Modified MTM1 genes and uses thereof

Abstract

Provided herein are modified nucleic acids comprising modified MTM1 genes, modified muscle-specific promoters, e.g., MHCK7, or a combination thereof. Also provided herein are expression cassettes, AAV vector genomes, and AAV particles comprising the same. Further provided herein are methods of delivering MTM1 to a muscle cell and methods of treating XLMTM.

Description

MODIFIED MTM1 GENES AND USES THEREOFCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims benefit of priority to U.S. Provisional Application Nos. 63 / 682,139, filed August 12, 2024, and 63 / 682,139, filed November 21, 2024, each of which is incorporated herein by reference in its entirety.SEQUENCE LISTING

[0002] The official copy of the sequence listing is submitted electronically via EFS-Web with a file named, “11705W001 Sequence Listing.xml,” created on July 29, 2025, and having a size of 1,070 kilobytes, and is filed concurrently with the specification. The sequence listing contained in the XML formatted document is part of the specification and is herein incorporated by reference in its entirety.BACKGROUND OF THE INVENTION

[0003] X-linked myotubular myopathy (XLMTM) results from a mutation in the MTM1 gene, which encodes the lipid phosphatase, myotubularin. Myotubularin is involved in endosomal trafficking and maintenance of skeletal muscle fibers. XLMTM patients have hypotrophic and centrally-nucleated myofibers, severe muscle weakness leading to respiratory insufficiency, and a shortened lifespan. Additionally, many XLMTM patients have reported signs of liver dysfunction, which may predispose them to AAV-mediated liver toxicity and severe adverse events when treated with an AAV-based gene therapy.

[0004] Thus, there is a need in the art for XLMTM gene therapies that have increased specificity for skeletal muscle cells, increased expression of MTM1 in skeletal muscle, reduced delivery to the liver, and / or reduced immunogenicity.SUMMARY OF THE INVENTION

[0005] Provided herein are modified MTM1 gene sequences, and modified muscle cellspecific promoter sequences, e.g., MHCK7, with increased expression in muscle cells and / or decreased immunogenicity in a mammalian host. Also provided are expression cassettes and AAV vector genomes comprising the modified sequences, AAV particles comprising themodified sequences, e.g., AAV particles with increased specificity for muscle cells, and packaging cells for making AAV particles comprising the modified sequences. Further provided herein are methods of making the same and methods of using the same, e.g., for the treatment of XLMTM.

[0006] In one aspect, a nucleic acid disclosed herein comprises a modified MTM1 gene sequence, wherein the modified MTM1 gene sequence comprises a substitution of a codon of a wildtype MTM1 gene with a degenerate codon, wherein the modified MTM1 gene sequence encodes myotubularin comprising an amino acid sequence as set forth in SEQ ID NO: 1398. In some embodiments, the wildtype MTM1 gene sequence comprises a nucleotide sequence as set forth in SEQ ID NO: 1399 or SEQ ID NO: 1400. In some embodiments, the modified MTM1 gene sequence exhibits reduced immunogenicity in a mammalian subject as compared to the wildtype MTM1 gene sequence. In some embodiments, the mammalian subject is a human subject. In some embodiments, the modified MTM1 gene sequence is CpG depleted. In some embodiments, the modified MTM1 gene sequence is CpG depleted via an algorithm selected from the group consisting of: DNA Chisel, IDT, and GeneArt. In some embodiments, the modified MTM1 gene sequence exhibits increased expression of myotubularin in a mammalian cell as compared to the wildtype MTM1 gene sequence. In some embodiments, the mammalian cell is a mammalian muscle cell. In some embodiments, the mammalian muscle cell is a human muscle cell. In some embodiments, the mammalian muscle cell is in vivo in a subject. In some embodiments, the modified MTM1 gene sequence is codon altered, such that the modified MTM1 gene sequence has a codon adaptation index of at least 0.7, or at least 0.75, or at least 0.8 or at least 0.85 or at least 0.87 or at least 0.89, or at least 0.90, or at least 0.91, or at least 0.92, or at least 0.93, or at least 0.94, or at least 0.95, or at least 0.96, or at least 0.97, or at least 0.98, or at least 0.99. In some embodiments, the modified MTM1 gene sequence is codon altered via an algorithm selected from the group consisting of: DNA Chisel, GenScript, IDT, GeneArt, NovoPro, TwistBio, and Vector Builder. In some embodiments, the modified MTM1 gene sequence comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence as set forth in SEQ ID NO: 1383 or SEQ ID NO: 1384. In some embodiments, the modified MTM1 gene sequence comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence as set forth in any one of SEQ ID NOs: 1401-1409.

[0007] In one aspect, a nucleic acid disclosed herein comprises a modified MHCK7 promoter sequence, wherein the MHCK7 promoter sequence comprises a substitution of at least one nucleotide of a wildtype MHCK7 promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, wherein the modified MHCK7 promoter sequence binds to a transcriptional protein and initiates transcription in muscle cells. In some embodiments, the modified MHCK7 promoter sequence exhibits reduced immunogenicity in a mammalian subject as compared to the wildtype MHCK7 promoter sequence. In some embodiments, the modified MHCK7 promoter sequence operably linked to a protein coding sequence exhibits reduced immunogenicity in a mammalian subject and comparable expression of the protein in a mammalian cell as compared to the wildtype MHCK7 promoter sequence operably linked to the protein coding sequence. In some embodiments, the wildtype MHCK7 promoter sequence comprises a nucleotide sequence as set forth in SEQ ID NO: 1410. In some embodiments, the modified MHCK7 promoter sequence comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence as set forth in SEQ ID NO: 1411 or SEQ ID NO: 1412.

