Patent Application
20190382506
The Sequence Listing contained in the files “761_190_026_US_Sequence_Listing_ST25.txt”, created on 2019-05-21, modified on 2019-05-21, file size 35,033 bytes, containing SEQ ID NOS: 1-30, and “761_190_025_US_Sequence_Listing_ST25.txt”, created on 2018-06-17, modified on 2018-06-17, file size 34,990 bytes, containing SEQ ID NOS: 1-30, are incorporated by reference in its entirety herein.
Monoclonal antibodies (MAbs) targeting one or more specific epitopes of aspartyl (asparaginyl) β-hydroxylase (ASPH), including humanized, bi-specific and other chimeric MAb variants, and fragments thereof (collectively ASPH epitope-specific MAbs, or simply ASPH MAbs), are disclosed. Methods of production, purification, and use of the ASPH epitope-specific MAbs, and compositions comprising them, as agents in therapeutic and diagnostic applications to interact with target molecules in cell-free samples, cell- and tissue-based assays, animal models, and in a subject are also disclosed. Other aspects of the invention relate to use of the molecules disclosed herein to diagnose, ameliorate, or treat cell proliferation disorders and related diseases.
Aspartyl(asparaginyl)-β-hydroxylase (ASPH) is an iron-dependent dioxygenase that catalyzes the hydroxylation of β carbons of aspartic acid and asparagine residues in calcium binding Epidermal Growth Factor (cbEGF)-like domains of a variety of proteins, including Notch and Notch ligand homologs (Dinchuk, Focht et al. 2002) extracellular matrix proteins, and low density lipoprotein (LDL) receptors. ASPH was first observed to be involved in the hydroxylation of a specific aspartic acid residue in the blood coagulation cascade proteins (Drakenberg, Fernlund et al. 1983) where the hydroxylated residue is underlined in the consensus sequence CX[D/N]X4[Y/F]XC. The role of hydroxylated residue is presently unknown, but the sole known crystal structure with a beta-hydroxylated asparagine (Crystal structure deposited as 5JZZ in 2016, but annotated by Pfeffer et al, as to be published).
ASPH is generally classified as a peptide-aspartate beta-dioxygenase (EC 1.14.11.16), a member of the alpha-ketoglutarate-dependent hydroxylases superfamily, which catalyzes the following chemical reaction, facilitated by iron as a cofactor.
peptide-L-aspartate+2-oxoglutarate+O2≈peptide-3-hydroxy-L-aspartate+succinate+CO2 (Reaction 1)
ASPH is not normally expressed in adult cells (Lavaissiere, Jia et al. 1996), but is expressed during invasion of the uterine wall by trophoblasts during development of the placenta (Gundogan, Elwood et al. 2007). ASPH is overexpressed in a variety of tumors, including hepatocellular, cholangiocarcinoma, gastric cancer, pancreatic cancer, non-small cell lung cancer, glioblastoma multiform, osteosarcoma, cervical cancer, ovarian cancer and breast cancer (Yang, Song et al. 2010), and enhances signaling in the Notch pathway (Cantarini, de la Monte et al. 2006).
Known and computationally predicted ASPH substrates are illustrated in
ASPH is known to contain multiple phosphorylation sites (Tong, Gao et al. 2013), including T748. Phosphorylation of ASPH is known to alter the expression and function of ASPH (Borgas, Gao et al. 2015), and plays a potential role in migration and tissue invasion of hepatocellular carcinoma (Borgas, Gao et al. 2015). Antibodies selective for ASPH phosphorylation state should be useful in the diagnosis of cancer and distinguishing normally expressed ASPH from tumor expressed ASPH.
Previously designed antibodies to ASPH did not result in direct suppression of tumor cell proliferation (Yeung, Finney et al. 2007). Despite the high affinity of these antibodies, the targeted epitope did not sufficiently disrupt catalytic activity of ASPH. Consequently, while the antibodies were internalized into the cancer cells expressing ASPH, there was no direct antibody activity leading to cellular senescence or cytotoxicity. To address this issue, radioisotopes have been conjugated to previously described high affinity ASPH antibodies, leading to modest activity (Revskaya, Jiang et al. 2017). Other previous anti-ASPH strategies include small molecule inhibitors of ASPH (Aihara, Huang et al. 2014), a dendritic cell approach (Noda, Shimoda et al. 2012), and a vaccine approach (Iwagami, Casulli et al. 2017).
This application describes the epitope selection for phospho-selective ASPH antibodies, as well as antibodies for ASPH catalytic activity inhibition, including epitopes on both the catalytic and non-catalytic domains, demonstration of high affinity for ASPH, strong IHC staining of cancerous but not normal tissue, and direct activity against cancer cells.
The present invention relates to monoclonal antibodies (MAbs) targeting one or more specific epitopes of aspartyl (asparaginyl) β-hydroxylase (ASPH), including chimeric and humanized MAb variants, and fragments thereof (collectively ASPH epitope-specific MAbs, or simply ASPH MAbs), are disclosed. Methods of production, purification, and use of the ASPH epitope-specific MAbs, and compositions comprising them, as agents in therapeutic and diagnostic applications to interact with target molecules in cell-free samples, cell- and tissue-based assays, animal models, and in a subject are also disclosed. Other aspects of the invention relate to use of the molecules disclosed herein to diagnose, ameliorate, or treat cell proliferation disorders and related diseases.
