Patent Application
20230149566
The contents of the text file named “NIGH-011 002US SeqList.txt,” which was created on Apr. 4, 2019 and is 72 KB in size, are hereby incorporated by reference in their entirety.
The invention relates to the fields of molecular biology, neurobiology and gene therapy treatments for degenerative eye diseases.
Macular degeneration is a medical condition, which may result in blurred or no vision in the center of the visual field. In macular degeneration, the photoreceptors in the part of the retina called the macula, which is responsible for central vision, degenerate or die. In some cases, macular degeneration is caused by mutations in the Bestrophin-1 gene (BEST1, also called VMD2). There is currently no treatment for this devastating disease. There is thus a long felt need in the art for additional therapeutic approaches to treat macular degeneration. The disclosure provides compositions and methods of treatment for macular degeneration.
The disclosure provides a composition comprising a nucleic acid sequence comprising: (a) a sequence encoding a vitelliform macular dystrophy-2 (VMD2) promoter, and (b) a sequence encoding a Bestrophin-1 (BEST1) protein. In some embodiments, the sequence encoding the VMD2 promoter encodes a human VMD2 promoter. In some embodiments, the sequence encoding the BEST1 protein encodes a human BEST1 protein. In some embodiments, the sequence encoding the BEST1 protein comprises a coding sequence. In some embodiments, the sequence encoding the BEST1 protein comprises a cDNA sequence.
The disclosure provides a composition comprising a nucleic acid sequence comprising: (a) a sequence encoding a ubiquitous promoter, and (b) a sequence encoding a Bestrophin-1 (BEST1) protein. In some embodiments, the sequence encoding the BEST1 protein encodes a human BEST1 protein. In some embodiments, the sequence encoding the BEST1 protein comprises a coding sequence. In some embodiments, the sequence encoding the BEST1 protein comprises a cDNA sequence. In some embodiments, the sequence encoding a ubiquitous promoter comprises a sequence encoding a CAG promoter.
In some embodiments of the compositions of the disclosure, the nucleic acid sequence further comprises: (c) a sequence encoding a posttranscriptional regulatory element (PRE). In some embodiments, the sequence encoding the PRE comprises a sequence isolated or derived from a naturally occurring sequence. In some embodiments, the sequence encoding the PRE comprises a sequence isolated or derived from a non-naturally-occurring sequence. In some embodiments, the sequence encoding the PRE comprises a sequence isolated or derived from a viral sequence. In some embodiments, the sequence encoding the PRE comprises a sequence isolated or derived from a woodchuck hepatitis virus (WPRE).
In some embodiments of the compositions of the disclosure, the nucleic acid sequence further comprises: (d) a sequence encoding a polyadenylation (polyA) signal. In some embodiments, the sequence encoding the polyA signal comprises a sequence isolated or derived from a naturally occurring sequence. In some embodiments, the sequence encoding the polyA signal comprises a sequence isolated or derived from a non-naturally-occurring sequence. In some embodiments, the sequence encoding the polyA signal comprises a sequence isolated or derived from a mammalian sequence. In some embodiments, the sequence encoding the polyA signal comprises a sequence isolated or derived from a human sequence. In some embodiments, the sequence encoding the polyA signal comprises a sequence isolated or derived from a mammalian Bovine Growth Hormone (BGH) gene.
In some embodiments of the compositions of the disclosure, the nucleic acid sequence further comprises: (e) a sequence encoding a 5′ untranslated region (UTR). In some embodiments, the sequence encoding the 5′ UTR comprises a sequence isolated or derived from a naturally occurring sequence. In some embodiments, the sequence encoding the 5′ UTR comprises a sequence isolated or derived from a non-naturally-occurring sequence. In some embodiments, the sequence encoding the 5′ UTR comprises a sequence isolated or derived from a mammalian sequence. In some embodiments, the sequence encoding the 5′ UTR comprises a sequence isolated or derived from a human sequence. In some embodiments, the sequence encoding the 5′ UTR comprises a sequence isolated or derived from a viral sequence. In some embodiments of the compositions of the disclosure, the nucleic acid sequence further comprises: (f) a sequence encoding an intron, and (g) a sequence encoding an exon, wherein the sequence encoding the intron and the sequence encoding the exon are operably linked. In some embodiments, the intron is located between the sequence encoding the VMD2 promoter and the sequence encoding the exon, wherein the sequence encoding the exon is located between the sequence encoding the intron and the sequence encoding the 5′ UTR, and wherein the sequence encoding the intron is spliced by a mammalian cell. In some embodiments, the sequence encoding the exon comprises a sequence isolated or derived from a mammalian gene. In some embodiments, the sequence encoding the exon comprises a sequence isolated or derived from a rabbit (Oryctolagus cuniculus) beta globin gene. In some embodiments, the sequence encoding the intron comprises a non-naturally occurring sequence. In some embodiments, the sequence encoding the intron comprises a fusion sequence. In some embodiments, the sequence encoding the intron comprises a sequence encoding a splice donor site, and a sequence encoding a splice branch point and acceptor site. In some embodiments, the sequence encoding the splice donor site comprises a sequence isolated or derived from a vertebrate gene. In some embodiments, the sequence encoding the splice donor site comprises a sequence isolated or derived from a chicken (Gallus gallus) beta actin gene (CBA). In some embodiments, the sequence encoding the splice branch point and acceptor site comprises a sequence isolated or derived from a vertebrate gene. In some embodiments, the sequence encoding the splice branch point and acceptor site comprises a sequence isolated or derived from a rabbit (Oryctolagus cuniculus) beta globin gene.
In some embodiments of the compositions of the disclosure, the sequence encoding the 5′ UTR comprises a sequence encoding a Kozak sequence or a portion thereof. In some embodiments, the sequence encoding a Kozak sequence has at least 50% identity to the nucleic acid sequence of GCCRCCATGG. In some embodiments, the sequence encoding a Kozak sequence comprises or consists of the nucleic acid sequence of GGCACCATGA.
In some embodiments of the compositions of the disclosure, the sequence encoding the human VMD2 promoter comprises or consists of
In some embodiments of the compositions of the disclosure, the sequence encoding the CAG promoter comprises or consists of
In some embodiments of the compositions of the disclosure, the sequence encoding the human BEST1 protein comprises or consists of
The disclosure provides a vector comprising a composition of the disclosure. In some embodiments, the vector is a plasmid.
The disclosure provides a delivery vector comprising the vector of the disclosure. In some embodiments, the delivery vector is a viral delivery vector. In some embodiments, the delivery vector comprises a single stranded viral genome. In some embodiments, the delivery vector comprises a double stranded viral genome. In some embodiments, the delivery vector comprises an RNA molecule.
The disclosure provides a delivery vector comprising the vector of the disclosure. In some embodiments, the delivery vector comprises a sequence isolated or derived from an adeno-associated virus (AAV) vector. In some embodiments, the delivery vector comprises a sequence isolated or derived from an AAV vector of serotype AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11 or any combination thereof. In some embodiments, the delivery vector comprises a sequence isolated or derived from an AAV vector of serotype AAV2. In some embodiments, the delivery vector comprises a sequence isolated or derived from an AAV vector of serotype AAV8. In some embodiments, the delivery vector comprises a sequence encoding a first inverted terminal repeat (ITR) and a second ITR isolated or derived from an AAV vector of serotype AAV2 and a sequence encoding a viral gene isolated or derived from an AAV vector of serotype AAV2. In some embodiments, the delivery vector comprises a sequence encoding a first inverted terminal repeat (ITR) and a second ITR isolated or derived from an AAV vector of serotype AAV8 and a sequence encoding a viral gene isolated or derived from an AAV vector of serotype AAV8. In some embodiments, the delivery vector comprises a sequence encoding a first inverted terminal repeat (ITR) and a second ITR isolated or derived from an AAV vector of serotype AAV2 and a sequence encoding a viral gene isolated or derived from an AAV vector of serotype AAV8.
