSPGK






113

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v2-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNPFEF

IgG-A Fc with signal




NPEDPIPVSFSPVDTNSTSGDSGGGSGGGSFNECRCIDTPCP

sequence



VPEPLGGPSVLIFPPKPKDTLLIARTPEVTCVVLDLGREDPE
C1q-



VQISWFVDGKEVHTAKTQSREQQFNGTYRVVSVLPIGHQDWL
Protein A+



TGKEFKCRVNHIDLPSPIERTISKARGRAHKPSVYVLPPSPK




ELSSSDTVSITCLIKDFYPPDIDVEWQSNGQQEPERKHRMTP




PQLDEDGSYFLYSKLSVDKSRWQQGDPFTCAVMHEALHNHYT




DLSLSHSPGK






171

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v2-variant canine




PSGRAAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGD
S

IgG-A Fc




GGGSGGGSFNECRCTDTPCPVPEPLGGPSVLIFPPKPKDTLL

C1q-



IARTPEVTCVVLDLGREDPEVQISWFVDGKEVHTAKTQSREQ
Protein A+



QFNGTYRVVSVLPIGHQDWLTGKEFKCRVNHIDLPSPIERTI




SKARGRAHKPSVYVLPPSPKELSSSDTVSITCLIKDFYPPDI




DVEWQSNGQQEPERKHRMTPPQLDEDGSYFLYSKLSVDKSRW




QQGDPFTCAVMHEALHNHYTDLSLSHSPGK






114

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGG

IgG-A Fc with signal




GSGGGSFNECRCTDTPCPVPEPLGGPSVLIFPPKPKDTLLIA

sequence



RTPEVTCVVLDLGREDPEVQISWFVDGKEVHTAKTQSREQQF
C1q-



NGTYRVVSVLPIGHQDWLTGKEFKCRVNHIDLPSPIERTISK
Protein A+



ARGRAHKPSVYVLPPSPKELSSSDTVSITCLIKDFYPPDIDV




EWQSNGQQEPERKHRMTPPQLDEDGSYFLYSKLSVDKSRWQQ




GDPFTCAVMHEALHNHYTDLSLSHSPGK






172

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3-variant canine




PSGRAAAFVMAAFMDNP
SGGGSGGGSFNECRCTDTPCPVPEP

IgG-A Fc



LGGPSVLIFPPKPKDTLLIARTPEVTCVVLDLGREDPEVQIS
C1q-



WFVDGKEVHTAKTQSREQQFNGTYRVVSVLPIGHQDWLTGKE
Protein A+



FKCRVNHIDLPSPIERTISKARGRAHKPSVYVLPPSPKELSS




SDTVSITCLIKDFYPPDIDVEWQSNGQQEPERKHRMTPPQLD




EDGSYFLYSKLSVDKSRWQQGDPFTCAVMHEALHNHYTDLSL




SHSPGK






115

MDMRVPAQLLGLLLLWLRGARC
FPASVQLHEAVELHHWCIPF

Exemplary canine TrkA




SVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRHGC

ECD v4-variant canine




LRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGGGS

IgG-A Fc with signal




GGGSFNECRCTDTPCPVPEPLGGPSVLIFPPKPKDTLLIART

sequence



PEVTCVVLDLGREDPEVQISWFVDGKEVHTAKTQSREQQFNG
C1q-



TYRVVSVLPIGHQDWLTGKEFKCRVNHIDLPSPIERTISKAR
Protein A+



GRAHKPSVYVLPPSPKELSSSDTVSITCLIKDFYPPDIDVEW




QSNGQQEPERKHRMTPPQLDEDGSYFLYSKLSVDKSRWQQGD




PFTCAVMHEALHNHYTDLSLSHSPGK






173

FPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET

Exemplary canine TrkA




SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAANPS

ECD v4-variant canine




GRAAAFVMAAFMDNP
SGGGSGGGSFNECRCTDTPCPVPEPLG

IgG-A Fc



GPSVLIFPPKPKDTLLIARTPEVTCVVLDLGREDPEVQISWF
C1q-



VDGKEVHTAKTQSREQQFNGTYRVVSVLPIGHQDWLTGKEFK
Protein A+



CRVNHIDLPSPIERTISKARGRAHKPSVYVLPPSPKELSSSD




TVSITCLIKDFYPPDIDVEWQSNGQQEPERKHRMTPPQLDED




GSYFLYSKLSVDKSRWQQGDPFTCAVMHEALHNHYTDLSLSH




SPGK






116

MDMRVPAQLLGLLLLWLRGAR
CVSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v2-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNPFEF

IgG-D Fc with signal




NPEDPIPVSFSPVDTNSTSGD
SGGGSGGGSPKESTCKCISPC

sequence



PVPESLGGPSVFIFPPKPKDTLLIARTPEITCVVLDLGREDP
C1q-



EVQISWFVDGKEVHTAKTQPREQQFNSTYRVVSVLPIGHQDW
Protein A+



LTGKEFKCRVNHIGLPSPIERTISKARGQAHQPSVYVLPPSP




KELSSSDTVTLTCLIKDFFPPEIDVEWQSNGQPEPESKYHTT




APQLDEDGSYFLYSKLSVDKSRWQQGDTFTCAVMHEALHNHY




TDLSLSHSPGK






174

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v2-variant canine




PSGRAAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGD
S

IgG-D Fc




GGGSGGGSPKESTCKCISPCPVPESLGGPSVFIFPPKPKDTL

C1q-





L
IARTPEITCVVLDLGREDPEVQISWFVDGKEVHTAKTQPRE

Protein A+



QQFNSTYRVVSVLPIGHQDWLTGKEFKCRVNHIGLPSPIERT




ISKARGQAHQPSVYVLPPSPKELSSSDTVTLTCLIKDFFPPE




IDVEWQSNGQPEPESKYHTTAPQLDEDGSYFLYSKLSVDKSR




WQQGDTFTCAVMHEALHNHYTDLSLSHSPGK






117

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGG

IgG-D Fc with signal




GSGGGSPKESTCKCISPCPVPESLGGPSVFIFPPKPKDTLLI

sequence





A
RTPEITCVVLDLGREDPEVQISWFVDGKEVHTAKTQPREQQ

C1q-



FNSTYRVVSVLPIGHQDWLTGKEFKCRVNHIGLPSPIERTIS
Protein A+



KARGQAHQPSVYVLPPSPKELSSSDTVTLTCLIKDFFPPEID




VEWQSNGQPEPESKYHTTAPQLDEDGSYFLYSKLSVDKSRWQ




QGDTFTCAVMHEALHNHYTDLSLSHSPGK






175

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3-variant canine




PSGRAAAFVMAAFMDNP
SGGGSGGGSPKESTCKCISPCPVPE

IgG-D Fc



QISLGGPSVFIFPPKPKDTLLIARTPEITCVVLDLGREDPEV
C1q-



SWFVDGKEVHTAKTQPREQQFNSTYRVVSVLPIGHQDWLTGK
Protein A+



EFKCRVNHIGLPSPIERTISKARGQAHQPSVYVLPPSPKELS




SSDTVTLTCLIKDFFPPEIDVEWQSNGQPEPESKYHTTAPQL




DEDGSYFLYSKLSVDKSRWQQGDTFTCAVMHEALHNHYTDLS




LSHSPGK






118

MDMRVPAQLLGLLLLWLRGARC
FPASVQLHEAVELHHWCIPF

Exemplary canine TrkA




SVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRHGC

ECD v4-variant canine




LRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGGGS

IgG-D Fc with signal




GGGSPKESTCKCISPCPVPESLGGPSVFIFPPKPKDTLLIAR

sequence



TPEITCVVLDLGREDPEVQISWFVDGKEVHTAKTQPREQQFN
C1q-



STYRVVSVLPIGHQDWLTGKEFKCRVNHIGLPSPIERTISKA
Protein A+



RGQAHQPSVYVLPPSPKELSSSDTVTLTCLIKDFFPPEIDVE




WQSNGQPEPESKYHTTAPQLDEDGSYFLYSKLSVDKSRWQQG




DTFTCAVMHEALHNHYTDLSLSHSPGK






176

FPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET

Exemplary canine TrkA




SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAANPS

ECD v4-variant canine




GRAAAFVMAAFMDNP
SGGGSGGGSPKESTCKCISPCPVPESL

IgG-D Fc



GGPSVFIFPPKPKDTLLIARTPEITCVVLDLGREDPEVQISW
C1q-



FVDGKEVHTAKTQPREQQFNSTYRVVSVLPIGHQDWLTGKEF
Protein A+



KCRVNHIGLPSPIERTISKARGQAHQPSVYVLPPSPKELSSS




DTVTLTCLIKDFFPPEIDVEWQSNGQPEPESKYHTTAPQLDE




DGSYFLYSKLSVDKSRWQQGDTFTCAVMHEALHNHYTDLSLS




HSPGK






119

METDTLLLWVLLLWVPGSTG
VSFPASVHLQTAVEQHHWCIPF

Exemplary equine TrkA




SVDGQPAPTLRWLFNGSVLNETSFIFTEFLESAANETMRHGC

ECD v2-variant equine




LRLNQPTHVNNGNYTLLATNPYGQDSASVMVAFMDNPFEFNP

IgG2 with IgG1 hinge




EDPIPVSFSPVDTNSTSRD
DMSKCPKCPAPELLGGPSVFIFP

with signal sequence



PNPKDTLMISRTPVVTCVVVNLSDQYPDVQFSWYVDNTEVHS
C1q-



AITKQREAQFNSTYRVVSVLPIQHQDWLSGKEFKCSVTNVGV
Protein A+



PQPISRAISRGKGPSRVPQVYVLPPHPDELAKSKVSVTCLVK




DFYPPDISVEWQSNRWPELEGKYSTTPAQLDGDGSYFLYSKL




SLETSRWQQVESFICAVMHEALHNHYTKTDISESLGK






177

VSFPASVHLQTAVEQHHWCIPFSVDGQPAPTLRWLFNGSVLN

Exemplary equine TrkA




ETSFIFTEFLESAANETMRHGCLRLNQPTHVNNGNYTLLATN

ECD v2-variant equine




PYGQDSASVMVAFMDNPFEFNPEDPIPVSFSPVDTNSTSRD
D

IgG2 with IgG1 hinge




MSKCPKCPAPELLGGPSVFIFPPNPKDTLMISRTPVVTCVVV

C1q-



NLSDQYPDVQFSWYVDNTEVHSAITKQREAQFNSTYRVVSVL
Protein A+



PIQHQDWLSGKEFKCSVTNVGVPQPISRAISRGKGPSRVPQV




YVLPPHPDELAKSKVSVTCLVKDFYPPDISVEWQSNRWPELE




GKYSTTPAQLDGDGSYFLYSKLSLETSRWQQVESFTCAVMHE




ALHNHYTKTDISESLGK






120

METDTLLLWVLLLWVPGSTG
VSFPASVHLQTAVEQHHWCIPF

Exemplary equine TrkA




SVDGQPAPTLRWLFNGSVLNETSFIFTEFLESAANETMRHGC

ECD v3-variant equine




LRLNQPTHVNNGNYTLLATNPYGQDSASVMVAFMDNPD
MSKC

IgG2 with IgG1 hinge




PKCPAPELLGGPSVFIFPPNPKDTLMISRTPVVTCVVVNLSD

with signal sequence



QYPDVQFSWYVDNTEVHSAITKQREAQFNSTYRVVSVLPIQH
C1q-



QDWLSGKEFKCSVTNVGVPQPISRAISRGKGPSRVPQVYVLP
Protein A+



PHPDELAKSKVSVTCLVKDFYPPDISVEWQSNRWPELEGKYS




TTPAQLDGDGSYFLYSKLSLETSRWQQVESFTCAVMHEALHN




HYTKTDISESLGK






178

VSFPASVHLQTAVEQHHWCIPFSVDGQPAPTLRWLFNGSVLN

Exemplary equine TrkA




ETSFIFTEFLESAANETMRHGCLRLNQPTHVNNGNYTLLATN

ECD v3-variant equine




PYGQDSASVMVAFMDNP
DMSKCPKCPAPELLGGPSVFIFPPN

IgG2 with IgG1 hinge



PKDTLMISRTPVVTCVVVNLSDQYPDVQFSWYVDNTEVHSAI
C1q-



TKQREAQFNSTYRVVSVLPIQHQDWLSGKEFKCSVTNVGVPQ
Protein A+



PISRAISRGKGPSRVPQVYVLPPHPDELAKSKVSVTCLVKDF




YPPDISVEWQSNRWPELEGKYSTTPAQLDGDGSYFLYSKLSL




ETSRWQQVESFICAVMHEALHNHYTKTDISESLGK






121

METDTLLLWVLLLWVPGSTG
FPASVHLQTAVEQHHWCIPFSV

Exemplary equine TrkA




DGQPAPTLRWLFNGSVLNETSFIFTEFLESAANETMRHGCLR

ECD v4-variant equine




LNQPTHVNNGNYTLLATNPYGQDSASVMVAFMDNP
DMSKCPK

IgG2 with IgG1 hinge




CPAPELLGGPSVFIFPPNPKDTLMISRTPVVTCVVVNLSDQY

with signal sequence



PDVQFSWYVDNTEVHSAITKQREAQFNSTYRVVSVLPIQHQD
C1q-



WLSGKEFKCSVTNVGVPQPISRAISRGKGPSRVPQVYVLPPH
Protein A+



PDELAKSKVSVTCLVKDFYPPDISVEWQSNRWPELEGKYSTT




PAQLDGDGSYFLYSKLSLETSRWQQVESFTCAVMHEALHNHY




TKTDISESLGK






179

FPASVHLQTAVEQHHWCIPFSVDGQPAPTLRWLFNGSVLNET

Exemplary equine TrkA




SFIFTEFLESAANETMRHGCLRLNQPTHVNNGNYTLLATNPY

ECD v4-variant equine




GQDSASVMVAFMDNP
DMSKCPKCPAPELLGGPSVFIFPPNPK

IgG2 with IgG1 hinge



DTLMISRTPVVTCVVVNLSDQYPDVQFSWYVDNTEVHSAITK
C1q



QREAQFNSTYRVVSVLPIQHQDWLSGKEFKCSVTNVGVPQPI
Protein A+



SRAISRGKGPSRVPQVYVLPPHPDELAKSKVSVTCLVKDFYP




PDISVEWQSNRWPELEGKYSTTPAQLDGDGSYFLYSKLSLET




SRWQQVESFTCAVMHEALHNHYTKTDISESLGK






122

MDMRVPAQLLGLLLLWLRGARC
VSFPASCQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v2-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRCAAFVMAAFMDNPFEF

IgG-B Fc with signal




NPEDPIPVSFSPVDTNSTSGD
SGGGSGGGSRPPDCPKCPAPE

sequence





P
LGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDREDPEVQI

Extra disulfide



SWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGK
Protein A+



QFTCRVNNKALPSPIERTISKARGQAHQPSVYVLPPSREELS
C1q-



KNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLD
CD16-



EDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESL




SHSPGK






180

VSFPASCQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v2-variant canine




PSGRCAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGD
S

IgG-B




GGGSGGGSRPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLIAR

Extra disulfide



TPEVTCVVVDLDREDPEVQISWFVDGKQMQTAKTQPREEQFN
Protein A+



GTYRVVSVLPIGHQDWLKGKQFTCRVNNKALPSPIERTISKA
C1q-



RGQAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEW
CD16-



QSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGD




TFICAVMHEALHNHYTQESLSHSPGK






123

MDMRVPAQLLGLLLLWLRGARC
VSFPASCQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRCAAFVMAAFMDNP
SGG

IgG-B Fc with signal




GSGGGSRPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLIARTP

sequence



EVTCVVVDLDREDPEVQISWFVDGKQMQTAKTQPREEQFNGT
Extra disulfide



YRVVSVLPIGHQDWLKGKQFTCRVNNKALPSPIERTISKARG
Protein A+



QAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQS
C1q-



NGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTF
CD16



ICAVMHEALHNHYTQESLSHSPGK






181

VSFPASCQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3-variant canine




PSGRCAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEPLGG

IgG-B Fc



PSVFIFPPKPKDTLLIARTPEVTCVVVDLDREDPEVQISWFV
Extra disulfide



DGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTC
Protein A+





R
VNNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTV

C1q-



SLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGS
CD16-



YFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSP




GK






124

MDMRVPAQLLGLLLLWLRGARC
FPASCQLHEAVELHHWCIPF

Exemplary canine TrkA




SVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRHGC

ECD v4-variant canine




LRLNQPTHVNNGNYILLAANPSGRCAAFVMAAFMDNP
SGGGS

IgG-B Fc with signal




GGGSRPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLIARTPEV

sequence



TCVVVDLDREDPEVQISWFVDGKQMQTAKTQPREEQFNGTYR
Extra disulfide



VVSVLPIGHQDWLKGKQFTCRVNNKALPSPIERTISKARGQA
Protein A+



HQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG
C1q-



QQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTFIC
CD16-



AVMHEALHNHYTQESLSHSPGK






182

FPASCQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET

Exemplary canine TrkA




SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAANPS

ECD v4-variant canine




GRCAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEPLGGPS

IgG-B Fc



VFIFPPKPKDTLLIARTPEVTCVVVDLDREDPEVQISWFVDG
Extra disulfide



KQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTCRV
Protein A+



NNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSL
C1q-



TCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYF
CD16-



LYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSPGK






125

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary Canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v2-variant canine




GCLRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNPFEF

IgG-B Fc with signal




NPEDPIPVSFSPVDTNSTSGD
SGGGSGGGSRPPDCPKCPAPE

sequence



MLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDPEDPEVQI
Protein A+



SWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGK
C1q-



QFTCRVNNIGLPSPIERTISKARGQAHQPSVYVLPPSREELS
CD16-



KNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLD




EDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESL




SHSPGK






183

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v2-variant canine




PSGRAAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGD
S

IgG-B Fc




GGGSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLLIAR

Protein A+



TPEVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFN
C1q-



GTYRVVSVLPIGHQDWLKGKQFTCRVNNIGLPSPIERTISKA
CD16-



RGQAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEW




QSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGD




TFICAVMHEALHNHYTQESLSHSPGK






126

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-variant canine




GCLRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNP
SGG

IgG-B Fc with signal




GSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLLIARTP

sequence



EVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGT
Protein A+



YRVVSVLPIGHQDWLKGKQFTCRVNNIGLPSPIERTISKARG
C1q-



QAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQS
CD16-



NGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTF




ICAVMHEALHNHYTQESLSHSPGK






184

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3-variant canine




PSGRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGG

IgG-B Fc



PSVFIFPPKPKDTLLIARTPEVTCVVVDLDPEDPEVQISWFV
Protein A+



DGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTC
C1q-





R
VNNIGLPSPIERTISKARGQAHQPSVYVLPPSREELSKNTV

CD16-



SLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGS




YFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSP




GK






127

MDMRVPAQLLGLLLLWLRGARC
FPASVQLHEAVELHHWCIPF

Exemplary canine TrkA




SVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRHGC

ECD v4-variant canine




LRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGGGS

IgG-B Fc with signal




GGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLLIARTPEV

sequence



TCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGTYR
Protein A+



VVSVLPIGHQDWLKGKQFTCRVNNIGLPSPIERTISKARGQA
C1q-



HQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG
CD16-



QQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTFIC




AVMHEALHNHYTQESLSHSPGK






185

FPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET

Exemplary canine TrkA




SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAANPS

ECD v4-variant canine




GRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGGPS

IgG-B Fc



VFIFPPKPKDTLLIARTPEVTCVVVDLDPEDPEVQISWFVDG
Protein A+



KQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTCRV
C1q-



NNIGLPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSL
CD16-



TCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYF




LYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSPGK






128

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v2-variant canine




GCLRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNPFEF

IgG-B Fc with signal




NPEDPIPVSFSPVDTNSTSGD
SGGGSGGGSRPPDCPKCPAPE

sequence





P
LGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLGREDPEVQI

Protein A+



SWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGK
C1q-



QFTCRVNNKALPSPIERTISKARGQAHQPSVYVLPPSREELS
CD16-



KNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLD




EDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESL




SHSPGK






186

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v2-variant canine




PSGRAAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGD
S

IgG-B Fc




GGGSGGGSRPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLIAR

Protein A+



TPEVTCVVVDLGREDPEVQISWFVDGKQMQTAKTQPREEQFN
C1q-



GTYRVVSVLPIGHQDWLKGKQFTCRVNNKALPSPIERTISKA
CD16-



RGQAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEW




QSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGD




TFICAVMHEALHNHYTQESLSHSPGK






129

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-variant canine




GCLRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNP
SGG

IgG-B Fc with signal




GSGGGSRPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLIARTP

sequence



EVTCVVVDLGREDPEVQISWFVDGKQMQTAKTQPREEQFNGT
Protein A+



YRVVSVLPIGHQDWLKGKQFTCRVNNKALPSPIERTISKARG
C1q-



QAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQS
CD16-



NGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTF




ICAVMHEALHNHYTQESLSHSPGK






187

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3-variant canine




PSGRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEPLGG

IgG-B Fc



PSVFIFPPKPKDTLLIARTPEVTCVVVDLGREDPEVQISWFV
Protein A+



DGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTC
C1q-





R
VNNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTV

CD16-



SLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGS




YFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSP




GK






130

MDMRVPAQLLGLLLLWLRGARC
FPASVQLHEAVELHHWCIPF

Exemplary canine TrkA




SVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRHGC

ECD v4-variant canine




LRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGGGS

IgG-B Fc with signal




GGGSRPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLIARTPEV

sequence



TCVVVDLGREDPEVQISWFVDGKQMQTAKTQPREEQFNGTYR
Protein A+



VVSVLPIGHQDWLKGKQFTCRVNNKALPSPIERTISKARGQA
C1q-



HQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG
CD16-



QQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTFIC




AVMHEALHNHYTQESLSHSPGK






188

FPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET

Exemplary canine TrkA




SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAANPS

ECD v4-variant canine




GRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEPLGGPS

IgG-B Fc



VFIFPPKPKDTLLIARTPEVTCVVVDLGREDPEVQISWFVDG
Protein A+



KQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTCRV
C1q-



NNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSL
CD16-



TCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYF




LYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSPGK






131

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3 x2-variant




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGG

canine IgG-B Fc with




GSGGGS
VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLF

signal sequence




NGSVLNETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNY

Protein A+




TLLAANPSGRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPA

C1q-



PEPLGGPSVFIFPPKPKDILLIARTPEVTCVVVDLGREDPEV
CD16-



QISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLK




GKQFTCRVNNKALPSPIERTISKARGQAHQPSVYVLPPSREE




LSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQ




LDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQE




SLSHSPGK






189

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3 x2-variant




PSGRAAAFVMAAFMDNP
SGGGSGGGS
VSFPASVQLHEAVELH

canine IgG-B Fc




HWCIPFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANE

Protein A+




TVRHGCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDN

C1q-




P
SGGGSGGGSRPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLI

CD16-



ARTPEVTCVVVDLGREDPEVQISWFVDGKQMQTAKTQPREEQ




FNGTYRVVSVLPIGHQDWLKGKQFTCRVNNKALPSPIERTIS




KARGQAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDV




EWQSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQR




GDTFICAVMHEALHNHYTQESLSHSPGK






132

MDMRVPAQLLGLLLLWLRGARCPKRENGRVPRPPDCPKCPAP

Exemplary variant



EPLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLGREDPEVQ
canine IgG-B Fc-



ISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKG
canine TrkA ECD v3



KQFTCRVNNKALPSPIERTISKARGQAHQPSVYVLPPSREEL
with signal sequence



SKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQL
Protein A+



DEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQES
C1q-



LSHSPGKSGGGSGGVSFPASVQLHEAVELHHWCIPFSVDGQP
CD16-




APSLRWLFNGSVLNETSFIFTEFLEPVANETVRHGCLRLNQP






THVNNGNYTLLAANPSGRAAAFVMAAFMDNP







190
PKRENGRVPRPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLIA
Exemplary variant



RTPEVTCVVVDLGREDPEVQISWFVDGKQMQTAKTQPREEQF
canine IgG-B Fc-



NGTYRVVSVLPIGHQDWLKGKQFTCRVNNKALPSPIERTISK
canine TrkA ECD v3



ARGQAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVE
Protein A+



WQSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRG
C1q-



DTFICAVMHEALHNHYTQESLSHSPGKSGGGSGGVSFPASVQ
CD16-




LHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNETSFIFTE






FLEPVANETVRHGCLRLNQPTHVNNGNYTLLAANPSGRAAAF






VMAAFMDNP







133

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNPSGG

IgG-B Fc-canine TrkA



GSGGGSRPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLIARTP
ECD v3 with signal



EVTCVVVDLGREDPEVQISWFVDGKQMQTAKTQPREEQFNGT
sequence



YRVVSVLPIGHQDWLKGKQFTCRVNNKALPSPIERTISKARG
Protein A+



QAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQS
C1q-



NGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTF
CD16-



ICAVMHEALHNHYTQESLSHSPGKSGGGSGGVSFPASVQLHE





AVELHHWCIPFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLE






PVANETVRHGCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMA






AFMDNP







191

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3-variant canine




PSGRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEPLGG

IgG-B Fc-canine TrkA



PSVFIFPPKPKDTLLIARTPEVTCVVVDLGREDPEVQISWFV
ECD v3



DGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTC
Protein A+





R
VNNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTV

C1q-



SLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGS
CD16-



YFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSP




GKSGGGSGGVSFPASVQLHEAVELHHWCIPFSVDGQPAPSLR





WLFNGSVLNETSFIFTEFLEPVANETVRHGCLRLNQPTHVNN






GNYTLLAANPSGRAAAFVMAAFMDNP







134
MAIAGDNRVAVTVAMGRIVGVVAMAVVAVVVLVVMPVSWLRG
Canine NGFR



GRARFRGWAGWAGRRRGRRTGFSQPLPPSARASGASASSGGR
NCBI Reference:



ALERSAAQPYPSAERTPLEAERCHRRRAVGAGAAGCAMDGPR
XP_022279621.1



LLLLLLLLLGVSLGGAKEACPTGLYTHSGECCKACNLGEGVA
[Canislupusfamiliaris]



QPCGANQTVCEPCLDSVTFSDVVSATEPCKPCTECVGLQSMS




APCVEADDAVCRCAYGYYQDETTGRCEACRVCEAGSGLVFSC




QDRQNTVCEECPDGTYSDEANHVDPCLPCTVCEDTERQLREC




TRWADAECEEIPGRWITRSTPSEDSDSTAPSTEEPELPPDQE




IIASTMADVVTTVMGSSQPVVTRGTADNLIPVYCSILAAVVV




GLVAYIAFKRWNSCKQNKQGANSRPVNQTPPPEGEKLHSDSG




ISVDSQSLHDQQPHTQTAAGQALKGDGGLYSSLPPAKREEVE




KLLNGSAGDTWRHLAGELGYQPEHIDSFTHEACPARALLASW




AAQDSATLDALLAALRRIQRADIVESLCSESTATSPV






135
AKEACPTGLYTHSGECCKACNLGEGVAQPCGANQTVCEPCLD
Exemplary canine



SVTFSDVVSATEPCKPCTECVGLQSMSAPCVEADDAVCRCAY
NGFR ECD



GYYQDETTGRCEACRVCEAGSGLVFSCQDRQNTVCEECPDGT




YSDEANHVDPCLPCTVCEDTERQLRECTRWADAECEE






136
MGAGAAGRAMDGPRPLLLLLPLLLGVSLGGAKEACPTGLFTH
Feline NGFR



SGECCKACNLGEGVAQPCGANQTVCEPCLDSVTFSDVVSATE
NBCBI Reference:



PCKPCTECVGLQSMSAPCVEADDAVCRCAYGYYQDETTGRCE
XP_023099534.1



ACRVCEAGSGLVFSCQDRQNTVCEECPDGTYSDEANHVDPCL
[Feliscatus]



PCTVCEDTERQLRECTRWADAECEEIPGRWITRSTPSEGSDS




TAPSTEEPEVPPEQDLIASTVADVVTTVMGSSQPVVTRGTAD




NLIPVYCSILAAVVVGLVAYIAFKRWNS




CKQDKQGANSRPVNQTPPPEGEKLHSDSGISVDSQSLHDQQS




HTQTAAGQALKGDGGLYSSLPSAKREEVEKLLNGSAGDTWRH




LAGELGYQPEHIDSFTREACPARALLASWAAQDSATLDALLA




ALRRIQRADIVESLCSESTATSPV






137
AKEACPTGLFTHSGECCKACNLGEGVAQPCGANQTVCEPCLD
Exemplary feline NGFR



SVTFSDVVSATEPCKPCTECVGLQSMSAPCVEADDAVCRCAY
ECD



GYYQDETTGRCEACRVCEAGSGLVFSCQDRQNTVCEECPDGT




YSDEANHVDPCLPCTVCEDTERQLRECTRWADAECEE






138
MRAGAADCAMDGPRLLLLLLLLGVCLLGGAKEVCPTDLYTHS
Equine NGFR



GECCKACNLGEGVAQPCGANQTVCEPCLDSVTFSDVVSATEP
NCBI Reference:



CKPCTECVGLQSMSAPCVEADDAVCRCAYGYYQDETTGRCEA
XP_023508464.1



CQVCEAGSGLVFSCQDKQNTVCEECPDGTYSDEANHVDPCLP
[Equuscaballus]