One aspect relates to an isolated monoclonal antibody, or a fragment thereof, which binds to a one or more peptide epitopes of human aspartyl (asparaginyl) β-hydroxylase (ASPH), wherein at least one of said peptide epitopes is located within or adjacent to the catalytic domain of ASPH.
Another aspect relates to a composition comprising any of the antibodies noted above, including compositions comprising at least one antibody that targets ASPH and one or more pharmaceutical excipients.
Another aspect relates to a method of using any of the antibodies noted above, to inhibit the proliferation of isolated tumor cell samples grown in culture.
Another aspect relates to a method of using any of the antibodies noted above, to inhibit the proliferation of tumor cells in tissue samples grown in culture.
Another aspect relates to a method of treating cancer in an mammalian subject, comprising administering to a subject in need thereof an antibody as noted above in an amount sufficient to treat cancer.
Another aspect relates to a kit for diagnosis of cancer in a mammalian subject, wherein said kit comprises an antibody, or a fragment thereof, of any of any of the antibodies noted above.
Another aspect relates to a humanized antibody comprising one or more complementarity determining regions (CDRs) derived from a non-human source targeting one or more peptide epitopes located within or adjacent to the catalytic domain of ASPH of any of the antibodies noted above, and one or more portions of the constant regions of a human antibody, and fragments thereof.
Another aspect relates to a bispecific antibody comprising one or more complementarity determining regions (CDRs) derived from a non-human source targeting one or more peptide epitopes located within or adjacent to the catalytic domain of ASPH of any of the antibodies noted above, and an antibody targeting other epitopes selected from the group consisting of the T-cell redirector class, comprising an antibody targeting one or more ASPH CDRs and an antibody targeting CD3; the NK-cell redirector class, comprising an antibody targeting one or more ASPH CDRs and an antibody targeting CD16A; the tumor targeting immunomodular class, comprising an antibody targeting one or more ASPH CDRs and an antibody targeting CD40 or 4-1BB; and the dual immunomodular class, comprising an antibody targeting one or more ASPH CDRs and an antibody targeting PD-L1, PD-1, CTLA-4, TGF-β, LAG-3, TIM-3, or OX40.
A better understanding of the invention will be obtained from the following detailed descriptions and accompanying drawings, which set forth illustrative embodiments that are indicative of the various ways in which the principals of the invention may be employed.
The provisional and non-provisional US patent or application files contain at least one drawing executed in color. Copies of these color drawing(s) associated with patent application files, published applications, or issued patents will be provided by the United States Patent and Trademark Office upon request and payment of the necessary fee. Provisional Application No. 62/686,107, filed Jun. 18, 2018, also contains 28 pages of color drawings, which are incorporated by reference, as noted above.
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
The following is a list of abbreviations, plus terms and their definitions, used throughout the specification and the claims:
General abbreviations and their corresponding meanings include: aa or AA=amino acid; mg=milligram(s); ml or mL=milliliter(s); mm=millimeter(s); mM=millimolar; nmol=nanomole(s); pmol=picomole(s); ppm=parts per million; RT=room temperature; U=units; ug, μg=micro gram(s); ul, μl=micro liter(s); uM, μM=micromolar.
Specific abbreviations and their corresponding meanings include:
The terms “cell” and “cells”, which are meant to be inclusive, refer to one or more cells which can be in an isolated or cultured state, as in a cell line comprising a homogeneous or heterogeneous population of cells, or in a tissue sample, or as part of an organism, such as a transgenic animal.
The term “amino acid” encompasses both naturally occurring and non-naturally occurring amino acids unless otherwise designated.
The term “complementarity-determining regions” or “CDRs” are defined by Wikipedia, as part of the variable chains in immunoglobulins (antibodies) and T cell receptors, generated by B-cells and T-cells respectively, where these molecules bind to their specific antigen. CDRs, which comprise the most variable parts of antibodies, are crucial to the diversity of antigen specificities generated by lymphocytes.
The term “paratope” refers to a set of CDRs.
The present invention relates to monoclonal antibodies (MAbs) targeting one or more specific epitopes of aspartyl (asparaginyl) β-hydroxylase (ASPH), including chimeric and humanized MAb variants, and fragments thereof (collectively ASPH epitope-specific MAbs, or simply ASPH MAbs), are disclosed. Methods of production, purification, and use of the ASPH epitope-specific MAbs, and compositions comprising them, as agents in therapeutic and diagnostic applications to interact with target molecules in cell-free samples, cell- and tissue-based assays, animal models, and in a subject are also disclosed. Other aspects of the invention relate to use of the molecules disclosed herein to diagnose, ameliorate, or treat cell proliferation disorders and related diseases.
One aspect relates to an isolated monoclonal antibody, or a fragment thereof, which binds to a one or more peptide epitopes of human aspartyl (asparaginyl) β-hydroxylase (ASPH), wherein at least one of said peptide epitopes is located within or adjacent to the catalytic domain of ASPH.