The disclosure provides a pharmaceutical composition comprising a composition of the disclosure and a pharmaceutically-acceptable carrier. In some embodiments, the pharmaceutically-acceptable carrier comprises TMN200.
The disclosure provides a pharmaceutical composition comprising a vector of the disclosure a pharmaceutically acceptable carrier. In some embodiments, the pharmaceutically acceptable carrier comprises TMN200.
The disclosure provides a pharmaceutical composition comprising a delivery vector of the disclosure and a pharmaceutically acceptable carrier. In some embodiments, the pharmaceutically acceptable carrier comprises TMN200.
The disclosure provides a cell comprising a composition of the disclosure. The disclosure provides a cell comprising a vector of the disclosure. The disclosure provides a cell comprising a delivery vector of the disclosure. The disclosure provides a cell comprising a pharmaceutical composition of the disclosure. In some embodiments, the cell is a mammalian cell. In some embodiments, the mammalian cell is a non-human primate cell, a rodent cell, a mouse cell, a rat cell or a rabbit cell. In some embodiments, the cell is a human cell. In some embodiments, the human cell is a neuronal cell, a glial cell, a retinal cell, a photoreceptor cell, a rod cell, a cone cell or a cuboidal cell of the retinal pigment epithelium (RPE). In some embodiments, the human cell is a photoreceptor cell. In some embodiments, the human cell is an HEK293 cell or an ARPE19 cell. In some embodiments, the human cell is isolated or derived from an RPE of a human retina. In some embodiments, the cell is in vivo, in vitro, ex vivo or in situ.
The disclosure provides a method of treating macular dystrophy in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a composition of the disclosure.
The disclosure provides a method of treating macular dystrophy in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a composition comprising the vector of the disclosure.
The disclosure provides a method of treating macular dystrophy in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a composition comprising the delivery vector of the disclosure.
In some embodiments of the methods of the disclosure, the subject is a human. In some embodiments, the subject is a non-human primate, a dog, a cat, a rodent, a mouse, a rat, or a rabbit. In some embodiments, the subject has macular dystrophy.
In some embodiments of the methods of the disclosure, the subject has a mutation in one or both copies of a BEST1 gene. In some embodiments, the mutation is heritable as a dominant mutation. In some embodiments, the dominant mutation causes Best Vitelliform Macular Dystrophy (BVMD) in the subject. In some embodiments, the mutation is heritable as a recessive mutation. In some embodiments, the recessive mutation causes Autosomal Recessive Bestrophinopathy (ARB) in the subject. In some embodiments, the mutation occurs in a coding sequence of one or both copies of a BEST1 gene. In some embodiments, the mutation occurs in a non-coding sequence of one or both copies of a BEST1 gene. In some embodiments, the mutation comprises a substitution, an insertion, a deletion, an inversion, a translocation, a frameshift, or a combination thereof in one both copies of a BEST1 gene.
In some embodiments of the methods of the disclosure, administering comprises an injection or an infusion via a subretinal, a suprachoroidal or an intravitreal route. In some embodiments, administering comprises an injection or an infusion via a subretinal route. In some embodiments, administering comprises a two-step injection or a two-step infusion via a subretinal route.
In some embodiments of the methods of the disclosure, the therapeutically effective amount is formulated in a volume of between 10 and 200 μL, inclusive of the endpoints. In some embodiments, the therapeutically effective amount is formulated in a volume of between 10 and 50 μL, between 50 and 100 μL, between 100 and 150 μL or between 150 and 200 μL, inclusive of the endpoints, for each range. In some embodiments, the therapeutically effective amount is formulated in a volume of between 70 and 120 μL, inclusive of the endpoints, and wherein the administering comprises an injection or an infusion via a subretinal route. In some embodiments, the therapeutically effective amount is formulated in a volume of 100 μL and wherein the administering comprises an injection or an infusion via a subretinal route.
In some embodiments of the methods of the disclosure, the therapeutically effective amount comprises a concentration of an AAV delivery vector of at least 1×1010 DRP/mL, at least 1×10″ DRP/mL, at least 1×1012 DRP/mL, at least 2×1012 DRP/mL, at least 5×1012 DRP/mL or at least 1.5×10″ DRP/mL. In some embodiments, the therapeutically effective amount comprises a concentration of an AAV delivery vector of at least 2×10″ DRP/mL, at least 5×10″ DRP/mL or at least 1.5×10″ DRP/mL. In some embodiments, the therapeutically effective amount comprises a concentration of an AAV delivery vector of at least 5×1012 DRP/mL. In some embodiments, the therapeutically effective amount comprises a concentration of an AAV delivery vector of at least 1.5×10″ DRP/mL.
In some embodiments of the methods of the disclosure, the therapeutically effective amount comprises a dose of 2×108 genome particles (gp), 5×108 gp, 1.5×109 gp, 2×109 gp, 5×109 gp, 2×1010 gp, 5×1010 gp, 6×1010 gp, 1.2×1011 gp, 1.5×1011 gp, 2×1011 gp, 4.5×1011 gp, 5×1011 gp, 1.2×1012 gp, 1.5×1012 gp, 2×1012 gp or 5×1012 gp. In some embodiments, the subject is a mouse and wherein the therapeutically effective amount comprises a dose of 5×108 gp, 1.5×109 gp or 5×109 gp. In some embodiments, the subject is a non-human primate and wherein the therapeutically effective amount comprises a dose of 1.2×1011 gp, 4.5×1011 gp or 1.2×1012 gp of AAV viral particles. In some embodiments, the subject is human and wherein the therapeutically effective amount comprises a dose of 5×1010 gp, 1.5×1011 gp, 1.5×1012 gp or 1.5×1012 gp of AAV viral particles.
In some embodiments of the methods of the disclosure, the composition further comprises a TMN200 buffer.
The disclosure provides a composition of the disclosure for use in treating macular dystrophy in a subject in need thereof.
The disclosure provides a vector of the disclosure for use in treating macular dystrophy in a subject in need thereof.
The disclosure provides a delivery vector of the disclosure for use in treating macular dystrophy in a subject in need thereof.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
The disclosure relates to the finding that in many cases macular degeneration may be caused by mutations in or the abnormal function of the protein Bestrophin-1 (BEST1, also known as VMD2). The macula is a region near the center of the retina, and is responsible for central, high-resolution color vision. The fovea, located near the center of the macula, contains the largest concentration of cone cell photoreceptors in the eye. Mutations in a gene called Bestrophin-1 (BEST1, or human BEST1 (hBEST1), also known as VMD2) are associated with at least five distinct retinal degeneration diseases, called bestrinopathies. Bestrinopathies comprise best vitelliform macular dystrophy (BVMD), autosomal recessive bestrophinopathy, adult-onset vitelliform macular dystrophy, autosomal dominant vitreoretinochoroidopathy and retinitis pigmentosa. These mutations can be either dominant (for example, BVMD) or recessive. Best Vitelliform Macular Dystrophy (BVMD) and Autosomal Recessive Bestrophinopathy may cause macular degeneration with an onset in late childhood or adolescence. However, in some cases, macular degeneration begins in adulthood. However, regardless of age of onset, bestrinopathies can have a devastating effect on vision, and there is currently no known effective treatment. Given the key role that BEST1 function plays in bestrophinopathies, one approach to the treatment of bestophinopathy is to deliver a functional BEST1 protein to the affected cells of the patient.