[0008] In one aspect, a nucleic acid disclosed herein comprises, in operable linkage: (a) a promoter sequence, wherein the promoter sequence does not comprise an MTM1 promoter sequence; and (b) a modified MTM1 gene sequence comprising a substitution of a codon of a wildtype MTM1 gene as set forth in SEQ ID NO: 1399 or SEQ ID NO: 1400 with a degenerate codon. In some embodiments, the promoter sequence comprises a wildtype MHCK7 promoter sequence. In some embodiments, the wildtype MHCK7 promoter sequence comprises a nucleotide sequence as set forth in SEQ ID NO: 1410. In some embodiments, the promoter sequence comprises a modified MHCK7 promoter sequence, wherein the modified MHCK7 promoter sequence comprises a substitution of at least one nucleotide of a wildtype MHCK7 promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, wherein the modified MHCK7 promoter sequence binds to a transcriptional protein and initiates transcription. In some embodiments, the modified MHCK7 promoter sequence comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence as set forth in SEQID NO: 1411 SEQ ID NO: 1412. In some embodiments, the wildtype MTM1 gene sequence comprises a nucleotide sequence as set forth in SEQ ID NO: 1399 or SEQ ID NO: 1400. In some embodiments, the modified MTM1 gene sequence exhibits reduced immunogenicity in a mammalian subject as compared to the wildtype MTM1 gene sequence. In some embodiments, the modified MTM1 gene sequence is CpG depleted. In some embodiments, the modified MTM1 gene is CpG depleted via an algorithm selected from the group consisting of: DNA Chisel, IDT, and GeneArt. In some embodiments, the modified MTM1 gene sequence comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence as set forth in SEQ ID NO: 1383 or SEQ ID NO: 1384. In some embodiments, wherein the modified MTM1 gene sequence exhibits increased expression of myotubularin in a mammalian cell as compared to the wildtype MTM1 gene sequence. In some embodiments, the modified MTM1 gene sequence is codon altered, such that the modified MTM1 gene sequence has a codon adaptation index of at least 0.7, or at least 0.75, or at least 0.8 or at least 0.85 or at least 0.87 or at least 0.89, or at least 0.90, or at least 0.91, or at least 0.92, or at least 0.93, or at least 0.94, or at least 0.95, or at least 0.96, or at least 0.97, or at least 0.98, or at least 0.99. In some embodiments, the modified MTM1 gene sequence is codon altered via an algorithm selected from the group consisting of: DNA Chisel, GenScript, IDT, GeneArt, NovoPro, TwistBio, and Vector Builder. In some embodiments, the modified MTM1 gene sequence comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence as set forth in SEQ ID NOs: 1401-1409.

[0009] In one aspect, disclosed herein is an expression cassette comprising a nucleic acid comprising a modified MTM1 gene as disclosed herein operably linked to an expression control sequence. In some embodiments, the expression control sequence comprises a muscle cellspecific promoter sequence. In some embodiments, the muscle cell-specific promoter sequence is selected from the group consisting of: MHCK7, CK1, CK8, Des.invi, skCRM4_Des, CK8e, CK7, unc45b_SCP1, skCRMl.Des, HSA1.5, MHCK1, MCK1.35, SP985, 2R5S_c5-12, c5-12, SP-301, tMCK, 0.7 DES, 1.0 DES, 1.7 DES, SCP, 1.0 DES(v2), or biologically equivalent variants thereof. In some embodiments, the muscle cell- specific promoter sequence comprises a modified muscle cell-specific promoter sequence that exhibits reduced immunogenicity in a mammalian subject as compared to the wildtype muscle cell-specific promoter sequence. Insome embodiments, the modified muscle cell-specific promoter sequence comprises a substitution of at least one nucleotide of the wildtypc muscle cell-specific promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, wherein the modified muscle cell-specific promoter sequence binds to transcriptional proteins and initiates transcription in muscle cells. In some embodiments, the modified muscle cell-specific promoter sequence is an MHCK7 promoter sequence. In some embodiments, the MHCK7 promoter sequence comprises the nucleic acid comprising a modified MHCK7 promoter sequence as disclosed herein. In some embodiments, the expression cassette comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence as set forth in any one of SEQ ID NOs: 1414-1427.

[0010] In one aspect, disclosed herein is an adeno-associated virus (AAV) vector genome comprising from 5’ to 3’ and in operable linkage: (a) a 5’ AAV inverted terminal repeat (ITR); (b) a promoter sequence; (c) a nucleic acid comprising the modified MTM1 gene sequence as disclosed herein; and (d) a 3’ AAV ITR. In one embodiment, an AAV vector genome disclosed herein comprises from 5’ to 3’ and in operable linkage: (a) a 5’ AAV ITR; (b) a nucleic acid comprising a modified MHCK7 promoter sequence disclosed herein; (c) a nucleic acid comprising the modified MTM1 gene sequence as disclosed herein; and (d) a 3’ AAV ITR. In one embodiment, an AAV vector genome disclosed herein comprises from 5’ to 3’ and in operable linkage: (a) a 5’ AAV ITR; (b) a nucleic acid comprising the promoter sequence that does not comprise an MTM1 promoter sequence in operable linkage to a modified MTM1 gene sequence disclosed herein, or an expression cassette comprising a modified MTM1 gene sequence disclosed herein; and (c) a 3’ AAV ITR. In some embodiments, the 5’ and 3’ AAV ITRs are AAV2 ITRs. In some embodiments, the 5’ AAV ITR comprises a sequence as set forth in SEQ ID NO: 1442 or 1443 and / or the 3’ ITR comprises a sequence as set forth in SEQ ID NO: 1444 or 1445. In some embodiments, the AAV vector genome comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence as set forth in any one of SEQ ID NOs: 1428-1441.