Another aspect relates to an antibody, or a fragment thereof, as noted above, wherein at least one of said peptide epitopes located within or adjacent to the catalytic domain of ASPH is located within 30 amino acids of the C-terminus of ASPH.
Another aspect relates to an antibody, which binds to one or more synthetic peptides selected from the group consisting of (a) a synthetic peptide comprising 29 amino acids with Cysteine at its amino terminus, plus 28 amino acids corresponding to positions 731-758 at the C-terminal end of human ASPH, with the Threonine at 19 (corresponding to 748 of ASPH) phosphorylated, as CASSFRLIFIVDVWHPEL-T(PO3H2)-PQQRRSLPAI represented by SEQ ID NO: 19; and (b) a synthetic peptide comprising 29 amino acids with Cysteine at its amino terminus, plus 28 amino acids corresponding to positions 731-758 at the C-terminal end of human ASPH, as CASSFRLIFIVDVWHPELTPQQRRSLPAI represented by SEQ ID NO: 20.
Related aspects include an antibody, which binds to an epitope comprising at least 4 consecutive amino acid residues located within 30 amino acids from the C-terminal end of human ASPH, including an antibody wherein said epitope comprising at least 4 consecutive amino acid residues located within 30 amino acids from the C-terminal end of human ASPH comprises the consecutive amino acid selected from the group consisting of PELT, ELTP, LTPQ, TPQQ, PQQR, QQRR, QRRS, RRSL, RSLP, SLPA, and LPAI. Related aspects also include an antibody, wherein said peptide epitope comprises a phosphorylated threonine, T(PO3H2).
Another aspect relates to an isolated monoclonal antibody, or a fragment thereof, which binds to a one or more peptide epitopes of human aspartyl (asparaginyl) β-hydroxylase (ASPH), wherein said antibody comprises a recombinant heavy chain and a recombinant light chain, wherein said recombinant heavy chain comprises a polypeptide sequence selected from the group consisting of SEQ ID NOS 21-25; and wherein said recombinant light chain comprises a polypeptide sequence selected from the group consisting of SEQ ID NOS 26-30.
Another aspect relates to an antibody selected from the group consisting of 5H4/5K3 and 9H2/9K1, wherein antibody 5H4/5K3 comprises a heavy chain designated 5H4, represented by the sequence SEQ ID NO: 25, and a light chain 5K3 represented by the sequence SEQ ID NO: 27; and wherein antibody 9H2/9K1 comprises a heavy chain designated 9H2, represented by the sequence SEQ ID NO: 29, and a light chain 9K1 represented by the sequence SEQ ID NO: 30.
Another aspect relates to an isolated monoclonal antibody, or a fragment thereof, which binds to a one or more peptide epitopes of human aspartyl (asparaginyl) β-hydroxylase (ASPH), wherein said antibody comprises a recombinant heavy chain comprising a CDR1 comprising a sequence selected from the group consisting of NFMC and NAMC; a CDR2 comprising a sequence selected from the group consisting of CIYF and CIDN; a CDR3 comprising a sequence selected from the group consisting of DGPGSISWKI and NFNI.
Another aspect relates to an isolated monoclonal antibody, or a fragment thereof, which binds to a one or more peptide epitopes of human aspartyl (asparaginyl) β-hydroxylase (ASPH), wherein said antibody comprises a recombinant light chain comprising a CDR1 comprising a sequence selected from the group consisting of SVYSKNR and SVYDNNR; a CDR2 comprising the sequence LAS; a CDR3 comprising a sequence selected from the group consisting of QGTYDSSGWYWA AND LGSYSGYIYI.
Related aspects include variants of the monoclonal antibodies or fragments thereof, that contain one or more conservative amino acid substitutions in which the functional activity relating to binding of the antibody or fragment thereof to an epitope of ASPH is retained. Related aspects also include truncated or fusion variants of the monoclonal antibodies comprising one or more insertions or deletions of amino acids in which the in which the functional activity relating to binding of the antibody or fragment thereof to an epitope of ASPH is retained. Related aspects also include variants comprising one or more combinations of conservative amino acid substitutions, insertions, and deletions, particularly where the number of residues that are altered by substitution, insertion, or deletion is small, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, 11-15, 16-20, and 21-25 residues compared to the parent antibody molecule. Related aspects also include molecules having one or more larger insertions or deletions of amino acid residues or polypeptide domains that do not alter the functional binding activity of the antibody to a desired epitope in a target molecule.
Another aspect relates to a composition comprising any of the antibodies noted above, including compositions comprising at least one antibody that targets ASPH and one or more pharmaceutical excipients.
Another aspect relates to a method of using any of the antibodies noted above, to inhibit the proliferation of isolated tumor cell samples grown in culture.
Another aspect relates to a method of using any of the antibodies noted above, to inhibit the proliferation of tumor cells in tissue samples grown in culture.
Another aspect relates to a method of treating cancer in a mammalian subject, comprising administering to a subject in need thereof an antibody as noted above in an amount sufficient to treat cancer. Related aspects include methods wherein said mammalian subject is a selected from the group consisting of a human, non-human primate, canine, feline, bovine, equine, and a porcine subject. A preferred aspect relates to a method, wherein said mammalian subject is a human subject.