Bestrophin-1 (BEST1) is an integral membrane protein found primarily in the retinal pigment epithelium of the eye (RPE) and predominantly localizes to the basolateral plasma membrane. BEST1 protein is thought to function as an ion channel and a regulator of intracellular calcium signaling. Human BEST1 can be found in the NCBI database with accession numbers NP_004174.1 and NM_004183.3, the contents of which are incorporated by reference in their entirety herein.
In some embodiments of the compositions of the disclosure, a sequence encoding a BEST1 protein of the disclosure comprises or consists of an amino acid sequence having at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity to the sequence of:
In some embodiments of the compositions of the disclosure, a sequence encoding a BEST1 protein of the disclosure comprises or consists of the amino acid sequence:
In some embodiments of the compositions of the disclosure, a nucleic acid sequence encoding a BEST1 protein of the disclosure comprises or consists of a nucleic acid having at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity to the nucleic acid sequence of:
In some embodiments of the compositions of the disclosure, a nucleic acid sequence encoding a BEST1 protein of the disclosure comprises or consists of the nucleic acid sequence:
In some embodiments of the compositions of the disclosure, a nucleic acid sequence encoding a BEST1 protein of the disclosure comprises a codon optimized sequence. In some embodiments, the sequence has been codon optimized for expression in a mammalian cell. In some embodiments, the sequence has been codon optimized for expression in a human cell.
In some embodiments of the compositions of the disclosure, a nucleic acid sequence encoding a BEST1 protein of the disclosure further comprises a sequence encoding a regulatory element that enhances or increases BEST1 transcript or BEST1 protein expression. Exemplary regulatory element that enhances or increases BEST1 transcript or BEST1 protein expression include, but are not limited to, a promoter, an enhancer, a superenhancer, an intron, an exon, a combination of an intron and exon, a sequence encoding an untranslated region (e.g. a 5′ untranslated region (UTR) or a 3′ UTR), a sequence comprising a polyadenylation (polyA) signal, and a posttranscriptional regulatory element (PRE).
Exemplary promoters of the disclosure include, but are not limited to, those promoters capable of expressing a sequence encoding a BEST1 protein or a BEST1 protein in a mammalian cell. Exemplary promoters of the disclosure include, but are not limited to, those promoters capable of expressing a sequence encoding a BEST1 protein or a BEST1 protein in a human cell. In some embodiments, the mammalian or the human cell may be in vivo, ex vivo, in vitro or in situ. In some embodiments, the promoter may be constitutively active. In some embodiments, the promoter may be cell-type specific. In some embodiments, the promoter may be inducible.
Exemplary constitutively active promoters of the disclosure include, but are not limited to, a viral promoter. Viral promoters of the disclosure may include, but are not limited to, a simian virus 40 (SV40) promoter, a cytomegalovirus (CMV) promoter, ubiquitin C (UBC) promoter, elongation factor-1 alpha (EF1A) promoter, phosphoglycerate kinase 1 (PGK) promoter and a CAG promoter (a combination of a (C) the cytomegalovirus (CMV) early enhancer element, (A) the promoter comprising the first exon and the first intron of chicken beta-actin gene, and (G) the splice acceptor of the rabbit beta-globin gene). In some embodiments, a CMV promoter is used to control expression of a nucleic acid sequence encoding a BEST1 protein of the disclosure. In some embodiments, a CAG promoter is used to control expression of a nucleic acid sequence encoding a BEST1 protein of the disclosure. Non-viral promoters of the disclosure may include, but are not limited to, a chicken beta actin (CBA) promoter. In some embodiments, the CBA promoter comprises the chicken beta actin the first exon and intron of the CBA gene. In some embodiments, the promoter comprises the chicken beta actin promoter and the cytomegalovirus early enhancer elements. In some embodiments, the promoter further comprises a rabbit beta globin splice acceptor sequence (the CAG promoter). In some embodiments, the CAG promoter comprises or consists of a nucleic acid sequence having at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity to the nucleic acid sequence of:
Exemplary cell-type specific promoters of the disclosure include, but are not limited to, a promoter capable of expressing a nucleic acid or a protein in a neuron, a promoter capable of expressing a nucleic acid or a protein in a retinal cell, a promoter capable of expressing a nucleic acid or a protein in a photoreceptor, a promoter capable of expressing a nucleic acid or a protein in a rod cell, and a promoter capable of expressing a nucleic acid or a protein in a cone cell. In some embodiments, a sequence encoding a tissue specific promoter comprises a sequence encoding a human VMD2 gene (also known as Bestrophin-1). In some embodiments, a tissue specific promoter comprises a human VMD2 promoter (also known as Bestrophin-1). In some embodiments, the human VMD2 promoter comprises or consists of a nucleic acid sequence having at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% identity to the nucleic acid sequence of:
In some embodiments, the human VMD2 promoter comprises or consists of a nucleic acid sequence having 100% identity to the nucleic acid sequence of:
In some embodiments of the compositions of the disclosure, the nucleic acid sequence comprising a sequence encoding a BEST1 protein and a sequence encoding a promoter, further comprises an intron and an exon. The presence of an intron and an exon increases levels of protein expression. In some embodiments, the intron is positioned between the VMD2 promoter and the exon. In some embodiments, including those embodiments wherein the intron is positioned between the VMD2 promoter and the exon, the exon is positioned 5′ of the BEST coding sequence.
The exon may comprise a coding sequence, a non-coding sequence, or a combination of both. In some embodiments, the exon comprises non-coding sequence. In some embodiments, the exon is isolated or derived from a mammalian gene. In embodiments, the mammal is a rabbit (Oryctolagus cuniculus). In some embodiments, the mammalian gene comprises a rabbit beta globin gene. In some embodiments, the exon comprises a nucleic acid sequence having at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to the nucleic acid sequence of:
In some embodiments, the exon comprises a nucleic acid sequence having 100% identify to the nucleic acid sequence of:
Introns may comprise a splice donor site, a splice acceptor site or a branch point. Introns may comprise a splice donor site, a splice acceptor site and a branch point. Exemplary splice acceptor sites comprise nucleotides “GT” (“GU” in the pre-mRNA) at the 5′ end of the intron. Exemplary splice acceptor sites comprise an “AG” at the 3′ end of the intron. In some embodiments, the branch point comprises an adenosine (A) between 20 and 40 nucleotides, inclusive of the endpoints, upstream of the 3′ end of the intron. The intron may be an artificial or non-naturally occurring sequence. Alternatively, the intron may be isolated or derived from a vertebrate gene. The intron may comprise a sequence encoding a fusion of two sequences, each of which may be isolated or derived from a plurality of vertebrate genes. In some embodiments, a vertebrate gene contributing to the intron nucleic acid sequence comprises a chicken (Gallus gallus) gene. In some embodiments, the chicken gene comprises the chicken beta actin gene. In some embodiments, a vertebrate gene contributing to the intron nucleic acid sequence comprises a rabbit (Oryctolagus cuniculus) gene. In some embodiments, the rabbit gene comprises the rabbit beta globin gene. In some embodiments, the intron comprises a nucleic acid sequence having at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to the nucleic acid sequence of:
In some embodiments, the intron comprises a nucleic acid sequence having 100% identify to the nucleic acid sequence of:
Kozak sequences are short sequence motifs that are recognized by the ribosome as the translation start site. Kozak sequences may be positioned immediately upstream, or surrounding the translational start site. In vertebrates, the Kozak consensus sequence comprises a sequence of having at least 50% identity to the consensus sequence of gccRccATGG, where R represents an A or G, and the ATG encoding the start methionine is bolded. An exemplary Kozak sequence of the disclosure comprises a sequence of GGCACCATGA. In some embodiments, the nucleic acid comprising a nucleic acid sequence encoding BEST1, further comprises a sequence encoding a 5′ untranslated sequence (5′ UTR). In some embodiments, the 5′ UTR comprises a Kozak sequence. In some embodiments, the 5′ UTR comprises a portion of a Kozak sequence. In some embodiments, the 5′ UTR comprises at least 50%, at least 60%, at least 70% or at least 80% of a Kozak sequence.