CTVCEDTERQLRECTRWADAECEEIPSRWITRATPPEGSDST




APSTQEPEGPPEKDLVASTVADVVTTVMGSSQPVVTRGTTDN




LIPVYCSILAAVVVGLVAYIAFKRWNSCKQNKQGANSRPVNQ




TPPPEGEKLHSDSGISVDSQSLHDQQPHTQTAAGQALKGDGG




LYSSLPLAKREEVEKLLNGSAGDTWRHLAGELGYQPEHIDSF




THEACPVRALLASWAAQDSATFDALLTALRRIQRADIVESLC




SESTATSPV






139
AKEVCPTDLYTHSGECCKACNLGEGVAQPCGANQTVCEPCLD
Exemplary equine



SVIFSDVVSATEPCKPCTECVGLQSMSAPCVEADDAVCRCAY
NGFR ECD



GYYQDETTGRCEACQVCEAGSGLVFSCQDKQNTVCEECPDGT




YSDEANHVDPCLPCTVCEDTERQLRECTRWADAECEE






140

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-canine NGFR




GCLRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNP
SGG

ECD variant canine




GSGGGS

AKEACPTGLYTHSGECCKACNLGEGVAQPCGANQTV


IgG-B Fc-canine TrkA





CEPCLDSVTFSDVVSATEPCKPCTECVGLQSMSAPCVEADDA


ECD v3 with signal





VCRCAYGYYQDETTGRCEACRVCEAGSGLVFSCQDRQNTVCE


sequence





ECPDGTYSDEANHVDPCLPCTVCEDTERQLRECTRWADAECE


Protein A+





E
RPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLIARTPEVTCV

C1q-



VVDLGREDPEVQISWFVDGKQMQTAKTQPREEQFNGTYRVVS
CD16-



VLPIGHQDWLKGKQFTCRVNNKALPSPIERTISKARGQAHQP




SVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQE




PESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVM




HEALHNHYTQESLSHSPGKSGGGSGGVSFPASVQLHEAVELH





HWCIPFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANE






TVRHGCLRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDN






P







192

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYILLAAN

ECD v3-canine NGFR




PSGRAAAFVMAAFMDNP
SGGGSGGGS

AKEACPTGLYTHSGEC


ECD variant canine





CKACNLGEGVAQPCGANQTVCEPCLDSVTFSDVVSATEPCKP


IgG-B Fc-canine TrkA





CTECVGLQSMSAPCVEADDAVCRCAYGYYQDETTGRCEACRV


ECD v3





CEAGSGLVFSCQDRQNTVCEECPDGTYSDEANHVDPCLPCTV


Protein A+





CEDTERQLRECTRWADAECEE
RPPDCPKCPAPEPLGGPSVFI

C1q-



FPPKPKDTLLIARTPEVTCVVVDLGREDPEVQISWFVDGKQM
CD16-



QTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTCRVNNK




ALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSLTCL




IKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYFLYS




KLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSPGKSGG





GSGG
VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNG






SVLNETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTL






LAANPSGRAAAFVMAAFMDNP







141

MDMRVPAQLLGLLLLWLRGARC

AKEACPTGLYTHSGECCKAC


Exemplary canine





NLGEGVAQPCGANQTVCEPCLDSVTFSDVVSATEPCKPCTEC


NGFR ECD-canine





VGLQSMSAPCVEADDAVCRCAYGYYQDETTGRCEACRVCEAG


TrkA ECD v3-variant





SGLVFSCQDRQNTVCEECPDGTYSDEANHVDPCLPCTVCEDT


canine IgG-B Fc-





ERQLRECTRWADAECEE

SGGGSGGGS
VSFPASVQLHEAVELH

canine TrkA ECD v3




HWCIPFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANE

with signal sequence




TVRHGCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDN

Protein A+




PRPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLIARTPEVTCV

C1q-



VVDLGREDPEVQISWFVDGKQMQTAKTQPREEQFNGTYRVVS
CD16-



VLPIGHQDWLKGKQFTCRVNNKALPSPIERTISKARGQAHQP




SVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQE




PESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVM




HEALHNHYTQESLSHSPGKSGGGSGGVSFPASVQLHEAVELH





HWCIPFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANE






TVRHGCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDN






P







193


AKEACPTGLYTHSGECCKACNLGEGVAQPCGANQTVCEPCLD


Exemplary canine





SVTFSDVVSATEPCKPCTECVGLQSMSAPCVEADDAVCRCAY


NGFR ECD-canine





GYYQDETTGRCEACRVCEAGSGLVFSCQDRQNTVCEECPDGT


TrkA ECD v3-variant





YSDEANHVDPCLPCTVCEDTERQLRECTRWADAECEE

SGGGS

canine IgG-B Fc-




GGGS
VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNG

canine TrkA ECD v3




SVLNETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTL

Protein A+




LAANPSGRAAAFVMAAFMDNPRPPDCPKCPAPEPLGGPSVFI

C1q-



FPPKPKDTLLIARTPEVTCVVVDLGREDPEVQISWFVDGKQM
CD16-



QTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTCRVNNK




ALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSLTCL




IKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYFLYS




KLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSPGKSGG





GSGG
VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNG






SVLNETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTL






LAANPSGRAAAFVMAAFMDNP







142

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGG

IgG-B Fc canine




GSGGGSRPPDCPKCPAPEPLGGPSVFIFPPKPKDTLLIARTP

NGFR ECD with signal



EVTCVVVDLGREDPEVQISWFVDGKQMQTAKTQPREEQFNGT
sequence



YRVVSVLPIGHQDWLKGKQFTCRVNNKALPSPIERTISKARG
Protein A+



QAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQS
C1q-



NGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTF
CD16-



ICAVMHEALHNHYTQESLSHSPGKSGGGSGGAKEACPTGLYT






HSGECCKACNLGEGVAQPCGANQTVCEPCLDSVTFSDVVSAT








EPCKPCTECVGLQSMSAPCVEADDAVCRCAYGYYQDETTGRC








EACRVCEAGSGLVFSCQDRQNTVCEECPDGTYSDEANHVDPC








LPCTVCEDTERQLRECTRWADAECEE








194

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3-variant canine




PSGRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEPLGG

IgG-B Fc canine



PSVFIFPPKPKDTLLIARTPEVTCVVVDLGREDPEVQISWFV
NGFR ECD



DGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTC
Protein A+





R
VNNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTV

C1q-



SLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGS
CD16-



YFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSP




GKSGGGSGGAKEACPTGLYTHSGECCKACNLGEGVAQPCGAN






QTVCEPCLDSVTFSDVVSATEPCKPCTECVGLQSMSAPCVEA








DDAVCRCAYGYYQDETTGRCEACRVCEAGSGLVFSCQDRQNT








VCEECPDGTYSDEANHVDPCLPCTVCEDTERQLRECTRWADA








ECEE








143
GSGS
Exemplary linker





144
GSGSGS
Exemplary linker





145
GGSGGS
Exemplary linker





146
GGSGGSGGS
Exemplary linker





147
GGGS
Exemplary linker





148
GGGSGGGS
Exemplary linker





149
GGGSGGGSGGGS
Exemplary linker





150
GSSGSS
Exemplary linker





151
GSSGSSGSS
Exemplary linker





152
GGSS
Exemplary linker





153
GGSSGGSS
Exemplary linker





154
GGSSGGSSGGS
Exemplary linker





155
SGGSGGS
Exemplary linker





156
SGGGSGGGS
Exemplary linker





157
GGSSGGSSGGSS
Exemplary linker





158
SGGG
Exemplary linker





195
MGVPRPRSWGLGFLLFLLPTLRAADSHLSLLYHLTAVSAPPP
Exemplary canine FcRn



GTPAFWASGMLGPQQYLSYNNLRAQAEPYGAMVMENQVSWYM
with poly-His



EKETTDLRTKEGLFLEALKALGDGGPYTLQGLLGCELGPDNT




SVPVAKFALNGEDFMTFDPKLGTWNGDMPETETVSKRWMQQA




GAVSKERTFLLYSCPQRLLGHLERGRGNLEMKEPPSMRLKAR




PGSPGFSVLTCSAFSFYPPELQLRFLRNGLAAGSGEGDFGPN




GDGSFHAWSSLTVKSGDEHHYRCLVQHAGLPQPLTVELESPA




KSSGSHHHHHH






196
MAPRPALATAGFLALLLILLAACRLDAVQHPPKIQVYSRHPA
Exemplary canine B2M



ENGKPNFLNCYVSGFHPPEIEIDLLKNGKEMKAEQTDLSFSK




DWTFYLLVHTEFTPNEQDEFSCRVKHVTLSEPQIVKWDRDN






197
PAPEMLGGPSVFIFPPKPKDTLFIARTPEVTCVVVDLDPEDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDM
canine IgG-B Fc



LKGKQFTCKVNNKALPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEMQSNGQQEPESKYRTTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16+



QESLSHSPGK
L(23)F (F00)





198
PAPEMLGGPSVFIFPPKPKDTLYIARTPEVTCVVVDLDPEDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDM
canine IgG-B Fc



LKGKQFTCKVNNKALPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEMQSNGQQEPESKYRTTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16+



QESLSHSPGK
L(23)Y (Y00)





199
PVPEPLGGPSVLIFPPKPKDTLFIARTPEVTCVVLDLGREDP
Exemplary variant canine



EVQISWFVDGKEVHTAKTQSREQQFNGTYRVVSVLPIGHQDM
IgG-A Fc (F00; Protein



LTGKEFKCRVNHIDLPSPIERTISKARGRAHKPSVYVLPPSP
A+; C1q-; CD16-)



KELSSSDTVSITCLIKDFYPPDIDVEMQSNGQQEPERKHRMT
I(21)T; R(23)F; T(25)A;



PPQLDEDGSYFLYSKLSVDKSRMQQGDPFICAVMHEALHNHY
E(80)G; T(205)A;



TDLSLSHSPGK
Q(207)H





200
PAPEMLGGPSVLIFPPKPKDTLLIARTPEVTCVVVDLDPEDP
Exemplary variant canine



EVQISWFVDGKEVHTAKTQSREEQFNGTYRVVSVLPIGHQDW
IgG-A Fc (Protein A+;



LTGKEFKCKVNNKALPSPIERTISKARGRAHKPSVYVLPPSP
C1q+; CD16+)



KELSSSDTVSITCLIKDFYPPDIDVEWQSNGQQEPERKHRMT
V2A; P5M; I21T; R23L;



PPQLDEDGSYFLYSKLSVDKSRWQQGDPFTCAVMHEALHNHY
T25A; L35V; G38D;



TDLSLSHSPGK
R39P; Q65E; E80G;




R93K; H96N; I97K;




D98A; T205A; Q207H





201
CPVPESLGGPSVFIFPPKPKDTLFIARTPEITCVVLDLGRED
Exemplary variant canine



PEVQISWFVDGKEVHTAKTQPREQQFNSTYRVVSVLPIGHQD
IgG-D Fc (F00; Protein



WLIGKEFKCRVNHIGLPSPIERTISKARGQAHQPSVYVLPPS
A+; C1q-; CD16-)



PKELSSSDTVTLTCLIKDFFPPEIDVEWQSNGQPEPESKYHT
I(21)T; R(23)F; T(25)A;



TAPQLDEDGSYFLYSKLSVDKSRWQQGDIFTCAVMHEALHNH
E(80)G; Q(205)A;



YTDLSLSHSPGK
Q(207)H





202
CPAPEMLGGPSVFIFPPKPKDTLLIARTPEITCVVVDLDPED
Exemplary variant canine



PEVQISWFVDGKEVHTAKTQPREEQFNSTYRVVSVLPIGHQD
IgG-D Fc (Protein A+;



WLIGKEFKCKVNNKALPSPIERTISKARGQAHQPSVYVLPPS
C1q+; CD16+)



PKELSSSDTVTLTCLIKDFFPPEIDVEWQSNGQPEPESKYHT
V2A; S5M; I21T; R23L;



TAPQLDEDGSYFLYSKLSVDKSRWQQGDIFTCAVMHEALHNH
T25A; L35V; G38D;



YTDLSLSHSPGK
R39P; Q65E; E80G;




R93K; H96N; I97K;




G98A; Q207H





203
PAPEMLGGPSVFIFPPKPKDILLIARTPEVTCVVVDLDPEDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHYDW
canine IgG-B Fc (0Y0)



LKGKQFTCKVNNKALPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q+



PQLDEDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYT
CD16+



QESLSHSPGK
Q(82)Y (0Y0)





204
PAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDP
Exemplary variant canine



EDPEVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLP
IgG-B Fc (0YH)



IGHYDWLKGKQFTCKVNNKALPSPIERTISKARGQAHQP
Gln82Tyr



SVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG
Asn207His



QQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDT




FICAVMHEALHHHYTQESLSHSPGK






205
PAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDP
Exemplary variant canine



EDPEVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLP
IgG-B Fc (0YY)



IGHYDWLKGKQFTCKVNNKALPSPIERTISKARGQAHQP
Gln82Tyr



SVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG
Asn207Tyr



QQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDT




FICAVMHEALHYHYTQESLSHSPGK






206
PAPEMLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDP
Exemplary variant canine



EDPEVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLP
IgG-B Fc (00Y)



IGHQDWLKGKQFTCKVNNKALPSPIERTISKARGQAHQP
Asn207Tyr



SVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG




QQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDT




FICAVMHEALHYHYTQESLSHSPGK






207
PAPEMLGGPSVFIFPPKPKDTLYITREPEVTCVVVDLDP
Exemplary variant canine



EDPEVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLP
IgG-B Fc (YTE)



IGHQDWLKGKQFTCKVNNKALPSPIERTISKARGQAHQP
Leu23Tyr



SVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG
Ala25Thr



QQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDT
Thr27Glu



FICAVMHEALHNHYTQESLSHSPGK






208
PAPEMLGGPSVFIFPPKPKDTLFIARTPEVTCVVVDLDPEDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCRVNNIGLPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q-



PQLDEDGSYFLYSKLSVDKSRWQRGDIFICAVMHEALHNHYT
CD16-



QESLSHSPGK
K(93)R




K(97)I




A(98)G




L(23)F (F00)





209
PAPEMLGGPSVFIFPPKPKDTLYIARTPEVTCVVVDLDPEDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDW
canine IgG-B Fc



LKGKQFTCRVNNIGLPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q-



PQLDEDGSYFLYSKLSVDKSRWQRGDIFICAVMHEALHNHYT
CD16-



QESLSHSPGK
K(93)R




K(97)I




A(98)G




L(23)Y (Y00)





210
PAPEMLGGPSVFIFPPKPKDILLIARTPEVTCVVVDLDPEDP
Exemplary variant



EVQISWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHYDW
canine IgG-B Fc



LKGKQFTCRVNNIGLPSPIERTISKARGQAHQPSVYVLPPSR
Protein A+



EELSKNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTP
C1q-



PQLDEDGSYFLYSKLSVDKSRWQRGDIFICAVMHEALHNHYT
CD16-



QESLSHSPGK
K(93)R




K(97)I




A(98)G




Q(82)Y (0Y0)





211

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v2-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNPFEF

IgG-B Fc with signal




NPEDPIPVSFSPVDTNSTSGD
SGGGSGGGSRPPDCPKCPAPE

sequence



MLGGPSVFIFPPKPKDTLFIARTPEVTCVVVDLDPEDPEVQI
Protein A+



SWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGK
C1q+



QFTCKVNNKALPSPIERTISKARGQAHQPSVYVLPPSREELS
CD16+



KNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTIPPQLD
L(23)F (F00)



EDGSYFLYSKLSVDKSRWQRGDIFICAVMHEALHNHYTQESL




SHSPGK






212

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v2-variant canine




PSGRAAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGD
S

IgG-B Fc




GGGSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLFIAR

Protein A+



TPEVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFN
C1q+



GTYRVVSVLPIGHQDWLKGKQFICKVNNKALPSPIERTISKA
CD16+



RGQAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEW
L(23)F (F00)



QSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGD




TFICAVMHEALHNHYTQESLSHSPGK






213

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-variant canine




GCLRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNP
SGG

IgG-B Fc with signal




GSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLFIARTP

sequence



EVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGT
Protein A+



YRVVSVLPIGHQDWLKGKQFICKVNNKALPSPIERTISKARG
C1q+



QAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQS
CD16+



NGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTF
L(23)F (F00)



ICAVMHEALHNHYTQESLSHSPGK






214

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYILLAAN

ECD v3-variant canine




PSGRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGG

IgG-B Fc



PSVFIFPPKPKDTLFIARTPEVTCVVVDLDPEDPEVQISWFV
Protein A+



DGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTC
C1q+



KVNNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTV
CD16+



SLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGS
L(23)F (F00)



YFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSP




GK






215

MDMRVPAQLLGLLLLWLRGARC
FPASVQLHEAVELHHWCIPF

Exemplary canine TrkA




SVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRHGC

ECD v4-variant canine




LRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNP
SGGGS

IgG-B Fc with signal




GGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLFIARTPEV

sequence



TCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGTYR
Protein A+



VVSVLPIGHQDWLKGKQFICKVNNKALPSPIERTISKARGQA
C1q+



HQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG
CD16+



QQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTFIC
L(23)F (F00)



AVMHEALHNHYTQESLSHSPGK






216

FPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET

Exemplary canine TrkA




SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYILLAANPS

ECD v4-variant canine




GRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGGPS

IgG-B Fc



VFIFPPKPKDTLFIARTPEVTCVVVDLDPEDPEVQISWFVDG
Protein A+



KQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTCKV
C1q+



NNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSL
CD16+



TCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYF
L(23)F (F00)



LYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSPGK






217

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v2-variant canine




GCLRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNPFEF

IgG-B Fc with signal




NPEDPIPVSFSPVDTNSTSGD
SGGGSGGGSRPPDCPKCPAPE

sequence



MLGGPSVFIFPPKPKDTLYIARTPEVTCVVVDLDPEDPEVQI
Protein A+



SWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGK
C1q+



QFICKVNNKALPSPIERTISKARGQAHQPSVYVLPPSREELS
CD16+



KNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLD
L(23)Y (Y00)



EDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESL




SHSPGK






218

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYILLAAN

ECD v2-variant canine




PSGRAAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGD
S

IgG-B Fc




GGGSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLYIAR

Protein A+



TPEVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFN
C1q+



GTYRVVSVLPIGHQDWLKGKQFICKVNNKALPSPIERTISKA
CD16+



RGQAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEW
L(23)Y (Y00)



QSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGD




TFICAVMHEALHNHYTQESLSHSPGK






219

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary Canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGG

IgG-B Fc with signal




GSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLYIARTP

sequence



EVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGT
Protein A+



YRVVSVLPIGHQDWLKGKQFTCKVNNKALPSPIERTISKARG
C1q+



QAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQS
CD16+



NGQQEPESKYRTIPPQLDEDGSYFLYSKLSVDKSRWQRGDIF
L(23)Y (Y00)



ICAVMHEALHNHYTQESLSHSPGK






220

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3-variant canine




PSGRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGG

IgG-B Fc



PSVFIFPPKPKDTLYIARTPEVTCVVVDLDPEDPEVQISWFV
Protein A+



DGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTC
C1q+



KVNNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTV
CD16+



SLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTIPPQLDEDGS
L(23)Y (Y00)



YFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSP




GK






221

MDMRVPAQLLGLLLLWLRGARC
FPASVQLHEAVELHHWCIPF

Exemplary canine TrkA




SVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRHGC

ECD v4-variant canine




LRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGGGS

IgG-B Fc with signal




GGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLYIARTPEV

sequence



TCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGTYR
Protein A+



VVSVLPIGHQDWLKGKQFTCKVNNKALPSPIERTISKARGQA
C1q+



HQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG
CD16+



QQEPESKYRTIPPQLDEDGSYFLYSKLSVDKSRWQRGDIFIC
L(23)Y (Y00)



AVMHEALHNHYTQESLSHSPGK






222

FPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET

Exemplary canine TrkA




SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAANPS

ECD v4-variant canine




GRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGGPS

IgG-B Fc



VFIFPPKPKDTLYIARTPEVTCVVVDLDPEDPEVQISWFVDG
Protein A+



KQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTCKV
C1q+



NNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSL
CD16+



TCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYF
L(23)Y (Y00)



LYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSPGK






223

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v2-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNPFEF

IgG-B Fc with signal




NPEDPIPVSFSPVDTNSTSGD
SGGGSGGGSRPPDCPKCPAPE

sequence



MLGGPSVFIFPPKPKDILLIARTPEVTCVVVDLDPEDPEVQI
Protein A+



SWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHYDWLKGK
C1q+



QFTCKVNNKALPSPIERTISKARGQAHQPSVYVLPPSREELS
CD16+



KNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTIPPQLD
Q(82)Y (0Y0)



EDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESL




SHSPGK






224

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v2-variant canine




PSGRAAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGDS

IgG-B Fc




GGGSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLLIAR

Protein A+



TPEVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFN
C1q+



GTYRVVSVLPIGHYDWLKGKQFTCKVNNKALPSPIERTISKA
CD16+



RGQAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEW
Q(82)Y (0Y0)



QSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGD




TFICAVMHEALHNHYTQESLSHSPGK






225

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary Canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGG

IgG-B Fc with signal




GSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLLIARTP

sequence



EVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGT
Protein A+



YRVVSVLPIGHYDWLKGKQFTCKVNNKALPSPIERTISKARG
C1q+



QAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQS
CD16+



NGQQEPESKYRTIPPQLDEDGSYFLYSKLSVDKSRWQRGDTF
Q(82)Y (0Y0)



ICAVMHEALHNHYTQESLSHSPGK






226

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3-variant canine




PSGRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGG

IgG-B Fc



PSVFIFPPKPKDILLIARTPEVTCVVVDLDPEDPEVQISWFV
Protein A+



DGKQMQTAKTQPREEQFNGTYRVVSVLPIGHYDWLKGKQFTC
C1q+



KVNNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTV
CD16+



SLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTIPPQLDEDGS
Q(82)Y (0Y0)



YFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSP




GK






227
MDMRVPAQLLGLLLLWLRGARCFPASVQLHEAVELHHWCIPF
Exemplary canine TrkA




SVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRHGC

ECD v4-variant canine




LRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGGGS

IgG-B Fc with signal




GGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLLIARTPEV

sequence



TCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGTYR
Protein A+



VVSVLPIGHYDWLKGKQFTCKVNNKALPSPIERTISKARGQA
C1q+



HQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG
CD16+



QQEPESKYRTIPPQLDEDGSYFLYSKLSVDKSRWQRGDTFIC
Q(82)Y (0Y0)



AVMHEALHNHYTQESLSHSPGK






228

FPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET

Exemplary canine TrkA




SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAANPS

ECD v4-variant canine




GRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGGPS

IgG-B Fc



VFIFPPKPKDILLIARTPEVTCVVVDLDPEDPEVQISWFVDG
Protein A+



KQMQTAKTQPREEQFNGTYRVVSVLPIGHYDWLKGKQFTCKV
C1q+



NNKALPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSL
CD16+



TCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYF
Q(82)Y (0Y0)



LYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSPGK






229

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v2-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNPFEF

IgG-B Fc with signal




NPEDPIPVSFSPVDTNSTSGD
SGGGSGGGSRPPDCPKCPAPE

sequence



MLGGPSVFIFPPKPKDTLFIARTPEVTCVVVDLDPEDPEVQI
Protein A+



SWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGK
C1q-



QFTCRVNNIGLPSPIERTISKARGQAHQPSVYVLPPSREELS
CD16-



KNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTIPPQLD
K(93)R



EDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESL
K(97)I



SHSPGK
A(98)G




L(23)F (F00)





230

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v2-variant canine




PSGRAAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGD
S

IgG-B Fc




GGGSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLFIAR

Protein A+



TPEVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFN
C1q-



GTYRVVSVLPIGHQDWLKGKQFTCRVNNIGLPSPIERTISKA
CD16-



RGQAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEW
K(93)R



QSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGD
K(97)I



TFICAVMHEALHNHYTQESLSHSPGK
A(98)G




L(23)F (F00)





231

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-variant canine




GCLRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNP
SGG

IgG-B Fc with signal




GSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLFIARTP

sequence



EVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGT
Protein A+



YRVVSVLPIGHQDWLKGKQFTCRVNNIGLPSPIERTISKARG
C1q-



QAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQS
CD16-



NGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTF
K(93)R



ICAVMHEALHNHYTQESLSHSPGK
K(97)I




A(98)G




L(23)F (F00)





232

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3-variant canine




PSGRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGG

IgG-B Fc



PSVFIFPPKPKDTLFIARTPEVTCVVVDLDPEDPEVQISWFV
Protein A+



DGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTC
C1q-





R
VNNIGLPSPIERTISKARGQAHQPSVYVLPPSREELSKNTV

CD16-



SLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGS
K(93)R



YFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSP
K(97)I



GK
A(98)G




L(23)F (F00)





233

MDMRVPAQLLGLLLLWLRGARC
FPASVQLHEAVELHHWCIPF

Exemplary canine TrkA




SVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRHGC

ECD v4-variant canine




LRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGGGS

IgG-B Fc with signal




GGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLFIARTPEV

sequence



TCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGTYR
Protein A+



VVSVLPIGHQDWLKGKQFTCRVNNIGLPSPIERTISKARGQA
C1q-



HQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG
CD16-



QQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTFIC
K(93)R



AVMHEALHNHYTQESLSHSPGK
K(97)I




A(98)G




L(23)F (F00)





234

FPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET

Exemplary canine TrkA




SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAANPS

ECD v4-variant canine




GRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGGPS

IgG-B Fc



VFIFPPKPKDTLFIARTPEVTCVVVDLDPEDPEVQISWFVDG
Protein A+



KQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTCRV
C1q-



NNIGLPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSL
CD16-



TCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYF
K(93)R



LYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSPGK
K(97)I




A(98)G




L(23)F (F00)





235

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v2-variant canine




GCLRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNPFEF

IgG-B Fc with signal




NPEDPIPVSFSPVDTNSTSGD
SGGGSGGGSRPPDCPKCPAPE

sequence



MLGGPSVFIFPPKPKDTLYIARTPEVTCVVVDLDPEDPEVQI
Protein A+



SWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGK
C1q-



QFTCRVNNIGLPSPIERTISKARGQAHQPSVYVLPPSREELS
CD16-



KNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLD
K(93)R



EDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESL
K(97)I



SHSPGK
A(98)G




L(23)Y (Y00)





236

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v2-variant canine




PSGRAAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGD
S

IgG-B Fc




GGGSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLYIAR

Protein A+



TPEVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFN
C1q-



GTYRVVSVLPIGHQDWLKGKQFTCRVNNIGLPSPIERTISKA
CD16-



RGQAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEW
K(93)R



QSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGD
K(97)I



TFICAVMHEALHNHYTQESLSHSPGK
A(98)G




L(23)Y (Y00)





237

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-variant canine




GCLRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNP
SGG

IgG-B Fc with signal




GSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLYIARTP

sequence



EVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGT
Protein A+



YRVVSVLPIGHQDWLKGKQFTCRVNNIGLPSPIERTISKARG
C1q-



QAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQS
CD16-



NGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTF
K(93)R



ICAVMHEALHNHYTQESLSHSPGK
K(97)I




A(98)G




L(23)Y (Y00)





238

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3-variant canine




PSGRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGG

IgG-B Fc



PSVFIFPPKPKDTLYIARTPEVTCVVVDLDPEDPEVQISWFV
Protein A+



DGKQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTC
C1q-





R
VNNIGLPSPIERTISKARGQAHQPSVYVLPPSREELSKNTV

CD16-



SLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGS
K(93)R



YFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSP
K(97)I



GK
A(98)G




L(23)Y (Y00)





239

MDMRVPAQLLGLLLLWLRGARC
FPASVQLHEAVELHHWCIPF

Exemplary canine TrkA




SVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRHGC

ECD v4-variant canine




LRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGGGS

IgG-B Fc with signal




GGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLYIARTPEV

sequence



TCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGTYR
Protein A+



VVSVLPIGHQDWLKGKQFTCRVNNIGLPSPIERTISKARGQA
C1q-



HQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG
CD16-



QQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTFIC
K(93)R



AVMHEALHNHYTQESLSHSPGK
K(97)I




A(98)G




L(23)Y (Y00)





240

FPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET

Exemplary canine TrkA




SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAANPS

ECD v4-variant canine




GRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGGPS

IgG-B Fc



VFIFPPKPKDTLYIARTPEVTCVVVDLDPEDPEVQISWFVDG
Protein A+



KQMQTAKTQPREEQFNGTYRVVSVLPIGHQDWLKGKQFTCRV
C1q-



NNIGLPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSL
CD16-



TCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYF
K(93)R



LYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSPGK
K(97)I




A(98)G




L(23)F (Y00)





241

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v2-variant canine




GCLRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNPFEF

IgG-B Fc with signal




NPEDPIPVSFSPVDTNSTSGD
SGGGSGGGSRPPDCPKCPAPE

sequence



MLGGPSVFIFPPKPKDTLLIARTPEVTCVVVDLDPEDPEVQI
Protein A+



SWFVDGKQMQTAKTQPREEQFNGTYRVVSVLPIGHYDWLKGK
C1q-



QFTCRVNNIGLPSPIERTISKARGQAHQPSVYVLPPSREELS
CD16-



KNTVSLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLD
K(93)R



EDGSYFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESL
K(97)I



SHSPGK
A(98)G




Q(82)Y (0Y0)





242

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v2-variant canine




PSGRAAAFVMAAFMDNPFEFNPEDPIPVSFSPVDTNSTSGD
S

IgG-B Fc




GGGSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLLIAR

Protein A+



TPEVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFN
C1q-



GTYRVVSVLPIGHYDWLKGKQFTCRVNNIGLPSPIERTISKA
CD16-



RGQAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEW
K(93)R



QSNGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGD
K(97)I



TFICAVMHEALHNHYTQESLSHSPGK
A(98)G




Q(82)Y (0Y0)





243

MDMRVPAQLLGLLLLWLRGARC
VSFPASVQLHEAVELHHWCI

Exemplary canine TrkA




PFSVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRH

ECD v3-variant canine




GCLRLNQPTHVNNGNYILLAANPSGRAAAFVMAAFMDNP
SGG

IgG-B Fc with signal




GSGGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLLIARTP

sequence



EVTCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGT
Protein A+



YRVVSVLPIGHYDWLKGKQFTCRVNNIGLPSPIERTISKARG
C1q-



QAHQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQS
CD16-



NGQQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTF
K(93)R



ICAVMHEALHNHYTQESLSHSPGK
K(97)I




A(98)G




Q(82)Y (0Y0)





244

VSFPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLN

Exemplary canine TrkA




ETSFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAAN

ECD v3-variant canine




PSGRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGG

IgG-B Fc



PSVFIFPPKPKDTLLIARTPEVTCVVVDLDPEDPEVQISWFV
Protein A+



DGKQMQTAKTQPREEQFNGTYRVVSVLPIGHYDWLKGKQFTC
C1q-





R
VNNIGLPSPIERTISKARGQAHQPSVYVLPPSREELSKNTV

CD16-



SLTCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGS
K(93)R



YFLYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSP
K(97)I



GK
A(98)G




Q(82)Y (0Y0)





245

MDMRVPAQLLGLLLLWLRGARC
FPASVQLHEAVELHHWCIPF

Exemplary canine TrkA




SVDGQPAPSLRWLFNGSVLNETSFIFTEFLEPVANETVRHGC

ECD v4-variant canine




LRLNQPTHVNNGNYTLLAANPSGRAAAFVMAAFMDNP
SGGGS

IgG-B Fc with signal




GGGSRPPDCPKCPAPEMLGGPSVFIFPPKPKDTLLIARTPEV

sequence



TCVVVDLDPEDPEVQISWFVDGKQMQTAKTQPREEQFNGTYR
Protein A+



VVSVLPIGHYDWLKGKQFTCRVNNIGLPSPIERTISKARGQA
C1q-



HQPSVYVLPPSREELSKNTVSLTCLIKDFFPPDIDVEWQSNG
CD16-



QQEPESKYRTTPPQLDEDGSYFLYSKLSVDKSRWQRGDTFIC
K(93)R



AVMHEALHNHYTQESLSHSPGK
K(97)I




A(98)G




Q(82)Y (0Y0)





246

FPASVQLHEAVELHHWCIPFSVDGQPAPSLRWLFNGSVLNET

Exemplary canine TrkA




SFIFTEFLEPVANETVRHGCLRLNQPTHVNNGNYTLLAANPS

ECD v4-variant canine




GRAAAFVMAAFMDNP
SGGGSGGGSRPPDCPKCPAPEMLGGPS

IgG-B Fc



VFIFPPKPKDTLLIARTPEVTCVVVDLDPEDPEVQISWFVDG
Protein A+



KQMQTAKTQPREEQFNGTYRVVSVLPIGHYDWLKGKQFTCRV
C1q-



NNIGLPSPIERTISKARGQAHQPSVYVLPPSREELSKNTVSL
CD16-



TCLIKDFFPPDIDVEWQSNGQQEPESKYRTTPPQLDEDGSYF
K(93)R



LYSKLSVDKSRWQRGDTFICAVMHEALHNHYTQESLSHSPGK
K(97)I




A(98)G




Q(82)Y (0Y0)









DESCRIPTION OF THE EMBODIMENTS

Contiguous polypeptides comprising at least one TrkA ECD polypeptide that binds an NGF polypeptide are provided. Methods of producing and purifying the contiguous polypeptides are also provided. Methods of treatment using TrkA ECD polypeptides that bind NGF and inhibit NGF-mediated signaling are provided. Such methods include, but are not limited to, methods of treating pain in companion animal species. Methods of detecting NGF in a sample from a companion animal species are also provided.