Related aspects also include methods noted above wherein said cancer is selected from the group consisting of cancers of the liver, hepatocellular carcinoma and cholangiocarcinoma, pancreatic cancer, gastric cancer, colon cancer, kidney cancer, non-small cell lung cancer, breast cancer, ovarian cancer, cervical cancer, head-and-neck cancers secondary to human papilloma virus infection, prostate cancer, brain cancer, glioblastoma multiform, neuroblastoma, retinoblastoma, and medullablastoma, and osteosarcoma.
Another aspect relates to a kit for diagnosis of cancer in a mammalian subject, wherein said kit comprises an antibody, or a fragment thereof, of any of any of the antibodies noted above.
Another aspect relates to a humanized antibody comprising one or more complementarity determining regions (CDRs) derived from a non-human source targeting one or more peptide epitopes located within or adjacent to the catalytic domain of ASPH of any of Claims 1-10, and one or more portions of the constant regions of a human antibody, and fragments thereof.
Another aspect relates to a bispecific antibody comprising one or more complementarity determining regions (CDRs) derived from a non-human source targeting one or more peptide epitopes located within or adjacent to the catalytic domain of ASPH of any of Claims 1-10, and an antibody targeting other epitopes selected from the group consisting of the T-cell redirector class, comprising an antibody targeting one or more ASPH CDRs and an antibody targeting CD3; the NK-cell redirector class, comprising an antibody targeting one or more ASPH CDRs and an antibody targeting CD16A; the tumor targeting immunomodular class, comprising an antibody targeting one or more ASPH CDRs and an antibody targeting CD40 or 4-1BB; and the dual immunomodular class, comprising an antibody targeting one or more ASPH CDRs and an antibody targeting PD-L1, PD-1, CTLA-4, TGF-β, LAG-3, TIM-3, or OX40.
Antibodies with direct activity against ASPH antibodies should be useful in the discovery and development of therapeutic drug products intended for use in the treatment of a variety of cancers. These include cancers of the liver, such as hepatocellular carcinoma and cholangiocarcinoma, pancreatic cancer, gastric cancer, colon cancer, kidney cancer, non-small cell lung cancer, breast cancer, ovarian cancer, cervical cancer, head-and-neck cancers secondary to human papilloma virus infection, prostate cancer, brain cancers of various types, including glioblastoma multiform, neuroblastoma, retinoblastoma, and medullablastoma, and osteosarcoma.
Related aspects of the invention are directed to compositions, including pharmaceutical compositions, comprising the compounds of the invention, noted above. One aspect of the invention is directed to a pharmaceutical composition comprising at least one pharmaceutically acceptable excipient and a therapeutically effective amount of the compound or salt disclosed above. Still another aspect of the invention relates to a method for pharmaceutical formulation of previously described compounds for use in oral and intravenous applications, and in implantable materials.
Another aspect of the present invention relates to a pharmaceutical composition including a pharmaceutically acceptable carrier and a compound according to the aspects of the present invention. The pharmaceutical composition can contain one or more of the above-identified compounds of the present invention.
While specific aspects of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only, and not limiting as to the scope of the invention, which is to be given the full breadth of the appended claims, and any equivalent, thereof.
The foregoing discussion may be better understood in connection with the following representative examples which are presented for purposes of illustrating the principle methods and compositions of the invention, and not by way of limitation. Various other examples will be apparent to the person skilled in the art after reading the present disclosure without departing from the spirit and scope of the invention. It is intended that all such other examples be included within the scope of the appended claims.
All parts are by weight (e.g., % w/w), and temperatures are in degrees centigrade (° C.), unless otherwise indicated. Table #T1 presents a summary of the nucleotide and amino acid sequences described in this application
KRRSNEVLR
corresponding to residues
DRQQFLGHM
corresponding to residues
GYLLIGDNDN
corresponding to residues
RSLYNVNG
corresponding to residues
PQQRRSLPAI
corresponding to residues
FLPEDENLRE
corresponding to residues
VWPHTGPTNC
corresponding to residues
LWQQGRRNE
corresponding to residues
KRRSNEVLR
corresponding to residues
DRQQFLGHM
corresponding to residues
GYLLIGDNNN
corresponding to residues
RSLYNVHG
corresponding to residues
PQQRHSLPAI
corresponding to residues
FLPEDENLRE
corresponding to residues
VWPHTGPTNC
corresponding to residues
LWQQGRKNE
corresponding to residues
APTVLIFPPA
APTVLIFPPA
APTVLIFPPA
APTVLIFPPA
APTVLIFPPA
Peptide #H2<428..436> Peptide #H3<463...470>
familiaris].
.605> Peptide #C6<648...657>
YNVHG
LKAQP WWTPKETGYT ELVKSLERNW KLIRDEGLAV MDKAKGLFLP EDENLREKGD
Peptide #C8<666..674> Peptide #C7<712.....