In some embodiments, the nucleic acid comprising a nucleic acid sequence encoding BEST1, further comprises a nucleic acid sequence encoding transcriptional response element (PRE). Exemplary PREs comprise a Woodchuck PRE (WPRE), which is derived from the Woodchuck hepatitis virus. In some embodiments, a sequence encoding a WPRE is positioned 3′ of the nucleic acid sequence encoding BEST1. In some embodiments, a sequence encoding a WPRE is positioned between the nucleic acid sequence encoding BEST1 and the sequence encoding a polyA signal. In some embodiments, a sequence encoding a WPRE comprises a nucleic acid sequence having at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to the nucleic acid sequence of:
In some embodiments, a sequence encoding a WPRE comprises a nucleic acid sequence having 100% identity to the nucleic acid sequence of:
In some embodiments, the nucleic acid comprising a nucleic acid sequence encoding BEST1, further comprises a sequence encoding a polyadenylation (polyA) signal. The polyA signal facilitates nuclear export, enhances translation and increases mRNA stability. In some embodiments, the sequence encoding the polyA signal comprises a synthetic or an artificial sequence. In some embodiments, the sequence encoding the polyA signal comprises a sequence isolated or derived from a mammalian gene. In some embodiments, the mammalian gene is a human gene. In some embodiments, the mammalian gene is a bovine growth hormone gene
(BGH). In some embodiments, the sequence encoding the polyA signal comprises a nucleic acid sequence having at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99% identity to the nucleic acid sequence of:
In some embodiments, the sequence encoding the polyA signal comprises a nucleic acid sequence having 100% identity to the nucleic acid sequence of:
A vector may comprise the nucleic acid comprising a nucleic acid sequence encoding BEST1. In some embodiments of the compositions of the disclosure, the vector may be a viral delivery vector. Viral delivery vectors of the disclosure may contain sequences necessary for packaging a nucleic acid sequence of the disclosure into a viral delivery system for delivery to a target cell or tissue. Typical viral delivery vectors of the disclosure include, but are not limited to, lentiviral, retroviral or adeno-associated viral (AAV) vectors.
An AAV viral delivery system of the disclosure may be in the form of a mature AAV particle or virion, i.e. nucleic acid surrounded by an AAV protein capsid. In some embodiments, the AAV viral delivery vector may comprise an AAV genome or a derivative thereof.
An AAV genome is a nucleic acid sequence which encodes functions needed for production of an AAV particle. These functions include those operating in the replication and packaging cycle of AAV in a host cell, including encapsidation of the AAV genome into an AAV particle. Naturally occurring AAVs are replication-deficient and rely on the provision of helper functions in trans for completion of a replication and packaging cycle. In preferred embodiments, an AAV genome of a vector of the disclosure is replication-deficient.
The AAV genome may be in single-stranded form, either positive or negative-sense, or alternatively in double-stranded form. The use of a double-stranded form allows bypass of the DNA replication step in the target cell and so can accelerate transgene expression. The AAV genome of a vector of the disclosure may be single-stranded form.
The AAV genome may be from any naturally derived serotype, isolate or Glade of AAV. Thus, the AAV genome may be the full genome of a naturally occurring AAV. As is known to the person skilled in the art, AAVs occurring in nature may be classified according to various biological systems.
AAVs are referred to in terms of their serotype. A serotype corresponds to a variant subspecies of AAV which, owing to its profile of expression of capsid surface antigens, has a distinctive reactivity which can be used to distinguish it from other variant subspecies. A virus having a particular AAV serotype does not efficiently cross-react with neutralizing antibodies specific for any other AAV serotype. AAV serotypes include AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10 and AAV11, and also recombinant serotypes, such as Rec2 and Rec3, recently identified from primate brain. Any of these AAV serotypes may be used in the invention. Thus, in some embodiments, an AAV vector of the invention may be derived from an AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, Rec2 or Rec3 AAV.
Reviews of AAV serotypes may be found in Choi et al. (2005) Cur. Gene There. 5: 299-310 and Wu et al. (2006) Molecular Therapy 14: 316-27. The sequences of AAV genomes or of elements of AAV genomes including ITR sequences, rep or cap genes may be derived from the following accession numbers for AAV whole genome sequences: Adeno-associated virus 1 NC_002077, AF063497; Adeno-associated virus 2 NC_001401; Adeno-associated virus 3 NC_001729; Adeno-associated virus 3B NC_001863; Adeno-associated virus 4 NC_001829; Adeno-associated virus 5 Y18065, AF085716; Adeno-associated virus 6 NC_001862; Avian AAV ATCC VR-865 AY186198, AY629583, NC_004828; Avian AAV strain DA-1 NC_006263, AY629583; Bovine AAV NC_005889, AY388617.
AAV may also be referred to in terms of clades or clones. This refers to the phylogenetic relationship of naturally derived AAVs, as well as to a phylogenetic group of AAVs which can be traced back to a common ancestor, and includes all descendants thereof. Additionally, AAVs may be referred to in terms of a specific isolate, i.e. a genetic isolate of a specific AAV found in nature. The term genetic isolate describes a population of AAVs which has undergone limited genetic mixing with other naturally occurring AAVs, thereby defining a recognizably distinct population at a genetic level.
The AAV serotype determines the tissue specificity of infection (or tropism) of an AAV virus. Accordingly, preferred AAV serotypes for use in AAVs administered to patients in accordance with the invention are those which have natural tropism for or a high efficiency of infection of target cells within the eye. In one embodiment, AAV serotypes for use in the invention are those which infect cells of the neurosensory retina, retinal pigment epithelium and/or macula.
The AAV genome of a naturally derived serotype, isolate or Glade of AAV comprises at least one inverted terminal repeat sequence (ITR). An ITR sequence acts in cis to provide a functional origin of replication and allows for integration and excision of the vector from the genome of a cell.
An AAV viral delivery vector may include at least one inverted terminal repeat sequence (ITR), preferably more than one ITR, such as two ITRs or more. One or more of the ITRs may be derived from AAV genomes having different serotypes, or may be a chimeric or mutant ITR. A preferred mutant ITR is one having a deletion of a trs (terminal resolution site). This deletion allows for continued replication of the genome to generate a single-stranded genome which contains both coding and complementary sequences, i.e. a self-complementary AAV genome. This allows for bypass of DNA replication in the target cell, and so enables accelerated transgene expression.