[0011] In one aspect, disclosed herein is an AAV particle comprising an AAV vector genome disclosed herein encapsidated by an AAV capsid. In some embodiments, the AAV capsid comprises a first member of a protein:protein binding pair, wherein the first member of the protein :protein binding pair is associated with the second member of the protein :proteinbinding pair. In some embodiments, the second member of the protein:protein binding pair comprises a targeting ligand the specifically binds a mammalian muscle ccll-spccific surface protein. In some embodiments, the mammalian muscle cell-specific surface protein is mammalian Calcium Voltage-Gaged Auxiliary Subunit Gamma 1 (CACNG1). In some embodiments, the mammalian muscle cell-specific surface protein is human CACNG1. In some embodiments, the targeting ligand is an antibody or an antigen-binding fragment thereof. In some embodiments, the targeting ligand comprises a first heavy chain comprising a first heavy chain variable region (VH) and a first heavy chain constant region (CH), wherein the first CHcomprises a first CH3region of a human IgG, wherein the human IgG is IgG1, IgG2, or IgG4. In some embodiments, the targeting ligand comprises a second heavy chain comprising a second VHand a second CH, wherein the second CHcomprises (i) a second CH3region of a human IgG, wherein the human IgG is IgG1, IgG2, or IgG4; and (ii) one or more modifications in the second CH3region that reduces or eliminates binding of the second CH3region to Protein A. In some embodiments, the one or more modifications in the second CH3region comprises a 435R mutation or 435R and 436F mutations, according to the EU numbering system. In some embodiments, the first heavy chain of the targeting ligand further comprises one or more modifications in a first hinge domain, and / or the second heavy chain of the targeting ligand further comprises one or more modifications in a second hinge domain. In some embodiments, the first hinge domain comprises one or more modifications at positions 233-236 and the second hinge domain comprises one or more modifications at positions 233-236. In some embodiments, the one or more modifications in the first hinge domain and / or the one or more modifications in the second hinge domain are G, G, G and unoccupied; G, G, unoccupied, and unoccupied; G, unoccupied, unoccupied, and unoccupied; or all unoccupied, with positions numbered by EU numbering. In some embodiments, positions 226-229 of the first hinge domain and the second hinge domain are CPPC. In some embodiments, the first hinge domain amino acid sequence and / or the second hinge domain amino acid sequence comprises CPPCPAPGGG-GPSVF (SEQ ID NO: 1497), CPPCPAPGG-GPSVF (SEQ ID NO: 1498), CPPCPAPG— GPSVF (SEQ ID NO: 1499), or CPPCPAP — GPSVF (SEQ ID NO: 1500). In some embodiments, the first heavy CHcomprises an amino acid sequence set forth as SEQ ID NO: 1480, and / or the second CHcomprises an amino acid sequence set forth as SEQ ID NO: 1486. In some embodiments, the first member of the protein:protein binding pair comprises an epitope, and wherein the secondmember of the protein :protein binding pair comprises an antibody paratope that specifically binds the epitope. In some embodiments, the epitope comprises an AAV amino acid sequence. In some embodiments, the epitope comprises an amino acid sequence heterologous to the AAV capsid. In some embodiments, the epitope comprises a c-myc amino acid sequence. In some embodiments, the c-myc amino acid sequence comprises a sequence as set forth in SEQ ID NO: 1466. In some embodiments, the second member of the protein:protein binding protein binds both the epitope and the mammalian muscle cell-specific surface protein. In some embodiments, the first member of the protein:protein binding pair and the second member of the protein:protein binding pair form an isopeptide bond. In some embodiments, In some embodiments of the AAV particle disclosed herein: (a) the first member of the protein:protein binding pair comprises SpyTag, Isopeptag, SnoopTag, SpyTag002, SpyTag003, or any biologically active portions or variants thereof; (b) the second member of the protein :protein binding pair comprises: (i) a SpyCatcher, KTag, pilin-C, SnoopCatcher, SpyCatcher002, SpyCatcher003, or any biologically active portions or variants thereof, and (ii) the targeting ligand that binds a mammalian muscle cell-specific surface protein; and (c) the first member of the protein:protein binding pair and the second member of the protein:protein binding pair are linked by an isopeptide bond. In some embodiments, the first member of the protein:protein binding pair comprises SpyTag, the second member of the protein:protein binding pair comprises SpyCatcher, and the targeting ligand comprises a first heavy chain comprising the amino acid sequence set forth as SEQ ID NO: 1482, and a second heavy chain comprising the amino acid sequence set forth as SEQ ID NO: 1490.

[0012] In one aspect, disclosed herein is a pharmaceutical composition comprising: (i) an AAV particle as disclosed herein, and (ii) a pharmaceutically acceptable carrier. In some embodiments, the pharmaceutical composition comprises the AAV particle at a concentration between 2 x 1012vg / kg and 2 x 1014vg / kg.

[0013] In one aspect, disclosed herein is a method of making a nucleic acid comprising a modified MTM1 gene sequence, the method comprising substituting a codon of a wildtype MTM1 gene with a degenerate codon, wherein the modified MTM1 gene sequence encodes myotubularin as set forth in SEQ ID NO: 1398.

[0014] In one aspect, disclosed herein is a method of making a nucleic acid comprising a modified MHCK7 promoter sequence, the method comprising substituting at least one nucleotideof a wildtype MHCK7 promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, wherein the modified MHCK7 promoter sequence binds to transcriptional proteins and initiates transcription.

[0015] In one aspect, disclosed herein is a method of making a modified MTM1 expression cassette, the method comprising operably linking a nucleic acid comprising a modified MTM1 gene sequence to a nucleic acid comprising a modified MHCK7 promoter sequence, wherein the modified MTM1 gene sequence comprises a substitution of a codon of a wildtype MTM1 gene with a degenerate codon, and the modified MTM1 gene sequence encodes myotubularin comprising an amino acid sequence as set forth in SEQ ID NO: 1398, and wherein the MHCK7 promoter sequence comprises a substitution of at least one nucleotide of a wildtype MHCK7 promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, and the modified MHCK7 promoter sequence binds to a transcriptional protein and initiates transcription in muscle cells. In some embodiments, the modified MTM1 expression cassette comprises a modified MTM1 gene sequence as disclosed herein. In some embodiments, the modified MTM1 expression cassette comprises a modified MHCK7 promoter sequence as disclosed herein.

[0016] In one aspect, disclosed herein is a packaging cell for producing AAV particles, comprising an AAV vector genome comprising from 5’ to 3’ and in operable linkage: (a) a 5’ AAV ITR; (b) a modified MHCK7 promoter sequence, wherein the modified MTM1 gene sequence comprises a substitution of a codon of a wildtype MTM1 gene with a degenerate codon, and the modified MTM1 gene sequence encodes myotubularin comprising an amino acid sequence as set forth in SEQ ID NO: 1398; (c) a modified MTM1 gene sequence, wherein the MHCK7 promoter sequence comprises a substitution of at least one nucleotide of a wildtype MHCK7 promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, and the modified MHCK7 promoter sequence binds to a transcriptional protein and initiates transcription in muscle cells; and (d) a 3’ AAV ITR. In some embodiments, the packaging cell comprises a modified MHCK7 promoter sequence disclosed herein. In some embodiments, the packaging cell comprises a modified MTM1 gene sequence disclosed herein.

[0017] In one aspect, disclosed herein is a method of making an AAV particle, the method comprising culturing a packaging cell disclosed herein in conditions sufficient to produce AAV particles.

[0018] In one aspect, disclosed herein is a method of delivering MTM1 protein to a mammalian muscle cell, the method comprising contacting the mammalian muscle cell with a pharmaceutical composition disclosed herein. In some embodiments, the mammalian muscle cell is in vitro. In some embodiments, the mammalian muscle cell is in vivo. In some embodiments, the mammalian muscle cell is a human muscle cell.

[0019] In one aspect, disclosed herein is a method for treating X-linked Myotubular Myopathy (XLMTM) in a human subject in need thereof, the method comprising administering to the human subject a therapeutically effective amount of a pharmaceutical composition disclosed herein. In a further embodiment, disclosed herein is the use of a pharmaceutical composition disclosed herein in the manufacture of a medicament for treating XLMTM in a subject in need thereof. In a further embodiment, disclosed herein is a pharmaceutical composition disclosed herein for use in the treatment of XLMTM in a subject in need thereof.BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 provides in vitro firefly luciferase (FLuc) expression levels as relative light units (RLU; y-axis) by primary human myotubes after treatment with AAV9 particles retargeted to CACNG1 and encapsidating an FLuc gene under the control of a wildtype MHCK7 promoter, a CpG depleted MHCK7 promoter sequence 1 (v1), or a CpG depleted MHCK7 promoter sequence 2 (v2) at a multiplicity of infection (MOI) of 3.00 x 105MOI, 1.00 x 105MOI, 3.33 x 104MOI, 1.11 x 104MOI, 3.70 x 103MOI, and 1.23 x 103MOI, or without treatment (0 MOI).