.721>
C
RLRMHLGLV IPKEGCKIRC ANETKTWEEG KVLIFDDSFE HEVWQDATSF RLIFIVDVWH
Peptide #C5<785...794>
familiaris]
Peptide #C3<499..508>
GYLLIGDNNN
AQKVYEEVLNVTPNDGFAKVHYGFILKAQNKIAESIPYLKEGIESGDPGT
GYLLIGDNDN
AKKVYEEVLSVTPNDGFAKVHYGFILKAQNKIAESIPYLKEGIESGDPGT
Peptide #H3<463..470>
Peptide #C4<598605>
Peptide #H4<562569>
Peptide #C6<648..657> #C8<666.674>
Peptide #H6<612..621> #H8<630.638>
Peptide #C7<712..721>
Peptide #H7<676..685>
Peptide #C5<785..794>
Peptide #H5<749..758>
Synthetic peptides derived from human and/or canine ASPH were designed that correspond to eight domain regions (#1-#8, as #H1-#H8 and #C1-#C8), as penultimate domain epitopes of the full length polypeptide, as illustrated in
KRRSNEVLR
DRQQFLGHM
GYLLIGDNDN
GYLLIGDNNN
RSLYNVNG
RSLYNVHG
PQQRRSLPAI
PQQRHSLPAI
FLPEDENLRE
VWPHTGPTNC
LWQQGRRNE
LWQQGRKNE
ImmunoPrecise Antibodies Ltd. (Victoria, British Columbia, Canada) carried out immunization of peptide candidates into rabbits, the testing of antibodies from rabbit B cells, cloning of variable regions into expression vectors, and DNA sequencing of selected rabbit MAbs (Examples 2-8) using standard procedures, under contract with principal investigators at Midwestern University (Glendale, Ariz.).
Synthetic peptides #1 and #2 (1 mg each) were prepared at a purity of >95%. The N-terminal Cysteine residue on each peptide is used to facilitate conjugation of each peptide to other molecules. BSA and KLH (2 mg each) were synthesized or obtained from commercial sources.
Briefly, 3-6 mg of immunizing/screening antigen were prepared and stored in a neutral pH, sterile, buffered solution, at a minimum concentration of 0.5 mg/L. Antigen (hapten) was conjugated to an appropriate carrier and emulsified in Freund's Complete adjuvant, and used to immunize two New Zealand White (NZW) rabbits by subcutaneous injections. Booster injections of antigen in Freund's Incomplete adjuvant were carried at 3 week intervals. Blood samples (test bleeds) were collected 7-10 days after the second boost and immune sera were tested for specific antibody titer by ELISA. Each rabbit was given a final boost, if required, and whole blood was used to obtain B cells to generate Monoclonal Antibodies (MAbs) by the methods noted below.
Whole rabbit blood was collected after the final boost, and B cells were isolated, purified, and cultured by ImmunoPrecise Antibodies Ltd.
Screening was performed on the immunizing antigen by an indirect ELISA performed by ImmunoPrecise Antibodies Ltd.
ELISA plates were obtained from Costar Corning (Catalog #0720039). Blocking solutions included BSA (Bovine serum albumin) and Skim milk powder (MP). Phosphate buffered saline (PBS) at pH 7.4, PBS with 0.05% Tween-20 at pH 7.4, and Carbonate coating buffer (CCB) at pH 9.6 were used in the ELISA tests. Primary antibodies being tested included the immune sera, B cell supernatants, and transfected supernatants (recombinant rabbit MAbs). Secondary antibodies included Goat Anti-Rabbit IgG-Fc-HRP, Subisotype IgG1, obtained from Jackson ImmunoResearch (Catalog #111-035-046), and AffiniPure goat anti-rabbit IgG (H+L), Subisotype IgG1, obtained from Jackson ImmunoResearch (Catalog #111-035-144). Substrate reagents included TMB (3,3′,5,5′-tetramethyl-benzidine buffer), TMB One Component HRP Microwell Substrate, and BioFx cat# TMBW-1000-01.
Briefly, B cell culture supernatants from 96-well plates were transferred to ELISA plates coated with antigen. An indirect ELISA was performed by probing each well with a secondary antibody that binds to rabbit IgG antibodies. Wells with cells that tested positive were retested with the immunizing antigen to confirm specificity and binding.
Samples corresponding to the top responding wells were preserved in lysis buffer.
Cell culture supernatants from positive wells (in a volume of <50 μL) were also preserved.
Cells from selected wells of B cells were amplified and samples of mRNA prepared from those cells by ImmunoPrecise Antibodies Ltd. Complementary DNAs corresponding to rabbit IgG heavy and kappa light chain variable regions were prepared and cloned separately into mammalian expression vectors comprising rabbit heavy and light chain constant regions, respectively.
Two plasmids, one comprising a heavy chain variable and a constant region and one comprising a light chain variable and constant region, were co-transfected into HEK293 cells, and allowed to express both chains of the rabbit antibodies.
The cell culture supernatants were assayed for activity by indirect ELISA against the immunizing peptide (Peptide #1, SEQ ID NO: 13). Ten clones (#1-#10) having positive activity against immunizing peptide were identified. One clone produced an antibody that reacted with the phosphorylated Peptide #1, and four clones produced antibodies that reacted against both the phosphorylated Peptide #1 (SEQ ID NO: 19) and the non-phosphorylated Peptide #2 (SEQ ID NO: 20).