For the convenience of the reader, the following definitions of terms used herein are provided.


As used herein, numerical terms such as Kd are calculated based upon scientific measurements and, thus, are subject to appropriate measurement error. In some instances, a numerical term may include numerical values that are rounded to the nearest significant figure.


As used herein, “a” or “an” means “at least one” or “one or more” unless otherwise specified. As used herein, the term “or” means “and/or” unless specified otherwise. In the context of a multiple dependent claim, the use of “or” when referring back to other claims refers to those claims in the alternative only.


Exemplary TrkA Polypeptides

TrkA ECD polypeptides that bind NGF are provided, for example, canine, feline, and equine TrkA ECD polypeptides that bind NGF.


“Amino acid sequence” means a sequence of amino acids in a protein, and includes sequences of amino acids in which one or more amino acids of the sequence have had their side-groups chemically modified, as well as those in which, relative to a known sequence, one or more amino acids have been replaced, inserted or deleted, without thereby eliminating a desired property, such as ability to bind EPO receptor. An amino acid sequence may also be referred to as a peptide, oligopeptide, polypeptide, or protein.


“TrkA,” or “TrkA polypeptide” as used herein, is a polypeptide comprising the entirety or a fragment of a tropomyosine receptor kinase A (TrkA) receptor that is capable of binding to NGF.


For example, “TrkA” refers to a TrkA polypeptide from any vertebrate source, including mammals such as primates (e.g., humans and cynomolgus monkeys), rodents (e.g., mice and rats), and companion animals (e.g., dogs, cats, and equine), unless otherwise indicated. In some embodiments, TrkA is an extracellular domain fragment that binds NGF. In some such embodiments, TrkA may be referred to as a TrkA extracellular domain (ECD). In some embodiments, TrkA comprises the amino acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32, or SEQ ID NO: 33.


“NGF receptor” or “NGFR,” as used herein, is a polypeptide comprising the entirety or a portion of a low affinity nerve growth factor receptor (also referred to as tumor necrosis factor receptor superfamily member 16) that binds NGF.


For example, “NGFR” refers to a NGFR polypeptide from any vertebrate source, including mammals such as primates (e.g., humans and cynomolgus monkeys), rodents (e.g., mice and rats), and companion animals (e.g., dogs, cats, and equine), unless otherwise indicated. In some embodiments, NGFR is an extracellular domain fragment that binds NGF. In some such embodiments, NGFR may be referred to as an NGFR extracellular domain (ECD). In some embodiments, NGFR comprises the amino acid sequence of SEQ ID NO: 134, SEQ ID NO: 135, SEQ ID NO: 136, SEQ ID NO: 137, SEQ ID NO: 138, or SEQ ID NO: 139.


The term “companion animal species” refers to an animal suitable to be a companion to humans. In some embodiments, a companion animal species is a small mammal, such as a canine, feline, dog, cat, horse, rabbit, ferret, guinea pig, rodent, etc. In some embodiments, a companion animal species is a farm animal, such as a cow, pig, etc.


An “extracellular domain” (“ECD”) is the portion of a polypeptide that extends beyond the transmembrane domain into the extracellular space. The term “extracellular domain,” as used herein, may comprise a complete extracellular domain or may comprise a truncated extracellular domain missing one or more amino acids, that binds to its ligand. The composition of the extracellular domain may depend on the algorithm used to determine which amino acids are in the membrane. Different algorithms may predict, and different systems may express, different extracellular domains for a given protein.


An extracellular domain of a TrkA polypeptide may comprise a complete extracellular domain or a truncated extracellular domain of TrkA that binds NGF. As used herein, the terms “extracellular domain of a TrkA polypeptide” or “TrkA ECD” refers to a TrkA polypeptide that does not comprise a transmembrane domain or cytoplasmic domain, even if the term follows an open transitional word, such as “comprising,” “comprises,” and the like. In some embodiments, an extracellular domain of a TrkA polypeptide is an extracellular domain of a TrkA from a companion species animal. For example, in some embodiments, an extracellular domain of a TrkA polypeptide is derived from canine TrkA, feline TrkA, or equine TrkA. In some embodiments, an extracellular domain of a TRKA polypeptide comprises the amino acid sequence of SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32, SEQ ID NO: 33, or any fragment thereof.


An extracellular domain of an NGFR polypeptide may comprise a complete extracellular domain or a truncated extracellular domain of NGFR that binds NGF. As used herein, the terms “extracellular domain of an NGFR polypeptide” or “NGFR ECD” refers to an NGFR polypeptide that does not comprise a transmembrane domain or cytoplasmic domain, even if the term follows an open transitional word, such as “comprising,” “comprises,” and the like. In some embodiments, an extracellular domain of an NGFR polypeptide is an extracellular domain of an NGFR polypeptide from a companion species animal. For example, in some embodiments, an extracellular domain of an NGFR polypeptide is derived from canine NGFR, feline NGFR, or equine NGFR. In some embodiments, an extracellular domain of an NGFR polypeptide comprises the amino acid sequence of SEQ ID NO: 135, SEQ ID NO: 137, SEQ ID NO: 139, or any fragment thereof.


“Wild-type” refers to a non-mutated version of a polypeptide that occurs in nature, or a fragment thereof. A wild-type polypeptide may be produced recombinantly.


A “variant” or “analog” are referred to herein interchangeably as a polypeptide that differs from a reference polypeptide by single or multiple amino acid substitutions, deletions, and/or additions and substantially retains at least one biological activity of the reference poly peptide.


A “biologically active” entity, or an entity having “biological activity,” is an entity having any function related to or associated with a metabolic or physiological process, and/or having structural, regulatory, or biochemical functions of a naturally-occurring molecule. A biologically active polypeptide or fragment thereof includes one that can participate in a biological reaction, including, but not limited to, a ligand-receptor interaction or antigen-antibody binding. The biological activity can include an improved desired activity, or a decreased undesirable activity. An entity may demonstrate biological activity when it participates in a molecular interaction with another molecule, when it has therapeutic value in alleviating a disease condition, when it has prophylactic value in inducing an immune response, when it has diagnostic and/or prognostic value in determining the presence of a molecule.


As used herein, “percent (%) amino acid sequence identity” and “homology” with respect to a polypeptide sequence are defined as the percentage of amino acid residues in a candidate sequence that are identical with the amino acid residues in the specific peptide or polypeptide sequence, after aligning the sequences and introducing gaps, if necessary to achieve the maximum percent sequence identity, and not considering any conservative substitutions as part of the sequence identity. Alignment for purposes of determining percent amino acid sequence identity can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software such as BLAST, BLAST-2, ALIGN, or MEGALIGN™ (DNASTAR) software. Those skilled in the art can determine appropriate parameters for measuring alignment, including any algorithms needed to achieve maximal alignment over the full length of sequences being compared.


In some embodiments, a variant has at least about 50% sequence identity with the reference polypeptide after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity, and not considering any conservative substitutions as part of the sequence identity. Such variants include, for instance, polypeptides wherein one or more amino acid residues are added, deleted, at the N- or C-terminus of the polypeptide. In some embodiments, a variant has at least about 50% sequence identity, at least about 60% sequence identity, at least about 65% sequence identity, at least about 70% sequence identity, at least about 75% sequence identity, at least about 80% sequence identity, at least about 85% sequence identity, at least about 90% sequence identity, at least about 91% sequence identity, at least about 92% sequence identity, at least about 93% sequence identity, at least about 94% sequence identity, at least about 95% sequence identity, at least about 96% sequence identity, at least about 97% sequence identity, at least about 98% sequence identity, or at least 99% sequence identity with the sequence of the reference polypeptide.


As used herein, “position corresponding to position n,” wherein n is any number, refers to an amino acid position of a subject polypeptide that aligns with position n of a reference polypeptide after aligning the amino acid sequences of the subject and reference polypeptides and introducing gaps. Alignment for purposes of whether a position of a subject polypeptide corresponds with position n of a reference polypeptide can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software such as BLAST, BLAST-2, CLUSTAL OMEGA, ALIGN, or MEGALIGN™ (DNASTAR) software. Those skilled in the art can determine appropriate parameters for alignment, including any parameters needed to achieve maximal alignment over the full length of two sequences being compared. In some embodiments, the subject polypeptide and the reference polypeptide are of different lengths.


A “point mutation” is a mutation that involves a single amino acid residue. The mutation may be the loss of an amino acid, substitution of one amino acid residue for another, or the insertion of an additional amino acid residue.


An “amino acid substitution” may include but is not limited to the replacement of one amino acid in a polypeptide with another amino acid. Exemplary substitutions are shown in Table 2. Amino acid substitutions may be introduced into a molecule of interest and the products screened for a desired activity, for example, retained/improved receptor binding, decreased immunogenicity, reduced ADCC and/or CDC, or enhanced pharmacokinetics.










TABLE 2





Original



Residue
Exemplary Substitutions







Ala (A)
Val; Leu; Ile


Arg (R)
Lys; Gln; Asn


Asn (N)
Gln; His; Asp; Lys; Arg


Asp (D)
Glu; Asn


Cys (C)
Ser; Ala


Gln (Q)
Asn; Glu


Glu (E)
Asp; Gln


Gly (G)
Ala


His (H)
Asn; Gln; Lys; Arg


Ile (I)
Leu; Val; Met; Ala; Phe;



Norleucine


Leu (L)
Norleucine; Ile; Val; Met; Ala;



Phe


Lys (K)
Arg; Gln; Asn


Met (M)
Leu; Phe; Ile


Phe (F)
Trp; Leu; Val; Ile; Ala; Tyr


Pro (P)
Ala


Ser (S)
Thr


Thr (T)
Val; Ser


Trp (W)
Tyr; Phe


Tyr (Y)
Trp; Phe; Thr; Ser


Val (V)
Ile; Leu; Met; Phe; Ala;



Norleucine









Amino acids may be grouped according to common side-chain properties:

    • (1) hydrophobic: Norleucine, Met, Ala, Val, Leu, Ile;
    • (2) neutral hydrophilic: Cys, Ser, Thr, Asn, Gln;
    • (3) acidic: Asp, Glu;
    • (4) basic: His, Lys, Arg;
    • (5) residues that influence chain orientation: Gly, Pro;
    • (6) aromatic: Trp, Tyr, Phe.


Non-conservative substitutions will entail exchanging a member of one of these classes with another class.


An “amino acid derivative,” as used herein, refers to any amino acid, modified amino acid, and/or amino acid analogue, that is not one of the 20 common natural amino acids found in humans. Exemplary amino acid derivatives include natural amino acids not found in humans (e.g., seleno cysteine and pyrrolysine, which may be found in some microorganisms) and unnatural amino acids. Exemplary amino acid derivatives, include, but are not limited to, amino acid derivatives commercially available through chemical product manufacturers (e.g., sigmaaldrich.com/chemistry/chemistry-products.html?TablePage=16274965, accessed on May 6, 2017, which is incorporated herein by reference). One or more amino acid derivatives may be incorporated into a polypeptide at a specific location using a translation system that utilizes host cells, orthogonal aminoacyl-tRNA synthetases derived from eubacterial synthetases, orthogonal tRNAs, and an amino acid derivative. For further descriptions, see, e.g., U.S. Pat. No. 9,624,485.


In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution with an amino acid derivative. In some embodiments, the amino acid derivative is an alanine derivative, a cysteine derivative, an aspartic acid derivative, a glutamic acid derivative, a phenylalanine derivative, a glycine derivative, a histidine derivative, an isoleucine derivative, a lysine derivative, a leucine derivative, a methionine derivative, an asparagine derivative, a proline derivative, a glutamine derivative, an arginine derivative, a serine derivative, a threonine derivative, a valine derivative, a tryptophan derivative, or a tyrosine derivative.


In some embodiments, the TrkA ECD polypeptide comprises the amino acid sequence of SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, or SEQ ID NO: 15 except for the presence of at least one N-linked glycosylation site not present in SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, or SEQ ID NO: 15. In some embodiments, the at least one N-linked glycosylation site comprises the sequence asparagine-xaa-serine, wherein xaa is any amino acid except proline. In some embodiments, the at least one N-linked glycosylation site comprises the sequence asparagine-xaa-threonine, wherein xaa is any amino acid except proline. In some embodiments, the at least one N-linked glycosylation site does not overlap with another N-linked glycosylation site.


In some embodiments, the TrkA ECD polypeptide comprises an N-linked glycosylation site at amino acid positions 6-8, 31-33, 84-86, 85-87, 86-88, 88-90, 90-92, 92-94, and/or 94-96 of SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 13, or SEQ ID NO: 14. In some embodiments, the TrkA ECD polypeptide comprises an N-linked glycosylation site at amino acid positions 4-6, 29-31, 82-84, 83-85, 84-86, 86-88, 89-90, 90-92, and/or 92-94 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15.


In some embodiments, the TrkA ECD polypeptide comprises an amino acid other than proline at an amino acid position corresponding to position 30 or position 85 of SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 13, or SEQ ID NO: 14. In some embodiments, the TrkA ECD polypeptide comprises an amino acid other than proline at an amino acid position corresponding to position 28 or position 83 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15.


In some embodiments, the TrkA ECD polypeptide comprises a valine, a glutamic acid, an alanine, or an isoleucine at an amino acid position corresponding to position 30 and/or position 85 of SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 13, or SEQ ID NO: 14. In some embodiments, the TrkA ECD polypeptide comprises a valine, a glutamic acid, an alanine, or an isoleucine at an amino acid position corresponding to position 28 and/or position 83 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15.


In some embodiments, the TrkA ECD polypeptide comprises one or more amino acid modifications listed in Table 3, Table 4, or Table 5, below.










TABLE 3








Amino acid substitutions for N-linked glycosylation sites










Based on canine TrkA ECD
Based on canine TrkA


Analog
v2 or v3 sequence
ECD v4 sequence


No.
(SEQ ID NOs: 3 or 4)
(SEQ ID NO: 5)












1
N6S8
N4S6


2
N6T8
N4T6


3
*X30N31S33
*X28N29S31


4
*X30N31T33
*X28N29T31


5
*X85
*X83


6
*X85T86
*X83T84


7
N85S87
N83S85


8
N85T87
N83T85


9
*X85N86S88
*X83N84S86


10
*X85N86T88
*X83N84T86


11
N88S90
N86S88


12
N88T90
N86T88


13
N90S92
N88S90


14
N90T92
N88T90


15
N92S94
N90S92


16
N92T94
N90T92


17
N94S96
N92S94


18
N94T96
N92T94





*X indicates any amino acid except proline (such as E, V, A, I, etc.).














TABLE 4








Amino acid substitutions for N-linked glycosylation sites










Based on feline TrkA ECD
Based on feline TrkA


Analog
v2 or v3 sequence
ECD v4 sequence


No.
(SEQ ID NOs: 8 or 9)
(SEQ ID NO: 10)












1
N6S8
N4S6


2
N6T8
N4T6


3
*X30N31S33
*X28N29S31


4
*X30N31T33
*X28N29T31


5
*X85
*X83


6
*X85T86
*X83T84


7
N85S87
N83S85


8
N85T87
N83T85


9
*X85N86S88
*X83N84S86


10
*X85N86T88
*X83N84T86


11
N88S90
N86S88


12
N88T90
N86T88


13
N90
N88


14
N90T92
N88T90


15
N92S94
N90S92


16
N92T94
N90T92


17
N94S96
N92S94


18
N94T96
N92T94





*X indicates any amino acid except proline (such as E, V, A, I, etc.).














TABLE 5








Amino acid substitutions for N-linked glycosylation sites










Based on equine TrkA ECD
Based on equine TrkA


Analog
v2 or v3 sequence
ECD v4 sequence


No.
(SEQ ID NOs: 13 or 14)
(SEQ ID NOs: 15)












1
N6S8
N4S6


2
N6T8
N4T6


3
*X30N31S33
*X28N29S31


4
*X30N31T33
*X28N29T31


5
*X85S86
*X83S84


6
*X85T86
*X83T84


7
N85S87
N83S85


8
N85T87
N83T85


9
*X85N86S88
*X83N84S86


10
*X85N86T88
*X83N84T86


11
N88
N86


12
N88T90
N86T88


13
N90
N88


14
N90T92
N88T90


15
N92S94
N90S92


16
N92T94
N90T92


17
N94S96
N92S94


18
N94T96
N92T94





*X indicates any amino acid except proline (such as E, V, A, I, etc.).






In some embodiments, a TrkA ECD polypeptide comprises one or more additional disulfide linkages. For example, in some embodiments, a TrkA ECD polypeptide comprises a cysteine at a position corresponding to position 7 and position 89 of SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 12, SEQ ID NO: 13, or SEQ ID NO: 14. In some embodiments, a TrkA ECD polypeptide comprises a cysteine at a position corresponding to position 5 and position 87 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15. In some embodiments, a TrkA ECD polypeptide comprises a cysteine at position 7 and position 89 of SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 12, SEQ ID NO: 13, or SEQ ID NO: 14. In some embodiments, a TrkA polypeptide comprises a cysteine at position 5 and position 87 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15.


In some embodiments, a TrkA ECD polypeptide comprises the amino acid sequence of SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32, or SEQ ID NO: 33.


“Glycosylated,” as used herein, refers to a polypeptide having one or more glycan moieties covalently attached.


A “glycan” or “glycan moiety,” as used herein, refers to monosaccharides linked glycosidically.


Glycans are attached to glycopeptides in several ways, of which N-linked to asparagine and O-linked to serine and threonine are the most relevant for recombinant therapeutic glycoproteins. N-linked glycosylation occurs at the consensus sequence Asn-Xaa-Ser/Thr, where Xaa can be any amino acid except proline.


“Sialylated,” as used herein, refers to a polypeptide having one or more sialyic acid moieties covalently attached.


A variety of approaches for producing glycosylated and sialylated proteins have been developed. See, e.g., Savinova, et al., Applied Biochem & Microbiol. 51(8):827-33 (2015).


“PEGylated,” as used herein, refers to a polypeptide having one or more polyethylene glycol (PEG) moieties associated or covalently or non-covalently attached.


In some embodiments, the TrkA ECD polypeptide is glycosylated. In some embodiments, the TrkA ECD polypeptide comprises at least one glycan moiety attached to an N-linked glycosylation site. In some embodiments, the TrkA ECD polypeptide is sialylated. In some embodiments, the TrkA ECD polypeptide is PEGylated. In some embodiments, the TrkA ECD polypeptide is PEGylated at a glycan. In some embodiments, the TrkA ECD polypeptide is PEGylated at a primary amine. In some embodiments, the TrkA ECD polypeptide is PEGylated at the N-terminal alpha-amine. In some embodiments, the TrkA ECD polypeptide is glycosylated, sialylated, and/or PEGylated.


Exemplary Variant IgG Fc Polypeptides and Fusion Molecules

Contiguous polypeptides comprising a TrkA polypeptide may comprise fusion partner, such as a wild-type or a variant IgG Fc polypeptide.


A “fusion molecule,” as used herein, refers to a molecule comprising one or more “fusion partners.” In some embodiments, the fusion partners are covalently linked (“fused”). If two fusion partners are both polypeptides, the fusion partner polypeptides may be part of a contiguous amino acid sequence (i.e., a contiguous polypeptide). A first fusion partner polypeptide may be linked to either the N-terminus or the C-terminus of a second fusion partner. In some embodiments, the fusion partners are translated as a single polypeptide from a coding sequence that encodes both fusion partners. Fusion partners may be covalently linked through other means, such as, for example, a chemical linkage other than a peptide bond. Many known methods of covalently linking polypeptides to other molecules (for example, fusion partners) may be used. In other embodiments, the fusion partners are fused through a “linker,” which is comprised of at least one amino acid or chemical moiety.


In some embodiments, a fusion partner is albumin, an albumin binding fragment, or a fragment of an immunoglobulin molecule. A fusion partner may comprise an oligomerization domain such as an Fc domain of a heavy chain immunoglobulin. In some embodiments, fusion partners comprise at least one TrkA ECD polypeptide and an IgG Fc polypeptide. In some embodiments, the fusion partners further comprise other therapeutic polypeptide(s), such as an NGFR ECD polypeptide. In some embodiments, a TrkA ECD polypeptide may be linked to either the N-terminus or the C-terminus of an IgG Fc polypeptide.


The term “contiguous polypeptide” herein is used to mean an uninterrupted sequence of amino acids. A contiguous polypeptide is typically translated from a single continuous DNA sequence. It can be made by genetic engineering, for example, by removing the stop codon from the DNA sequence of the first protein, then appending the DNA sequence of the second protein in frame, so that the DNA sequence is expressed as a single protein. Typically, this is accomplished by cloning a cDNA into an expression vector in frame with an existing gene.


A “linker” refers to one or more amino acid residues that connects a first polypeptide with a second polypeptide.


In some embodiments, the linker is a flexible, non-structural linker. In some embodiments, the linker is a glycine-rich, serine-rich, or glycine- and serine-rich linker. In some embodiments, a linker comprises 100%, at least 95%, at least 90%, or at least 85% serine and/or glycine amino acid residues. In some embodiments, the linker is a glycine-rich, serine-rich, or GS-rich flexible, non-structural linker. In some embodiments, a linker comprises the amino acids G (Gly) and/or S (Ser). For example, a linker may comprise G or a repeat of G (e.g., GG, GGG, etc.); US or a repeat of GS (e.g., GSGS (SEQ ID NO: 143), GSGSGS (SEQ ID NO: 144), etc.); GGS or a repeat of GGS (e.g., GGSGGS (SEQ ID NO: 145), GGSGGSGGS (SEQ ID NO: 146), etc.); GGGS (SEQ ID NO: 147) or a repeat of GGGS (SEQ ID NO: 147) (e.g., GGGSGGGS (SEQ ID NO: 148), GGGSGGGSGGGS (SEQ ID N:O 149), etc.); GSS or a repeat of OSS (e.g., GSSGSS (SEQ ID NO: 150), GSSGSSGSS (SEQ ID NO: 151), etc.); GGSS (SEQ ID NO: 152) or a repeat of GGSS (SEQ ID NO: 152) (e.g., GGSSGGSS (SEQ ID NO: 153), GGSSGGSSGGSS (SEQ ID NO: 157), etc.); SGGG (SEQ ID NO: 158) or a repeat of SGGG (SEQ ID NO: 158) (e.g., SGGGSGGGS (SEQ ID NO: 156)).


An “extension,” as used herein, refers to one or more amino acid residues that are connected to a polypeptide at its C-terminus or at its N-terminus.


In some embodiments, an extension is flexible. In some embodiments, the extension adds flexibility to the polypeptide without interfering with the biological activity of the polypeptide. In some embodiments, the extension increases solubility of the polypeptide. In some embodiments, the extension comprises one or more glycine residues. In some embodiments, the extension comprises one glycine residue, two glycine residues, a three glycine residues, four glycine residues, five glycine residues, six glycine residues, seven glycine residues, eight glycine residues, or more glycine residues.


A “variant IgG Fc” as used herein is an IgG Fc polypeptide that differs from a reference IgG Fc polypeptide by single or multiple amino acid substitutions, deletions, and/or additions and substantially retains at least one biological activity of the reference IgG Fc polypeptide.


A “fragment crystallizable polypeptide” or “Fc polypeptide” is the portion of an antibody molecule that interacts with effector molecules and cells. It comprises the C-terminal portions of the immunoglobulin heavy chains. As used herein, an Fc polypeptide includes fragments of the Fc domain having one or more biological activities of an entire Fc polypeptide. In some embodiments, a biological activity of an Fc polypeptide is the ability to bind FcRn. In some embodiments, a biological activity of an Fc polypeptide is the ability to bind C1q. In some embodiments, a biological activity of an Fc polypeptide is the ability to bind CD16. In some embodiments, a biological activity of an Fc polypeptide is the ability to bind Protein A. An “effector function” of the Fc polypeptide is an action or activity performed in whole or in part by any antibody in response to a stimulus and may include complement fixation and/or ADCC (antibody-dependent cellular cytotoxicity) induction.


“IgX Fc” or “IgX Fc polypeptide” refers to an Fc polypeptide derived from a particular antibody isotype (e.g., IgG, IgA, IgD, IgE, IgM, etc.), where “X” denotes the antibody isotype. Thus, “IgG Fc” denotes that the Fc polypeptide is derived from a y chain, “IgA Fc” denotes that the Fc polypeptide is derived from an a chain, “IgD Fc” denotes that the Fc polypeptide is derived from a 6 chain, “IgE Fc” denotes that the Fc polypeptide is derived from a chain, “IgM Fc” denotes that the Fc polypeptide is derived from a μ chain, etc. In some embodiments, the IgG Fc polypeptide comprises the hinge, CH2, and CH3, but does not comprise CH1 or CL. In some embodiments, the IgG Fc polypeptide comprises CH2 and CH3, but does not comprise CH1, the hinge, or CL. In some embodiments, the IgG Fc polypeptide comprises CH1, hinge, CH2, CH3, with or without CL. In some embodiments, the IgG Fc polypeptide comprises CH1, hinge, CH2, and CH3, with or without CL1. In some embodiments, an Fc polypeptide, such as an IgG Fc polypeptide, lacks one or more C-terminal amino acids, such as 1 to 20, 1 to 15, 1 to 10, 1 to 5, or 1 to 2 amino acids, while retaining biological activity. In some embodiments, the biological activity is the ability to bind FcRn. An “effector function” of the Fc polypeptide is an action or activity performed in whole or in part by any antibody in response to a stimulus and may include complement fixation and/or ADCC (antibody-dependent cellular cytotoxicity) induction. “IgX-N Fc” or “IgGXN Fc” denotes that the Fc polypeptide is derived from a particular subclass of antibody isotype (such as canine IgG subclass IgG-A, IgG-B, IgG-C, or IgG-D; feline IgG subclass IgG1a, IgG1b, or IgG2; or equine IgG subclass IgG1, IgG2, IgG3, IgG4, IgG5, IgG6, or IgG7, etc.), where “N” denotes the subclass.


“Hinge” refers to any portion of an Fc polypeptide or variant Fc polypeptide that is proline-rich and comprises at least one cysteine residue located between CH1 and CH2 of a full-length heavy chain constant region.


In some embodiments, a hinge is capable of forming a disulfide linkage within the same hinge region, within the same Fc polypeptide, with a hinge region of a separate Fc polypeptide, or with a separate Fc polypeptide. In some embodiments, a hinge comprises at least one, at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, or at least ten proline residues.


In some embodiments, IgX or IgXN regions are derived from a companion animal, such as a dog, a cat, or a horse. In some embodiments, IgG regions are isolated from canine y heavy chains, such as IgGA, IgGB, IgGC, or IgGD. In some instances, IgG Fc regions are isolated from feline y heavy chains, such as IgG1, IgG2a, or IgG2b. In other instances, IgG regions are isolated from equine y heavy chains, such as IgG1, IgG2, IgG3, IgG4, IgG5, IgG6, or IgG7. Polypeptides comprising an Fc region of IgGA, IgGB, IgGC, or IgGD may provide for higher expression levels in recombination production systems.


In some embodiments, an IgX Fc polypeptide or an IgX-N Fc polypeptide is derived from a companion animal, such as a dog, a cat, or a horse. In some embodiments, IgG Fc polypeptides are isolated from canine y heavy chains, such as IgG-A, IgG-B, IgG-C, or IgG-D. In some instances, IgG Fc polypeptides are isolated from feline y heavy chains, such as IgG1a, IgG1b, or IgG2. In other instances, IgG Fc polypeptides are isolated from equine y heavy chains, such as IgG1, IgG2, IgG3, IgG4, IgG5, IgG6, or IgG7.


The terms “IgX Fc” and “IgX Fc polypeptide” include wild-type IgX Fc polypeptides and variant IgX Fc polypeptides, unless indicated otherwise.


In some embodiments, a wild-type IgG Fc polypeptide comprises the amino acid sequence of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 72, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID N:O 88, SEQ ID NO: 89, or SEQ ID NO: 90.


A “variant Fc polypeptide” is an Fc polypeptide that differs from a reference Fc polypeptide by single or multiple non-native amino acid substitutions, deletions, and/or additions. In some embodiments, a variant Fc polypeptide retains at least one biological activity of the reference Fc polypeptide. In some embodiments, a variant Fc polypeptide (e.g., a variant canine IgG-A Fc, a variant canine IgG-C Fc, a variant canine IgG-D Fc, variant equine IgG2 Fc, variant equine IgG5 Fc, or variant equine IgG6 Fc) has an activity that the reference Fc polypeptide substantially lacks. For example, in some embodiments, a variant canine IgG-A Fc, a variant canine IgG-C Fc, a variant canine IgG-D Fc, variant equine IgG2 Fc, variant equine IgG5 Fc, or variant equine IgG6 Fc binds Protein A.


In some embodiments, a variant IgG Fc polypeptide comprises a variant IgG Fc polypeptide of a companion animal species. In some embodiments, a variant IgG Fc polypeptide comprises a variant canine IgG Fc polypeptide, a variant equine IgG Fc polypeptide, or a feline IgG Fc polypeptide.


Exemplary Variant IgG Fc Polypeptides with Modified Protein a Binding


In some embodiments, a variant IgG Fc polypeptide has modified Protein A binding affinity. In some embodiments, a variant IgG Fc polypeptide has increased binding affinity to Protein A. In some embodiments, a variant IgG Fc polypeptide may be purified using Protein A column chromatography.