[0021] Figure 2 provides in vivo FLuc RNA expression levels in tissues isolated from the gastrocnemius, quadriceps, diaphragm, heart, or liver of mice (n=5 for each group) three weeks after retro-orbital systemic delivery of either buffer or 5 x 1011vg / mouse AAV9 particles retargeted to CACNG1 and encapsidating an FLuc gene under the control of a Desmin promoter, a wildtype MHCK7 promoter, or a CpG depleted MHCK7 promoter sequence 2 (v2). Results shown are normalized to the RNA expression levels seen with the Desmin promoter.

[0022] Figures 3A-3D provide in vitro expression levels of wildtype or codon altered / CpG depleted MTM1 coding sequences tagged to HiBiT by primary human myotubes after treatment with AAV9 particles retargeted to CACNG1 and encapsidating: green fluorescence protein (GFP), a wildtype HiBiT-tagged MTM1 coding sequence, or a HiBiT-tagged, codon altered / CpG depleted MTM1 coding sequence (#1-#9) at a multiplicity of infection (MOI) of 0, 4.12 x 103, 1.23 x 104, 3.70 x 104, 1.11 x 105, lx 106, 3.33 x 105. Figure 3 A provides the HiBiT luminescence of the primary human myotubes as relative light units (RLU, y-axis) four days following treatment with AAV9 particles. Figure 3B provides images of western blots used to quantify HiBiT and GAPDH protein levels in primary human myotubes four days following treatment with AAV9 particles. Figure 3C provides a chart correlating RNA expression levels and luminescence seen in the primary human myotubes after infection at an MOI of 3.33 x 105with AAV9 encapsidating the wildtype or codon altered / CpG depleted MTM1 coding sequences (#1-#9). Figure 3D provides the RNA sequencing read coverage along the MTM1 coding determining sequence (CDS) of codon altered / CpG depleted MTM1 coding sequences (#1-9) by primary human myotubes four days following treatment with AAV9 particles encapsidating the wildtype or codon altered / CpG depleted MTM1 coding sequences (#1-#9).

[0023] Figures 4A and 4B provide in vivo expression levels of HiBiT-tagged wildtype or codon altered / CpG depleted MTM1 coding sequences in quadricep muscle tissue isolated from mice three weeks after retro-orbital systemic delivery of buffer or 5 x 1011vg / mouse of AAV9 particles retargeted to CACNG1 and encapsidating a HiBiT-tagged wildtype MTM1 coding sequence, or a HiBiT-tagged, codon altered / CpG depleted MTM1 coding sequence (#1, #2, #4, or #9). Figure 4A provides western blots used to quantify HiBiT-tagged MTM1 or GAPDH protein levels and Figure 4B provides the protein levels measured as area under the curve (AUC; y-axis).

[0024] Figures 5A and 5B provide in vivo expression levels of HiBiT-tagged wildtype or codon altered / CpG depleted MTM1 coding sequences, by quadricep muscle tissue isolated from mice three weeks after retro-orbital systemic delivery of buffer or 5 x 1011vg / mouse of AAV9 particles retargeted to CACNG1 and encapsidating a HiBiT-tagged wildtype MTM1 coding sequence, or a HiBiT-tagged, codon altered / CpG depleted MTM1 coding sequence (#1, #2, #4, or #9) operably linked to a desmin promoter or a CpG depleted MHCK7 promoter sequence 2 (v2). Figure 5 A provides images of western blots used to quantify HiBiT-tagged MTM1 or GAPDH protein levels and Figure 5B provides the protein levels measured as area under the curve (AUC; y-axis).

[0025] Figures 6A and 6B depict schematic representations of anti-AAV x anti- CACNG1 alternative format (AF) antibodies AF70, AF71, AF71x, AF72a, AF72b, AF73, AF74A, AF74B, and AF76. Figure 6A: AF70 comprises anti-AAV#70 (REGN1388O) scFv fused to the N-terminus of anti-CACNG1 REGN10717 hlgG1 N297G antibody. AF71 comprises anti-AAV#70 (REGN13880) scFv fused to the C-terminus of anti-CACNG1 REGN10717 hlgG1 N297G antibody. Disulfide bonds are indicated by S-S. Figure 6B provides schematic depictions and descriptions for AF71x, AF72a, AF72b, AF73, AF74A, AF74B, and AF76. The black fill represents the anti-CACNG1 REGN10717 hlgG1 N297G antibody heavy chain variable region (HCVR), the gray fill represents the anti-CACNG1 REGN10717 hlgG1 N297G antibody light chain variable region (LCVR), the dotted fill pattern represents the anti-AAV#70 (REGN13880) antibody HCVR, and the striped fill pattern represents the anti-AAV#70 (REGN13880) antibody LCVR. Star mutations (H435R and Y436F) are depicted with an asterisk (*) and knob-in-hole (KiH) mutations are depicted with a triangle (◄).

[0026] Figures 7A and 7B depict transgene mRNA expression (Figure 7A) and genome copy number per diploid genome (vg / dg; Figure 7B) in diaphragm, tibialis anterior, gastrocnemius, and quadriceps tissues of mice three weeks after retro-orbital systemic delivery of 5 x 1011, 1 x 1012, or 2 x 1012vg of HA-tagged wildtype MTM1 coding sequence operably linked to a CK8 promoter and encapsidated by (i) wildtype AAV9 (“WT AAV9”), (ii) SpyTag- inserted AAV9 W503A retargeted to CACNG1 via conjugation to an anti-CACNG1 homodimeric monoclonal antibody (“homodimeric mAb”) comprising identical heavy chains, wherein each heavy chain is operably linked at its C-terminus to SpyCatcher, or (iii) SpyTag- inserted AAV9 W503A retargeted to CACNG1 via conjugation to an anti-CACNG1 heterodimeric monoclonal antibody (“heterodimeric mAb”) comprising a first heavy chain comprising a first CH3region of a human IgG, and a second heavy chain comprising a second CH3region of a human IgG comprising one or more mutations that reduces or eliminates binding of the second CH3region to Protein A, wherein the second heavy chain is operably linked at its C-terminus to SpyCatcher.