The inclusion of one or more ITRs is preferred to aid concatamer formation of a viral delivery vector of the invention in the nucleus of a host cell, for example following the conversion of single-stranded vector DNA into double-stranded DNA by the action of host cell DNA polymerases. The formation of such episomal concatamers protects the vector construct during the life of the host cell, thereby allowing for prolonged expression of the transgene in vivo.
In some embodiments, ITR elements are the only sequences retained from the native AAV genome in the viral delivery vector. Thus, in some embodiments, a viral delivery vector does not include either the rep or cap genes of the native genome and, furthermore, lacks any other sequences of the native genome. This is preferred for the reasons described above, and also to reduce the possibility of integration of the vector into the host cell genome. Additionally, reducing the size of the AAV genome allows for increased flexibility in incorporating other sequence elements (such as regulatory elements) within the vector in addition to the transgene. In some embodiments, the viral delivery vector of the disclosure comprises sequences encoding AAV2 ITRs. In some embodiments, the sequences encoding the two AAV2 ITRs may comprise or consist of a nucleic acid sequence of:
and/or
The AAV genome may comprise a nucleic acid sequence of about 4.7 kb in length. Thus, in those embodiments where the nucleic acid sequence to be delivered by an AAV viral vector is less than 4.7 kb in length, a stuffer or filler sequence may be used. The presence of a stuffer sequence can, in some embodiments, aid in AAV viral vector packaging into the viral particle. In some embodiments, the stuffer sequence comprises a random sequence. An exemplary stuffer sequence of the disclosure may comprise or consist of the nucleic acid sequence of:
In some embodiments, the AAV viral delivery vector comprises a nucleic acid sequence comprising a sequence encoding a VMD2 promoter, a sequence encoding a BEST1 protein, and a sequence encoding a WPRE. An exemplary AAV viral delivery vector of the disclosure comprising this nucleic acid sequence (VMD2.BEST1.WPRE.pA) comprises or consists of the nucleic acid sequence of:
In some embodiments, the AAV viral delivery vector comprising a nucleic acid sequence comprising a sequence encoding a VMD2 promoter, a sequence encoding a BEST1 protein, a sequence encoding an intron, a sequence encoding an exon and a sequence encoding a WPRE. An exemplary AAV viral delivery vector of the disclosure comprises a nucleic acid sequence encoding a VMD2. IntEx.BEST1.WPRE.pA sequence comprising or consisting of the nucleic acid sequence of:
In some embodiments, the AAV viral delivery vector comprises a nucleic acid sequence comprising a sequence encoding a CAG promoter, a sequence encoding a BEST1 protein and a sequence encoding a WPRE. An exemplary AAV viral delivery vector of the disclosure comprising a nucleic acid sequence encoding a CAG.BEST1.WPRE.pA sequence comprises or consists of the nucleic acid sequence of:
In some embodiments of the compositions of the disclosure, a vector may comprise a sequence encoding a marker, which may be expressed in a cell when the cell is either in vitro or in vivo. For example, in a vector or nucleic acid sequence of the disclosure, a sequence encoding a marker may be used in place of or may replace a sequence encoding a BEST1 protein of the disclosure (e.g. a sequence comprising a coding sequence of a BEST1 gene). Exemplary markers of the disclosure include, but are not limited to, fluorophore proteins such as GFP, YFP or dsRED as well as various epitope tags such as FLAG, HA, His or Myc. The fluorophore or epitope tag may be fused to the BEST1 coding sequence, for example as an N or C terminal fusion, or may be used in place of BEST1 to characterize a vector of the disclosure. Exemplary uses for a vector containing a marker of the disclosure include, but are not limited to characterizing gene expression, for example levels of expression, or characterizing the cell type specificity of a vector of the disclosure.
An exemplary a vector of the disclosure comprising a marker includes VMD2.GFP.WPRE.pA. A nucleic acid sequence encoding a VMD2.GFP.WPRE.pA construct comprises or consists of:
An exemplary a vector of the disclosure comprising a marker includes VMD. IntEx.GFP.WPRE.pA. A nucleic acid sequence encoding a VMD. IntEx.GFP.WPRE.pA construct comprises or consists of:
The AAV vectors of the disclosure contain an AAV genome that has been derivatized for the purpose of administration to patients. Such derivatization is standard in the art and the invention encompasses the use of any known derivative of an AAV genome, and derivatives which could be generated by applying techniques known in the art. Derivatization of the AAV genome and of the AAV capsid are reviewed in Coura and Nardi (2007) Virology Journal 4: 99, and in Choi et al. and Wu et al., referenced above.
Derivatives of an AAV genome include any truncated or modified forms of an AAV genome which allow for expression of a transgene from a vector of the invention in vivo. It is possible to truncate the AAV genome significantly to include minimal viral sequence yet retain the above function. This is preferred for safety reasons to reduce the risk of recombination of the vector with wild-type virus, and also to avoid triggering a cellular immune response by the presence of viral gene proteins in the target cell.
The following portions could therefore be removed in a derivative of the invention: one inverted terminal repeat (ITR) sequence, the replication (rep) and capsid (cap) genes. However, in some embodiments, derivatives may additionally include one or more rep and/or cap genes or other viral sequences of an AAV genome. Naturally occurring AAV integrates with a high frequency at a specific site on human chromosome 19, and shows a negligible frequency of random integration, such that retention of an integrative capacity in the vector may be tolerated in a therapeutic setting.
The AAV genome comprises packaging genes, such as rep and/or cap genes which encode packaging functions for an AAV particle. The rep gene encodes one or more of the proteins Rep78, Rep68, Rep52 and Rep40 or variants thereof. The cap gene encodes one or more capsid proteins such as VP1, VP2 and VP3 or variants thereof. These proteins make up the capsid of an AAV particle.
Where a derivative comprises capsid proteins i.e. VP1, VP2 and/or VP3, the derivative may be a chimeric, shuffled or capsid-modified derivative of one or more naturally occurring AAVs. In particular, the invention encompasses the provision of capsid protein sequences from different serotypes, clades, clones, or isolates of AAV within the same vector (i.e. a pseudotyped vector).
Chimeric, shuffled or capsid-modified derivatives are selected to provide one or more desired functionalities for the viral vector. Thus, these derivatives may display increased efficiency of gene delivery, decreased immunogenicity (humoral or cellular), an altered tropism range and/or improved targeting of a particular cell type compared to an AAV vector comprising a naturally occurring AAV genome, such as that of AAV2. Increased efficiency of gene delivery may be effected by improved receptor or co-receptor binding at the cell surface, improved internalization, improved trafficking within the cell and into the nucleus, improved uncoating of the viral particle and improved conversion of a single-stranded genome to double-stranded form. Increased efficiency may also relate to an altered tropism range or targeting of a specific cell population, such that the vector dose is not diluted by administration to tissues where it is not needed.
Chimeric capsid proteins include those generated by recombination between two or more capsid coding sequences of naturally occurring AAV serotypes. This may be performed for example by a marker rescue approach in which non-infectious capsid sequences of one serotype are co-transfected with capsid sequences of a different serotype, and directed selection is used to select for capsid sequences having desired properties. The capsid sequences of the different serotypes can be altered by homologous recombination within the cell to produce novel chimeric capsid proteins.