In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 21, position 23, position 25, position 80, position 205, and/or position 207 of SEQ ID NO: 34. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 21, position 23, and/or position 24 of SEQ ID NO: 37. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 21, position 23, position 25, position 80, and/or position 207 of SEQ ID NO: 39.


In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 15, and/or position 203 of SEQ ID NO: 71. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 199 and/or position 200 of SEQ ID NO: 75. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 199, position 200, position 201, and/or 202 of SEQ ID NO: 76.


In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 21, position 23, position 25, position 80, position 205, and/or position 207 of SEQ ID NO: 34. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 21, position 23, and/or position 24 of SEQ ID NO: 37. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 21, position 23, position 25, position 80, and/or position 207 of SEQ ID NO: 39.


In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 15 and/or position 203 of SEQ ID NO: 71. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 199 and/or position 200 of SEQ ID NO: 75. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 199, position 200, position 201, and/or position 202 of SEQ ID NO: 76.


In some embodiments, a variant IgG Fc polypeptide comprises a threonine at a position corresponding to position 21 of SEQ ID NO: 34, a leucine at a position corresponding to position 23 of SEQ ID NO: 34, an alanine at a position corresponding to position 25 of SEQ ID NO: 34, a glycine at a position corresponding to position 80 of SEQ ID NO: 34, an alanine at a position corresponding to position 205 of SEQ ID NO: 34, and/or a histidine at a position corresponding to position 207 of SEQ ID NO: 34. In some embodiments, a variant IgG Fc polypeptide comprises a threonine at a position corresponding to position 21 of SEQ ID NO: 37, a leucine at a position corresponding to position 23 of SEQ ID NO: 37, and/or an isoleucine at a position corresponding to position 24 of SEQ ID NO: 37. In some embodiments, a variant IgG Fc polypeptide comprises a threonine at a position corresponding to position 21 of SEQ ID NO: 39, a leucine at a position corresponding to position 23 of SEQ ID NO: 39, an alanine at a position corresponding to position 25 of SEQ ID NO: 39, a glycine at a position corresponding to position 80 of SEQ ID NO: 39, and/or a histidine at a position corresponding to position 207 of SEQ ID NO: 39.


In some embodiments, a variant IgG Fc polypeptide comprises a threonine or a valine at a position corresponding to position 15 of SEQ ID NO: 71, and/or a tyrosine or a valine at a position corresponding to position 203 of SEQ ID NO: 71. In some embodiments, a variant IgG Fc polypeptide comprises a leucine at a position corresponding to position 199 of SEQ ID NO: 75, and/or a histidine at a position corresponding to position 200 of SEQ ID NO: 75. In some embodiments, a variant IgG Fc polypeptide comprises an isoleucine at a position corresponding to position 199 of SEQ ID NO: 76, a histidine at a position corresponding to position 200 of SEQ ID NO: 76, an asparagine at a position corresponding to position 201 of SEQ ID NO: 76, and/or a histidine at a position corresponding to position 202 of SEQ ID NO: 76.


In some embodiments, a variant IgG Fc polypeptide comprises a threonine at position 21 of SEQ ID NO: 34, a leucine at position 23 of SEQ ID NO: 34, an alanine at position 25 of SEQ ID NO: 34, a glycine at position 80 of SEQ ID NO: 34, an alanine at position 205 of SEQ ID NO: 34, and/or a histidine at position 207 of SEQ ID NO: 34. In some embodiments, a variant IgG Fc polypeptide comprises a threonine at position 21 of SEQ ID NO: 47, a leucine at position 23 of SEQ ID NO: 47, and/or an isoleucine at position 24 of SEQ ID NO: 47. In some embodiments, a variant IgG Fc polypeptide comprise a threonine at a position 21 of SEQ ID NO: 39, a leucine at position 23 of SEQ ID NO: 39, an alanine at position 25 of SEQ ID NO: 39, a glycine at position 80 of SEQ ID NO: 39, and/or a histidine at position 207 of SEQ ID NO: 39.


In some embodiments, a variant IgG Fc polypeptide comprises a threonine or a valine at position 15 of SEQ ID NO: 71, and/or a tyrosine or a valine at position 203 of SEQ ID NO: 71. In some embodiments, a variant IgG Fc polypeptide comprises a leucine at position 199 of SEQ ID NO: 75, and/or a histidine at position 200 of SEQ ID NO: 75. In some embodiments, a variant IgG Fc polypeptide comprises an isoleucine at position 199 of SEQ ID NO: 76, a histidine at position 200 of SEQ ID NO: 76, an asparagine at position 201 of SEQ ID NO: 76, and/or a histidine at position 202 of SEQ ID NO: 76.


Exemplary Variant IgG Fc Polypeptides with Modified CD16 Binding


In some embodiments, a variant IgG Fc polypeptide has modified CD16 binding affinity. In some embodiments, a variant IgG Fc polypeptide has decreased binding affinity to CD16. In some embodiments, a variant IgG Fc may have a reduced ADCC immune response.


In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 5, position 38, position 39, position 97, and/or position 98 of SEQ ID NO: 35. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 5, position 38, position 39, position 97, and/or position 98 of SEQ ID NO: 37.


In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 5, position 38, position 39, position 97, and/or position 98 of SEQ ID NO: 35. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 5, position 38, position 39, position 97, and/or position 98 of SEQ ID NO: 37.


In some embodiments, a variant IgG Fc polypeptide comprises a proline at a position corresponding to position 5, a glycine at a position corresponding to position 38, an arginine at a position corresponding to position 39, a isoleucine at a position corresponding to position 97, and/or a glycine at a position corresponding to position 98 of SEQ ID NO: 36. In some embodiments, a variant IgG Fc polypeptide comprises a proline at a position corresponding to position 5, a glycine at a position corresponding to position 38, an arginine at a position corresponding to position 39, a isoleucine at a position corresponding to position 97, and/or a glycine at a position corresponding to position 98 of SEQ ID NO: 37.


In some embodiments, a variant IgG Fc polypeptide comprises a proline at position 5, a glycine at position 38, an arginine at position 39, a isoleucine at position 97, and/or a glycine at position 98 of SEQ ID NO: 35. In some embodiments, a variant IgG Fc polypeptide comprises a proline at position 5, a glycine at position 38, an arginine at position 39, a isoleucine at position 97, and/or a glycine at position 98 of SEQ ID NO: 37.


Exemplary Variant IgG Fc Polypeptides with Modified C1q Binding


In some embodiments, a variant IgG Fc polypeptide has modified C1q binding affinity. In some embodiments, a variant IgG Fc polypeptide has reduced binding affinity to C1q. In some embodiments, a variant IgG Fc polypeptide may have reduced complement fixation. In some embodiments, a variant IgG Fc may have a reduced complement-mediated immune response.


In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 93 of SEQ ID NO: 35. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 93 of SEQ ID NO: 37. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 87 of SEQ ID NO: 70. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 87 of SEQ ID NO: 73. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 87 of SEQ ID NO: 74. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 87 of SEQ ID NO: 77. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 198 of SEQ ID NO: 86, of SEQ ID NO: 87, of SEQ ID NO: 88, or of SEQ ID NO: 89.


In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 93 of SEQ ID NO: 35. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 93 of SEQ ID NO: 37. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 87 of SEQ ID NO: 70. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 87 of SEQ ID NO: 73. In some embodiments, a variant IgG Fc polypeptide comprises or an amino acid substitution at position 87 of SEQ ID NO: 74. In some embodiments, a variant IgG Fc polypeptide comprises or an amino acid substitution at position 87 of SEQ ID NO: 77. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 198 of SEQ ID NO: 86, of SEQ ID NO: 87, of SEQ ID NO: 88, or of SEQ ID NO: 89.


In some embodiments, a variant IgG Fc polypeptide comprises an arginine at a position corresponding to position 93 of SEQ ID NO: 35. In some embodiments, a variant IgG Fc polypeptide comprises an arginine at a position corresponding to position 93 of SEQ ID NO: 37. In some embodiments, a variant IgG Fc polypeptide comprises a serine at a position corresponding to position 87 of SEQ ID NO: 70. In some embodiments, a variant IgG Fc polypeptide comprises a serine substitution at a position corresponding to position 87 of SEQ ID NO: 73. In some embodiments, a variant IgG Fc polypeptide comprises a serine at a position corresponding to position 87 of SEQ ID NO: 74. In some embodiments, a variant IgG Fc polypeptide comprises a serine at a position corresponding to position 87 of SEQ ID NO: 77. In some embodiments, a variant IgG Fc polypeptide comprises an alanine at a position corresponding to position 198 of SEQ ID NO: 86, of SEQ ID NO: 87, of SEQ ID NO: 88, or of SEQ ID NO: 89.


In some embodiments, a variant IgG Fc polypeptide comprises an arginine at position 93 of SEQ ID NO: 35. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 93 of SEQ ID NO: 37. In some embodiments, a variant IgG Fc polypeptide comprises a serine at position 87 of SEQ ID NO: 70. In some embodiments, a variant IgG Fc polypeptide comprises a serine at position 87 of SEQ ID NO: 73. In some embodiments, a variant IgG Fc polypeptide comprises a serine at position 87 of SEQ ID NO: 74. In some embodiments, a variant IgG Fc polypeptide comprises a serine at position 87 of SEQ ID NO: 77. In some embodiments, a variant IgG Fc polypeptide comprises an alanine at position 198 of SEQ ID NO: 86, of SEQ ID NO: 87, of SEQ ID NO: 88, or of SEQ ID NO: 89.


Exemplary Variant IgG Fc Polypeptides with Modified FcRn Binding


In some embodiments, a variant IgG Fc polypeptide has modified neonatal receptor (FcRn) binding affinity. In some embodiments, a variant IgG Fc polypeptide has increased binding affinity to FcRn.


In some embodiments, a variant IgG Fc polypeptide binds to FcRn with an affinity greater than the wild-type IgG Fc polypeptide, as measured by biolayer interferometry, surface plasmon resonance, or any protein-protein interaction tool at a pH in the range of from about 5.0 to about 6.5, such as at a pH of about 5.0, a pH of about 5.2, a pH of about 5.5, a pH of about 6.0, a pH of about 6.2, or a pH of about 6.5.


In some embodiments, a variant IgG Fc polypeptide binds to FcRn with a dissociation constant (Kd) of less than 5×10−6 M, less than 1×10−6 M, less than 5×10−7 M, less than 1×10−7 M, less than 5×10−8 M, less than 1×10−8 M, less than 5×10−9 M, less than 1×10−9 M, less than 5×10−10 M, less than 1×10−10 M, less than 5×10−11 M, less than 1×10−11M, less than 5×10−12 M, or less than 1×10−12 M, as measured by biolayer interferometry, surface plasmon resonance, or any protein-protein interaction tool at a pH in the range of from about 5.0 to about 6.5, such as at a pH of about 5.0, a pH of about 5.5, a pH of about 6.0, or a pH of about 6.5.


In some embodiments, a contiguous polypeptide comprises a variant IgG Fc polypeptide capable of binding to FcRn with an increased affinity relative to the wild-type Fc polypeptide and wherein the contiguous polypeptide has increased serum half-life relative to a contiguous polypeptide comprising a wild-type Fc polypeptide.


In some embodiments a variant IgG Fc polypeptide comprises a tyrosine or a phenylalanine at a position corresponding to position 23 of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90. In some embodiments a variant IgG Fc polypeptide comprises a tyrosine at a position corresponding to position 82 of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90. In some embodiments, a variant IgG Fc polypeptide comprises a tyrosine at a position corresponding to position 82 and a histidine at a position corresponding to position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90. In some embodiments a variant IgG Fc polypeptide comprises a tyrosine at a position corresponding to position 82 and a tyrosine at a position corresponding to position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90. In some embodiments a variant IgG Fc polypeptide comprises a tyrosine at a position corresponding to position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90. In some embodiments a variant IgG Fc polypeptide comprises a tyrosine at a position corresponding to position 82 and a histidine at a position corresponding to position 208 of SEQ ID NO: 34 or SEQ ID NO: 39. In some embodiments a variant IgG Fc polypeptide comprise a tyrosine at a position corresponding to position 82 and a tyrosine at a position corresponding to position 208 of SEQ ID NO: 34 or SEQ ID NO: 39. In some embodiments a variant IgG Fc polypeptide comprises a tyrosine at a position corresponding to position 208 of SEQ ID NO: 34 or SEQ ID NO: 39.


In some embodiments a variant IgG Fc polypeptide comprises a tyrosine or a phenylalanine at position 23 of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90. In some embodiments a variant IgG Fc polypeptide comprises a tyrosine at position 82 of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90. In some embodiments a variant IgG Fc polypeptide comprises a tyrosine at position 82 and a histidine at position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90. In some embodiments a variant IgG Fc polypeptide comprises a tyrosine at position 82 and a tyrosine at position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90. In some embodiments a variant IgG Fc polypeptide comprises a tyrosine at position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90. In some embodiments a variant IgG Fc polypeptide comprises a tyrosine at position 82 and a histidine at position 208 of SEQ ID NO: 34 or SEQ ID NO: 39. In some embodiments a variant IgG Fc polypeptide comprises a tyrosine at position 82 and a tyrosine at position 208 of SEQ ID NO: 34 or SEQ ID NO: 39. In some embodiments a variant IgG Fc polypeptide comprises a tyrosine at position 208 of SEQ ID NO: 34 or SEQ ID NO: 39.


Exemplary Variant IgG Fc Polypeptides with a Modified Inter-Chain Disulfide Linkage


In some embodiments, a variant feline IgG Fc polypeptide has at least one additional inter-chain disulfide linkage relative to the wild-type feline IgG Fc polypeptide. In some embodiments, a variant feline IgG Fc polypeptide has at least one additional inter-chain disulfide linkage in the hinge region. In some embodiments, a variant feline IgG2 Fc polypeptide with at least one additional inter-chain disulfide linkage has increased inter-chain stability relative to the wild-type feline IgG Fc polypeptide. In some embodiments, a variant IgG polypeptide has at least one amino acid modification to a hinge region relative to a wild-type IgG Fc polypeptide. In some embodiments, the wild-type IgG Fc polypeptide is a wild-type feline or equine IgG Fc polypeptide. In some embodiments, the variant IgG Fc polypeptide comprises a hinge region or a portion of a hinge region from an IgG Fc polypeptide of a different isotype. In some embodiments, the variant IgG Fc polypeptide comprises a hinge region from a wild-type feline IgG-1a Fc polypeptide, from a wild-type feline IgG-1b Fc polypeptide, or from a wild-type equine IgG1 Fc polypeptide. In some embodiments, a variant IgG2 Fc polypeptide has increased recombinant production and/or increased hinge disulfide formation relative to the wild-type IgG Fc polypeptide. In some embodiments, the increased recombinant production and/or increased hinge disulfide formation can be determined by SDS-PAGE analysis under reducing and/or non-reducing conditions.


In some embodiments, a variant IgG Fc polypeptide comprises a cysteine at a position corresponding to position 8, position 9, position 10, position 11, position 12, position 13, position 14, position 15, or position 16 of SEQ ID NO: 90. In some embodiments, a variant IgG Fc polypeptide comprises a cysteine at position 8, position 9, position 10, position 11, position 12, position 13, position 14, position 15, or position 16 of SEQ ID NO: 90.


In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 16 of SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, or SEQ ID NO: 90. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 3 and/or at a position corresponding to position 20 of SEQ ID NO: 72.


In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 16 of SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, or SEQ ID NO: 90. In some embodiments, a variant IgG Fc polypeptide comprises an amino acid substitution at position 3 and/or at a position corresponding to position 20 of SEQ ID NO: 72.


In some embodiments, a variant IgG Fc polypeptide comprises a proline at a position corresponding to position 16 of SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, or SEQ ID NO: 90. In some embodiments, a variant IgG Fc polypeptide comprises a serine at a position corresponding to position 3 and/or a proline at a position corresponding to position 20 of SEQ ID NO: 72.


In some embodiments, a variant IgG Fc polypeptide comprises a proline at position 16 of SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, or SEQ ID NO: 90. In some embodiments, a variant IgG Fc polypeptide comprises a serine at position 3 and/or a proline at position 20 of SEQ ID NO: 72.


In some embodiments, a variant IgG Fc polypeptide comprises the amino acid sequence of SEQ ID NO: 40, SEQ ID NO: 41, SEQ ID NO: 42, SEQ ID NO: 43, SEQ ID NO: 44, SEQ ID NO: 45, SEQ ID NO: 46, SEQ ID NO: 47, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 50, SEQ ID NO: 51, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54, SEQ ID NO: 55, SEQ ID NO: 56, SEQ ID NO: 57, SEQ ID NO: 58, SEQ ID NO: 59, SEQ ID NO: 60, SEQ ID NO: 61, SEQ ID NO: 62, SEQ ID NO: 63, SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68, SEQ ID NO: 69, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99, SEQ ID NO: 100, SEQ ID NO: 101, SEQ ID NO: 102, SEQ ID NO: 103, SEQ ID NO: 104, SEQ ID NO: 105, SEQ ID NO: 106, SEQ ID NO: 107, SEQ ID NO: 108, SEQ ID NO: 109, SEQ ID NO: 197, SEQ ID NO: 198, SEQ ID NO: 199, SEQ ID NO: 200, SEQ ID NO: 201, SEQ ID NO: 202, SEQ ID NO: 203, SEQ ID NO: 204, SEQ ID NO: 205, SEQ ID NO: 206, SEQ ID NO: 207, SEQ ID NO: 208, SEQ ID NO: 209, and/or SEQ ID NO: 210.


In some embodiments, a contiguous polypeptide comprises at least one TrkA ECD polypeptide (e.g., ECD v1, v2, v3, and/or v4) and a wild-type or variant canine, feline, or equine IgG Fc polypeptide described herein may be prepared based on the following formulas:





TrkA ECD 1-L1-Fc;  Formula (I):





Fc-L1-TrkA ECD 1;  Formula (II):





TrkA ECD 1-L1-Fc-L2-TrkA ECD 2;  Formula (III):





TrkA ECD 1-L1-TrkA ECD 2-L2-Fc;  Formula (IV): or





Fc-L1-TrkA ECD 1-L2-TrkA ECD 2,  Formula (V):


wherein TrkA ECD 1 is a first TrkA ECD polypeptide, TrkA ECD 2 is a second TrkA ECD polypeptide (e.g., the same TrkA ECD polypeptide or a different TrkA ECD polypeptide); L1 and L2 are optional linkers; and Fc is a wild type or variant IgG Fc polypeptide of a companion animal species. Optionally, the contiguous polypeptide comprises a signal sequence. The exemplary constructs of Formulas I-V may comprise a third, fourth, or fifth, etc. TrkA ECD following or before any TrkA ECD 1 or TrkA ECD 2. A third, fourth, or fifth, etc. TrkA ECD may be the same TrkA ECD polypeptide or a different TrkA ECD polypeptide as TrkA ECD 1 or TrkA ECD 2.


For example, a contiguous polypeptide may comprise at least one canine TrkA ECD polypeptide (e.g., SEQ ID NO: 2, 3, 4, 5, 25, 26, or 27) and a wild-type canine IgG polypeptide (e.g., SEQ ID NO: 34, 35, 36, 37, 38, or 39), a variant canine IgG-A Fc polypeptide (e.g., SEQ ID NO: 40, 43, 199, or 200), a variant canine IgG-B Fc polypeptide (e.g., SEQ ID NO: 46, 48, 49, 50, 51, 52, 53, 54, 55, 64, 65, 66, 67, 197, 198, 203, 204, 205, 206, 207, 208, 209, or 210), a variant canine IgG-C Fc polypeptide (e.g., SEQ ID NO: 41, 44, 47, 56, 57, 58, 59, 60, 61, 52, 63, 68, or 69), or a variant canine IgG-D Fc polypeptide (e.g., SEQ ID NO: 42, 45, 201, or 202), as described herein.


A contiguous polypeptide may comprise at least one feline TrkA ECD polypeptide (e.g., SEQ ID NO: 7, 8, 9, 10, 28, 29, or 30) and a wild-type feline IgG Fc polypeptide (e.g., 86, 87, 88, 89, or 90), a variant feline IgG1a Fc polypeptide (e.g., SEQ ID NO: 91, 92, 96, or 97), a variant feline IgG1b Fc polypeptide (e.g., SEQ ID NO: 93, 94, 98, or 99), or a variant feline IgG2 Fc polypeptide (e.g., SEQ ID NO: 95, 100, or 107), as described herein.


A contiguous polypeptides may comprise at least one equine TrkA ECD polypeptide (e.g., SEQ ID NO: 12, 13, 14, 15, 31, 32, or 33) and a wild-type equine IgG Fc polypeptide (e.g., SEQ ID NO: 70, 71, 72, 73, 74, 75, 76, or 77), a variant equine IgG1Fc polypeptide (e.g., SEQ ID NO: 82), a variant equine IgG2 Fc polypeptide (e.g., SEQ ID NO: 78, 79, 101, 102, 103, 104, 105, 106, 108, or 109), a variant equine IgG3 Fc polypeptide (e.g., SEQ ID NO: 83), a variant equine IgG4 Fc polypeptide (e.g., SEQ ID NO: 84), a variant equine IgG5 Fc polypeptide (e.g., SEQ ID NO: 80), a variant equine IgG6 Fc polypeptide (e.g., SEQ ID NO: 81), or a variant equine IgG7 Fc polypeptide (e.g., SEQ ID NO: 85).


In some embodiments, a contiguous polypeptide comprising a TrkA ECD polypeptide may further comprise at least one NGFR ECD polypeptide. In some embodiments, the NGFR ECD polypeptide comprises the amino acid sequence of SEQ ID NO: 135, SEQ ID NO: 137, and/or SEQ ID NO: 139.


In some embodiments, a contiguous polypeptide comprises the amino acid sequence of SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21, SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO: 110, SEQ ID NO: 111, SEQ ID NO: 112, SEQ ID NO: 113, SEQ ID NO: 114, SEQ ID NO: 115, SEQ ID NO: 116, SEQ ID NO: 117, SEQ ID NO: 118, SEQ ID NO: 119, SEQ ID NO: 120, SEQ ID NO: 121, SEQ ID NO: 122, SEQ ID NO: 123, SEQ ID NO: 124, SEQ ID NO: 125, SEQ ID NO: 126, SEQ ID NO: 127, SEQ ID NO: 128, SEQ ID NO: 129, SEQ ID NO: 130, SEQ ID NO: 131, SEQ ID NO: 132, SEQ ID NO: 133, SEQ ID NO: 140, SEQ ID NO: 141, SEQ ID NO: 142, SEQ ID NO: 159, SEQ ID NO: 160, SEQ ID NO: 161, SEQ ID NO: 162, SEQ ID NO: 163, SEQ ID NO: 164, SEQ ID NO: 165, SEQ ID NO: 166, SEQ ID NO: 167, SEQ ID NO: 168, SEQ ID NO: 169, SEQ ID NO: 170, SEQ ID NO: 171, SEQ ID NO: 172, SEQ ID NO: 173, SEQ ID NO: 174, SEQ ID NO: 175, SEQ ID NO: 176, SEQ ID NO: 177, SEQ ID NO: 178, SEQ ID NO: 179, SEQ ID NO: 180, SEQ ID NO: 181, SEQ ID NO: 182, SEQ ID NO: 183, SEQ ID NO: 184, SEQ ID NO: 185, SEQ ID NO: 186, SEQ ID NO: 187, SEQ ID NO: 188, SEQ ID NO: 189, SEQ ID NO: 190, SEQ ID NO: 191, SEQ ID NO: 192, SEQ ID NO: 193, SEQ ID NO: 194, SEQ ID NO: 211, SEQ ID NO: 212, SEQ ID NO: 213, SEQ ID NO: 214, SEQ ID NO: 215, SEQ ID NO: 216, SEQ ID NO: 217, SEQ ID NO: 218, SEQ ID NO: 219, SEQ ID NO: 220, SEQ ID NO: 221, SEQ ID NO: 222, SEQ ID NO: 223, SEQ ID NO: 224, SEQ ID NO: 225, SEQ ID NO: 226, SEQ ID NO: 227, SEQ ID NO: 228, SEQ ID NO: 229, SEQ ID NO: 230, SEQ ID NO: 231, SEQ ID NO: 232, SEQ ID NO: 233, SEQ ID NO: 234, SEQ ID NO: 235, SEQ ID NO: 236, SEQ ID NO: 237, SEQ ID NO: 238, SEQ ID NO: 239, SEQ ID NO: 240, SEQ ID NO: 241, SEQ ID NO: 242, SEQ ID NO: 243, SEQ ID NO: 244, SEQ ID NO: 245, SEQ ID NO: 246.


The molecule may be further constructed using the format: R-(link)-Fc-TrkA. R can be any proteins such as TNFR, IL13R, IL4R, IL17R etc. The bispecific format may provide additional therapeutic benefit.


TrkA can also be fused to an antibody, for example, to IgG heavy chain C-terminal. The antibody can be anti TNF, anti CGRP, anti IL17, anti IL4R, anti EGFR etc. The antibody fusion may have enhanced effect on the treatment.


Exemplary TrkA ECD Polypeptide Expression and Production

Polynucleotide sequences that encode all or part (e.g., the extracellular domain) of a TrkA polypeptide with or without a signal sequence are provided. If a homologous signal sequence (i.e., a signal sequence of TRKA) is not used in the construction of the nucleic acid molecule, then another signal sequence may be used, for example, any one of the signal sequences described in PCT US06/02951.


Typically, nucleotide sequence encoding the polypeptide of interest, such as an TrkA polypeptide, is inserted into an expression vector, suitable for expression in a selected host cell.


A “vector” is a plasmid that can be used to transfer DNA sequences from one organism to another or to express a gene of interest. A vector typically includes an origin of replication and regulatory sequences which regulate the expression of the gene of interest, and may or may not carry a selective marker gene, such as an antibiotic resistance gene. A vector is suitable for the host cell in which it is to be expressed. A vector may be termed a “recombinant vector” when the gene of interest is present in the vector.


A “host cell” refers to a cell that may be or has been a recipient of a vector or isolated polynucleotide. Host cells may be prokaryotic cells or eukaryotic cells. Exemplary eukaryotic cells include mammalian cells, such as primate or non-primate animal cells; fungal cells, such as yeast; plant cells; and insect cells. Nonlimiting exemplary mammalian cells include, but are not limited to, NS0 cells, PER.C6® cells (Crucell), 293 cells, and CHO cells, and their derivatives, such as 293-6E, DG44, CHO-S, and CHO-K cells. Host cells include progeny of a single host cell, and the progeny may not necessarily be completely identical (in morphology or in genomic DNA complement) to the original parent cell due to natural, accidental, or deliberate mutation. A host cell includes cells transfected in vivo with a polynucleotide(s) encoding an amino acid sequence(s) provided herein.


The term “isolated” as used herein refers to a molecule that has been separated from at least some of the components with which it is typically found in nature or produced. For example, a polypeptide is referred to as “isolated” when it is separated from at least some of the components of the cell in which it was produced. Where a polypeptide is secreted by a cell after expression, physically separating the supernatant containing the polypeptide from the cell that produced it is considered to be “isolating” the polypeptide. Similarly, a polynucleotide is referred to as “isolated” when it is not part of the larger polynucleotide (such as, for example, genomic DNA or mitochondrial DNA, in the case of a DNA polynucleotide) in which it is typically found in nature, or is separated from at least some of the components of the cell in which it was produced, for example, in the case of an RNA polynucleotide. Thus, a DNA polynucleotide that is contained in a vector inside a host cell may be referred to as “isolated.”


In some embodiments, the TrkA polypeptide is isolated using chromatography, such as size exclusion chromatography, ion exchange chromatography, protein A column chromatography, hydrophobic interaction chromatography, and CHT chromatography.


The terms “label” and “detectable label” mean a moiety attached to a TrkA polypeptide to render it detectable. In some embodiments, the label is a detectable marker that can produce a signal that is detectable by visual or instrumental means, for example, incorporation of a radiolabeled amino acid or attachment to a polypeptide of biotinyl moieties that can be detected by marked avidin (for example, streptavidin containing a fluorescent marker or enzymatic activity that can be detected by optical or colorimetric methods). Examples of labels for polypeptides include, but are not limited to, the following: radioisotopes or radionuclides (for example, 3H, 14C, 35S, 90Y, 99Tc, 111In, 125I, 131I, 177Lu, 166Ho, or 153Sm); chromogens, fluorescent labels (for example, FITC, rhodamine, lanthanide phosphors), enzymatic labels (for example, horseradish peroxidase, luciferase, alkaline phosphatase); chemiluminescent markers; biotinyl groups; predetermined polypeptide epitopes recognized by a secondary reporter (for example, leucine zipper pair sequences, binding sites for secondary antibodies, metal binding domains, epitope tags); and magnetic agents, such as gadolinium chelates. Representative examples of labels commonly employed for immunoassays include moieties that produce light, for example, acridinium compounds, and moieties that produce fluorescence, for example, fluorescein. In this regard, the moiety itself may not be detectably labeled but may become detectable upon reaction with yet another moiety.


Exemplary TrkA Polypeptides as Decoy Receptor Traps

The TRKA polypeptides of the invention can function as decoy receptors for trapping NGF and inhibiting their interaction with NGF and TRKA on cell surfaces. Decoy receptors, such as those of the invention, recognize their ligands with high affinity and specificity but are structurally incapable of signaling. They compete with wild-type receptors for ligand binding and participate in ligand/receptor interactions, thus modulating the activity of or the number of functioning receptors and/or the cellular activity downstream from the receptors. Decoy receptors can act as molecular traps for agonist ligands and thereby inhibit ligand-induced receptor activation.


“NGF” as used herein refers to any native NGF that results from expression and processing of NGF in a cell. The term includes NGF from any vertebrate source, including mammals such as primates (e.g., humans and cynomolgus monkeys) and rodents (e.g., mice and rats), and companion animals (e.g., dogs, cats, and equine), unless otherwise indicated. The term also includes naturally occurring variants of NGF, e.g., splice variants or allelic variants.


The invention provides TrkA ECD polypeptides as therapeutic agents. The TrkA ECD polypeptides of the invention bind to NGF, described in more detail herein, which have been demonstrated to be associated with chronic or inflammatory pain. In various embodiments, TrkA polypeptides can bind NGF with high affinity. In various embodiments, the TrkA polypeptides can interfere with NGF signaling.


The term “affinity” means the strength of the sum total of noncovalent interactions between a single binding site of a molecule (for example, a receptor) and its binding partner (for example, a ligand). The affinity of a molecule X for its partner Y can generally be represented by the dissociation constant (KD). Affinity can be measured by common methods known in the art, such as, for example, immunoblot, ELISA KD, KinEx A, biolayer interferometry (BLI), or surface plasmon resonance devices.