[0027] Figures 8A-8E provide in vivo functional rescue data in MTM1 KO mice. MTM1 KO mice (“KO male”) beginning at seven days of age were assessed over the course of six months after retro-orbital systemic delivery of either 2 x 1012vg / kg (“2E12 vg / kg”) or 2 x 1013vg / kg (“2E13 vg / kg”) of wildtype AAV9 particles (“WT AAV9”) or SpyTag-inserted AAV9W503A retargeted to CACNG1 via conjugation to an anti-CACNG1 antibody (“CACNG1”) cncapsidating a wildtypc human MTM1 coding sequence (“hMTM1 (Native)”), or a codon altered / CpG depleted human MTM1 coding sequence (“hMTM1(#1)” or “hMTM1(#9)”) operably linked to a desmin promoter (“Desmin”) or a CpG depleted MHCK7 promoter sequence (“MHCK7(v2)”). Wild type (“WT male”) mice and MTM1 KO mice administered buffer (“untreated”) served as controls. Figure 8A provides percentage change of body weight over the duration of the study, normalized to body weight one week after dosing (2 weeks of age). Figure 8B tracks the percentage survival of mice per treatment group over six months. Figure 8C provides longitudinal measurements of forelimb grip strength. Figure 8D provides terminal tissue weights from animals surviving to study termination. Figure 8E depicts total MTM1 protein from quadriceps tissue lysates. Female mice heterozygous for the MTM1 null allele are used to benchmark halved expression of endogenous MTM1 protein expression.

[0028] Figure 9A depicts quantification of vector genomes per diploid genome (vg / dg) via digital PCR in quadriceps and liver. Probes specific to ITR2 and Rpp30 were used to quantify vector genomes per diploid genome using the following calculation: ITR2 / (Rpp30 / 2). Figure 9B depicts quantification of MTM1 RNA levels via digital PCR across various tissues. Distinct probes were designed to detect endogenous mMTM1 and exogenously expressed hMTM1. MTM1 KO mice were administered either a low dose of 2 x 1012vg / kg (“LD”) or a high dose of 2 x 1013vg / kg (“HD”) of wildtype AAV9 particles (“AAV9”) or SpyTag-inserted AAV9 W503A retargeted to CACNG1 via conjugation to an anti-CACNG1 antibody (“SpyT / C- CACNG1 AAV9-W503A”) encapsidating a wildtype human MTM1 coding sequence (“hMTM1”), or a codon altered / CpG depleted human MTM1 coding sequence (“hMTM1- CpG#1” or “hMTM1 -CpG#9”) operably linked to a desmin promoter (“Desmin-intron”) or a CpG depleted MHCK7 promoter sequence (“MHCK7(v2)”). Wild type (“WT”) mice administered phosphate buffered saline (“PBS”) served as a control and were used to establish endogenous murine MTM1 (mMTM1) levels.

[0029] Figures 10A-10F provide additional In vivo functional rescue data in MTM1 KO mice. MTM1 KO mice (“KO male”) beginning at seven days of age were assessed over the course of one month after retro-orbital systemic delivery of either 2 x 1012vg / kg (“2E12 vg / kg”) or 2 x 1013vg / kg (“2E13 vg / kg”) of wildtype AAV9 particles (“WT AAV9” or “AAV9”) or SpyTag-inserted AAV9 W5O3A particles (“CACNG1” or “SpyT / C”) retargeted to CACNG1 viaSpyCatcher-mediated conjugation to an anti-CACNG1 antibody (“CACNG1” or “SpyT / C”) or a bispccific anti-CACNG1 x anti- AAV antibody (“AF72a” or“AF72A” and “AF76v3”) encapsidating a wildtype human MTM1 coding sequence operably linked to a desmin promoter (“Desmin-hMTM1 (Native)” or “Desmin-MTM1”), or a codon altered / CpG depleted human MTM1 coding sequence operably linked to a CpG depleted MHCK7 promoter sequence (“MHCK7(v2)-hMTM1(#1)” or “CpG1”). For bispecific antibody formulations, AAV capsid and bispecific antibody were administered at a 1:1 ratio (“1:1”) or a 1:3 ratio (“1:3”). Wild type (“WT male” or “WT”) mice and MTM1 KO mice administered buffer (“untreated” or “PBS”) served as controls. Figure 10A provides percentage change of body weight over the duration of the study, normalized to body weight one week after dosing (1 week of age). Figure 10B provides results of forelimb grip strength testing. Figure 10C provides terminal tissue weights from animals surviving to study termination. The x-axes for Figure 10C are identical to those for the bar graph presented in Figure 10B. Figure 10D provides total human MTM1 protein (“hMTM1”) from quadriceps tissue lysates. The housekeeping gene, glyceraldehyde-3-phosphate dehydrogenase (“GAPDH”), was used as a loading control. Figure 10E depicts quantification of vector genomes per diploid genome (vg / dg) via digital PCR in quadriceps and liver. Probes specific to ITR2 were used to quantify vector genomes, probes specific to Rpp30 were used to quantify diploid genomes, and the calculation for determining vg / dg was as follows: ITR2 / (Rpp30 / 2). Figure 10F depicts quantification of MTM1 mRNA levels via digital PCR across various tissues. Probes used were specific to endogenous murine MTM1, wildtype human MTM1, and codon altered / CpG depleted human MTM1.

[0030] Figures 11A-11C provide in vivo functional rescue data in MTM1 KO mice administered bispecific anti-CACNG1 x anti- AAV retargeted AAV9 W503A particles. Mice were administered AAV9 W503A retargeted to CACNG1 via complexation with a bispecific anti-CACNG1 x anti- AAV antibody encapsidating a wildtype human MTM1 coding sequence operably linked to a desmin promoter (“Desmin-hMTM1 (Native)”), or a codon altered / CpG depleted human MTM1 coding sequence operably linked to a CpG depleted MHCK7 promoter sequence (“CpG1” or “CpG9”). Wild type mice administered buffer (“WT-PBS”) served as controls. Figure 11A tracks the percentage of survival for each experimental group over the course of the experiment. Figure 11B tracks the weight of each experimental group over thecourse of the experiment. Figure 11C provides results for forelimb grip strength assessed over the course of the experiment.DESCRIPTION

[0031] Described herein are muscle-specific promoter sequences, e.g., MHCK7, and MTM1 gene sequences that have been modified to achieve properties desirable for use in vivo to treat XLMTM. These properties include, for example, (a) degenerate codon alterations of an MTM1 gene sequence that improve protein expression in muscle cells but do not alter the encoded protein sequence and / or (b) CpG depletion of an MTM1 coding sequence and / or muscle-specific promoter sequences e.g., MHCK7, to reduce immunogenicity in mammalian hosts. Further described herein are AAV particles comprising the modified sequences with improved specificity for muscle cells, e.g., CACNG1 retargeted AAV particles, to reduce off- target effects of AAV administration in vivo.

[0032] The description herein is not limited to particular embodiments, compositions, methods and experimental conditions described, as such embodiments, compositions, methods and conditions may vary. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0033] Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing as described herein, some preferred methods and materials are now described. All publications cited herein are incorporated herein by reference to describe in their entirety. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

[0034] Singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. Thus, for example, a reference to “a method” includes one or more methods, and / or steps of the type described herein and / or which will become apparent to those persons skilled in the art upon reading this disclosure.