Ten clones were selected, five comprising heavy chains (1H2, 5H1, 5H3, 5H4 and 9H2), and five comprising kappa chains (1K6, 5K1, 5K3, 5K6 and 9K1). Purified plasmid DNA samples were prepared and sent to Macrogen USA for sequencing and analyzed by SnapGene Version 4.0.4.
The rabbit IgG heavy chain sequence is about 1200 bp in length, and can be sequenced from its 5′ end to obtain a reliable full-length variable sequence. The rabbit kappa light chain is about 700 bp in length, and full-length variable sequence can be reliably obtained from sequencing in the 5′ direction.
The nucleotide sequences of the variable regions of five heavy chains and five kappa chains were analyzed. Table #T4 discloses the translated variable regions encoded by the nucleotide sequences of the top 10 clones. Sequences highlighted in bold with a single underline (as GQPK) show the start of the constant region for heavy chains, and sequences highlighted in italic and double underline (as ) show the start of the constant region of kappa chains.
APTVLIFPPA
APTVLIFPPA
APTVLIFPPA
APTVLIFPPA
APTVLIFPPA
These results demonstrate that recombinant monoclonal antibodies derived from rabbits, were generated successfully against Peptide #1 (SEQ ID NO: 13). Recombinant Clones 5H1, 5H3, 5H4, and 9H2 have the same heavy chain sequences, and recombinant clones 5K1, 5K3 and 9K1 have the same kappa chain sequence.
A multiple sequence alignment of five clones comprising heavy chains illustrates slight differences in the encoded polypeptide sequences in regions within and just flanking CDR1, CDR2, CDR3, with notable divergence for sequences after CDR3 for clone 5H1.
The CDR1 regions from the heavy chain clones include the sequences NFMC and NAMC. The CDR2 regions from the heavy chain clones include CIYF and CIDN. The CDR3 regions from the heavy chain clones include DGPGSISWDI and NFNI.
A multiple sequence alignment of five clones comprising kappa light chains illustrates slight differences in the encoded polypeptide sequences in regions within and just flanking CDR1, CDR2, CDR3, with notable divergence for sequences within CDR3 for clone 1K6.
The CDR1 regions from the kappa chain clones include SVYSKNR and SVYDNNR. The CDR2 regions from the kappa chain clones were all LAS. The CDR3 regions from the kappa chain clones included QGTYDSSGWYWA and LGSYSGYIYI.
Antibody triage (Phase I) was performed by Reveal Biosciences (San Diego, Calif.) on a Leica Bond automated immunostainer, testing each antibody at 8 μg/mL, in parallel with a negative control performed in absence of primary antibody. FFPE human hepatocellular carcinoma was used for antibody testing.
Heat induced antigen retrieval was performed using Leica Bond Epitope Retrieval Buffer 1 (Citrate Buffer, pH6.0) and Leica Bond Epitope Retrieval Buffer 2 (EDTA solution, pH9.0) for 20 minutes (ER2(20)). Non-specific antibody binding was blocked using 3% Normal Goat Serum in PBST. Tests for positive reactions were carried out by using Novocastra Bond Refine Polymer Detection reagent, and visualized with 3′3-diaminobenzidine (DAB; brown). A Hematoxylin nuclear counterstain (blue) was also applied.
When Phase I optimization slides were evaluated, only two samples, 5H4/5K3 and 9H2/9K1, showed positive staining in Epitope Retrieval Buffer, ER2(20), as noted below.
Two antibodies, 5H4/5K3 and 9H2/9K1, that showed positive staining in ER2(20) were selected for further testing in Phase II.
Immunohistochemistry (IHC) Optimization was performed by Reveal Biosciences (San Diego, Calif.) on a Leica Bond automated immunostainer, by testing each antibody at 2 μg/mL, 4 μg/mL, 8 μg/mL, and 10 μg/mL.
Heat induced antigen retrieval was performed using Leica Bond Epitope Retrieval Buffer 2 (EDTA solution, pH9.0) for 20 minutes (ER2(20)). Non-specific antibody binding was blocked using 3% Normal Goat Serum in PBST. Tests for positive reactions were carried out by using Novocastra Bond Refine Polymer Detection and visualized with 3′3-diaminobenzidine (DAB; brown). A Hematoxylin nuclear counterstain (blue) was applied.
When Phase II optimization samples were evaluated, no staining was observed at 2 μg/mL for 5H4/5K3 and 9H2/9K1. A strong signal was detected at both 8 μg/mL and 10 μg/mL for 5H4/5K3, as illustrated in
These results demonstrate that 5H4/5K3 and 9H2/9K1 are notable as leads for the development of diagnostic agents, and also as therapeutic drug products suitable for use in mammals, such as humans, by grafting the CDRs onto a suitable antibody framework that will facilitate the targeting of one or more drug products to cancerous tissues in a human subject.
Immunohistochemistry (IHC) was performed on a Leica Bond automated immunostainer using 5H4/5K3 at 8 μg/mL on TMAs (Table #T5).
Heat induced antigen retrieval was performed using Leica Bond Epitope Retrieval Buffer 2 (EDTA solution, pH9.0) for 20 minutes (ER2(20)). Non-specific antibody binding was blocked using 3% Normal Goat Serum in PBST.