The terms “KD,” “Kd,” “Kd” or “Kd value” as used interchangeably to refer to the equilibrium dissociation constant of a receptor fusion-ligand interaction. In some embodiments, the Kd of the fusion molecule to its ligand is measured by using biolayer interferometry assays using a biosensor, such as an Octet® System (Pall ForteBio LLC, Fremont, Calif.) according to the supplier's instructions. Briefly, biotinylated antigen is bound to the sensor tip and the association of fusion molecule is monitored for ninety seconds and the dissociation is monitored for 600 seconds. The buffer for dilutions and binding steps is 20 mM phosphate, 150 mM NaCl, pH 7.2. A buffer only blank curve is subtracted to correct for any drift. The data are fit to a 2:1 binding model using ForteBio data analysis software to determine association rate constant (kon), dissociation rate constant (koff), and the Kd. The equilibrium dissociation constant (Kd) is calculated as the ratio of koff/kon. The term “kon” refers to the rate constant for association of a molecule X to its partner Y and the term “koff” refers to the rate constant for dissociation of a molecule X or partner Y from the molecule X/partner Y complex.


The term “binds” to a substance is a term that is well understood in the art, and methods to determine such binding are also well known in the art. A molecule is said to exhibit “binding” if it reacts, associates with, or has affinity for a particular cell or substance and the reaction, association, or affinity is detectable by one or more methods known in the art, such as, for example, immunoblot, ELISA KD, KinEx A, biolayer interferometry (BLI), surface plasmon resonance devices, or etc.


“Surface plasmon resonance” denotes an optical phenomenon that allows for the analysis of real-time biospecific interactions by detection of alterations in protein concentrations within a biosensor matrix, for example using the BIAcore™ system (BIAcore International AB, a GE Healthcare company, Uppsala, Sweden and Piscataway, N.J.). For further descriptions, see Jonsson et al. (1993) Ann. Biol. Clin. 51: 19-26.


“Biolayer interferometry” refers to an optical analytical technique that analyzes the interference pattern of light reflected from a layer of immobilized protein on a biosensor tip and an internal reference layer. Changes in the number of molecules bound to the biosensor tip cause shifts in the interference pattern that can be measured in real-time. A nonlimiting exemplary device for biolayer interferometry is an Octet® system (Pall ForteBio LLC). See, e.g., Abdiche et al., 2008, Anal. Biochem. 377: 209-277.


In some embodiments, a TrkA polypeptide binds to canine NGF, feline NGF, equine NGF, or human NGF with a dissociation constant (Kd) of less than 5×10−6M, less than 1×10−6M, less than 5×10−7 M, less than 1×10−7 M, less than 5×10−8M, less than 1×10−8M, less than 5×10−9M, less than 1×10−9M, less than 5×10−10 M, less than 1×10−10 M, less than 5×10−11 M, less than 1×10−11 M, less than 5×10−12 M, or less than 1×10−12 M, as measured by biolayer interferometry. In some embodiments, an TRKA polypeptide binds to canine NGF, feline NGF, or equine NGF with a Kd of between 5×10−6M and 1×10−6M, between 5×10−6M and 5×10−7 M, between 5×10−6M and 1×10−7M, between 5×10−6M and 5×10−8M, 5×10−6M and 1×10−8M, between 5×10−6M and 5×10−9 M, between 5×10−6M and 1×10−9M, between 5×10−6M and 5×10−10 M, between 5×10−6M and 1×10−10 M, between 5×10−6M and 5×10−11 M, between 5×10−6M and 1×10−11M, between 5×10−6M and 5×10−12 M, between 5×10−6M and 1×10−12 M, between 1×10−6M and 5×10−7 M, between 1×10−6M and 1×10−7 M, between 1×10−6M and 5×10−8M, 1×10−6M and 1×10−8M, between 1×10−6 M and 5×10−9M, between 1×10−6M and 1×10−9 M, between 1×10−6M and 5×10−10 M, between 1×10−6M and 1×10−10 M, between 1×10−6 M and 5×10−11 M, between 1×10−6 M and 1×10−11M, between 1×10−6 M and 5×10−12 M, between 1×10−6M and 1×10−12M, between 5×10−7M and 1×10−7M, between 5×10−7M and 5×10−8M, 5×10−7M and 1×10−8M, between 5×10−7M and 5×10−9M, between 5×10−7 M and 1×10−9 M, between 5×10−7M and 5×10−10 M, between 5×10−7M and 1×10−10 M, between 5×10−7M and 5×10−11 M, between 5×10−7M and 1×10−11M, between 5×10−7M and 5×10−12 M, between 5×10−7 M and 1×10−12 M, between 1×10−7 M and 5×10−8 M, 1×10−7 M and 1×10−8 M, between 1×10−7M and 5×10−9 M, between 1×10−7M and 1×10−9 M, between 1×10−7M and 5×10−10 M, between 1×10−7M and 1×10−10 M, between 1×10−7M and 5×10−11 M, between 1×10−7M and 1×10−11 M, between 1×10−7M and 5×10−12 M, between 1×10−7 M and 1×10−12 M, between 5×10−8M and 1×10−8M, between 5×10−8M and 5×10−9M, between 5×10−8M and 1×10−9 M, between 5×10−8M and 5×10−10 M, between 5×10−8M and 1×10−10 M, between 5×10−8M and 5×10−11 M, between 5×10−8 M and 1×10−11 M, between 5×10−8M and 5×10−12M, between 5×10−8M and 1×10−12M, 1×10−8M and 5×10−9M, between 1×10−8M and 1×10−9 M, between 1×10−8M and 5×10−10 M, between 1×10−8 M and 1×10−10 M, between 1×10−8M and 5×10−11 M, between 1×10−8 M and 1×10−11M, between 1×10−8 M and 5×10−12M, between 1×10−8M and 1×10−12M, between 5×10−9M and 1×10−9M, between 5×10−9 M and 5×10−10 M, between 5×10−9 M and 1×10−10 M, between 5×10−9 M and 5×10−11M between 5×10−9 M and 1×10−11 M, between 5×10−9 M and 5×10−12 M, between 5×10−9 M and 1×10−12 M, between 1×10−9 M and 5×10−10 M, between 1×10−9 M and 1×10−10 M, between 1×10−9M and 5×10−11M, between 1×10−9M and 1×10−11M, between 1×10−9M and 5×10−12 M, between 1×10−9M and 1×10−12 M, between 5×10−10 M and 1×10−10 M, between 5×10−10 M and 5×10−11 M, between, 1×10−10 M and 5×10−11 M, 1×10−10 M and 1×10−11 M, between 1×10−10 M and 5×10−12 M, between 1×10−10 M and 1×10−12 M, between 5×10−11 M and 1×10−12 M, between 5×10−11 M and 5×10−12 M, between 5×10−11 M and 1×10−12 M, between 1×10−11 M and 5×10−12 M, or between 1×10−11 M and 1×10−12 M, as measured by biolayer interferometry. In some embodiments, a TRKA polypeptide binds to canine NGF, feline NGF, and/or equine NGF.


To “reduce” or “inhibit” means to decrease, reduce, or arrest an activity, function, or amount as compared to a reference. In some embodiments, by “reduce” or “inhibit” is meant the ability to cause an overall decrease of 20% or greater. In some embodiments, by “reduce” or “inhibit” is meant the ability to cause an overall decrease of 50% or greater. In some embodiments, by “reduce” or “inhibit” is meant the ability to cause an overall decrease of 75%, 85%, 90%, 95%, or greater. In some embodiments, the amount noted above is inhibited or decreased over a period of time, relative to a control dose (such as a placebo) over the same period of time. A “reference” as used herein, refers to any sample, standard, or level that is used for comparison purposes. A reference may be obtained from a healthy or non-diseased sample. In some examples, a reference is obtained from a non-diseased or non-treated sample of a companion animal. In some examples, a reference is obtained from one or more healthy animals of a particular species, which are not the animal being tested or treated.


The term “substantially reduced,” as used herein, denotes a sufficiently high degree of reduction between a numeric value and a reference numeric value such that one of skill in the art would consider the difference between the two values to be of statistical significance within the context of the biological characteristic measured by said values. In some embodiments, the substantially reduced numeric values is reduced by greater than about any one of 10%, 15% 20%, 25%, 30%, 35%, 40%, 45%, 50%, 60%, 70%, 80%, 90%, or 100% compared to the reference value.


In some embodiments, a TrkA polypeptide may reduce NGF signaling in a companion animal species by at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or 100% compared to NGF signaling in the absence of the fusion molecule. In some embodiments, signaling is measured by a reduction in NGF-dependent TF-1 cell proliferation. In some embodiments, the reduction in NGF signaling or the reduction in proliferation is between 10% and 15%, between 10% and 20%, between 10% and 25%, between 10% and 30%, between 10% and 35%, between 10% and 40%, between 10% and 45%, between 10% and 50%, between 10% and 60%, between 10% and 70%, between 10% and 80%, between 10% and 90%, between 10% and 100%, between 15% and 20%, between 15% and 25%, between 15% and 30%, between 15% and 35%, between 15% and 40%, between 15% and 45%, between 15% and 50%, between 15% and 60%, between 15% and 70%, between 15% and 80%, between 15% and 90%, between 15% and 100%, between 20% and 25%, between 20% and 30%, between 20% and 35%, between 20% and 40%, between 20% and 45%, between 20% and 50%, between 20% and 60%, between 20% and 70%, between 20% and 80%, between 20% and 90%, between 20% and 100%, between 25% and 30%, between 25% and 35%, between 25% and 40%, between 25% and 45%, between 25% and 50%, between 25% and 60%, between 25% and 70%, between 25% and 80%, between 25% and 90%, between 25% and 100%, between 30% and 35%, between 30% and 40%, between 30% and 45%, between 30% and 50%, between 30% and 60%, between 30% and 70%, between 30% and 80%, between 30% and 90%, between 30% and 100%, between 35% and 40%, between 35% and 45%, between 35% and 50%, between 35% and 60%, between 35% and 70%, between 35% and 80%, between 35% and 90%, between 35% and 100%, between 40% and 45%, between 40% and 50%, between 40% and 60%, between 40% and 70%, between 40% and 80%, between 40% and 90%, between 40% and 100%, between 45% and 50%, between 45% and 60%, between 45% and 70%, between 45% and 80%, between 45% and 90%, between 45% and 100%, between 50% and 60%, between 50% and 70%, between 50% and 80%, between 50% and 90%, between 50% and 100%, between 60% and 70%, between 60% and 80%, between 60% and 90%, between 60% and 100%, between 70% and 80%, between 70% and 90%, between 70% and 100%, between 80% and 90%, between 80% and 100%, or between 90% and 100%.


Exemplary Pharmaceutical Compositions

The terms “pharmaceutical formulation” and “pharmaceutical composition” refer to a preparation which is in such form as to permit the biological activity of the active ingredient(s) to be effective, and which contains no additional components that are unacceptably toxic to a subject to which the formulation would be administered.


A “pharmaceutically acceptable carrier” refers to a non-toxic solid, semisolid, or liquid filler, diluent, encapsulating material, formulation auxiliary, or carrier conventional in the art for use with a therapeutic agent that together comprise a “pharmaceutical composition” for administration to a subject. A pharmaceutically acceptable carrier is non-toxic to recipients at the dosages and concentrations employed and is compatible with other ingredients of the formulation. The pharmaceutically acceptable carrier is appropriate for the formulation employed. Examples of pharmaceutically acceptable carriers include alumina; aluminum stearate; lecithin; serum proteins, such as human serum albumin, canine or other animal albumin; buffers such as phosphate, citrate, tromethamine or HEPES buffers; glycine; sorbic acid; potassium sorbate; partial glyceride mixtures of saturated vegetable fatty acids; water; salts or electrolytes, such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts, colloidal silica, or magnesium trisilicate; polyvinyl pyrrolidone, cellulose-based substances; polyethylene glycol; sucrose; mannitol; or amino acids including, but not limited to, arginine.


The pharmaceutical composition can be stored in lyophilized form. Thus, in some embodiments, the preparation process includes a lyophilization step. The lyophilized composition may then be reformulated, typically as an aqueous composition suitable for parenteral administration, prior to administration to the dog, cat, or horse. In other embodiments, particularly where the fusion molecule is highly stable to thermal and oxidative denaturation, the pharmaceutical composition can be stored as a liquid, i.e., as an aqueous composition, which may be administered directly, or with appropriate dilution, to the dog, cat, or horse. A lyophilized composition can be reconstituted with sterile Water for Injection (WFI). Bacteriostatic reagents, such benzyl alcohol, may be included. Thus, the invention provides pharmaceutical compositions in solid or liquid form.


The pH of the pharmaceutical compositions may be in the range of from about pH 5 to about pH 8, when administered. The compositions of the invention are sterile if they are to be used for therapeutic purposes. Sterility can be achieved by any of several means known in the art, including by filtration through sterile filtration membranes (e.g., 0.2 micron membranes). Sterility may be maintained with or without anti-bacterial agents.


Exemplary Uses of TrkA Polypeptides and Pharmaceutical Compositions

The TrkA polypeptides or pharmaceutical compositions comprising the TrkA polypeptides of the invention may be useful for treating a NGF-induced condition. As used herein, an “NGF-induced condition” means a disease associated with, caused by, or characterized by, elevated levels or altered distribution of NGF. Such NGF-induced conditions include, but are not limited to, a osteoarthritis pain, cancer pain, low back pain. In some embodiments, the NGF-induced condition is a chronic or inflammatory pain. An NGF-induced condition may be exhibited in a companion animal, including, but not limited to, canine, feline, or equine.


As used herein, “treatment” is an approach for obtaining beneficial or desired clinical results. “Treatment” as used herein, covers any administration or application of a therapeutic for disease in a mammal, including a companion animal. For purposes of this disclosure, beneficial or desired clinical results include, but are not limited to, any one or more of: alleviation of one or more symptoms, diminishment of extent of disease, preventing or delaying spread of disease, preventing or delaying recurrence of disease, delay or slowing of disease progression, amelioration of the disease state, inhibiting the disease or progression of the disease, inhibiting or slowing the disease or its progression, arresting its development, and remission (whether partial or total). Also encompassed by “treatment” is a reduction of pathological consequence of a proliferative disease. The methods provided herein contemplate any one or more of these aspects of treatment. In-line with the above, the term treatment does not require one-hundred percent removal of all aspects of the disorder.


In some embodiments, a TrkA polypeptide or pharmaceutical compositions comprising it can be utilized in accordance with the methods herein to treat NGF-induced conditions. In some embodiments, a TrkA polypeptide or pharmaceutical compositions is administered to a companion animal, such as a canine, a feline, or equine, to treat a NGF-induced condition.


A “therapeutically effective amount” of a substance/molecule, agonist or antagonist may vary according to factors such as the type of disease to be treated, the disease state, the severity and course of the disease, the type of therapeutic purpose, any previous therapy, the clinical history, the response to prior treatment, the discretion of the attending veterinarian, age, sex, and weight of the animal, and the ability of the substance/molecule, agonist or antagonist to elicit a desired response in the animal. A therapeutically effective amount is also one in which any toxic or detrimental effects of the substance/molecule, agonist or antagonist are outweighed by the therapeutically beneficial effects. A therapeutically effective amount may be delivered in one or more administrations. A therapeutically effective amount refers to an amount effective, at dosages and for periods of time necessary, to achieve the desired therapeutic or prophylactic result.


In some embodiments, TrkA polypeptide or pharmaceutical composition comprising an TrkA polypeptide is administered parenterally, by subcutaneous administration, intravenous infusion, or intramuscular injection. In some embodiments, a TrkA polypeptide or pharmaceutical composition comprising a TrkA polypeptide is administered as a bolus injection or by continuous infusion over a period of time. In some embodiments, a TrkA polypeptide or pharmaceutical composition comprising a TrkA polypeptide is administered by an intramuscular, an intraperitoneal, an intracerebrospinal, a subcutaneous, an intra-arterial, an intrasynovial, an intrathecal, or an inhalation route.


An TrkA polypeptide described herein may be administered in an amount in the range of 0.1 mg/kg body weight to 100 mg/kg body weight per dose. In some embodiments, TrkA fusion may be administered in an amount in the range of 0.5 mg/kg body weight to 50 mg/kg body weight per dose. In some embodiments, TrkA fusion may be administered in an amount in the range of 1 mg/kg body weight to 10 mg/kg body weight per dose. In some embodiments, fusion molecule may be administered in an amount in the range of 0.5 mg/kg body weight to 100 mg/kg body, in the range of 1 mg/kg body weight to 100 mg/kg body weight, in the range of 5 mg/kg body weight to 100 mg/kg body weight, in the range of 10 mg/kg body weight to 100 mg/kg body weight, in the range of 20 mg/kg body weight to 100 mg/kg body weight, in the range of 50 mg/kg body weight to 100 mg/kg body weight, in the range of 1 mg/kg body weight to 10 mg/kg body weight, in the range of 5 mg/kg body weight to 10 mg/kg body weight, in the range of 0.5 mg/kg body weight to 10 mg/kg body weight, or in the range of 5 mg/kg body weight to 50 mg/kg body weight.


An TrkA polypeptide or a pharmaceutical composition comprising an TrkA polypeptide can be administered to a companion animal at one time or over a series of treatments. For example, a TrkA polypeptide or a pharmaceutical composition comprising a TrkA may be administered at least once, more than once, at least twice, at least three times, at least four times, or at least five times.


In some embodiments, the dose is administered once per week for at least two or three consecutive weeks, and in some embodiments, this cycle of treatment is repeated two or more times, optionally interspersed with one or more weeks of no treatment. In other embodiments, the therapeutically effective dose is administered once per day for two to five consecutive days, and in some embodiments, this cycle of treatment is repeated two or more times, optionally interspersed with one or more days or weeks of no treatment.


Administration “in combination with” one or more further therapeutic agents includes simultaneous (concurrent) and consecutive or sequential administration in any order. The term “concurrently” is used herein to refer to administration of two or more therapeutic agents, where at least part of the administration overlaps in time or where the administration of one therapeutic agent falls within a short period of time relative to administration of the other therapeutic agent. For example, the two or more therapeutic agents are administered with a time separation of no more than about a specified number of minutes. The term “sequentially” is used herein to refer to administration of two or more therapeutic agents where the administration of one or more agent(s) continues after discontinuing the administration of one or more other agent(s), or wherein administration of one or more agent(s) begins before the administration of one or more other agent(s). For example, administration of the two or more therapeutic agents are administered with a time separation of more than about a specified number of minutes. As used herein, “in conjunction with” refers to administration of one treatment modality in addition to another treatment modality. As such, “in conjunction with” refers to administration of one treatment modality before, during or after administration of the other treatment modality to the animal.


In some embodiments, the method comprises administering in combination with an TrkA polypeptide or a pharmaceutical composition comprising an TrkA polypeptide, a NGF kinase inhibitor, a PI3K inhibitor, a ras inhibitor, and/or a Phospholipase C pathway inhibitor. In some embodiments, the method further comprises administering one or more pain therapy drugs such as a corticosteroid, a non-steroidal anti-inflammatory drug (NSAID), a cyclooxygenase inhibitor, an opioid, and/or a cannabinoid.


Provided herein are methods of exposing to a cell a TrkA polypeptide or a pharmaceutical composition comprising a TrkA polypeptide under conditions permissive for binding to NGF. In some embodiments, the cell is exposed to a TrkA polypeptide or pharmaceutical composition ex vivo. In some embodiments, the cell is exposed to a TrkA polypeptide or pharmaceutical composition in vivo. In some embodiments, a cell is exposed to a TrkA polypeptide. In some embodiments, a cell is exposed to a TrkA polypeptide or the pharmaceutical composition under conditions permissive for binding of the fusion molecule to extracellular NGF. In some embodiments, a cell may be exposed in vivo to a TrkA polypeptide or the pharmaceutical composition by any one or more of the administration methods described herein, including but not limited to, intraperitoneal, intramuscular, intravenous injection into the subject. In some embodiments, a cell may be exposed ex vivo to a TrkA polypeptide or the pharmaceutical composition by exposing the cell to a culture medium comprising the fusion molecule or the pharmaceutical composition. In some embodiments, the permeability of the cell membrane may be affected using any number of methods understood by those of skill in the art (such as electroporating the cells or exposing the cells to a solution containing calcium chloride) before exposing the cell to a culture medium comprising the fusion molecule or the pharmaceutical composition.


In some embodiments, the exposure results in a reduction of NGF signaling function by the cell. In some embodiments, a TrkA polypeptide may reduce NGF signaling in a cell by at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or 100% compared to NGF signaling function in the absence of a TrkA polypeptide. In some embodiments, the reduction in NGF signaling or the reduction in TF-1 proliferation is between 10% and 15%, between 10% and 20%, between 10% and 25%, between 10% and 30%, between 10% and 35%, between 10% and 40%, between 10% and 45%, between 10% and 50%, between 10% and 60%, between 10% and 70%, between 10% and 80%, between 10% and 90%, between 10% and 100%, between 15% and 20%, between 15% and 25%, between 15% and 30%, between 15% and 35%, between 15% and 40%, between 15% and 45%, between 15% and 50%, between 15% and 60%, between 15% and 70%, between 15% and 80%, between 15% and 90%, between 15% and 100%, between 20% and 25%, between 20% and 30%, between 20% and 35%, between 20% and 40%, between 20% and 45%, between 20% and 50%, between 20% and 60%, between 20% and 70%, between 20% and 80%, between 20% and 90%, between 20% and 100%, between 25% and 30%, between 25% and 35%, between 25% and 40%, between 25% and 45%, between 25% and 50%, between 25% and 60%, between 25% and 70%, between 25% and 80%, between 25% and 90%, between 25% and 100%, between 30% and 35%, between 30% and 40%, between 30% and 45%, between 30% and 50%, between 30% and 60%, between 30% and 70%, between 30% and 80%, between 30% and 90%, between 30% and 100%, between 35% and 40%, between 35% and 45%, between 35% and 50%, between 35% and 60%, between 35% and 70%, between 35% and 80%, between 35% and 90%, between 35% and 100%, between 40% and 45%, between 40% and 50%, between 40% and 60%, between 40% and 70%, between 40% and 80%, between 40% and 90%, between 40% and 100%, between 45% and 50%, between 45% and 60%, between 45% and 70%, between 45% and 80%, between 45% and 90%, between 45% and 100%, between 50% and 60%, between 50% and 70%, between 50% and 80%, between 50% and 90%, between 50% and 100%, between 60% and 70%, between 60% and 80%, between 60% and 90%, between 60% and 100%, between 70% and 80%, between 70% and 90%, between 70% and 100%, between 80% and 90%, between 80% and 100%, or between 90% and 100%.


Provided herein are methods of using TrkA polypeptides and polynucleotides for detection, diagnosis and monitoring of an NGF-induced condition. Provided herein are methods of determining whether a companion animal will respond to TrkA polypeptide therapy. In some embodiments, the method comprises detecting whether the animal has cells that express NGF using a TrkA polypeptide. In some embodiments, the method of detection comprises contacting the sample with an antibody, polypeptide, or polynucleotide and determining whether the level of binding differs from that of a reference or comparison sample (such as a control). In some embodiments, the method may be useful to determine whether the TrkA polypeptides described herein are an appropriate treatment for the subject animal.


In some embodiments, the sample is a biological sample. The term “biological sample” means a quantity of a substance from a living thing or formerly living thing. In some embodiments, the biological sample is a cell or cell/tissue lysate. In some embodiments, the biological sample includes, but is not limited to, blood, (for example, whole blood), plasma, serum, urine, synovial fluid, and epithelial cells.


In some embodiments, the cells or cell/tissue lysate are contacted with a TrkA polypeptide and the binding between the TrkA polypeptide and the cell is determined. When the test cells show binding activity as compared to a reference cell of the same tissue type, it may indicate that the subject would benefit from treatment with a TrkA polypeptide. In some embodiments, the test cells are from tissue of a companion animal.


Various methods known in the art for detecting specific antibody-antigen binding can be used. Exemplary immunoassays which can be conducted include fluorescence polarization immunoassay (FPIA), fluorescence immunoassay (FIA), enzyme immunoassay (EIA), nephelometric inhibition immunoassay (NIA), enzyme linked immunosorbent assay (ELISA), and radioimmunoassay (RIA). An indicator moiety, or label group, can be attached to the subject antibodies and is selected to meet the needs of various uses of the method which are often dictated by the availability of assay equipment and compatible immunoassay procedures. Appropriate labels include, without limitation, radionuclides (for example 125I, 131I, 35S 3H, or 32P), enzymes (for example, alkaline phosphatase, horseradish peroxidase, luciferase, or p-galactosidase), fluorescent moieties or proteins (for example, fluorescein, rhodamine, phycoerythrin, GFP, or BFP), or luminescent moieties (for example, Qdot™ nanoparticles supplied by the Quantum Dot Corporation, Palo Alto, Calif.). General techniques to be used in performing the various immunoassays noted above are known to those of ordinary skill in the art.


For purposes of diagnosis, a TrkA polypeptide can be labeled with a detectable moiety including but not limited to radioisotopes, fluorescent labels, and various enzyme-substrate labels know in the art. Methods of conjugating labels to polypeptides are known in the art. In some embodiments, a TrkA polypeptide need not be labeled, and the presence thereof can be detected, for example, using an antibody that binds to a TrkA polypeptide. In some embodiments, the TRKA polypeptide can be employed in any known assay method, such as competitive binding assays, direct and indirect sandwich assays, and immunoprecipitation assays. Zola, Monoclonal Antibodies: A Manual of Techniques, pp. 147-158 (CRC Press, Inc. 1987). The anti-NGF antibodies and polypeptides can also be used for in vivo diagnostic assays, such as in vivo imaging. Generally, the antibody or the polypeptide is labeled with a radionuclide (such as 111In, 99Tc, 14C, 131I, 125I, 3H, or any other radionuclide label, including those outlined herein) so that the cells or tissue of interest can be localized using immunoscintiography. The TRKA polypeptide may also be used as staining reagent in pathology using techniques well known in the art.


In some embodiments, a TrkA polypeptide is used for a diagnostic and a TrkA polypeptide is used as a therapeutic. In some embodiments, the first and second TrkA polypeptides are different.


The following examples illustrate particular aspects of the disclosure and are not intended in any way to limit the disclosure.


EXAMPLES
Example 1
Extracellular Domains of TrkA

Extracellular domains of canine, feline, and equine TrkA that are responsible for binding canine, feline and equine NGF were identified and boundaries defined. Full-length extracellular domains (ECD v1) of canine TrkA (SEQ ID NO: 2), feline TrkA (SEQ ID NO: 7), and equine TrkA (SEQ ID NO: 12), were identified from the corresponding full-length polypeptide sequences (SEQ ID NO: 1, SEQ ID NO: 6, and SEQ ID NO: 11, respectively). Exemplary truncated extracellular domain polypeptides of (exemplary ECDs v2, v3, and v4) of canine TrkA, feline TrkA, and equine TrkA postulated to retain NGF binding were identified (e.g., SEQ ID NOs: 3, 4, and 5 (canine TrkA ECD v2, v3, and v4); SEQ ID NOs: 8, 9, and 10 (feline TrkA ECD v2, v3, and v4); and SEQ ID NOs: 13, 14, and 15 (equine TrkA ECD v2, v3, and v4).


Example 2
Design, Expression, Purification, and Stability of TrkA ECD Polypeptides from CHO Cells

To enhance in vivo half-life, NGF binding avidity, and purification, exemplary TrkA ECDs were fused to an IgG Fc polypeptide bridged with a linker. Preferably the IgG Fc polypeptide can bind Protein A.


Nucleotide sequences encoding a signal sequence, canine TrkA ECD v2 (SEQ ID NO: 3) or canine TrkA ECD v3 (SEQ ID NO: 4), a linker, and a wildtype canine IgG-B Fc polypeptide were designed, synthesized chemically, and inserted into an expression vector suitable for transfection into a CHO host cell. In addition, separate nucleotide sequences encoding (1) a signal sequence, feline TrkA ECD v2 (SEQ ID NO: 8) or feline TrkA ECD v3 (SEQ ID NO: 9), a linker, and a wildtype feline IgG-2 Fc polypeptide; and (2) a signal sequence, equine TrkA ECD v2 (SEQ ID NO: 13) or equine TrkA ECD v3 (SEQ ID NO: 14), and a variant equine IgG-2 Fc polypeptide (SEQ ID NO: 104; protein A+, C1q−, CD16−) were similarly designed, synthesized, and cloned into expression vectors. After transfection into CHO cells and culture, the fusion proteins (SEQ ID NOs: 16, 17, 19, 20, 22, and 23, respectively) were purified from the media by single step Protein A column chromatography.


Differential scanning fluorimetry was used to assess the stability of TrkA ECD v2 and TrkA ECD v3 at various pH, as reflected by mean melting point temperature (Table 6, below). In this example, the equine TrkA ECD v2 and equine TrkA ECD v3 fusion polypeptides (SEQ ID NO: 22 and SEQ ID NO: 23) prepared above were compared. Across the pH tested, equine TrkA ECD v3 (SEQ ID NO: 23) was slightly more stable than equine TrkA ECD v2 (SEQ ID NO: 22), in terms of thermostability.












TABLE 6






SEQ ID
Buffer
Melting temperature


Fusion protein
NO.
pH
Tm ° C. (Triplicate Avg.)


















Equine TrkA ECD v2 −
22
5
No curve


variant equine IgG2 Fc

6
63.7


(Protein A+, C1q−, CD16−)

7
62.5




8
61.6


Equine TrkA ECD v3 −
23
5
No curve


variant equine IgG2 Fc

6
65.6


(Protein A+, C1q−, CD16−)

7
63.7




8
63.3









Example 3
Demonstration of NGF Binding Activity

Binding activity of canine, feline, and equine TrkA ECD v2 and v3 fusion polypeptides prepared in Example 2 (SEQ ID NOs: 16, 17, 19, 20, 22, and 23) to commercially-available human NGF was considered. The binding analysis was performed using a biosensor Octet as follows. Briefly, human NGF (Sino Biological, Inc.; Catalog No. 11050-HNAC) was biotinylated. The free unreacted biotin was removed from biotinylated NGF by extensive dialysis. Biotinylated NGF was captured on streptavidin sensor tips. The association of NGF with TrkA-Fc (25 ug/mL) was monitored for 600 seconds. Dissociation was monitored for 600 seconds. A buffer only blank curve was subtracted to correct for any drift. The data were fit to a 1:1 binding model using ForteBio™ data analysis software to determine the kon, koff, and the Kd. The buffer for dilutions and all binding steps was: 20 mM phosphate, 150 mM NaCl, pH 7.2.



FIG. 1 and FIG. 2 are sensorgrams showing that canine, feline, and equine TrkA ECD v2 and v3 fusion polypeptides all bind NGF. FIG. 1 shows a sensorgram comparing the binding affinities of canine and feline TrkA v2 and v3 with NGF. Irrelevant canine and feline IgG-Fc fusion proteins were used as a negative control. FIG. 2 shows a sensorgram comparing the binding affinities of equine TrkA v2 and v3 with NGF. The Kd for all TrkA ECDs and NGF was in the 1×10−9 M range across the three species.