[0035] The term “antibody” includes immunoglobulin molecules comprising four polypeptide chains, two heavy (H) chains and two light (L) chains inter-connected by disulfide bonds. Each heavy chain comprises a heavy chain variable domain (VH) and a heavy chain constant region (CH). The heavy chain constant region comprises at least three domains, CH1, CH2, CH3 and optionally CH4. Each light chain comprises a light chain variable domain (CH) anda light chain constant region (CL). The heavy chain and light chain variable domains can be further subdivided into regions of hypervariability, termed complementarity determining regions (CDR), interspersed with regions that are more conserved, termed framework regions (FR). Each heavy and light chain variable domain comprises three CDRs and four FRs, arranged from amino-terminus to carboxy-terminus in the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4 (heavy chain CDRs may be abbreviated as HCDR1, HCDR2 and HCDR3; light chain CDRs may be abbreviated as LCDR1, LCDR2 and LCDR3. Typical tetrameric antibody structures comprise two identical antigen-binding domains, each of which formed by association of the VHand VLdomains, and each of which together with respective CHand CLdomains form the antibody Fv region. Single domain antibodies comprise a single antigen-binding domain, e.g., a VHor a VL. The antigen-binding domain of an antibody, e.g., the part of an antibody that recognizes and binds to the first member of a specific binding pair of an antigen, is also referred to as a “paratope.” It is a small region (of 5 to 10 amino acids) of an antibody's Fv region, part of the fragment antigen-binding (Fab region), and may contain parts of the antibody's heavy and / or light chains. A paratope specifically binds a first member of a specific binding pair when the paratope binds the first member of a specific binding pair with a high affinity. The term “high affinity” antibody refers to an antibody that has a KDwith respect to its target first member of a specific binding pair about of 10-9M or lower (e.g., about 1 x 10-9M, 1 x 10-10M, 1 x 10-11M, or about 1 x 10-12M). In one embodiment, KDis measured by surface plasmon resonance, e.g., BIACORE™; in another embodiment, KDis measured by ELISA. The term “antibody” may encompass any type of antibody, such as e.g., monoclonal or polyclonal. Moreover, the antibody may be or any origin, such as e.g., mammalian or non-mammalian. In one embodiment, the antibody may be mammalian or avian. In a further embodiment, the antibody may be of human origin and may further be a human monoclonal antibody.

[0036] The term “antibody” also includes antigen-binding fragments of full antibody molecules. The terms “antigen-binding portion” of an antibody, “antigen-binding fragment” of an antibody, and the like include any naturally occurring, enzymatically obtainable, synthetic, or genetically engineered polypeptide or glycoprotein that specifically binds an antigen to form a complex. Antigen-binding fragments of an antibody may be derived, e.g., from full antibody molecules using any suitable standard techniques such as proteolytic digestion or recombinant genetic engineering techniques involving the manipulation and expression of DNA encodingantibody variable and optionally constant domains. Such DNA is known and / or is readily available from, e.g., commercial sources, DNA libraries (including, e.g., phage-antibody libraries), or can be synthesized. The DNA may be sequenced and manipulated chemically or by using molecular biology techniques, for example, to arrange one or more variable and / or constant domains into a suitable configuration, or to introduce codons, create cysteine residues, modify, add or delete amino acids, etc.

[0037] Non-limiting examples of antigen-binding fragments include: (i) Fab fragments;(ii) F(ab’)2 fragments; (iii) Fd fragments; (iv) Fv fragments; (v) single-chain Fv (scFv) molecules; (vi) dAb fragments; and (vii) minimal recognition units consisting of the amino acid residues that mimic the hypervariable region of an antibody (e.g., an isolated complementarity determining region (CDR) such as a CDR3 peptide), or a constrained FR3- CDR3-FR4 peptide. Other engineered molecules, such as domain-specific antibodies, single domain antibodies, domain-deleted antibodies, chimeric antibodies, CDR-grafted antibodies, diabodies, triabodies, tetrabodies, minibodies, nanobodies (e.g., monovalent nanobodies, bivalent nanobodies, etc.), small modular immunopharmaceuticals (SMIPs), and shark variable IgNAR domains, are also encompassed within the expression “antigen-binding fragment”.

[0038] An antigen-binding fragment of an antibody will typically comprise at least one variable domain. The variable domain may be of any size or amino acid composition and will generally comprise at least one CDR which is adjacent to or in frame with one or more framework sequences. In antigen-binding fragments having a VHdomain associated with a VLdomain, the VHand VLdomains may be situated relative to one another in any suitable arrangement. For example, the variable region may be dimeric and contain VH-VH, VH-VLor VL-VLdimers. Alternatively, the antigen-binding fragment of an antibody may contain a monomeric VHor VLdomain.

[0039] The phrase “complementarity determining region,” or the term “CDR,” includes an amino acid sequence encoded by a nucleic acid sequence of an organism’s immunoglobulin genes that normally (i.e., in a wild-type animal) appears between two framework regions in a variable region of a light or a heavy chain of an immunoglobulin molecule (e.g., an antibody or a T cell receptor). A CDR can be encoded by, for example, a germ line sequence or a rearranged or unrearranged sequence, and, for example, by a naive or a mature B cell or a T cell. A CDRcan be somatically mutated (e.g., vary from a sequence encoded in an animal’s germ line), humanized, and / or modified with amino acid substitutions, additions, or deletions. In some circumstances (e.g., for a CDR3), CDRs can be encoded by two or more sequences (e.g., germ line sequences) that are not contiguous (e.g., in an unrearranged nucleic acid sequence) but are contiguous in a B cell nucleic acid sequence, e.g., as the result of splicing or connecting the sequences (e.g., V-D-J recombination to form a heavy chain CDR3).

[0040] A “biologically equivalent variant thereof’, as used herein, refers to any variant of a macromolecule that maintains at least one function of that macromolecule. The function can be the same, enhanced or diminished as long as the function is present. For example, a biologically equivalent variant of a wildtype promoter may be a chimeric promoter that increases expression of a coding region when in operable linkage to the same.