Chimeric capsid proteins also include those generated by engineering of capsid protein sequences to transfer specific capsid protein domains, surface loops or specific amino acid residues between two or more capsid proteins, for example between two or more capsid proteins of different serotypes.
Shuffled or chimeric capsid proteins may also be generated by DNA shuffling or by error-prone PCR. Hybrid AAV capsid genes can be created by randomly fragmenting the sequences of related AAV genes e.g. those encoding capsid proteins of multiple different serotypes and then subsequently reassembling the fragments in a self-priming polymerase reaction, which may also cause crossovers in regions of sequence homology. A library of hybrid AAV genes created in this way by shuffling the capsid genes of several serotypes can be screened to identify viral clones having a desired functionality. Similarly, error prone PCR may be used to randomly mutate AAV capsid genes to create a diverse library of variants which may then be selected for a desired property.
The sequences of the capsid genes may also be genetically modified to introduce specific deletions, substitutions or insertions with respect to the native wild-type sequence. In particular, capsid genes may be modified by the insertion of a sequence of an unrelated protein or peptide within an open reading frame of a capsid coding sequence, or at the N- and/or C-terminus of a capsid coding sequence. The unrelated protein or peptide may advantageously be one which acts as a ligand for a particular cell type, thereby conferring improved binding to a target cell or improving the specificity of targeting of the vector to a particular cell population. The unrelated protein may also be one which assists purification of the viral particle as part of the production process, i.e. an epitope or affinity tag. The site of insertion will is selected so as not to interfere with other functions of the viral particle e.g. internalization, trafficking of the viral particle. The skilled person can identify suitable sites for insertion based on their common general knowledge. Particular sites are disclosed in Choi et al., referenced above.
The invention additionally encompasses the provision of sequences of an AAV genome in a different order and configuration to that of a native AAV genome. The invention also encompasses the replacement of one or more AAV sequences or genes with sequences from another virus or with chimeric genes composed of sequences from more than one virus. Such chimeric genes may be composed of sequences from two or more related viral proteins of different viral species.
AAV vectors of the invention include transcapsidated forms wherein an AAV genome or derivative having an ITR of one serotype is packaged in the capsid of a different serotype. AAV vectors of the invention also include mosaic forms wherein a mixture of unmodified capsid proteins from two or more different serotypes makes up the viral capsid. An AAV vector may also include chemically modified forms bearing ligands adsorbed to the capsid surface. For example, such ligands may include antibodies for targeting a particular cell surface receptor.
Thus, for example, AAV vectors of the invention include those with an AAV2 genome and AAV2 capsid proteins (AAV2/2), those with an AAV2 genome and AAV5 capsid proteins (AAV2/5) and those with an AAV2 genome and AAV8 capsid proteins (AAV2/8). An AAV vector of the invention may comprise a mutant AAV capsid protein. In one embodiment, an AAV vector of the invention comprises a mutant AAV8 capsid protein. Preferably the mutant AAV8 capsid protein is an AAV8 Y733F capsid protein.
Methods of making AAV viral particles of the disclosure will be known to one of skill in the art. An exemplary, but non-limiting method of preparing AAV viral particles of the disclosure is described below. For generation of a given AAV vector, three plasmids are required: one comprising the viral delivery vector encoding the nucleic acid sequence of interest to be delivered (i.e. the nucleic acid sequence encoding BEST1), a plasmid encoding the rep and cap genes, and a third helper plasmid that contains the required adenoviral genes necessary for successful AAV generation. A promoter may be operably linked to each of the packaging genes. Specific examples of such promoters include the p5, p19 and p40 promoters (Laughlin et al. (1979) Proc. Natl. Acad. Sci. USA 76: 5567-5571). For example, the p5 and p19 promoters are generally used to express the rep gene, while the p40 promoter is generally used to express the cap gene. The plasmids are used to transfect suitable cells that are capable of replicating the AAV viral vector, transcribing and translating the AAV protein, and packaging the AAV viral vector into an AAV viral particle. Exemplary suitable cells comprise HEK293 cells. Post-transfection, the cells are collected and lysed. AAV particles can then be purified from the lysate through a variety of methods. Alternatively, AAV particles can be purified from the supernatant. For example, the lysate can be treated with Benzonase and clarified before applying to an iodixanol gradient comprised of 15%, 25%, 40% and 60% phases. The gradients can spun at 59,000 rpm for 1 hour 30 minutes and the 40% fraction then withdrawn. This AAV phase can then purified and concentrated using an Amicon Ultra-15 100K filter unit.
The AAV vectors of the invention may be formulated into pharmaceutical compositions. These compositions may comprise, in addition to the medicament, a pharmaceutically acceptable carrier, diluent, excipient, buffer, stabilizer or other materials well known in the art. Such materials should be non-toxic and should not interfere with the efficacy of the active ingredient. The precise nature of the carrier or other material may be determined by the skilled person according to the route of administration, e.g. subretinal, direct retinal or intravitreal injection.
The pharmaceutical composition may be formulated as a liquid. Liquid pharmaceutical compositions may include a liquid carrier such as water, petroleum, animal or vegetable oils, mineral oil or synthetic oil. Physiological saline solution, magnesium chloride, dextrose or other saccharide solution, or glycols such as ethylene glycol, propylene glycol or polyethylene glycol may be included. In some cases, a surfactant, such as pluronic acid (PF68) 0.001% may be used.
For injection at the site of affliction, the active ingredient may be in the form of an aqueous solution which is pyrogen-free, and has suitable pH, isotonicity and stability. The skilled person is well able to prepare suitable solutions using, for example, isotonic vehicles such as Sodium Chloride Injection, Ringer's Injection or Lactated Ringer's Injection. Preservatives, stabilisers, buffers, antioxidants and/or other additives may be included as required.
Buffers may have an effect on the stability and biocompatibity of the viral vectors and vector particles of the disclosure following storage and passage through injection devices for AAV gene therapy. In some embodiments, the viral vectors and vector particles of the disclosure may be diluted in TMN 200 buffer to maintain biocompatibility and stability. TMN 200 buffer comprises 20 mM Tris (pH adjusted to 8.0), 1 mM MgCl2 and 200 mM NaCl.
The determination of the physical viral genome titer comprises part of the characterization of the viral vector or viral particle. In some embodiments, determination of the physical viral genome titre comprises a step in ensuring the potency and safety of viral vectors and viral particles during gene therapy. In some embodiments, a method to determine the AAV titer comprises quantitative PCR (qPCR). There are different variables that can influence the results, such as the conformation of the DNA used as standard or the enzymatic digestion during the sample preparation. The viral vector or particle preparation whose titer may be measured may be compared against a standard dilution curve generated using a plasmid. In some embodiments, the plasmid DNA used in the standard curve is in the supercoiled conformation. In some embodiments, the plasmid DNA used in the standard curve is in the linear conformation. Linearized plasmid can be prepared, for example by digestion with HindIII restriction enzyme, visualized by agarose gel electrophoresis and purified using the QIAquick Gel Extraction Kit (Qiagen) following manufacturer's instructions. Other restriction enzymes that cut within the plasmid used to generate the standard curve may also be appropriate. In some embodiments, the use of supercoiled plasmid as the standard increased the titre of the AAV vector compared to the use of linearized plasmid.
To extract the DNA from purified AAV vectors for quantification of AAV genome titer, two enzymatic methods can be used. In some embodiments, the AAV vector may be singly digested with DNase I. In some embodiments, the AAV vector may be double digested with DNase I and an additional proteinase K treatment. QPCR can then performed with the CFX Connect Real-Time PCR Detection System (BioRad) using primers and Taqman probe specific to the transgene sequence.