Example 4
Cellular Functional Activity of TrkA ECD-IgG Fc Polypeptides

TF1 cells (ATCC cat #CRL-2003), a human Erythroleukemic cell line which expresses NGF receptors on the cell surface, were used in a proliferation assay. Recombinant human NGF stimulates cell proliferation of TF-1 cells in the absence of other necessary growth factors (e.g., erythropoietin, IL3, or GM-CSF). See Kitamura, T. et al., “Establishment and characterization of a unique human cell line that proliferates dependently on GM-CSF, IL-3, or erythropoietin.” J. Cell Physiol. 140(2):323-34 (1989); rndsystems.com/products/recombinant-human-beta-ngf-protein_256-gf #product-details. Cells were grown in RPMI1640 (Gibco, Catalog No. 11875) supplemented with 10% heat-inactivated Fetal Bovine Serum (Sigma, Catalog No. 2868) and 2 nM/ml Human GM-CSF (R&D System, Catalog No. 215-GM-010). Cells at exponential growth phase were washed with PBS, resuspended in the above medium without GM-CSF, and plated in a 96-well plate. Equine TrkA ECD v2-variant equine IgG2 Fc (SEQ ID NO: 22; Protein A+, C1q−, CD16−) was added at a series of dilutions followed by addition of NGF (Sino Biological, Inc.; Catalog No. 11050-HNAC) at 10 ng/ml. An irrelevant monoclonal antibody was used as a negative control.


The cells were incubated in 37° C., 5% CO2 for 48 hours in a total volume of 100 μl. At the end of the incubation, the cells were cooled in room temperature and assayed for proliferation/viability by measuring cellular ATP content using CellTiter-Glo® Luminescent Cell Viability Assay (Promega, Catalog No. G7570). In this assay, 100 μl of premixed reagent A and B were added to each well. After shaking on an orbital shaker for approximately 2 mins, the cells were lysed. Mono-oxygenation of luciferin was catalyzed by luciferase in the presence of Mg2+ and ATP that presented in cells, resulting in the generation of a luminescent signal proportional to the amount of ATP in the cells. The amount of ATP is directly proportional to the number of cells present in culture. The plate was incubated at room temperature for 10 minutes to stabilize the luminescent signal and luminescence was detected using a Synergy HT microplate reader (Biotek, Winooski, Vt.). The data were analyzed using 4 parameter logistic fit and demonstrate that the TrkA ECD-IgG Fc polypeptide neutralized NGF activity in this TF1 cell proliferation assay. The IC50 for TrkA ECD-Fc polypeptide was 5.4 nM. See FIG. 3.


Example 5
N-Linked Glycosylation Engineering for TrkA ECD Polypeptides

To further enhance the pharmacokinetics of TrkA ECD polypeptides, additional N-linked glycosylation sites may be introduced into wildtype canine TrkA, feline TrkA and equine TrkA. For example, one, two, three, or four additional N-linked glycosylation sites may be introduced into TrkA ECD amino acid sequences at non-overlapping positions. The N-linked glycosylation site may have a consensus sequence of Asn-Xaa-Ser/Thr, where Xaa is any amino acid except proline. Addition of one or more glycosylation sites may increase the molecular size of a TrkA ECD polypeptide, provide more sialylation sites, and/or improve the half-life of the polypeptide in an animal's serum.


TrkA ECD polypeptides may be produced by mammalian cells under a condition that enhances sialylation. In addition, TrkA ECD polypeptides may be further pegylated or polysialylated through amine conjugations or to the glycans. For example, chemical polysialylation can be introduced to glycosylation sites.


Table 7 lists amino acid substitutions of canine TrkA ECD v2, v3, and v4 that may be used to generate one or more additional N-linked glycosylation sites.










TABLE 7








Amino acid substitutions for N-linked glycosylation sites










Based on canine TrkA
Based on canine TrkA


Analog
ECD v2 or v3 sequence
ECD v4 sequence


No.
(SEQ ID NOs: 3 or 4)
(SEQ ID NO: 5)












1
N6S8
N4S6


2
N6T8
N4T6


3
*X30N31S33
*X28N29S31


4
*X30N31T33
*X28N29T31


5
*X85
*X83


6
*X85T86
*X83T84


7
N85S87
N83S85


8
N85T87
N83T85


9
*X85N86S88
*X83N84S86


10
*X85N86T88
*X83N84T86


11
N88S90
N86S88


12
N88T90
N86T88


13
N90S92
N88S90


14
N90T92
N88T90


15
N92S94
N90S92


16
N92T94
N90T92


17
N94S96
N92S94


18
N94T96
N92T94





*X indicates any amino acid except proline (such as E, V, A, I, etc.).






Table 8 lists amino acid substitutions of feline TrkA ECD v2, v3, and v4 that may be used to generate one or more additional N-linked glycosylation sites.












TABLE 8










Amino acid substitutions for N-linked glycosylation sites












Based on feline TrkA
Based on feline TrkA



Analog
ECD v2 or v3 sequence
ECD v4 sequence



No.
(SEQ ID NOs: 8 or 9)
(SEQ ID NO: 10)















1
N6S8
N4S6



2
N6T8
N4T6



3
*X30N31S33
*X28N29S31



4
*X30N31T33
*X28N29T31



5
*X85
*X83



6
*X85T86
*X83T84



7
N85S87
N83S85



8
N85T87
N83T85



9
*X85N86S88
*X83N84S86



10
*X85N86T88
*X83N84T86



11
N88S90
N86S88



12
N88T90
N86T88



13
N90
N88



14
N90T92
N88T90



15
N92S94
N90S92



16
N92T94
N90T92



17
N94S96
N92S94



18
N94T96
N92T94







*X indicates any amino acid except proline (such as E, V, A, I, etc.).






Table 9 lists amino acid substitutions of equine TrkA ECD v2, v3, and v4 that may be used to generate one or more additional N-linked glycosylation sites.












TABLE 9










Amino acid substitutions for N-linked glycosylation sites












Based on equine TrkA
Based on equine TrkA



Analog
ECD v2 or v3 sequence
ECD v4 sequence



No.
(SEQ ID NOs: 13 or 14)
(SEQ ID NOs: 15)















1
N6S8
N4S6



2
N6T8
N4T6



3
*X30N31S33
*X28N29S31



4
*X30N31T33
*X28N29T31



5
*X85S86
*X83S84



6
*X85T86
*X83T84



7
N85S87
N83S85



8
N85T87
N83T85



9
*X85N86S88
*X83N84S86



10
*X85N86T88
*X83N84T86



11
N88
N86



12
N88T90
N86T88



13
N90
N88



14
N90T92
N88T90



15
N92S94
N90S92



16
N92T94
N90T92



17
N94S96
N92S94



18
N94T96
N92T94







*X indicates any amino acid except proline (such as E, V, A, I, etc.).






Example 6
TrkA ECD Intramolecular Disulfides

To increase stability of TrkA ECD polypeptides, suitable positions for additional intramolecular disulfide binding were identified by three-dimensional protein modeling and analysis. Additional disulfide binding may prevent TrkA ECD polypeptides from unfolding and enhance protease resistance leading to enhanced product shelf-life stability and enhanced in vivo pharmacokinetics. For example, a cysteine residue may be incorporated into canine, feline, or equine TrkA ECD v2 or v3 at amino acid positions 7 and 89 of SEQ ID NOs: 3, 4, 8, 9, 13, or 14 (V7C and A89C (for canine or feline sequences) or D89C (for equine sequences)). A cysteine residue may also be incorporated into canine, feline, or equine TrkA ECD v4 at amino acid positions 5 and 87 of SEQ ID NOs: 5, 10, or 15 (V5C and A87C (for canine or feline sequence) or D87C (for equine sequence)). Exemplary TrkA ECD polypeptides having an additional disulfide pair include SEQ ID NOs: 25, 26, 27 28, 29, 30, 31, 32, and 33.


Example 7
Exemplary Contiguous Polypeptides Comprising TrkA ECD and IgG Fc

Contiguous polypeptides comprising a canine, feline, or equine TrkA ECD v1, v2, v3, or v4 polypeptide (e.g., SEQ ID NOs: 2, 3, 4, 5, 7, 8, 9, 10, 12, 13, 14, 15, 25, 26, 27, 28, 29, 30, 31, 32, or 33) and a wild-type IgG Fc polypeptide or a variant IgG Fc polypeptide of the corresponding companion animal may be designed, expressed, and purified for characterization. A TrkA ECD linked to an IgG Fc polypeptide having Protein A binding, reduced or no measurable binding to C1q (e.g., to reduce CDC function), and/or reduced or no measurable binding to CD16 (e.g., to reduce ADCC function) is preferred for administering to a companion animal having NGF-induced pain. Exemplary wild-type canine, feline, and equine IgG Fc polypeptides comprise amino acid sequences of SEQ ID NOs: 33-39, 70-77, or 86-90. Exemplary variant canine, feline, and equine IgG Fc polypeptides comprise amino acid sequences of such as those described in Examples 8 to 11 (e.g., SEQ ID NOs: 40-69, 78-85, or 91-109).


Contiguous polypeptides comprising at least one TrkA ECD polypeptide (e.g., ECD v1, v2, v3, and/or v4) and a wild-type or variant canine, feline, or equine IgG Fc polypeptide described herein may be prepared based on the following formulas:





TrkA ECD 1-L1-Fc;  Formula (I):





Fc-L1-TrkA ECD 1;  Formula (II):





TrkA ECD 1-L1-Fc-L2-TrkA ECD 2;  Formula (III):





TrkA ECD 1-L1-TrkA ECD 2-L2-Fc;  Formula (IV): or





Fc-L1-TrkA ECD 1-L2-TrkA ECD 2,  Formula (V):


wherein TrkA ECD 1 is a first TrkA ECD polypeptide, TrkA ECD 2 is a second TrkA ECD polypeptide (e.g., the same TrkA ECD polypeptide or a different TrkA ECD polypeptide); L1 and L2 are optional linkers; and Fc is a wild type or variant IgG Fc polypeptide of a companion animal species. Optionally, the contiguous polypeptide comprises a signal sequence. The exemplary constructs of Formulas I-V may comprise a third, fourth, or fifth, etc. TrkA ECD following or before any TrkA ECD 1 or TrkA ECD 2. A third, fourth, or fifth, etc. TrkA ECD may be the same TrkA ECD polypeptide or a different TrkA ECD polypeptide as TrkA ECD 1 or TrkA ECD 2.


For example, a contiguous polypeptide may comprise at least one canine TrkA ECD polypeptide (e.g., SEQ ID NO: 2, 3, 4, 5, 25, 26, or 27) and a wild-type canine IgG polypeptide (e.g., SEQ ID NO: 34, 35, 36, 37, 38, or 39), a variant canine IgG-A Fc polypeptide (e.g., SEQ ID NO: 40, 43, 199, or 200), a variant canine IgG-B Fc polypeptide (e.g., SEQ ID NO: 46, 48, 49, 50, 51, 52, 53, 54, 55, 64, 65, 66, 67, 197, 198, 203, 204, 205, 206, 207, 208, 209, or 210), a variant canine IgG-C Fc polypeptide (e.g., SEQ ID NO: 41, 44, 47, 56, 57, 58, 59, 60, 61, 52, 63, 68, or 69), or a variant canine IgG-D Fc polypeptide (e.g., SEQ ID NO: 42, 45, 201, or 202), as described herein.


A contiguous polypeptide may comprise at least one feline TrkA ECD polypeptide (e.g., SEQ ID NO: 7, 8, 9, 10, 28, 29, or 30) and a wild-type feline IgG Fc polypeptide (e.g., 86, 87, 88, 89, or 90), a variant feline IgG1a Fc polypeptide (e.g., SEQ ID NO: 91, 92, 96, or 97), a variant feline IgG1b Fc polypeptide (e.g., SEQ ID NO: 93, 94, 98, or 99), or a variant feline IgG2 Fc polypeptide (e.g., SEQ ID NO: 95, 100, or 107), as described herein.


A contiguous polypeptides may comprise at least one equine TrkA ECD polypeptide (e.g., SEQ ID NO: 12, 13, 14, 15, 31, 32, or 33) and a wild-type equine IgG Fc polypeptide (e.g., SEQ ID NO: 70, 71, 72, 73, 74, 75, 76, or 77), a variant equine IgG1Fc polypeptide (e.g., SEQ ID NO: 82), a variant equine IgG2 Fc polypeptide (e.g., SEQ ID NO: 78, 79, 101, 102, 103, 104, 105, 106, 108, or 109), a variant equine IgG3 Fc polypeptide (e.g., SEQ ID NO: 83), a variant equine IgG4 Fc polypeptide (e.g., SEQ ID NO: 84), a variant equine IgG5 Fc polypeptide (e.g., SEQ ID NO: 80), a variant equine IgG6 Fc polypeptide (e.g., SEQ ID NO: 81), or a variant equine IgG7 Fc polypeptide (e.g., SEQ ID NO: 85).


The linker may be a flexible, non-structural linker, such as a glycine- and/or serine-rich linker. A flexible extension may be added to the C-terminus of a contiguous polypeptide. The extension may comprise one, two, three, four, five, six, seven, eight, or more glycine residue(s).


A contiguous polypeptide comprising a TrkA ECD may further comprise at least one ECD of an NGFR polypeptide, such as SEQ ID NO: 135, SEQ ID NO: 137, or SEQ ID NO: 139.


Contiguous polypeptides comprising an Fc IgG polypeptide having Protein A binding may be affinity purified using a Protein A column (CaptivA® Protein A Affinity Resin, Repligen). A contiguous polypeptide may also be isolated via other chromatographic methods, such as ion exchange column chromatography, hydrophobic interaction column chromatography, mixed mode column chromatography such as CHT, or multimodal mode column chromatography such as CaptoMMC. Low pH or other viral inactivation and viral removal steps can be applied. The purified protein may be admixed with excipients, and sterilized by filtration to prepare a pharmaceutical composition of the invention.


Dimerization, aggregation, and/or the presence of sulfide linkage of resultant proteins may be assessed by HPLC gel filtration and/or SDS-PAGE analysis in the absence and presence of reducing agent (DTT).


Example 8
Variant Canine IgG Fc Polypeptides for Increased Protein a Binding and/or Decreased Complement Binding and/or Decreased CD16 Binding

Purification of antibodies using Protein A affinity is a well-developed process. However, among four subtypes of canine IgG, only IgG-B Fc (e.g., SEQ ID NO: 35 or SEQ ID NO: 36) has Protein A binding affinity. Canine IgG-A Fc (e.g., SEQ ID NO: 34), IgG-C Fc (e.g., SEQ ID NO: 37 or SEQ ID NO: 38), and IgG-D Fc (e.g., SEQ ID NO: 39) have weak or no measurable Protein A binding affinity. Variant canine IgG-A Fc, IgG-C Fc, and IgG-D Fc polypeptides were designed for altered Protein A binding.


In addition, canine IgG-B Fc and IgG-C Fc have complement activity and bind to C1q, while canine IgG-A Fc and IgG-D Fc have weak or no measurable binding affinity to C1q. To potentially reduce the C1q binding and/or potentially reduce complement-mediated immune responses, variant canine IgG-B Fc and IgG-C Fc polypeptides were designed.


Furthermore, canine IgG-B Fc and IgG-C Fc have CD16 binding activity. To potentially reduce the binding of CD16 to IgG-B Fc and IgG-C Fc, and/or potentially reduce ADCC, variant canine IgG-B Fc and IgG-C Fc polypeptides were designed.


Table 10, below summarizes the Protein A, C1q, and CD16 binding characteristics of canine IgG Fc subtypes. Notably, none of the wild-type canine IgG Fc subtypes binds Protein A and lacks C1q binding and/or CD16 binding.














TABLE 10







Wild-type Canine
Protein A
C1q
CD16



IgG Fc
Binding
Binding
Binding









IgG-A Fc






IgG-B Fc
+
+
+



IgG-C Fc

+
+



IgG-D Fc










(−) denotes low or no measurable binding activity.






Using three-dimensional protein modeling and protein sequence analysis, the sequences of canine IgG-B Fc that are likely in contact with Protein A were identified. Two approaches were used to design variant canine IgG-A, IgG-C, and IgG-D Fc polypeptides for increased Protein A binding. For the first approach, variant canine IgG-A, IgG-C, and IgG-D Fc polypeptides were designed to have the same Protein A binding motif sequences as canine IgG-B Fc (e.g., SEQ ID NO: 40, SEQ ID NO: 41, and SEQ ID NO: 42, respectively). For the second approach, variant canine IgG-A Fc I(21)T/Q(207)H (SEQ ID NO: 43), variant canine IgG-C Fc I(21)T (SEQ ID NO: 44), and variant canine IgG-D Fc I(21)T/Q(207)H (SEQ ID NO: 45) were designed with one or two amino acid substitutions in the Protein A binding region to correspond with the canine IgG-B Fc sequence.


In addition, variant canine IgG-A Fc, IgG-C Fc, and IgG-D Fc polypeptides with increased Protein A binding may be prepared having one or more of the amino acid substitutions listed in Table 11.









TABLE 11







Variant Canine IgG Fc Amino Acid Substitutions* (Protein A +)











Canine IgG-A Fc
Canine IgG-C Fc
Canine IgG-D Fc



(SEQ ID NO: 34)
(SEQ ID NO: 37)
(SEQ ID NO: 39)







Ile (21) Thr
Ile (21) Thr
Ile (21) Thr



Arg (23) Leu
Val (23) Leu
Arg (23) Leu



Thr (25) Ala
Thr (24) Ile
Thr (25) Ala



Glu (80) Gly

Glu (80) Gly



Thr (205) Ala

Gln (207) His



Gln (207) His







*The amino acid positions listed are relative to the SEQ ID NO. indicated.






To potentially reduce the binding of C1q to canine IgG-B Fc and IgG-C Fc, and/or potentially reduce complement-mediated immune responses, variant canine IgG-B Fc and IgG-C Fc polypeptides may be prepared having an amino acid substitution of Lys with any amino acid except Lys at an amino acid position corresponding to position 93 of SEQ ID NO: 35 or of SEQ ID NO: 37, respectively. These amino acid substitutions were identified after analysis of the protein sequence and 3-D structure modeling of canine IgG-B Fc and IgG-C Fc compared to canine IgG-A Fc and IgG-D Fc, which are understood to not exhibit complement activity. For example, variant canine IgG-B Fc K(93)R (SEQ ID NO: 46) and variant canine IgG-C Fc K(93)R (SEQ ID NO: 47) may be prepared. Reduced binding between human C1q and a fusion protein comprising variant canine IgG-B Fc K(93)R was observed when compared to a fusion protein comprising wild-type canine IgG-B Fc.


To potentially reduce the binding of CD16 to IgG-B Fc and IgG-C Fc, and/or potentially reduce ADCC, variant canine IgG-B Fc and IgG-C Fc polypeptides may be prepared having one or more of the amino acid substitutions listed in Table 12 (e.g., SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 50, SEQ ID NO: 51, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54, SEQ ID NO: 55, SEQ ID NO: 56, SEQ ID NO: 57, SEQ ID NO: 58, SEQ ID NO: 59, SEQ ID NO: 60, SEQ ID NO: 61, and/or SEQ ID NO: 62). The amino acid substitution(s) were identified after analysis of the protein sequence and 3-D structure modeling of canine IgG-B and IgG-C compared to IgG-A and IgG-D, which are understood to not exhibit ADCC activity.










TABLE 12







Original residue position*










Canine IgG-B Fc
Canine IgG-C Fc



(SEQ ID NO: 35)
(SEQ ID NO: 37)
Substitution(s)





Met (5)
Leu (5)
Any amino acid except original




residue, such as Pro


Asp (38)
Asp (38)
Any amino acid except original




residue, such as Gly


Pro (39)
Pro (39)
Any amino acid except original




residue, such as Arg


Lys (97)
Lys (97)
Any amino acid except original




residue, such as Ile


Ala (98)
Ala (98)
Any amino acid except original




residue, such as Gly





*The amino acid positions listed are relative to the SEQ ID NO. indicated.






Since wild-type canine IgG-C Fc lacks Protein A binding and has C1q binding, a double variant canine IgG-C Fc that binds Protein A and has reduced binding to C1q may be prepared by combining one or more of the amino acid substitutions listed in Table 11 with a K(93)R substitution or K(93)X substitution, wherein X is any amino acid except Lys (e.g., SEQ ID NO: 63). A double variant canine IgG-B Fc or double variant canine IgG-C Fc with reduced binding to C1q and reduced binding to CD16 may be prepared by combining one or more of the amino acid substitutions listed in Table 12 with a K(93)R substitution or K(93)X substitution, wherein X is any amino acid except Lys (e.g., SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68, and/or SEQ ID NO: 69). A triple variant canine-IgG-C Fc that binds Protein A and has reduced binding to C1q and CD16 may be prepared by combining one or more of the amino acid substitutions listed in Table 11 and one or more of the amino acid substitutions listed in Table 12 with a K(93)R substitution or K(93)X substitution, wherein X is any amino acid except Lys.


The binding of any variant canine IgG Fc to Protein A, CD16, and/or C1q may be determined and compared to the binding of another IgG Fc to Protein A, CD16, and/or C1q (e.g., the corresponding wild-type canine IgG Fc, another wild-type or variant canine IgG Fc, or a wild-type or variant IgG Fc of another companion animal, etc.).


Binding analysis may be performed using an Octet biosensor. Briefly, the target molecule (e.g., Protein A, C1q, CD16, etc.) may be biotinylated and free unreacted biotin removed (e.g., by dialysis). The biotinylated target molecule is captured on streptavidin sensor tips. Association of the target molecule with various concentrations (e.g., 10 μg/mL) of IgG Fc polypeptide is monitored for a specified time or until steady state is reached. Dissociation is monitored for a specified time or until steady state is reached. A buffer only blank curve may be subtracted to correct for any drift. The data are fit to a 1:1 binding model using ForteBio′ data analysis software to determine the kon, koff, and the Kd.


Example 9
Variant Equine IgG Fc Polypeptides for Increased Protein a Binding and/or Decreased Complement Binding

Of the seven subtypes of equine IgG, IgG1 Fc (e.g., SEQ ID NO: 70), IgG3 Fc (e.g., SEQ ID NO: 73), IgG4 Fc (e.g., SEQ ID NO: 74), IgG7 Fc (e.g., SEQ ID NO: 77) have Protein A binding affinity. Equine IgG2 Fc (e.g., SEQ ID NO: 71 or SEQ ID NO: 72), IgG5 Fc (e.g., SEQ ID NO: 75), and IgG6 Fc (e.g., SEQ ID NO: 76) have weak or no measurable Protein A binding affinity. Variant equine IgG2 Fc, IgG5 Fc, and IgG6 Fc polypeptides were designed for altered Protein A binding.


In addition, equine IgG2 Fc, IgG5 Fc, and IgG6 Fc have weak or no measurable binding affinity to C1q, while equine IgG1 Fc, IgG3 Fc, IgG4 Fc, and IgG7 Fc bind to C1q. To potentially reduce the C1q binding and/or potentially reduce complement-mediated immune responses, variant equine IgG1 Fc, IgG3 Fc, IgG4 Fc, and IgG7 Fc polypeptides were designed.


Table 13, below summarizes the Protein A and C1q binding characteristics of equine IgG Fc subtypes. Notably, none of the wild-type equine IgG Fc subtypes lacks C1q binding and binds Protein A.











TABLE 13





Wild-type Equine
Protein A
C1q


IgG Fc
Binding
Binding







IgG1 Fc
+
+


IgG2 Fc




IgG3 Fc
+
+


IgG4 Fc
+
+


IgG5 Fc




IgG6 Fc




IgG7 Fc
+
+





(−) denotes low or no measurable binding activity.






Using three-dimensional protein modeling and protein sequence analysis, the sequences of equine IgG1 Fc, IgG3 Fc, IgG4 Fc, and IgG7 Fc that are likely in contact with Protein A were identified. Variant equine IgG2 Fc, IgG5 Fc, and IgG6 Fc polypeptides with increased Protein A binding may be prepared having one or more of the amino acid substitutions listed in Table 14.









TABLE 14







Variant Equine IgG Fc Amino Acid Substitutions* (Protein A +)











Equine IgG2 Fc
Equine IgG5 Fc
Equine Ig6 Fc



(SEQ ID NO: 71)
(SEQ ID NO: 75)
(SEQ ID NO: 76)







Ala (15) Thr
Val (199) Leu
Ile (199) Leu



Phe (203) Tyr
Glu (200) Tyr
Arg (200) His





His (201) Asn





Thr (202) His







*The amino acid positions listed are relative to the SEQ ID NO. indicated






For example, variant equine IgG2 Fc, IgG5 Fc, and IgG6 Fc polypeptides were designed with one or multiple amino acid substitutions in the Protein A binding region to correspond with the amino acid sequence of wild-type equine IgG Fcs that bind Protein A. Variant equine IgG2 Fc F(203)Y (SEQ ID NO: 78); variant equine IgG2 Fc A(15)T/F(203)Y (SEQ ID NO: 79); variant equine IgG5 Fc V(199)L/E(200)Y (SEQ ID NO: 80); and variant equine IgG6 Fc I(199)L/R(200)H/H(201)N/T(202)H (SEQ ID NO: 81) with increased Protein A binding may be prepared.


To potentially reduce the binding of C1q to equine IgG1 Fc, IgG3 Fc, IgG4 Fc, and IgG7 Fc, and/or potentially reduce complement-mediated immune responses, variant canine IgG1 Fc, IgG3 Fc, IgG4 Fc, and IgG7 Fc polypeptides may be prepared having an amino acid substitution of Lys with any amino acid except Lys at an amino acid position corresponding to position 87 of SEQ ID NO: 70, of SEQ ID NO: 73, of SEQ ID NO: 74, of SEQ ID NO: 77, respectively. These amino acid substitutions were identified after analysis of the protein sequence and 3-D structure modeling of equine IgG1 Fc, IgG3 Fc, IgG4 Fc, and IgG7 Fc compared to equine IgG2 Fc, IgG5 Fc, and IgG6 Fc, which are understood to not exhibit complement activity. For example, variant equine IgG1 Fc K(87)S (SEQ ID NO: 82), variant equine IgG3 Fc K(87)S (SEQ ID NO: 83), variant equine IgG4 Fc K(87)S (SEQ ID NO: 84), and variant equine IgG7 Fc K(87)S (SEQ ID NO: 85) may be prepared.


The binding of any variant equine IgG Fc to Protein A and/or C1q may be determined and compared to the binding of another IgG Fc to Protein A and/or C1q (e.g., the corresponding wild-type equine IgG Fc, another wild-type or variant equine IgG Fc, or a wild-type or variant IgG Fc of another companion animal, etc.). The binding assay described in Example 8 may be used.


Example 10
Variant Feline IgG Fc Polypeptides for Decreased Complement Binding

Each of the three subtypes of feline IgG, IgG1a Fc (SEQ ID NO: 86 or SEQ ID NO: 87), IgG1b Fc (SEQ ID NO: 88 or SEQ ID NO: 89), and IgG2 Fc (SEQ ID NO: 90) have Protein A binding affinity. However, only feline IgG2 Fc has weak or no measurable binding affinity to C1q, while feline IgG1a Fc, IgG1b Fc bind to C1q. To potentially reduce the C1q binding and/or potentially reduce complement-mediated immune responses, variant feline IgG1a Fc and IgG1b Fc polypeptides were designed.


Table 15, below summarizes the Protein A and C1q binding characteristics of feline IgG Fc subtypes. Notably, none of the wild-type equine IgG Fc subtypes lacks C1q binding and binds Protein A.











TABLE 15





Wild-type
Protein A
C1q


Feline IgG Fc
Binding
Binding







IgG1a Fc
+
+


IgG1b Fc
+
+


IgG2 Fc
+






(−) denotes low or no measurable binding activity.






To potentially reduce the binding of C1q to feline IgG1a Fc and IgG1b Fc, and/or potentially reduce complement-mediated immune responses, variant feline IgG1a Fc and IgG1b Fc polypeptides may be prepared having an amino acid substitution of Pro with any amino acid except Pro at an amino acid position corresponding to position 198 of SEQ ID NO: 86, of SEQ ID NO: 87, of SEQ ID NO: 88, or of SEQ ID NO: 89. These amino acid substitutions were identified after analysis of the protein sequence and 3-D structure modeling of feline IgG1a Fc and IgG1b Fc compared to feline IgG2 Fc, which is understood to not exhibit complement activity. For example, variant feline IgG1a Fc P(198)A (e.g., SEQ ID NO: 91 or SEQ ID NO: 92) and variant feline IgG1b Fc P(198)A (e.g., SEQ ID NO: 93 or SEQ ID NO: 94) may be prepared.


The binding of any variant feline IgG Fc to C1q may be determined and compared to the binding of another IgG Fc to C1q (e.g., the corresponding wild-type feline IgG Fc, another wild-type or variant feline IgG Fc, or a wild-type or variant IgG Fc of another companion animal, etc.). The binding assay described in Example 8 may be used.


Example 11
Variant IgG Fc Polypeptides for Increased and/or Enhanced Disulfide Formation

Three-dimensional protein modeling analysis of several ortholog hinge structures was used to determine the approximate locations for modifying the feline IgG2 hinge to increase disulfide formation. To increase disulfide formation at the feline IgG2 hinge, the hinge sequence may be modified by substituting an amino acid with cysteine. For example, a variant feline IgG2 Fc (SEQ ID NO: 95) having a modified hinge may be prepared by substituting glycine with cysteine at an amino acid position corresponding to position 14 of SEQ ID NO: 90. Other variant feline IgG2 Fc polypeptides having a modified hinge comprising a cysteine at an amino acid position corresponding to position 8, position 9, position 10, position 11, position 12, position 13, position 15, or position 16 of SEQ ID NO: 90 may be prepared.


Additional three-dimensional protein modeling analysis of several ortholog hinge structures was used to modify feline and equine IgG hinges to enhance disulfide formation. To enhance disulfide formation at the feline IgG hinge, the hinge sequence may be modified by substituting lysine with proline at a position corresponding to position 16 of a wildtype or variant feline IgG1a (e.g., SEQ ID NO: 86 or SEQ ID NO: 87), of feline IgG1b (e.g., SEQ ID NO: 88 or SEQ ID NO: 89), or of feline IgG2 (e.g., SEQ ID NO: 90) (e.g., K16P). Examples of amino acid sequences of variant feline IgG polypeptides having a modified hinge include SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99, and SEQ ID NO: 100.