[0041] The phrase “bispecific antibody” includes an antibody capable of selectively binding two or more epitopes. Bispecific antibodies generally comprise two different heavy chains, with each heavy chain specifically binding a different epitope — either on two different molecules (e.g., antigens) or on the same molecule (e.g., on the same antigen). If a bispecific antibody is capable of selectively binding two different epitopes (a first epitope and a second epitope), the affinity of the first heavy chain for the first epitope will generally be at least one to two or three or four orders of magnitude lower than the affinity of the first heavy chain for the second epitope, and vice versa. The epitopes recognized by the bispecific antibody can be on the same or a different target (e.g., on the same or a different protein). Bispecific antibodies can be made, for example, by combining heavy chains that recognize different epitopes of the same antigen. For example, nucleic acid sequences encoding heavy chain variable sequences that recognize different epitopes of the same antigen can be fused to nucleic acid sequences encoding different heavy chain constant regions, and such sequences can be expressed in a cell that expresses an immunoglobulin light chain. A typical bispecific antibody has two heavy chains each having three heavy chain CDRs, followed by (N-terminal to C -terminal) a CH1 domain, a hinge, a CH2 domain, and a CH3 domain, and an immunoglobulin light chain that either does not confer antigen-binding specificity but that can associate with each heavy chain, or that can associate with each heavy chain and that can bind one or more of the epitopes bound by the heavy chain antigen-binding regions, or that can associate with each heavy chain and enable binding or one or both of the heavy chains to one or both epitopes.

[0042] A “codon adaptation index,” as used herein, refers to a measure of codon usage bias. A codon adaptation index (CAI) measures the deviation of a given protein coding gene sequence with respect to a reference set of genes (Sharp P M and Li W H, Nucleic Acids Res. 15(3): 1281 -95 (1987)). CAI is calculated by determining the geometric mean of the weight associated to each codon over the length of the gene sequence (measured in codons):

[0043] For each amino acid, the weight of each of its codons, in CAI, is computed as the ratio between the observed frequency of the codon (fi) and the frequency of the synonymous codon (fj) for that amino acid:

[0044] “Codon altered”, as used herein with respect to a nucleotide sequence, refers to an alteration of codons or sequences in the gene or coding regions therein to reflect typical codon usage of a host organism (e.g., a mammal such as a human) or cell thereof without altering the polypeptide encoded by the nucleotide sequence. A codon altered transgene therefore is modified for expression in a particular organism, organ, tissue or cell type, especially a mammal or mammalian organ, tissue or cell type. Alternatively, “codon altered” means an alteration of codons or sequences in a gene to improve protein expression as compared to a sequence that lacks the alteration by, for example, eliminating or changing sites that may be latent splice sites, stop codons, miRNA recognition sequences and the like. An entire nucleotide sequence may be codon altered or only one or more parts, portions or regions of a nucleotide sequence may be codon altered. For example, a gene sequence may be codon altered to improve expression of the encoded protein in a host cell, without altering the protein amino acid sequence. Various algorithms for codon alteration exist in the art and would be readily available to a skilled artisanmotivated to do so. Non-limiting examples of codon alteration algorithms include those developed by DNA Chisel, GcnScript, IDT, GcncArt, NovoPro, TwistBio, and Vector Builder.

[0045] As used herein, a “coding region” or “coding sequence” is a portion of polynucleotide which consists of codons translatable into amino acids. Although a “stop codon” (TAG, TGA, or TAA) is typically not translated into an amino acid, it can be considered to be part of a coding region, but any flanking sequences, for example promoters, ribosome binding sites, transcriptional terminators, introns, and the like, are not part of a coding region. The boundaries of a coding region are typically determined by a start codon at the 5’ terminus, encoding the amino terminus of the resultant polypeptide, and a translation stop codon at the 3’ terminus, encoding the carboxyl terminus of the resulting polypeptide.

[0046] “CpG” or “CG” depletion, as used herein, refers to the modification of a nucleotide sequence to reduce the number of CpG dinucleotides. Generally, the function of the nucleotide sequence is maintained. TLR9 is an endosomal DNA sensor that recognizes unmethylated cytosine-phosphate-guanine (CpG) motifs commonly present in viral and bacterial DNA genomes. Importantly, TLR9 sensing of AAV vector genomes has been shown to be required for anti-capsid CD8+T cell responses. Specifically, TLR9 signaling in plasmacytoid dendritic cells (pDCs) is required for adaptive immune responses to AAV. Thus, CpG motifs present in the DNA genome of AAV gene therapy vectors can be determinants of vector immunogenicity. Accordingly, CpG depletion may be employed to reduce the immunogenicity of a nucleotide sequence, e.g., an AAV vector genome. Various algorithms for CpG depletion exist in the art and would be readily available to a skilled artisan motivated to do so. Nonlimiting examples of CpG depletion algorithms include those developed by DNA Chisel, IDT, and GeneArt.

[0047] A “degenerate codon”, as used herein, refers to a codon that encodes the same amino acid as the wildtype codon, but with a different nucleotide sequence. A skilled artisan would readily recognize that due to the degeneracy of the genetic code, varying nucleotide sequences can encode the same polypeptide. For example, a wildtype nucleotide sequence may comprise a substitution of one or more codons with degenerate codons for the purpose of improving protein expression in a target cell.

[0048] As used herein, the term “epitope” refers to the portion of the antigen which is recognized by the multi- specific antigen-binding polypeptide. A single antigen (such as anantigenic polypeptide) may have more than one epitope. Epitopes may be defined as structural or functional. Functional epitopes arc generally a subset of structural epitopes and arc defined as those residues that directly contribute to the affinity of the interaction between the antigenbinding polypeptide and the antigen. Epitopes may also be conformational, that is, composed of non-linear amino acids. In certain embodiments, epitopes may include determinants that are chemically active surface groupings of molecules such as amino acids, sugar side chains, phosphoryl groups, or sulfonyl groups, and, in certain embodiments, may have specific three- dimensional structural characteristics, and / or specific charge characteristics. Epitopes formed from contiguous amino acids are typically retained on exposure to denaturing solvents, whereas epitopes formed by tertiary folding are typically lost on treatment with denaturing solvents.

[0049] The term “expression” as used herein, refers to a process by which a polynucleotide produces a gene product, for example, an RNA or a polypeptide. It includes without limitation transcription of the polynucleotide into messenger RNA (mRNA), transfer RNA (tRNA), small hairpin RNA (shRNA), small interfering RNA (siRNA) or any other RNA product, and the translation of an mRNA into a polypeptide. Expression produces a “gene product.” As used herein, a gene product can be either a nucleic acid, e.g., a messenger RNA produced by transcription of a gene, or a polypeptide which is translated from a transcript. Gene products described herein further include nucleic acids with post transcriptional modifications, e.g., polyadenylation or splicing, or polypeptides with post translational modifications, e.g., methylation, glycosylation, the addition of lipids, association with other protein subunits, or proteolytic cleavage.