For delayed release, the medicament may be included in a pharmaceutical composition which is formulated for slow release, such as in microcapsules formed from biocompatible polymers or in liposomal carrier systems according to methods known in the art.
As used herein, the term “Dnase resistant particle (DRP)” refers to AAV particles that are resistant to Dnase digestion, and are therefore thought to completely encapsulate and protect the AAV vector of the disclosure from Dnase digestion. AAV particles may also be quantified in terms of the total numbers of genome particles (gp) administered in a dose, or gp/mL, the number genome particles per milliliter (mL) of solution. As used herein, genome particle (gp) refers to AAV particles containing a copy of an AAV delivery vector (or AAV genome) of the disclosure. As used herein, the term genome content (GC) per mL refers to the number of viral genomes per mL of solution, and may be determined, for example, by qPCR as described above. The terms GC and VG (viral genomes) may be used synonymously to characterize AAV dosages and concentrations of the disclosure.
In some embodiments of the compositions of the disclosure, a composition comprising an AAV vector or an AAV vector is administered to a subject as a single dose.
In some embodiments of the compositions of the disclosure, a composition comprising an AAV vector or an AAV vector may be formulated as a liquid suspension wherein the AAV vectors are suspended in a pharmaceutically-acceptable carrier. In some embodiments, compositions of the disclosure may comprise a plurality of AAV vectors at a concentration of 1−2×109, 1−2×1010, 1−2×1011, 1−2×1012 or 1−2×1013 genome particles (gp) per mL. In some embodiments, compositions of the disclosure may comprise a plurality of AAV vectors at a concentration of 5×1011 DRP/mL, 1.5×1012 DRP/mL, 5×1012 DRP/mL, 1.2×1012 DRP/mL, 4.5×1012 DRP/mL, 1.2×1013 DRP/mL, 1.5×1013 DRP/mL or 5×1013 DRP/1.2×1012 DRP/mL. In some embodiments, compositions of the disclosure may comprise a plurality of AAV vectors at a concentration of 5×1012 DRP per mL. In some embodiments, compositions of the disclosure may comprise a plurality of AAV vectors at a concentration of 1.5×1013 DRP per mL. Thus, to administer a dose of AAV vector of about 2×1010 gp, for example, a single injection of about 10 microliters of a pharmaceutical composition having a concentration of about 2×1012 gp per mL will achieve the desired dose in vivo.
In some embodiments of the compositions of the disclosure, a composition comprising an AAV vector or an AAV vector may comprise a volume of between 1 and 500 μl, inclusive of the endpoints. In some embodiments of the compositions of the disclosure, a composition comprising an AAV vector or an AAV vector may comprise a volume of between 10-500, 50-500, 100-500, 200-500, 300-500, 400-500, 50-250, 100-250, 200-250, 50-150, 1-100 or 1-10 μl, inclusive of the endpoints for each range. In some embodiments of the compositions of the disclosure, a composition comprising an AAV vector or an AAV vector may comprise a volume of 1, 2, 5, 10, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500 μl or any number of microliters in between. In some embodiments, a composition comprising an AAV vector or an AAV vector may comprise 100 μl.
In some embodiments of the compositions of the disclosure, an entire volume of a composition comprising an AAV vector or an AAV vector may be injected in a single injection. In some embodiments, a portion of a volume of a composition comprising an AAV vector or an AAV vector may be injected in a single injection. In some embodiments, a first portion of a volume of a composition comprising an AAV vector or an AAV vector may be injected in a first single injection and a second portion of a volume of a composition comprising an AAV vector or an AAV vector may be injected in a second single injection
In some embodiments of the compositions of the disclosure, a composition comprising an AAV vector or an AAV vector is administered at a dosage of at least 2×107, 2×108, 5×108, 1.5×109, 2×109, 5×109, 2×1010, 5×1010, 6×1010, 1.2×1011, 2×1011, 4.5×1011, 5×1011, 1.2×1012, 1.5×1012, 2×1012 or 5×1012 gp per eye. In some embodiments, a composition comprising an AAV vector or an AAV vector is administered at a dosage of about 5×1010, 1.5×1011, 5×1011 or 1.5×1011 gp per eye. In some embodiments, a composition comprising an AAV vector or an AAV vector is administered at a dosage of about 5×1011 DRP per eye, by subretinal injection. In some embodiments, a composition comprising an AAV vector or an AAV vector is administered at a dosage of about 2×1010 gp per eye, by subretinal injection. In some embodiments, a composition comprising an AAV vector or an AAV vector is administered at a dosage of about 5×1010 gp per eye, by subretinal injection. In some embodiments, the AAV vector is administered at a dosage of about 6×1010 gp per eye, by subretinal injection. In some embodiments, a composition comprising an AAV vector or an AAV vector is administered at a dosage of about 1.5×1011 gp per eye, by subretinal injection. In some embodiments, a composition comprising an AAV vector or an AAV vector is administered at a dosage of about 2×1011 gp per eye, by subretinal injection. In some embodiments, a composition comprising an AAV vector or an AAV vector is administered at a dosage of about 5×1011 gp per eye, by subretinal injection. In some embodiments, a composition comprising an AAV vector or an AAV vector is administered at a dosage of about 1.5×1012 gp per eye, by subretinal injection.
Dosages or volumes may be calculated based on allometric scaling between species based on vitreal volume. “Allometry”, as used herein, refers to the changes in organisms with respect to body size. Some factors to take into account when comparing species include body volume, surface area, metabolic rate, and unique anatomical, physiological or biochemical processes. The human equivalent dose can be normalized to body surface area, body weight or a combination of surface area and weight. Other factors may also be taken into account.
The viral vectors of the invention may be administered to the eye of a subject by subretinal, direct retinal, suprachoroidal or intravitreal injection. A skilled person will be familiar with and well able to carry out individual subretinal, direct retinal or intravitreal injections.
Subretinal injections are injections into the subretinal space, i.e. underneath the neurosensory retina. During a subretinal injection, the injected material is directed into, and creates a space between, the photoreceptor cell and retinal pigment epithelial (RPE) layers. When the injection is carried out through a small retinotomy, a retinal detachment may be created. The detached, raised layer of the retina that is generated by the injected material is referred to as a “bleb”. The hole created by the subretinal injection must be sufficiently small that the injected solution does not significantly reflux back into the vitreous cavity after administration. Such reflux would be particularly problematic when a medicament is injected, because the effects of the medicament would be directed away from the target zone. Preferably, the injection creates a self-sealing entry point in the neurosensory retina, i.e. once the injection needle is removed, the hole created by the needle reseals such that very little or substantially no injected material is released through the hole.
To facilitate this process, specialist subretinal injection needles are commercially available (e.g. DORC 41G Teflon subretinal injection needle, Dutch Ophthalmic Research Center International BV, Zuidland, The Netherlands). These are needles designed to carry out subretinal injections.
Alternatively, subretinal injections can be performed by delivering the composition comprising AAV particles under direct visual guidance using an operating microscope (Leica Microsystems, Germany). One exemplary approach is that of using a scleral tunnel approach through the posterior pole to the superior retina with a Hamilton syringe and 34-gauge needle (ESS labs, UK). Alternatively, sub-retinal injections can be performed using an anterior chamber paracentesis with a 33G needle prior to the subretinal injection using a WPI syringe and a beveled 35G-needle system (World Precision Instruments, UK). An additional alternative is a WPI Nanofil Syringe (WPI, part #NANOFIL) and a 34 gauge WBI Nanofil needle (WPI, part # NF34BL-2).