To enhance disulfide formation at the equine IgG hinge, the hinge sequence may be modified by substituting cysteine with serine at a position corresponding to position 3 of a wildtype or variant equine IgG with a hinge (e.g., IgG2 Fc (SEQ ID NO: 72)) and/or substituting glutamine with proline at a position corresponding to position 20 of an equine IgG with a hinge (e.g., IgG2 Fc (SEQ ID NO: 72) (e.g., C3S and/or Q20P). Examples of amino acid sequences of variant equine IgG polypeptides having a modified hinge include SEQ ID NO: 101, SEQ ID NO: 102, SEQ ID NO: 103, SEQ ID NO: 104, SEQ ID NO: 105, and SEQ ID NO: 106.


The amino acid substitutions described above may be incorporated into the hinge of a wildtype or variant Fc polypeptide described herein.


Three-dimensional protein modeling was used to design feline and equine variant IgG Fc polypeptides comprising sequences from the hinge region from a different IgG isotype for enhanced recombinant production and improved hinge disulfide formation. Variant feline IgG2 Fc polypeptides may be prepared that comprise sequences from the hinge region of feline IgG1a or IgG1b (e.g., SEQ ID NO: 107). In addition, variant equine IgG2 Fc polypeptides may be prepared that comprise sequences from the hinge region of equine IgG1 (e.g., SEQ ID NO: 108 and SEQ ID NO: 109).


Levels of recombinant production of variant IgG Fc polypeptides and/or levels of hinge disulfide formation may be determined and compared to that of another IgG Fc by SDS-PAGE analysis under reducing and non-reducing conditions (e.g., the corresponding wild-type IgG Fc of the same or different isotype, or a wild-type or variant IgG Fc of another companion animal, etc.).


Example 12
TrkA-Fc Buffer Formulations

Thermostability of canine TrkA-Fc in various buffer formulations was analyzed. Buffers containing 20 mM sodium phosphate (pH 6.2, 6.6, 7.2, and 7.6), 20 mM sodium citrate (pH 4.4, 5.2, 5.8, and 6.4), 20 mM Histidine (pH 5.5, 6.0, and 6.5), and 20 mM sodium acetate (pH 5.2) were considered. Sodium chloride at a final concentration of 40 mM or 140 mM was used in all buffers. The melting temperatures (Tm 1 and Tm 2) of an exemplary canine TrkA-Fc polypeptide (SEQ ID NO: 126) at a concentration of 6 μg/μL in each buffer were measured in duplicate by differential scanning fluorescence technique from 20° C. to 95° C. Table 16 lists the average Tm values of canine TrkA in the various buffers tested.











TABLE 16







Formulation

Melting Temperatures










Designation
Buffer Formulation
Tm 1 (° C.)
Tm 2 (° C.)













 1A
20 mM sodium phosphate
59.64
69.70



40 mM sodium chloride





pH 6.2




 1B
20 mM sodium phosphate
60.24
67.92



140 mM sodium chloride





pH 6.2




 2A
20 mM sodium phosphate
58.83
69.80



40 mM sodium chloride





pH 6.6




 2B
20 mM sodium phosphate
59.06
69.30



140 mM sodium chloride





pH 6.6




 3A
20 mM sodium phosphate
57.44
70.06



40 mM sodium chloride





pH 7.2




 3B
20 mM sodium phosphate
57.86
68.83



140 mM sodium chloride





pH 7.2




 4A
20 mM sodium phosphate
57.73
70.16



40 mM sodium chloride





pH 7.6




 4B
20 mM sodium phosphate
58.14
68.75



140 mM sodium chloride





pH 7.6




 5A
20 mM sodium citrate
58.73
68.22*



40 mM sodium chloride





pH 4.4




 5B
20 mM sodium citrate
56.95
67.90*



140 mM sodium chloride





pH 4.4




 6A
20 mM sodium citrate
61.20
73.46*



40 mM sodium chloride





pH 5.2




 6B
20 mM sodium citrate
60.70
72.77



140 mM sodium chloride





pH 5.2




 7A
20 mM sodium citrate
59.09
68.97



40 mM sodium chloride





pH 5.8




 7B
20 mM sodium citrate
61.33
68.10



140 mM sodium chloride





pH 5.8




 8A
20 mM sodium citrate
59.37
69.80



40 mM sodium chloride





pH 6.4




 8B
20 mM sodium citrate
60.15
68.75



140 mM sodium chloride





pH 6.4




 9A
20 mM Histidine
61.47
73.34*



40 mM sodium chloride





pH 5.5




 9B
20 mM Histidine
60.79
73.95



140 mM sodium chloride





pH 5.5




10A
20 mM Histidine
60.47
67.97



40 mM sodium chloride





pH 6.0




10B
20 mM Histidine
59.97
68.75



140 mM sodium chloride





pH 6.0




11A
20 mM Histidine
59.82
69.43



40 mM sodium chloride





pH 6.5




11B
20 mM Histidine
59.69
68.65



140 mM sodium chloride





pH 6.5




12A
20 mM sodium acetate
61.20
74.37



40 mM sodium chloride





pH 5.2




12B
20 mM sodium acetate
60.34
73.69



140 mM sodium chloride





pH 5.2





*result from one sample






Formulations 6A, 7B, 9A, and 12B, which contain a lower concentration sodium citrate, histidine, or sodium acetate buffer and a pH of between 5 and 6, may be more desirable for TrkA ECD fusion polypeptides.


Formulations 6A, 7B, 9A, 12B, and PBS (pH 7.2) were used to investigate stability of an exemplary canine TrkA-Fc polypeptide (SEQ ID NO: 126) sample stored under stress at 45° C. for 3 days. The aggregation state of the five samples was evaluated by HPLC gel filtration analysis and no appreciable aggregations were identified. The five samples were then stored for an additional day at 55° C. Noticeable aggregation was observed in the sample stored in PBS (pH 7.2), but not among the samples stored in formulations 6A, 7B, 9A, and 12B.


Example 13
In Vivo Reduction in NGF with TrkA-Fc Polypeptides

NGF levels are elevated in the synovial fluid of human patients suffering from various types of chronic arthritis. See Aloe L, et al., “Nerve growth factor in the synovial fluid of patients with chronic arthritis,” Arthritis Rheum. 1992, 35(3):351-5. The effect of canine TrkA-Fc polypeptides on NGF levels was tested in a rat MIA-induced osteoarthritis model.


The study protocol was reviewed and approved (Approval No: B-070) by the Institutional Animal Ethics Committee (IAEC). Male Sprague Dawley rats were anesthetized with isoflurane and given a single intra-articular injection of 3 mg Monosodium Iodoacetate (Sigma, Cat #12512, St. Louis, Mo.) through the infrapatellar ligament of the right knee (osteoarthritic). MIA was dissolved in physiological saline and administered in a volume of 50 μl using a 30 gauge, 0.5 inch needle. See Combe R, et al., “The monosodium iodoacetate model of osteoarthritis: a model of chronic nociceptive pain in rats?” Neurosci Lett. 2004, 370(2-3):236-40. Control rats were injected with an equivalent volume of saline and allowed to recover. After recovery from the procedure, the animals were returned to cages in groups of three, with 12 h light/dark cycle and food and water ad libitum.


Once-weekly administration of canine TrkA-Fc polypeptide (1 mg/kg (group 3) and 10 mg/kg (group 4)) on days 8, 15, and 22 post-MIA injection was performed. On day 28, synovial NGF levels were measured. The treatment groups are summarized in Table 17, below.













TABLE 17










Dose















Number

Volume
Route of


Group
Treatment
of Rats
mg/kg
(mL/kg)
Administration















1
Saline
8
NA

i.p.


2
MIA + Vehicle
10
NA
0.5
i.p.


3
MIA + Canine TrkA-Fc
10
1
0.5
i.p.


4
MIA + Canine TrkA-Fc
10
10
0.5
i.p.









Knee joint samples from 3-4 rats from each treatment group was collected after completion of behavioral and knee joint diameter measurements. The trimmed samples of soft tissue inside the knee, (synovial membrane and anterior to the lateral capsule of the ipsilateral knees), was collected and minced into small pieces about 2 mm in size, well-rinsed in PBS, and frozen in liquid nitrogen until use. The tissue samples were crushed into powder and homogenized in a 200-μl lysis reagent (CelLytic™ MT Cell Lysis Reagent (C3228), Sigma-Aldrich) with protease inhibitor (cOmplete™, EDTA-free Protease Inhibitor Cocktail, Cat. No. 4693132001, Sigma-Aldrich). The samples were centrifuged at 14,000 rpm for 10 min at 4° C., and then the supernatants were collected for the assay. The concentration of the NGF was measured using ELISA kits (Millipore, Temecula, Calif.). The total protein concentration in all samples was measured using the BCA protein assay kit (Cat. No. BCA1-1KT, Sigma, USA).



FIG. 4 shows the concentration of NGF in synovial membrane of each of the four animal groups. The MIA-induced animal groups (groups 3 and 4) that received canine TrkA-Fc polypeptide showed a dose-dependent decrease in NGF concentration in synovial membrane compared to the untreated MIA-induced control group (group 2). For reasons still under investigation, in this experiment, the treated animals did not evidence a corresponding decrease in pain as would have been expected based on published studies involving treatment of pain in animals using NGF antibodies and TrkA-IgG fusion molecules. See Ro L S, et al., “Effect of NGF and anti-NGF on neuropathic pain in rats following chronic constriction injury of the sciatic nerve.” Pain. 1999, 79(2-3):265-74; Gearing D, et al., “A fully caninised anti-NGF monoclonal antibody for pain relief in dogs.” BMC Vet Res. 2013, 9:226 doi: 10.1186/1746-6148-9-226; Gearing D, et al., “In vitro and in vivo characterization of a fully felinized therapeutic anti-nerve growth factor monoclonal antibody for the treatment of pain in cats.” J Vet Intern Med. 2016, 30(4):1129-37; McMahon S B, et al., “The biological effects of endogenous nerve growth factor on adult sensory neurons revealed by a trkA-IgG fusion molecule.” Nat Med. 1995, 1(8):774-80.


Example 14
Screening Variant Canine IgG-B Polypeptides with Enhanced Canine FcRn/B2M Binding

Canine FcRn with a poly-His tag (SEQ ID NO: 195) and canine B2M (SEQ ID NO: 196) heterodimer complex was transiently expressed in HEK cells and purified using Ni-NTA chromatography.


Fast Screening for Expression, Biophysical Properties and Affinity (FASEBA) of canine IgG-B Fc phage libraries was performed. Briefly, the open reading frame of canine IgG-B Fc polypeptide was subcloned into plasmid pFASEBA. Based on three-dimensional protein modeling of the canine IgG-B/canine FcRn/canine B2M complex, twelve amino acid positions of canine IgG-B were identified as being potentially involved in the binding between IgG-B and FcRn/B2M. The twelve positions of canine IgG-B identified were Thr(21), Leu(22), Leu(23), Ile(24), Ala(25), Thr (27), Gly (80), His (81), Gln (82), Leu (85), Met (201), and Asn (207) of SEQ ID NO: 35 or SEQ ID NO: 36.


Twelve single site NNK mutation libraries of canine IgG-B Fc were prepared such that each library should have included variant IgG-B Fc polypeptides having each of the 20 possible amino acids substituted at each of the twelve sites. Each phage library was panned against canine FcRn/B2M complex at pH 6.0. After three rounds of panning, a total of 53 Fc phage clones were identified as potentially having enhanced FcRn/B2M binding and the mutations were identified by sequencing.


Single E. coli colonies expressing each of the 53 variant canine IgG-B Fc polypeptides with an SASA tag were cultured and induced to express the Fc polypeptides. Cell culture media containing the variant canine IgG-B Fc polypeptides was exposed to immobilized BSA either on a plate or a Biacore chip. The plates or chips with bound variant canine IgG-B Fc polypeptides were exposed to soluble canine FcRn/B2M complex to screen for slow off rate (koff) at pH 6. Each variant IgG-B Fc polypeptide exhibiting a slower koff with canine FcRn/B2M complex compared to wildtype IgG-B Fc polypeptide was identified. Four lead variant canine IgG-B polypeptides were identified: L(23)Y (SEQ ID NO: 198; “Y00”); L(23)F (SEQ ID NO: 197; “F00”); L(23)M; and L(23)S.


The koff of each of the lead variant canine IgG-B polypeptides was further investigated. Biotinylated canine FcRn/B2M complex was immobilized on a Biacore chip and exposed to each variant canine IgG-B polypeptide as an analyte using a Biacore T200 at pH 6.0. The koff (1/s) for wild-type canine IgG-B Fc polypeptide was 1.22×10−1; the koff (1/s) for variant canine IgG-B Fc polypeptide L(23)Y (“Y00”) was 1.38×10−2; the koff (1/s) for variant IgG-B Fc polypeptide L(23)F (“F00”) was 6.31×10−2 and 8.47×10−2; the koff (1/s) for variant canine IgG-B polypeptide L(23)M was 1.26×10−1; and the koff (1/s) for variant canine IgG-B polypeptide L(23)S was 2.41×10−1.


Binding analysis was performed using a Biacore T200. Briefly, the lead variant canine IgG-B Fc polypeptides with an SASA tag were each immobilized to a Series S Sensor Chip CM5. Association of each variant IgG-B Fc polypeptide with various concentrations of canine FcRn/B2M complex (12.5, 25, 50, 100, and 200 nM) was monitored at 25° C. until steady state was reached. A running buffer of 10 mM HEPES, 500 mM NaCl, 3 mM EDTA, 0.005% Tween-20, pH 6.0 was used. A buffer only blank curve was used as a control. The results are presented in FIGS. 5-9. The steady state Kd for wild-type canine IgG-B Fc polypeptide was 1.25×10−6 (FIG. 5); the steady state Kd for variant canine IgG-B Fc polypeptide L(23)Y (“Y00”) was 1.13×10−7 (FIG. 6); the steady state Kd for variant canine IgG-B Fc polypeptide L(23)F (“F00”) was 3.67×10−7 (FIG. 7); and the steady state Kd for variant canine IgG-B Fc polypeptide L(23)M was 4.06×10−7 (FIG. 8); and the steady state Kd for variant canine IgG-B Fc polypeptide YTE was 8.62×10−8 (FIG. 9).


Example 15
Phe Mutation in Canine IgG Enhances Canine FcRn Interaction

The affinity of variant canine Fc polypeptides for FcRn was evaluated in the context of a chimeric antibody. Antibody variable light chains fused to canine kappa light chain and variable heavy chains fused to variant canine IgG-A Fc polypeptides comprising SEQ ID NO: 199 (F00; Protein A+; C1q−; CD16−) or SEQ ID NO: 200 (Protein A+; C1q+; CD16+) and to variant canine IgG-D Fc polypeptides comprising SEQ ID NO: 201 (F00; Protein A+; C1q−; CD16−), or SEQ ID NO: 202 (Protein A+; C1q+; CD16+) were expressed.


The binding analysis was performed using a biosensor OctetRed as follows. Briefly, biotinylated TNFα was captured on streptavidin sensor tips. The association of antibody at 20 μg/mL was bound to TNFα. The complex was then used to bind to canine FcRn (50 μg/mL) at pH 6.0. Dissociation was performed at pH 7.2.


The Phe mutation enhanced canine FcRn binding at low pH (pH6.0, 20 mM NaCitrate, 140 mM NaCl), as illustrated by the binding profiles of chimeric variant canine IgG-A “F00” antibody (FIG. 10, A) and IgG-D “F00” antibody (FIG. 10, B) compared to chimeric variant canine IgG-A without the Phe mutation (FIG. 10, C) and IgG-D without the Phe mutation (FIG. 10, D). The chimeric variant canine IgG-A and IgG-D antibodies with the Phe mutation (FIG. 10, A and B) exhibited enhanced association with canine FcRn at low pH (pH 6.0) and fast dissociation at neutral pH (PBS pH7.2). A similar enhanced binding profile was also observed with chimeric variant canine IgG-B “F00” antibody.


Example 16
Pharmacokinetics of Phe Mutation in Canine IgG

Pharmacokinetics analysis was performed using Sprague Dawley rats. The rats were subcutaneously administered with 2 mg/kg of chimeric variant canine IgG-A “F00” antibody and chimeric variant canine IgG-A without the Phe mutation (two rats per group). Serum samples were collected from the rats at pre-injection and at 0.5, 1, 6, 24, 48, 72, 168, 216, and 336 hours post injection. The canine chimeric antibody concentrations in the serum samples were determined by ELISA, as follows.


Capture antibody (1 μg/mL in PBS) was coated on a 96-well Maxisorp plate with 100 μl in each well. The plate was incubated overnight at 4° C. and washed five times with PBST (PBS containing 0.05% Tween-20). Each well was blocked with 200 μl 5% BSA in PBST and the plate incubated for 1 hour at room temperature. The plate was washed five times with PBST. Dilutions of control antibody (1,000 ng/mL to 0.1 ng/mL) were added to the plate in duplicate and along with a blank well containing no control antibody were used to generate a standard curve. The serum samples were prepared by 10-fold, 20-fold, and 40-fold dilutions in 5% BSA-PBST and added to the plate. The plate was incubated at room temperature for 1 hour and washed 5 times with PBST. 100 μl HRP-conjugated antibody (Bio-Rad, catalog no. HCA204P) was added to each well at 0.25 μg/mL in 5% BSA-PBST. The plate was incubated for 1 hour at room temperature and washed 5 times with PBST. 100 μl QuantaBlu (Thermo Scientific, catalog no. 15169) was added to each well. The fluorescence was measured after 10-15 minutes incubation at 325 nm/420 nm (emission/excitation). The titer of anti-TNFα in the serum samples was calculated against the standard curve.


The AUC0-336h for IgG-A was 150970, while IgG-A “F00” was 848924 ng/mL*hr (FIG. 11). The terminal half-life was estimated to be 33 hours and 152 hours, respectively. Thus, the single Phe mutation significantly improved the pharmacokinetic profile of the antibody in rat.


Example 17
Phe Mutation in Canine, Feline, and Equine IgG Fcs

The interaction between the Phe mutation in canine IgG-A, IgG-B, IgG-C, and IgG-D Fc and FcRn was modeled using three-dimensional protein structure analysis. The aromatic side chain of Phe appears to have a hydrophobic interaction with canine FcRn at the Pro hydrophobic ring (it-CH) of the “WPE” motif. In addition, the Phe hydrophobic side chain may be in direct contact with the Glu side chain next to the Pro of the same “WPE” motif. This interaction may have energy penalty if the Glu side chain is deprotonated to be negative charged, such as at a neutral pH. Thus, some level of protonation of the Glu residue may be required to minimize the aromatics to Glu-H interaction. That may explain why the interaction between variant IgGs having the Phe mutation and FcRn is reduced at neutral pH. Based on protein structure analysis, the interaction appears to be conserved among canine IgG-A, IgG-B, IgG-C, and IgG-D Fc.


Furthermore, the interactions between a Phe mutation in feline IgG1a and IgG2 Fc were modeled when complexed with feline FcRn. The same interactions observed with the canine IgG Fcs appeared to be conserved with the feline IgG Fcs.


The interactions between a Phe mutation in equine IgG1, IgG2, IgG3, IgG4, IgG5, IgG6, and IgG7 Fc in complex with equine FcRn were also modeled. The same interactions appeared to be maintained with the equine IgG Fcs.


Example 18
Other Exemplary Variant Canine IgG Fcs Enhance Canine FcRn Interaction

The affinity of additional variant canine Fc polypeptides for FcRn was evaluated in the context of a chimeric antibody. Antibody variable light chain fused to canine kappa light chain and variable heavy chain sequences fused to wild-type IgG-B Fc polypeptide (comprising SEQ ID NO: 35), variant canine IgG-B Fc polypeptide 0Y0 (comprising SEQ ID NO: 203), variant canine IgG-B Fc polypeptide 0YH (comprising SEQ ID NO: 204), variant canine IgG-B Fc polypeptide 0YY (comprising SEQ ID NO: 205), and variant canine IgG-B Fc polypeptide 00Y (comprising SEQ ID NO: 206) were expressed.


The binding analysis was performed using a biosensor OctetRed as follows. Briefly, biotinylated target was captured on streptavidin sensor tips. The association of antibody at 20 μg/mL was bound to the biotinylated target. The complex was then used to bind to canine FcRn (50 m/mL) at pH 6.0. Dissociation was performed at pH 7.2.


Each of the chimeric variant canine IgG-B antibodies exhibited enhanced binding to canine FcRn at pH 6.0 compared to the chimeric wild-type canine IgG-B antibody and each had an appreciable rate of dissociation at neutral pH (FIG. 12).


Example 19
Variant Canine IgG Fcs Extend Half-Life of Antibodies In Vivo in Canine

In vivo half-life of variant canine Fc polypeptides for FcRn was evaluated in the context of a chimeric antibody. Antibody variable light chain fused to canine kappa light chain and variable heavy chains fused to wild-type IgG-B Fc polypeptide (comprising SEQ ID NO: 35), variant canine IgG-B Fc polypeptide YTE (comprising SEQ ID NO: 207), variant canine IgG-B Fc polypeptide 0Y0 (comprising SEQ ID NO: 203), variant canine IgG-B Fc polypeptide F00 (comprising SEQ ID NO: 197), variant canine IgG-B Fc polypeptide 0YH (comprising SEQ ID NO: 204), and variant canine IgG-B Fc polypeptide Y00 (comprising SEQ ID NO: 198) were expressed and purified to 40 mg/mL in PBS, pH7.2.


Canine pharmacokinetics were performed at Absorption Systems California, LLC. Male beagles (˜8-14 kg) were obtained from Marshall Bioresources, North Rose, N.Y. A total of 12 dogs were used for study with n=2 dogs per group. The six antibodies were subcutaneously administered to the dogs at 4 mg/Kg. Serum samples were collected at pre-injection and at 6, 24, 48, 72, 96, 120, 144, 168, 216, 264, 336, 504 and 672 hours post-injection. The canine chimeric antibody concentrations were determined by ELISA as described. The Cp between time at 144 hour and 336 hour was transformed to Ln [Cp], then fit to linear equation in the form of Ln[Cp]t=−k*t+Ln[Cp]144h. The terminal half-life was then calculated from slope k, as listed in Table 18, below. The 0Y0, F00, 0YH, and Y00 mutations in canine IgG-B Fc greatly improved the half-life of the antibody in vivo in dogs.









TABLE 18







Effect of variant canine IgG Fcs on antibody half-life in dog










Dog
Half-life (days)