Positivity was detected using Novocastra Bond Refine Polymer Detection and visualized with 3′3-diaminobenzidine (DAB; brown). A Hematoxylin nuclear counterstain (blue) was applied.
Isotype controls were performed on Human Hepatocellular carcinoma slide and each TMA type alongside their respective positive (with primary) slide using Rabbit IgG (Abcam ab172730, lot#GR3179509-3).
A human hepatocellular carcinoma FFPE block was sectioned at 4 um thickness and mounted onto positively charged slides for assay development.
These results demonstrate that antibody 5H4/5K3 stains a broad range of ovarian cancer samples, from granuloma to serous to endometrioid cancers. Malignant cancers stain intensely, while benign and normal ovarian tissue samples do not stain under these conditions.
These and similar antibodies, plus fragments or derivatives thereof, should be useful as a key reagent in a kit to diagnose the presence of cancer cells in wide variety of research and clinical samples.
These and similar antibodies, plus fragments or derivatives thereof, may also be useful in the development of pharmaceutical compositions comprising a therapeutic agent when the CDRs are grafted onto an appropriate framework suitable to produce a drug product suitable for mammals, particularly non-human primate and human subjects, and livestock, and domestic pets, including dogs and cats.
These results confirm activity of the 5H4/5K3 antibody against a variety of cancerous tissue samples, and a lack of activity against cells in normal tissue samples.
The interaction between ASPH and a set of 6 antibodies were characterized by Essai Sciences LLC (Stillwater, Okla.) on a SensiQ Pioneer SPR Platform. The COOH2 sensor chip, which contains a planar dextran surface, was used for target immobilization. The buffer system was 10 mM HEPES, pH 7.4, 150 mM NaCl, and 0.01% Tween-20.
All channels of a COOH2 sensor chip were activated with a five minute injection of 40 mM EDC and 10 mM NHS. Protein G was then injected across channels 1 and 2. 1 M ethanolamine, pH 8.0 was then injected across all three channels. Approximately 1000 response units of Protein G were captured on both channels 1 and 2 (
All experimental results shown are from fixed-concentration analyses of the interactions. Given material constraints, as well as the nature of the interacting molecules, immobilization of the antibodies, and fixed-concentration injection of ASPH was the most feasible experimental setup for this study.
The response curves for each tested concentration of ASPH against each captured antibody are displayed below.
The interaction of the ASPH protein with a set of antibodies captured via Protein G was studied. A range of affinities from ˜60 nM to ˜920 nM for the binding antibodies was observed. A mock sample, and a phospho-selective antibody were also tested. No observable binding to the protein for the mock sample or the phospho-selective antibody was noted.
Experiments to determine the half maximal inhibitory concentration (IC50) of the potency of samples comprising selected antibodies in different types of cultured tumor cells were carried out by Translational Drug Development LLC.
These results demonstrate that the antibodies designated as 5H4/5K3 and 9H2/9K1 both affect the viability of three tumor cell lines being tested, with the Mab designated 9H2/9K1 being more potent than the Mab designated 5H4/5K3.
The antibody designated as 5H4/5K3 appears to be more selective for breast tumors 4T1 and MCF-7.
Humanized versions of non-human antibodies are chimeric antibodies that a minimal amount of polypeptide domains comprising amino acid sequences derived from the non-human antibody. Typically, residues from the hypervariable region of a human antibody are replaced with hypervariable residues from the non-human antibody, that have the desired specificity, affinity, and/or capacity. Humanized versions can also be prepared from non-human species, such as mouse, rat, rabbit, non-human primates, and other vertebrate species. Other regions, comprising amino acid residues that may contribute to structural integrity of the human antibody (framework region) may also be replaced by amino acid residues from the corresponding non-human residues. The humanized chimeric monoclonal antibodies may also comprise amino acid residues that are not found in the recipient human antibody or the non-human donor antibody. Generally, the humanized antibody comprises at least one, and preferably all of the variable domains of the donor antibody, and substantially all of the framework regions of the human antibody.
Variants may also comprise one or more portions of the constant region of an antibody, typically, a human antibody. Other types of variants, include fragments, and variants comprising one or more conservative substitutions, insertions, or deletions, that do not substantially alter the specificity, affinity, and/or capacity of the variant molecule compared to its parent molecule, but may offer additional advantages in terms of ease of production or purification, ability to be conjugated to other chemical moieties, which may facilitate covalent or non-covalent binding to other molecules comprising polypeptide domains or other reactive or non-reactive moieties, capable of providing a secondary reporter function, such as emission of fluorescent light, or conversion of a colorless substrate to an easily detectable, colored product, which may be useful as components in diagnostic kits for use in research and in clinical settings. Aspects of the invention also include variants that are >80%, >85%, >90%, >91%, >92%, >93%, >94%, >95%, >96%, >98%, >99%, or >99.5% identical to at least one of the variable regions of the donor antibody.