Vectors or compositions of the disclosure may be administered via suprachoroidal injection. Any means of suprachoroidal injection is envisaged as a potential delivery system for a vector or a composition of the disclosure. Suprachoroidal injections are injections into the suprachoroidal space, which is the space between the choroid and the sclera. Injection into the suprachoroidal space is thus a potential route of administration for the delivery of compositions to proximate eye structures such as the retina, retinal pigment epithelium (RPE) or macula. In some embodiments, injection into the suprachoroidal space is done in an anterior portion of the eye using a microneedle, microcannula, or microcatheter. An anterior portion of the eye may comprise or consist of an area anterior to the equator of the eye. The vector composition or AAV viral particles may diffuse posteriorly from an injection site via a suprachoroidal route. In some embodiments, the suprachoroidal space in the posterior eye is injected directly using a catheter system. In this embodiment, the suprachoroidal space may be catheterized via an incision in the pars plana. In some embodiments, an injection or an infusion via a suprachoroidal route traverses the choroid, Bruch's membrane and/or RPE layer to deliver a vector or a composition of the disclosure to a subretinal space. In some embodiments, including those in which a vector or a composition of the disclosure is delivered to a subretinal space via a suprachoroidal route, one or more injections is made into at least one of the sclera, the pars plana, the choroid, the Bruch's membrane, and the RPE layer. In some embodiments, including those in which a vector or a composition of the disclosure is delivered to a subretinal space via a suprachoroidal route, a two-step procedure is used to create a bleb in a suprachoroidal or a subretinal space prior to delivery of a vector or a composition of the disclosure.
In those embodiments where mice are injected, animals can be anaesthetized by intraperitoneal injection containing ketamine (40-80 mg/kg) and xylazine (1-10 mg/kg) and pupils fully dilated with tropicamide eye drops (Mydriaticum 1%, Bausch & Lomb, UK) and phenylephrine eye drops (phenylephrine hydrochloride 2.5%, Bausch & Lomb, UK). Proxymetacaine eye drops (proxymetacaine hydrochloride 0.5%, Bausch & Lomb, UK) can also applied prior to sub-retinal injection. Post-injection, chloramphenicol eye drops can applied (chloramphenicol 0.5%, Bausch & Lomb, UK) and anaesthesia reversed with atipamezole (2 mg/kg) and carbomer gel applied (Viscotears, Novartis, UK) to prevent cataract formation.
Unless damage to the retina occurs during the injection, and as long as a sufficiently small needle is used, substantially all injected material remains localized between the detached neurosensory retina and the RPE at the site of the localized retinal detachment (i.e. does not reflux into the vitreous cavity). Indeed, the typical persistence of the bleb over a short time frame indicates that there is usually little escape of the injected material into the vitreous. The bleb may dissipate over a longer time frame as the injected material is absorbed.
Visualizations of the eye, in particular the retina, for example using optical coherence tomography, may be made pre-operatively.
The AAV vectors of the invention may be delivered with increased accuracy and safety by using a two-step method in which a localized retinal detachment is created by the subretinal injection of a first solution. The first solution does not comprise the vector. A second subretinal injection is then used to deliver the medicament comprising the vector into the subretinal fluid of the bleb created by the first subretinal injection. Because the injection delivering the medicament is not being used to detach the retina, a specific volume of solution may be injected in this second step. An AAV vector of the invention may be delivered by: (a) administering a solution to the subject by subretinal injection in an amount effective to at least partially detach the retina to form a subretinal bleb, wherein the solution does not comprise the vector; and (b) administering a medicament composition by subretinal injection into the bleb formed by step (a), wherein the medicament comprises the vector.
HEK293 cells were transduced with an AAV2/2 vector containing the CAG promoter driving Best1 expression with a WPRE (AAV2/2 CAG.BEST1.WPRE.pA,
Bestrophin-1 expression in HEK293 cells was quantified from Western Blot (
HEK293 cells expressing Bestrophin-1 were additionally assayed with whole-cell patch clamp recording.
Appropriately differentiated ARPE19 are known to have gene expression profiles similar to those of native retinal pigment epithelium (RPE) cells, and can be used as an alternative to native RPE cells to test gene expression. Differentiated ARPE19 cells were used to test the ability of the VMD2 and CAG promoters to drive BEST1 expression in RPE cells, and to test the effect of the intron-exon (IntEx) sequence on expression from the VMD2 promoter.
ARPE19 cells were transfected and assayed for BEST1 expression using the protocol outlined in
In ARPE19 cells that were differentiated for one month before transfection, the untransfected cells showed no expression. In contrast, both the pCAG.BEST1.WPRE and pVMD2. IntEx.BEST1.WPRE were able to drive the expression of BEST1 protein in differentiated ARPE19 cells (see
ARPE19 cells were transduced and assayed for BEST1 expression using the protocol outlined in
ARPE19 cells differentiated for 4 months, pre-treated with 400 nM doxorubicin and transduced with AAV2/2.CAG.GFP.WPRE and AAV2/2.VMD2. InEx.GFP.WPRE at 2, 4 and 8×104 gp/cell showed higher GFP fluorescence compared to transduced cells without pre-treatment with doxorubicin 10 days after transduction (contrast top and bottom row of each panel of
In ARPE19 cells differentiated for 4 months, pre-treated with 400 nM doxorubicin and transduced with AAV2/2.CAG.BEST1.WPRE and AAV2/2.VMD2. InEx.BEST1.WPRE at 1 and 4×104 gp/cell, BEST1 expression could be detected by immunostaining with anti-hBEST1 (red, third column, second to fifth row of
The ability of the VMD2.BEST1.WPRE and VMD2. IntEx.BEST1.WPRE constructs to drive the expression BEST1 was assayed in vivo. The protocol of the 4/8 week in vivo pilot study is shown in
OCT imaging at 4 and 8 weeks showed that neither VMD2 construct showed photoreceptor toxicity when compared to the sham treatment (
Three animals were sacrificed at both the 4- and 8-week time points, and BEST1 protein expression was further characterized by western blot (
An additional 4 and 13 week in vivo proof of concept (PoC) study was carried out in mice to confirm the results of the pilot study, assay the effect of AAV viral particle dosage, and look at the effects at later time points post AAV injection. An outline of the protocol for the 4/13 week Proof of Concept study is set forth in
OCT imaging at 4 weeks and 13 weeks showed that neither VMD2 construct (with or without the intron-exon sequence) at either the high dose (1×109 GC/eye) or the low dose (1×108 GC/eye) showed toxicity as evidenced by retinal thinning when compared to the sham control (
The safety and expression of BEST1 AAV over longer periods of time is verified in mice with a Good Laboratory Practice (GLP) toxicity study in mice. An outline of the study is set forth in
Every document cited herein, including any cross referenced or related patent or application is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the disclosure have been illustrated and described, various other changes and modifications can be made without departing from the spirit and scope of the disclosure. The scope of the appended claims includes all such changes and modifications that are within the scope of this disclosure.
This application claims the benefit of provisional application U.S. Ser. No. 62/653,131, filed Apr. 5, 2018, the contents of which are herein incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62653131 | Apr 2018 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16376808 | Apr 2019 | US |
| Child | 17945344 | US |