WT 1
13



WT 2
13



YTE 1
*NR



YTE 2
15



0Y0 1
*NR



0Y0 2
28



F00 1
*NR



F00 2
23



0YH 1
22



0YH 2
23



Y00 1
33



Y00 2
39







*NR: result was not reliable





Claims
  • 1. A contiguous polypeptide comprising at least one extracellular domain of a TrkA polypeptide (TrkA ECD polypeptide) from a companion animal species and a fusion partner.
  • 2. The contiguous polypeptide of claim 1, wherein the contiguous polypeptide binds to an NGF polypeptide with a dissociation constant (Kd) of less than 5×10−6 M, less than 1×10−6 M, less than 5×10−7 M, less than 1×10−7 M, less than 5×10−8M, less than 1×10−8M, less than 5×10−9M, less than 1×10−9M, less than 5×10−10 M, less than 1×10−10 M, less than 5×10−11 M, less than 1×10−11M, less than 5×10−12 M, or less than 1×10−12 M, as measured by biolayer interferometry.
  • 3. The contiguous polypeptide of claim 2, wherein the NGF polypeptide is a human NGF polypeptide, a canine NGF polypeptide, a feline NGF polypeptide, or an equine polypeptide.
  • 4. The contiguous polypeptide of any one of the preceding claims, wherein the contiguous polypeptide reduces NGF signaling in the companion animal species.
  • 5. The contiguous polypeptide of any one of the preceding claims, wherein the companion animal species is canine, feline, or equine.
  • 6. The contiguous polypeptide of any one of the preceding claims, wherein the amino acid sequence of the TrkA ECD polypeptide is at least 90% identical, at least 91% identical, at least 92% identical, at least 93% identical, at least 94% identical, at least 95% identical, at least 96% identical, at least 97% identical, at least 98% identical, or at least 99% identical to the amino acid sequence of SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, or SEQ ID NO: 15.
  • 7. The contiguous polypeptide of any one of the preceding claims, wherein the TrkA ECD polypeptide comprises: a) a cysteine at a position corresponding to position 7 and position 89 of SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 12, SEQ ID NO: 13, or SEQ ID NO: 14; orb) a cysteine at a position corresponding to position 5 and position 87 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15.
  • 8. The contiguous polypeptide of any one of the preceding claims, wherein the TrkA ECD polypeptide comprises: a) a cysteine at position 7 and position 89 of SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 12, SEQ ID NO: 13, or SEQ ID NO: 14; orb) a cysteine at position 5 and position 87 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15.
  • 9. The contiguous polypeptide of any one of the preceding claims, wherein the TrkA ECD polypeptide comprises at least one N-linked glycosylation site not present in the corresponding wild-type TrkA ECD polypeptide, wherein the N-linked glycosylation site comprises the sequence asparagine-xaa-serine or asparagine-xaa-threonine, wherein xaa is any amino acid except proline, and wherein one N-linked glycosylation site does not overlap with another N-linked glycosylation site.
  • 10. The contiguous polypeptide of any one of the preceding claims, wherein the TrkA ECD comprises at least one N-linked glycosylation site at one or more position(s) selected from: a) amino acid positions 6-8, 31-33, 84-86, 85-87, 86-88, 88-90, 90-92, 92-94, and/or 94-96 of SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 13, or SEQ ID NO: 14; orb) amino acid positions 4-6, 29-31, 82-84, 83-85, 84-86, 86-88, 89-90, 90-92, and/or 92-94 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15.
  • 11. The contiguous polypeptide of any one of the preceding claims, wherein the TrkA ECD polypeptide comprises: a) an amino acid other than proline at an amino acid position corresponding to position 30 and/or position 85 of SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 13, or SEQ ID NO: 14; and/orb) an amino acid other than proline at an amino acid position corresponding to position 28 or position 83 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15.
  • 12. The contiguous polypeptide of any one of the preceding claims, wherein the TrkA ECD polypeptide comprises: a) a valine, a glutamic acid, an alanine, or an isoleucine at an amino acid position corresponding to position 30 and/or position 85 of SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 13, or SEQ ID NO: 14; and/orb) a valine, a glutamic acid, an alanine, or an isoleucine at an amino acid position corresponding to position 28 or position 83 of SEQ ID NO: 5, SEQ ID NO: 10, or SEQ ID NO: 15.
  • 13. The contiguous polypeptide of any one of the preceding claims, wherein the TrkA ECD polypeptide comprises one or more amino acid modifications listed in Table A:
  • 14. The contiguous polypeptide of any one of the preceding claims, wherein the TrkA ECD polypeptide comprises an amino acid sequence selected from SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 7, SEQ ID NO: 8, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 25, SEQ ID NO: 26, SEQ ID NO: 27, SEQ ID NO: 28, SEQ ID NO: 29, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32, and SEQ ID NO: 33.
  • 15. The contiguous polypeptide of any one of the preceding claims, wherein the contiguous polypeptide comprises a linker.
  • 16. The contiguous polypeptide of claim 15, wherein the linker comprises an amino acid sequence selected from G, GG, GGG, S, SS, SSS, GS, GSGS (SEQ ID NO: 143), GSGSGS (SEQ ID NO: 144), GGS, GGSGGS (SEQ ID NO: 145), GGSGGSGGS (SEQ ID NO: 146), GGGS (SEQ ID NO: 147), GGGSGGGS (SEQ ID NO: 148), GGGSGGGSGGGS (SEQ ID NO: 149), GSS, GSSGSS (SEQ ID NO: 150), GSSGSSGSS (SEQ ID NO: 151), GGSS (SEQ ID NO: 152), GGSSGGSS (SEQ ID NO: 153), GGSSGGSSGGS (SEQ ID NO: 154), SGGSGGS (SEQ ID NO: 155), and SGGGSGGGS (SEQ ID NO: 156).
  • 17. The contiguous polypeptide of any one of the preceding claims, wherein the fusion partner is selected from an Fc polypeptide, albumin, and an albumin binding fragment.
  • 18. The contiguous polypeptide of any one of preceding claims, wherein the fusion partner is a Fc polypeptide comprising (a) a wild-type or a variant canine IgG-A, IgG-B, IgG-C, or IgG-D polypeptide; (b) a wild-type or a variant feline IgG1a, IgG1b, or IgG2 polypeptide; or (c) a wild-type or a variant equine IgG1, IgG2, IgG3, IgG4, IgG5, IgG6, or IgG7 polypeptide.
  • 19. The contiguous polypeptide of any one of the preceding claims comprising: TrkA ECD 1-L1-Fc;  formula (I):Fc-L1-TrkA ECD 1;  formula (II):TrkA ECD 1-L1-Fc-L2-TrkA ECD 2;  formula (III):TrkA ECD 1-L1-TrkA ECD 2-L2-Fc;  formula (IV): orFc-L1-TrkA ECD 1-L2-TrkA ECD 2,  formula (V):
  • 20. The contiguous polypeptide of claim 19, wherein TrkA ECD 1 and TrkA ECD 2 are the same polypeptide.
  • 21. The contiguous polypeptide of claim 19, wherein TrkA ECD 1 and TrkA ECD 2 are different polypeptides.
  • 22. The contiguous polypeptide of any one of the preceding claims, wherein the fusion partner or Fc is a variant Fc polypeptide comprising: a) at least one amino acid modification relative to a wild-type IgG Fc polypeptide of a companion animal species, wherein the variant IgG Fc polypeptide has increased binding affinity to Protein A relative to the wild-type IgG Fc polypeptide;b) at least one amino acid modification relative to a wild-type IgG Fc polypeptide of a companion animal species, wherein the variant IgG Fc polypeptide has reduced binding affinity to C1q relative to the wild-type IgG Fc polypeptide;c) at least one amino acid modification relative to a wild-type IgG Fc polypeptide of a companion animal species, wherein the variant IgG Fc polypeptide has reduced binding affinity to CD16 relative to the wild-type IgG Fc polypeptide;d) a hinge region comprising at least one amino acid modification to relative to a wild-type feline or equine IgG Fc polypeptide;e) at least one amino acid substitution relative to a wild-type feline IgG Fc polypeptide, wherein the at least one amino acid substitution is a cysteine, and wherein the variant IgG Fc polypeptide is capable of forming at least one additional inter-chain disulfide linkage relative to the wild-type feline IgG Fc polypeptide;f) at least one amino acid substitution relative to a wild-type IgG Fc polypeptide derived from a companion animal species, wherein the variant Fc polypeptide is capable of binding to neonatal Fc receptor (FcRn) with an increased affinity relative to the wild-type Fc polypeptide.
  • 23. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide that binds to C1q and/or CD16 with a dissociation constant (Kd) of greater than 5×10−6 M, greater than 1×10−5M, greater than 5×10−5M, greater than 1×10−4 M, greater than 5×10−4 M, or greater than 1×10−3M, as measured by biolayer interferometry.
  • 24. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide binds to Protein A with a dissociation constant (Kd) of less than 5×10−6 M, less than 1×10−6 M, less than 5×10−7 M, less than 1×10−7 M, less than 5×10−8M, less than 1×10−8 M, less than 5×10−9M, less than 1×10−9 M, less than 5×10−10 M, less than 1×10−10 M, less than 5×10−11 M, less than 1×10−11M, less than 5×10−12 M, or less than 1×10−12M, as measured by biolayer interferometry.
  • 25. The contiguous polypeptide of any one of the preceding claims, comprising a variant IgG Fc polypeptide that binds to FcRn with an affinity greater than the wild-type IgG Fc polypeptide, as measured by biolayer interferometry, surface plasmon resonance, or any protein-protein interaction tool at a pH in the range of from about 5.0 to about 6.5, such as at a pH of about 5.0, a pH of about 5.2, a pH of about 5.5, a pH of about 6.0, a pH of about 6.2, or a pH of about 6.5.
  • 26. The contiguous polypeptide of any one of the preceding claims, comprising a variant IgG Fc polypeptide that binds to FcRn with a dissociation constant (Kd) of less than 5×10−6 M, less than 1×10−6 M, less than 5×10−7 M, less than 1×10−7 M, less than 5×10−8M, less than 1×10−8 M, less than 5×10−9M, less than 1×10−9 M, less than 5×10−10 M, less than 1×10−10 M, less than 5×10−11 M, less than 1×10−11M, less than 5×10−12 M, or less than 1×10−12M, as measured by biolayer interferometry, surface plasmon resonance, or any protein-protein interaction tool at a pH in the range of from about 5.0 to about 6.5, such as at a pH of about 5.0, a pH of about 5.5, a pH of about 6.0, or a pH of about 6.5.
  • 27. The contiguous polypeptide of any one of the preceding claims, comprising a variant IgG Fc polypeptide that binds to FcRn with an increased affinity relative to the wild-type Fc polypeptide and wherein the contiguous polypeptide has increased serum half-life relative to a contiguous polypeptide comprising a wild-type Fc polypeptide.
  • 28. The contiguous polypeptide of any one of the preceding claims, wherein the wild-type IgG Fc polypeptide is: a) a canine IgG-A Fc, IgG-B Fc, IgG-C Fc, or IgG-D Fc;b) an equine IgG1 Fc, IgG2 Fc, IgG3 Fc, IgG4 Fc, IgG5 Fc, IgG6 Fc, or IgG7 Fc; orc) a feline IgG1a Fc, IgG1b Fc, or IgG2 Fc.
  • 29. The contiguous polypeptide of any one of the preceding claims, wherein the wild-type IgG Fc polypeptide comprises the amino acid sequence of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 36, SEQ ID NO: 37, SEQ ID NO: 38, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 72, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, or SEQ ID NO: 90.
  • 30. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising: a) at least one amino acid substitution relative to a wild-type feline IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 16 of SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, or SEQ ID NO: 90;b) at least one amino acid substitution relative to a wild-type equine IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 3 of SEQ ID NO: 72; and/orc) at least one amino acid substitution relative to a wild-type equine IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises an amino acid substitution at a position corresponding to position 20 of SEQ ID NO: 72.
  • 31. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising: a) at least one amino acid substitution relative to a wild-type feline IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises an amino acid substitution at position 16 of SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, or SEQ ID NO: 90;b) at least one amino acid substitution relative to a wild-type equine IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises an amino acid substitution at position 3 of SEQ ID NO: 72; and/orc) at least one amino acid substitution relative to a wild-type equine IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises an amino acid substitution at position 20 of SEQ ID NO: 72.
  • 32. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising: a) at least one amino acid substitution relative to a wild-type feline IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises a proline at a position corresponding to position 16 or at position 16 of SEQ ID NO: SEQ ID NO: 86, SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, or SEQ ID NO: 90;b) at least one amino acid substitution relative to a wild-type equine IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises a serine at a position corresponding to position 3 or at position 3 of SEQ ID NO: 72; and/orc) at least one amino acid substitution relative to a wild-type equine IgG Fc polypeptide, wherein the variant IgG Fc polypeptide comprises a proline at a position corresponding to position 20 or at position 20 of SEQ ID NO: 72.
  • 33. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising a hinge region or a portion of a hinge region from an IgG Fc polypeptide of a different isotype.
  • 34. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising a hinge region or a portion of a hinge region from a wild-type feline IgG-1 Fc polypeptide or from a wild-type equine IgG1 Fc polypeptide.
  • 35. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising a cysteine at a position corresponding to position 8, position 9, position 10, position 11, position 12, position 13, position 14, position 15, or position 16 of SEQ ID NO: 90.
  • 36. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising a cysteine at a position corresponding to position 14 of SEQ ID NO: 90.
  • 37. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising a cysteine at position 14 of SEQ ID NO: 90.
  • 38. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising: a) an amino acid substitution at a position corresponding to position 21 of SEQ ID NO: 34, an amino acid substitution at a position corresponding to position 23 of SEQ ID NO: 34, an amino acid substitution at a position corresponding to position 25 of SEQ ID NO: 34, an amino acid substitution at a position corresponding to position 80 of SEQ ID NO: 34, an amino acid substitution at a position corresponding to position 205 of SEQ ID NO: 34, and/or an amino acid substitution at a position corresponding to position 207 of SEQ ID NO: 34;b) an amino acid substitution at a position corresponding to position 21 of SEQ ID NO: 37, an amino acid substitution at a position corresponding to position 23 of SEQ ID NO: 37, and/or an amino acid substitution at a position corresponding to position 24 of SEQ ID NO: 37;c) an amino acid substitution at a position corresponding to position 21 of SEQ ID NO: 39, an amino acid substitution at a position corresponding to position 23 of SEQ ID NO: 39, an amino acid substitution at a position corresponding to position 25 of SEQ ID NO: 39, an amino acid substitution at a position corresponding to position 80 of SEQ ID NO: 39, and/or an amino acid substitution at a position corresponding to position 207 of SEQ ID NO: 39;d) an amino acid substitution at a position corresponding to position 15 of SEQ ID NO: 71, and/or an amino acid substitution at a position corresponding to position 203 of SEQ ID NO: 71;e) an amino acid substitution at a position corresponding to position 199 of SEQ ID NO: 75, and/or an amino acid substitution at a position corresponding to position 200 of SEQ ID NO: 75; and/orf) an amino acid substitution at a position corresponding to position 199 of SEQ ID NO: 76, an amino acid substitution at a position corresponding to position 200 of SEQ ID NO: 76, an amino acid substitution at a position corresponding to position 201 of SEQ ID NO: 76, and/or an amino acid substitution at a position corresponding to position 202 of SEQ ID NO: 76.
  • 39. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising: a) an amino acid substitution at position 21 of SEQ ID NO: 34, an amino acid substitution at position 23 of SEQ ID NO: 34, an amino acid substitution at position 25 of SEQ ID NO: 34, an amino acid substitution at position 80 of SEQ ID NO: 34, an amino acid substitution at position 205 of SEQ ID NO: 34, and/or an amino acid substitution at position 207 of SEQ ID NO: 34;b) an amino acid substitution at position 21 of SEQ ID NO: 37, an amino acid substitution at position 23 of SEQ ID NO: 37, and/or an amino acid substitution at position 24 of SEQ ID NO: 37;c) an amino acid substitution at position 21 of SEQ ID NO: 39, an amino acid substitution at position 23 of SEQ ID NO: 39, an amino acid substitution at position 25 of SEQ ID NO: 39, an amino acid substitution at position 80 of SEQ ID NO: 39, and/or an amino acid substitution at position 207 of SEQ ID NO: 39;d) an amino acid substitution at position 15 of SEQ ID NO: 71, and/or an amino acid substitution at position 203 of SEQ ID NO: 71;e) an amino acid substitution at position 199 of SEQ ID NO: 75, and/or an amino acid substitution at position 200 of SEQ ID NO: 75; and/orf) an amino acid substitution at position 199 of SEQ ID NO: 76, an amino acid substitution at position 200 of SEQ ID NO: 76, an amino acid substitution at position 201 of SEQ ID NO: 76, and/or an amino acid substitution at position 202 of SEQ ID NO: 76.
  • 40. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising: a) a threonine at a position corresponding to position 21 of SEQ ID NO: 34, a leucine at a position corresponding to position 23 of SEQ ID NO: 34, an alanine at a position corresponding to position 25 of SEQ ID NO: 34, a glycine at a position corresponding to position 80 of SEQ ID NO: 34, an alanine at a position corresponding to position 205 of SEQ ID NO: 34, and/or a histidine at a position corresponding to position 207 of SEQ ID NO: 34;b) a threonine at a position corresponding to position 21 of SEQ ID NO: 37, a leucine at a position corresponding to position 23 of SEQ ID NO: 37, and/or an isoleucine at a position corresponding to position 24 of SEQ ID NO: 37;c) a threonine at a position corresponding to position 21 of SEQ ID NO: 39, a leucine at a position corresponding to position 23 of SEQ ID NO: 39, an alanine at a position corresponding to position 25 of SEQ ID NO: 39, a glycine at a position corresponding to position 80 of SEQ ID NO: 39, and/or a histidine at a position corresponding to position 207 of SEQ ID NO: 39;d) a threonine or a valine at a position corresponding to position 15 of SEQ ID NO: 71, and/or a tyrosine or a valine at a position corresponding to position 203 of SEQ ID NO: 71;e) a leucine at a position corresponding to position 199 of SEQ ID NO: 75, and/or a histidine at a position corresponding to position 200 of SEQ ID NO: 75; and/orf) a leucine at a position corresponding to position 199 of SEQ ID NO: 76, a histidine at a position corresponding to position 200 of SEQ ID NO: 76, an asparagine at a position corresponding to position 201 of SEQ ID NO: 76, and/or a histidine at a position corresponding to position 202 of SEQ ID NO: 76.
  • 41. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising: a) a threonine at position 21 of SEQ ID NO: 34, a leucine at position 23 of SEQ ID NO: 34, an alanine at position 25 of SEQ ID NO: 34, a glycine at position 80 of SEQ ID NO: 34, an alanine at position 205 of SEQ ID NO: 34, and/or a histidine at position 207 of SEQ ID NO: 34;b) a threonine at position 21 of SEQ ID NO: 37, a leucine at position 23 of SEQ ID NO: 37, and/or an isoleucine at position 24 of SEQ ID NO: 37;c) a threonine at a position 21 of SEQ ID NO: 39, a leucine at position 23 of SEQ ID NO: 39, an alanine at position 25 of SEQ ID NO: 39, a glycine at position 80 of SEQ ID NO: 39, and/or a histidine at position 207 of SEQ ID NO: 39;d) a threonine or a valine at position 15 of SEQ ID NO: 71, and/or a tyrosine or a valine at position 203 of SEQ ID NO: 71;e) a leucine at position 199 of SEQ ID NO: 75, and/or a histidine at position 200 of SEQ ID NO: 75; and/orf) a leucine at position 199 of SEQ ID NO: 76, a histidine at position 200 of SEQ ID NO: 76, an asparagine at position 201 of SEQ ID NO: 76, and/or a histidine at position 202 of SEQ ID NO: 76.
  • 42. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising: a) an amino acid substitution at a position corresponding to position 93 of SEQ ID NO: 35, or an amino acid substitution at a position corresponding to position 93 of SEQ ID NO: 37;b) an amino acid substitution at a position corresponding to position 87 of SEQ ID NO: 70, an amino acid substitution at a position corresponding to position 87 of SEQ ID NO: 73, an amino acid substitution at a position corresponding to position 87 of SEQ ID NO: 74, or an amino acid substitution at a position corresponding to position 87 of SEQ ID NO: 77; orc) an amino acid substitution at a position corresponding to position 198 of SEQ ID NO: 86, an amino acid substitution at a position corresponding to position 198 of SEQ ID NO: 87, an amino acid substitution at a position corresponding to position 198 of SEQ ID NO: 88, or an amino acid substitution at a position corresponding to position 198 of SEQ ID NO: 89.
  • 43. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising: a) an amino acid substitution at position 93 of SEQ ID NO: 35, or an amino acid substitution at position 93 of SEQ ID NO: 37;b) an amino acid substitution at position 87 of SEQ ID NO: 70, an amino acid substitution at position 87 of SEQ ID NO: 73, an amino acid substitution at position 87 of SEQ ID NO: 74, or an amino acid substitution at position 87 of SEQ ID NO: 77; orc) an amino acid substitution at position 198 of SEQ ID NO: 86, an amino acid substitution at position 198 of SEQ ID NO: 87, an amino acid substitution at position 198 of SEQ ID NO: 88, or an amino acid substitution at position 198 of SEQ ID NO: 89.
  • 44. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising: a) an arginine at a position corresponding to position 93 of SEQ ID NO: 35, or an arginine at a position corresponding to position 93 of SEQ ID NO: 37;b) a serine at a position corresponding to position 87 of SEQ ID NO: 70, a serine substitution at a position corresponding to position 87 of SEQ ID NO: 73, a serine at a position corresponding to position 87 of SEQ ID NO: 74, or a serine at a position corresponding to position 87 of SEQ ID NO: 77; orc) an alanine at a position corresponding to position 198 of SEQ ID NO: 86, an alanine at a position corresponding to position 198 of SEQ ID NO: 87, an alanine at a position corresponding to position 198 of SEQ ID NO: 88, or an alanine at a position corresponding to position 198 of SEQ ID NO: 89.
  • 45. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising: a) an arginine at position 93 of SEQ ID NO: 35, or an arginine at position 93 of SEQ ID NO: 37;b) a serine at position 87 of SEQ ID NO: 70, a serine at position 87 of SEQ ID NO: 73, a serine at position 87 of SEQ ID NO: 74, or a serine at position 87 of SEQ ID NO: 77; orc) an alanine at position 198 of SEQ ID NO: 86, an alanine at position 198 of SEQ ID NO: 87, an alanine at position 198 of SEQ ID NO: 88, or alanine at position 198 of SEQ ID NO: 89.
  • 46. The contiguous polypeptide of any one of the preceding claims, comprising a variant IgG Fc polypeptide comprising: a) a tyrosine or a phenylalanine at a position corresponding to position 23 of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;b) a tyrosine at a position corresponding to position 82 of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;c) a tyrosine at a position corresponding to position 82 and a histidine at a position corresponding to position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;d) a tyrosine at a position corresponding to position 82 and a tyrosine at a position corresponding to position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;e) a tyrosine at a position corresponding to position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;f) a tyrosine at a position corresponding to position 82 and a histidine at a position corresponding to position 208 of SEQ ID NO: 34 or SEQ ID NO: 39;g) a tyrosine at a position corresponding to position 82 and a tyrosine at a position corresponding to position 208 of SEQ ID NO: 34 or SEQ ID NO: 39; orh) a tyrosine at a position corresponding to position 208 of SEQ ID NO: 34 or SEQ ID NO: 39.
  • 47. The contiguous polypeptide of any one of the preceding claims, comprising a variant IgG Fc polypeptide comprising: a) a tyrosine or a phenylalanine at position 23 of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;b) a tyrosine at position 82 of SEQ ID NO: 34, SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 39, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;c) a tyrosine at position 82 and a histidine at position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;d) a tyrosine at position 82 and a tyrosine at position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;e) a tyrosine at position 207 of SEQ ID NO: 35, SEQ ID NO: 37, SEQ ID NO: 70, SEQ ID NO: 71, SEQ ID NO: 73, SEQ ID NO: 74, SEQ ID NO: 75, SEQ ID NO: 76, SEQ ID NO: 77, SEQ ID NO: 86, SEQ ID NO: 88, or SEQ ID NO: 90;f) a tyrosine at position 82 and a histidine at position 208 of SEQ ID NO: 34 or SEQ ID NO: 39;g) a tyrosine at position 82 and a tyrosine at position 208 of SEQ ID NO: 34 or SEQ ID NO: 39; orh) a tyrosine at position 208 of SEQ ID NO: 34 or SEQ ID NO: 39.
  • 48. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising an amino acid sequence having at least 90% identity, at least 91% identity, at least 92% identity, at least 93% identity, at least 94% identity, at least 95% identity, at least 96% identity, at least 97% identity, at least 98% identity, or at least 99% identity to the amino acid sequence of SEQ ID NO: 40, SEQ ID NO: 41, SEQ ID NO: 42, SEQ ID NO: 43, SEQ ID NO: 44, SEQ ID NO: 45, SEQ ID NO: 46, SEQ ID NO: 47, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 50, SEQ ID NO: 51, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54, SEQ ID NO: 55, SEQ ID NO: 56, SEQ ID NO: 57, SEQ ID NO: 58, SEQ ID NO: 59, SEQ ID NO: 60, SEQ ID NO: 61, SEQ ID NO: 62, SEQ ID NO: 63, SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68, SEQ ID NO: 69, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99, SEQ ID NO: 100, SEQ ID NO: 101, SEQ ID NO: 102, SEQ ID NO: 103, SEQ ID NO: 104, SEQ ID NO: 105, SEQ ID NO: 106, SEQ ID NO: 107, SEQ ID NO: 108, SEQ ID NO: 109, SEQ ID NO: 197, SEQ ID NO: 198, SEQ ID NO: 199, SEQ ID NO: 200, SEQ ID NO: 201, SEQ ID NO: 202, SEQ ID NO: 203, SEQ ID NO: 204, SEQ ID NO: 205, SEQ ID NO: 206, SEQ ID NO: 207, SEQ ID NO: 208, SEQ ID NO: 209, and/or SEQ ID NO: 210.
  • 49. The contiguous polypeptide of any one the preceding claims, comprising a variant IgG Fc polypeptide comprising an amino acid sequence of SEQ ID NO: 40, SEQ ID NO: 41, SEQ ID NO: 42, SEQ ID NO: 43, SEQ ID NO: 44, SEQ ID NO: 45, SEQ ID NO: 46, SEQ ID NO: 47, SEQ ID NO: 48, SEQ ID NO: 49, SEQ ID NO: 50, SEQ ID NO: 51, SEQ ID NO: 52, SEQ ID NO: 53, SEQ ID NO: 54, SEQ ID NO: 55, SEQ ID NO: 56, SEQ ID NO: 57, SEQ ID NO: 58, SEQ ID NO: 59, SEQ ID NO: 60, SEQ ID NO: 61, SEQ ID NO: 62, SEQ ID NO: 63, SEQ ID NO: 64, SEQ ID NO: 65, SEQ ID NO: 66, SEQ ID NO: 67, SEQ ID NO: 68, SEQ ID NO: 69, SEQ ID NO: 78, SEQ ID NO: 79, SEQ ID NO: 80, SEQ ID NO: 81, SEQ ID NO: 82, SEQ ID NO: 83, SEQ ID NO: 84, SEQ ID NO: 85, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID NO: 99, SEQ ID NO: 100, SEQ ID NO: 101, SEQ ID NO: 102, SEQ ID NO: 103, SEQ ID NO: 104, SEQ ID NO: 105, SEQ ID NO: 106, SEQ ID NO: 107, SEQ ID NO: 108, SEQ ID NO: 109, SEQ ID NO: 197, SEQ ID NO: 198, SEQ ID NO: 199, SEQ ID NO: 200, SEQ ID NO: 201, SEQ ID NO: 202, SEQ ID NO: 203, SEQ ID NO: 204, SEQ ID NO: 205, SEQ ID NO: 206, SEQ ID NO: 207, SEQ ID NO: 208, SEQ ID NO: 209, and/or SEQ ID NO: 210.
  • 50. The contiguous polypeptide of any one of the preceding claims further comprising at least one extracellular domain of an NGFR polypeptide (NGFR ECD polypeptide).
  • 51. The contiguous polypeptide of any one of the preceding claims further comprising at least one NGFR ECD polypeptide comprising the amino acid sequence of SEQ ID NO: 135, SEQ ID NO: 137, and/or SEQ ID NO: 139.
  • 52. The contiguous polypeptide of any one of the preceding claims comprising the amino acid sequence of SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21, SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO: 110, SEQ ID NO: 111, SEQ ID NO: 112, SEQ ID NO: 113, SEQ ID NO: 114, SEQ ID NO: 115, SEQ ID NO: 116, SEQ ID NO: 117, SEQ ID NO: 118, SEQ ID NO: 119, SEQ ID NO: 120, SEQ ID NO: 121, SEQ ID NO: 122, SEQ ID NO: 123, SEQ ID NO: 124, SEQ ID NO: 125, SEQ ID NO: 126, SEQ ID NO: 127, SEQ ID NO: 128, SEQ ID NO: 129, SEQ ID NO: 130, SEQ ID NO: 131, SEQ ID NO: 132, SEQ ID NO: 133, SEQ ID NO: 140, SEQ ID NO: 141, SEQ ID NO: 142, SEQ ID NO: 159, SEQ ID NO: 160, SEQ ID NO: 161, SEQ ID NO: 162, SEQ ID NO: 163, SEQ ID NO: 164, SEQ ID NO: 165, SEQ ID NO: 166, SEQ ID NO: 167, SEQ ID NO: 168, SEQ ID NO: 169, SEQ ID NO: 170, SEQ ID NO: 171, SEQ ID NO: 172, SEQ ID NO: 173, SEQ ID NO: 174, SEQ ID NO: 175, SEQ ID NO: 176, SEQ ID NO: 177, SEQ ID NO: 178, SEQ ID NO: 179, SEQ ID NO: 180, SEQ ID NO: 181, SEQ ID NO: 182, SEQ ID NO: 183, SEQ ID NO: 184, SEQ ID NO: 185, SEQ ID NO: 186, SEQ ID NO: 187, SEQ ID NO: 188, SEQ ID NO: 189, SEQ ID NO: 190, SEQ ID NO: 191, SEQ ID NO: 192, SEQ ID NO: 193, SEQ ID NO: 194, SEQ ID NO: 211, SEQ ID NO: 212, SEQ ID NO: 213, SEQ ID NO: 214, SEQ ID NO: 215, SEQ ID NO: 216, SEQ ID NO: 217, SEQ ID NO: 218, SEQ ID NO: 219, SEQ ID NO: 220, SEQ ID NO: 221, SEQ ID NO: 222, SEQ ID NO: 223, SEQ ID NO: 224, SEQ ID NO: 225, SEQ ID NO: 226, SEQ ID NO: 227, SEQ ID NO: 228, SEQ ID NO: 229, SEQ ID NO: 230, SEQ ID NO: 231, SEQ ID NO: 232, SEQ ID NO: 233, SEQ ID NO: 234, SEQ ID NO: 235, SEQ ID NO: 236, SEQ ID NO: 237, SEQ ID NO: 238, SEQ ID NO: 239, SEQ ID NO: 240, SEQ ID NO: 241, SEQ ID NO: 242, SEQ ID NO: 243, SEQ ID NO: 244, SEQ ID NO: 245, or SEQ ID NO: 246.
  • 53. A contiguous polypeptide comprising the amino acid sequence of SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21, SEQ ID NO: 22, SEQ ID NO: 23, SEQ ID NO: 24, SEQ ID NO: 110, SEQ ID NO: 111, SEQ ID NO: 112, SEQ ID NO: 113, SEQ ID NO: 114, SEQ ID NO: 115, SEQ ID NO: 116, SEQ ID NO: 117, SEQ ID NO: 118, SEQ ID NO: 119, SEQ ID NO: 120, SEQ ID NO: 121, SEQ ID NO: 122, SEQ ID NO: 123, SEQ ID NO: 124, SEQ ID NO: 125, SEQ ID NO: 126, SEQ ID NO: 127, SEQ ID NO: 128, SEQ ID NO: 129, SEQ ID NO: 130, SEQ ID NO: 131, SEQ ID NO: 132, SEQ ID NO: 133, SEQ ID NO: 140, SEQ ID NO: 141, SEQ ID NO: 142, SEQ ID NO: 159, SEQ ID NO: 160, SEQ ID NO: 161, SEQ ID NO: 162, SEQ ID NO: 163, SEQ ID NO: 164, SEQ ID NO: 165, SEQ ID NO: 166, SEQ ID NO: 167, SEQ ID NO: 168, SEQ ID NO: 169, SEQ ID NO: 170, SEQ ID NO: 171, SEQ ID NO: 172, SEQ ID NO: 173, SEQ ID NO: 174, SEQ ID NO: 175, SEQ ID NO: 176, SEQ ID NO: 177, SEQ ID NO: 178, SEQ ID NO: 179, SEQ ID NO: 180, SEQ ID NO: 181, SEQ ID NO: 182, SEQ ID NO: 183, SEQ ID NO: 184, SEQ ID NO: 185, SEQ ID NO: 186, SEQ ID NO: 187, SEQ ID NO: 188, SEQ ID NO: 189, SEQ ID NO: 190, SEQ ID NO: 191, SEQ ID NO: 192, SEQ ID NO: 193, SEQ ID NO: 194, SEQ ID NO: 211, SEQ ID NO: 212, SEQ ID NO: 213, SEQ ID NO: 214, SEQ ID NO: 215, SEQ ID NO: 216, SEQ ID NO: 217, SEQ ID NO: 218, SEQ ID NO: 219, SEQ ID NO: 220, SEQ ID NO: 221, SEQ ID NO: 222, SEQ ID NO: 223, SEQ ID NO: 224, SEQ ID NO: 225, SEQ ID NO: 226, SEQ ID NO: 227, SEQ ID NO: 228, SEQ ID NO: 229, SEQ ID NO: 230, SEQ ID NO: 231, SEQ ID NO: 232, SEQ ID NO: 233, SEQ ID NO: 234, SEQ ID NO: 235, SEQ ID NO: 236, SEQ ID NO: 237, SEQ ID NO: 238, SEQ ID NO: 239, SEQ ID NO: 240, SEQ ID NO: 241, SEQ ID NO: 242, SEQ ID NO: 243, SEQ ID NO: 244, SEQ ID NO: 245, or SEQ ID NO: 246.
  • 54. The contiguous polypeptide of any one of the preceding claims, wherein the Trk A ECD polypeptide is glycosylated.
  • 55. The contiguous polypeptide of any one of the preceding claims, wherein the Trk A ECD polypeptide comprises at least one glycan moiety.
  • 56. The contiguous polypeptide of any one of the preceding claims, wherein the Trk A ECD polypeptide is PEGylated.
  • 57. The contiguous polypeptide of any one of the preceding claims, wherein the Trk A ECD polypeptide is PEGylated at a glycan, at a primary amine, and/or the N-terminal alpha-amine.
  • 58. An isolated nucleic acid encoding the contiguous polypeptide of any one of the preceding claims.
  • 59. A host cell comprising the nucleic acid of claim 58.
  • 60. A method of producing a polypeptide comprising culturing the host cell of claim 59 and isolating the contiguous polypeptide.
  • 61. A pharmaceutical composition comprising the contiguous polypeptide of any one of claims 1 to 57 and a pharmaceutically acceptable carrier.
  • 62. The pharmaceutical composition of claim 61, wherein the pharmaceutical acceptable carrier comprises from about 5 to about 50 mM sodium citrate; from about 5 to about 50 mM histidine; or from about 5 to about 50 mM sodium acetate.
  • 63. The pharmaceutical composition of claim 61 or claim 62, wherein the pharmaceutical composition has a pH of from 5 to 6.
  • 64. A method of treating a companion animal species having an NGF-induced condition, the method comprising administering to the companion animal species a therapeutically effective amount of the contiguous polypeptide of any one of claims 1 to 57 or the pharmaceutical composition of any one of claims 61 to 63.
  • 65. A method of treating a companion animal species having pain, the method comprising administering to the companion animal species a therapeutically effective amount of the contiguous polypeptide of any one of claims 1 to 57 or the pharmaceutical composition of any one of claims 61 to 63.
  • 66. The method of claim 64 or claim 65, wherein the companion animal species is canine, feline, or equine.
  • 67. The method of any one of claims 64 to 66, wherein the NGF-induced condition or the pain is chronic pain, acute pain, and/or inflammatory pain.
  • 68. The method of any one of claims 64 to 67, wherein the NGF-induced condition or the pain is osteoarthrititic pain, back pain, cancer pain, and/or a neuropathic pain.
  • 69. The method of any one of claims 64 to 68, wherein the NGF-induced condition or the pain is pain associated with a surgery, a broken or fractured bone, dental work, a burn, a cut, and/or labor.
  • 70. The method of any one of claims 64 to 69, wherein the contiguous polypeptide or the pharmaceutical composition is administered parenterally.
  • 71. The method of any one of claims 64 to 70, wherein the contiguous polypeptide or the pharmaceutical composition is administered by an intramuscular route, an intraperitoneal route, an intracerebrospinal route, a subcutaneous route, an intra-arterial route, an intrasynovial route, an intrathecal route, or an inhalation route.
  • 72. The method of any one of claims 64 to 71, wherein the method further comprises administering an NGF kinase inhibitor, a PI3K inhibitor, a ras inhibitor, a CGRP inhibitor, a TNF inhibitor, an IL17 inhibitor, an EGFR inhibitor, and/or a Phospholipase C pathway inhibitor.
  • 73. The method of any one of claims 64 to 72, wherein the method further comprises administering one or more pain therapy drugs, such as a corticosteroid, a non-steroidal anti-inflammatory drug (NSAID), a cyclooxygenase inhibitor, an opioid, and/or a cannabinoid.
  • 74. A method of reducing NGF signaling activity in a cell, the method comprising exposing the cell to the contiguous polypeptide of any one of claims 1 to 57 or the pharmaceutical composition of any one of claims 61 to 63 under conditions permissive for binding of the contiguous polypeptide to NGF.
  • 75. The method of claim 74, wherein the cell is exposed to the contiguous polypeptide or the pharmaceutical composition ex vivo.
  • 76. The method of claim 74, wherein the cell is exposed to the contiguous polypeptide or the pharmaceutical composition in vivo.
  • 77. The method of any one of claims 74 to 76, wherein the cell is a canine cell, a feline cell, or an equine cell.
  • 78. A method for detecting NGF in a sample from a companion animal species comprising contacting the sample with the contiguous polypeptide of any one of claims 1 to 57 or the pharmaceutical composition of any one of claims 61 to 63 under conditions permissive for binding of the contiguous polypeptide to NGF, and detecting whether a complex is formed between the polypeptide and NGF in the sample.
  • 79. The method of claim 78, wherein the sample is a biological sample obtained from a canine, a feline, or an equine.
Parent Case Info

This application claims the benefit of U.S. Provisional Application No. 62/821,438, filed Mar. 20, 2019, which is incorporated by reference herein in its entirety for any purpose.

PCT Information
Filing Document Filing Date Country Kind
PCT/US2020/023846 3/20/2020 WO 00
Provisional Applications (1)
Number Date Country
62821438 Mar 2019 US