In the examples noted above, recombinant monoclonal antibodies were generated against Peptide #1 (SEQ ID NO: 13). Recombinant Clones 5H1, 5H3, 5H4, and 9H2 have the same heavy chain sequences, and recombinant clones 5K1, 5K3 and 9K1 have the same kappa chain sequence. The CDR1 regions from the heavy chain clones include the sequences NFMC and NAMC. The CDR2 regions from the heavy chain clones include CIYF and CIDN. The CDR3 regions from the heavy chain clones include DGPGSISWDI and NFNI. The CDR1 regions from the kappa chain clones include SVYSKNR and SVYDNNR. The CDR2 regions from the kappa chain clones were all LAS. The CDR3 regions from the kappa chain clones included QGTYDSSGWYWA and LGSYSGYIYI.
Plasmids comprising cDNAs encoding rabbit antibodies targeting epitopes of ASPH described in Examples 5-8 are used as a source of nucleic acids comprising variable regions to generate humanized monoclonal antibodies that target at least one epitope in the catalytic domain of ASPH. One or more codons within the rabbit cDNAs may be altered to represent codons that are optimally used in the host cell expression system, to enhance expression of the encoded chimeric polypeptide under the control of operably-linked promoters and other genetic elements. Random and targeted mutagenesis of specific residues within the variable regions may result in antibodies that have increased affinity to its intended target, and/or reduced affinity to other targets.
Bispecific antibodies combine the structural domains of two distinct molecules into one molecule with the goal of preserving and perhaps enhancing functional properties of the chimeric molecule compared to its parent mono-specific molecules (Dahlen E. et al, Bispecific antibodies in cancer immunotherapy. Therapeutic Advances in Vaccines and Immunotherapy, 2018, 6:(1)3-17). In some cases, bispecific antibodies have superior therapeutic properties compared to compositions comprising mixtures of monospecific compounds.
Several classes of immunotherapeutic bispecific antibodies have been recognized, including T-cell redirectors, which act on malignant cells by targeting a tumor antigen and CD3; NK-cell redirectors, which act on malignant cells targeting a tumor antigen and CD16A; Tumor-targeted immunomodulators, which direct co-stimulation of tumor-infiltrating immune cells by targeting a tumor antigen and co-stimulatory molecules, such as CD40 or 4-1BB; and Dual immunomodulators, which simultaneously act on two immunomodulatory targets, resulting in blockade of inhibitory targets, depletion of suppressive cells, or activation of effector cells (See Table 1 of Dahlen et al).
A non-limiting list of exemplary tumor antigens includes CD19, EpCAM, CD20, CD23, BCMA, B7H3, and PSMA.
A non-limiting list of T-cell specific epitopes includes CD3, CD3e, OX40, CD27, ICOS and GITR.
A non-limiting list of co-stimulatory molecules includes CD40 and 4-1BB.
A non-limiting list of immunomodulating targets includes PD-L1, CTLA-4, TGF-β, LAG-2, TIM-3, and OX40.
Bispecific antibodies comprising at least one complementarity-determining region (CDR) targeting one or more epitopes of ASPH selected from the group consisting of CDR1, CDR2, and CDR3 from the heavy chain or the light chain clones of Example 13 are prepared by fusing rabbit, other non-human, human, or humanized antibodies comprising these regions with an antibody targeting one or more tumor antigens, T-cell specific epitopes, co-stimulatory molecules, or immunomodulating targets, as noted above.
Exemplary bi-specific antibodies include a molecule comprising the CDRs of the 5H4/5K3 antibody disclosed herein, where the 5H4 CDR1=NAMC, CDR2=CIDN, and CDR3=NFNI, and the 5K3 (CDR1=SVYDNNR), CDR2=LAS, CDR3=LGSYSGYIYI) or 9H2/9K1 antibody where the 9H2 CDR1=NAMC, CDR2=CIDN, and CDR3=NFNI, and the 9K1 CDR1=SVYDNNR, CDR2=LAS, and CDR3=LGSYSGYIYI, combined with an antibody molecule comprising one or more tumor antigens, T-cell specific epitopes, co-stimulatory molecules, or immunomodulating targets, as noted above.
An exemplary bispecific antibody of the T-cell redirector class includes an antibody targeting one or more ASPH CDRs with an antibody targeting CD3.
An exemplary bispecific antibody of the NK-cell redirector class includes an antibody targeting one or more ASPH CDRs with an antibody targeting CD16A.
An exemplary bispecific antibody of the tumor targeting immunomodular class includes an antibody targeting one or more ASPH CDRs with an antibody targeting CD40 or 4-1BB.
An exemplary bispecific antibody of the dual immunomodular class includes an antibody targeting one or more ASPH CDRs with an antibody targeting PD-L1, PD-1, CTLA-4, TGF-β, LAG-3, TIM-3, or OX40.
While the preferred aspects of the invention have been illustrated and described in detail, it will be appreciated by those skilled in the art that that various changes can be made therein without departing from the spirit and scope of the invention. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention, which is to be given the full breadth of the appended claims and any equivalent thereof.
All references, patents, or applications cited herein are incorporated by reference in their entirety, as if written herein.
This application claims priority to, and the benefit of, U.S. Provisional Application No. 62/686,107, filed Jun. 18, 2018, the entire contents of which are incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62686107 | Jun 2018 | US |