[0050] “Expression control sequences” or “translational control sequences” refer to DNA regulatory sequences, such as promoters, enhancers, terminators, and the like, that provide for the expression of a coding sequence in a host cell. A variety of expression control sequences are known to those skilled in the art. These include, without limitation, expression control sequences which function in vertebrate cells, such as, but not limited to, promoter and enhancer segments from cytomegaloviruses (the immediate early promoter, in conjunction with intron- A), simian virus 40 (the early promoter), and retroviruses (such as Rous sarcoma virus). Other expression control sequences include those derived from vertebrate genes such as actin, heat shock protein, bovine growth hormone and rabbit beta-globin, as well as other sequences capable of controllinggene expression in eukaryotic cells. Additional suitable transcription control regions include tissue-specific promoters and enhancers, e.g., muscle-specific promoters, e.g., MHCK7.

[0051] “Immunogenic” or “immunogenicity” as used herein refers to the ability to produce an immune response in a subject, e.g., a mammalian subject, e.g., a human subject. Accordingly, a modified macromolecule, e.g., a modified gene sequence, has reduced immunogenicity relative to a reference macromolecule, e.g., a wildtype gene sequence, if the magnitude of the immune response in a subject administered the modified macromolecule is decreased relative to the reference macromolecule. Methods of evaluating the immunogenicity of a macromolecule are well-known in the art.

[0052] As used herein interchangeably “FORCE” or “format chain exchange” refers to a high-throughput method for the combinatorial generation of bispecific antibodies. In this method, bispecific antibody assembly is performed from monospecific educt molecules harboring different binders in different formats. Assembly occurs via heavy-chain exchange reactions driven by engineered Fc-dummy chains contained in the monospecific input molecules. The method is based on CH3-interface driven exchange reactions of input molecules representing different binder / format combinations. Educt molecules are knob-into-hole heterodimers of one half-antibody-like productive side and one knob or hole dummy Fc. The dummy associates with the knob or hole Fc of the productive side (covalently linked by hinge interchain disulfides) and thereby covers the CH3 interface. The presence of the dummy chain prevents aggregation and / or dimerization frequently observed with half-antibody-like molecules that possess free CH3 interfaces. The productive sides have antigen-binding Fab arms attached to KiH-Fc-dummy heterodimers either N-terminal via a regular IgG1 -hinge, or C-terminal via flexible (Gly4Ser)n linkers, or N- as well as C-terminal. Different mutations built into the knob or hole dummy chains lead to limited repulsions within CH3 interfaces, yet without affecting expression, purification or biophysical properties of educt molecules. Limited reduction of hinge disulfides initiates an exchange reaction between complementary educts driven by their partially destabilized interfaces. The reaction resolves the flawed CH3-educt interfaces to perfect complementarity in the products of the exchange reaction. Those products are bispecific antibodies with regular CH3-CH3 interface-disulfide stabilized knob-into-hole Fc’s and dummydimers, each with non-repulsing interfaces. Affinity tags attached only to the dummy-chains enables absorbing any remaining educts, dummy dimers and potential aggregates from theexchange reaction. This provides a single-step robust purification step to obtain pure bispecific antibodies. FORCE is described in further detail in, e.g., Dcngl, et al. Format chain exchange (FORCE) for high-throughput generation of bispecific antibodies in combinatorial binder-format matrices. Nat. Commun. 11, 4974 (2020).

[0053] As used herein “knob-into-hole” or “knob-in-hole” (KiH) modifications refer to modifications made in the Fc portion of an IgG to promoter the formation of Fc heterodimers. KiH comprise a “knob” modification in one of the Fc domains and a “hole” modification in the other Fc domain. The knob-into-hole technology is described e.g. in U.S. Patent No. 5,731,168; US 7,695,936; Ridgway et al., 1996, Prot Eng 9:617-621, and Carter, 2001, Immunol Meth 248:7-15. Generally, the method involves introducing a protuberance (“knob”) at the interface of a first polypeptide and a corresponding cavity (“hole”) in the interface of a second polypeptide, such that the protuberance can be positioned in the cavity so as to promote heterodimer formation and hinder homodimer formation. Protuberances are constructed by replacing small amino acid side chains from the interface of the first polypeptide with larger side chains (e.g., tyrosine or tryptophan). Compensatory cavities of identical or similar size to the protuberances are created in the interface of the second polypeptide by replacing large amino acid side chains with smaller ones (e.g., alanine or threonine).

[0054] As used herein, the term “nucleic acid” is interchangeable with “polynucleotide” or “nucleic acid molecule” and a polymer of nucleotides is intended.

[0055] A polynucleotide which encodes a gene product, e.g., a polypeptide, can include a promoter and / or other transcription or translation control elements operably linked with one or more coding regions. In an operable linkage a coding region for a gene product, e.g., a polypeptide, is associated with one or more regulatory regions in such a way as to place expression of the gene product under the influence or control of the regulatory region(s). For example, a coding region and a promoter are “operably linked” if induction of promoter function results in the transcription of mRNA encoding the gene product encoded by the coding region, and if the nature of the linkage between the promoter and the coding region does not interfere with the ability of the promoter to direct the expression of the gene product or interfere with the ability of the DNA template to be transcribed. Other transcription control elements, besides a promoter, for example enhancers, operators, repressors, and transcription termination signals, can also be operably linked with a coding region to direct gene product expression.

[0056] “Promoter” and “promoter sequence” are used interchangeably and refer to a DNA sequence capable of controlling the expression of a coding sequence or functional RNA. In general, a coding sequence is located 3’ to a promoter sequence. Promoters may be derived in their entirety from a wildtype gene, or be composed of different elements derived from different promoters found in nature, or even comprise synthetic DNA segments. It is understood by those skilled in the art that different promoters can direct the expression of a gene in different tissues or cell types, or at different stages of development, or in response to different environmental or physiological conditions. Promoters that cause a gene to be expressed in most cell types at most times are commonly referred to as “constitutive promoters.” Promoters that cause a gene to be expressed in a specific cell type are commonly referred to as “cell- specific promoters” or “tissuespecific promoters.” Promoters that cause a gene to be expressed at a specific stage of development or cell differentiation are commonly referred to as “developmentally- specific promoters” or “cell differentiation-specific promoters.” Promoters that are induced and cause a gene to be expressed following exposure or treatment of the cell with an agent, biological molecule, chemical, ligand, light, or the like that induces the promoter are commonly referred to as “inducible promoters” or “regulatable promoters.” It is further recognized that since in most cases the exact boundaries of regulatory sequences have not been completely defined, DNA fragments of different lengths can have identical promoter activity. Accordingly, a “promoter” as used herein encompasses a promoter operably linked to other regulatory elements. For example, regulatory element comprising an enhancer and a promoter may be more simply referred to herein as a “promoter”. Promoters as used herein encompass wildtype promoters, truncated variants of wildtype promoters, chimeric promoters, and synthetic promoters.

[0057] The “percent (%) identity” or the like may be readily determined for amino acid or nucleotide sequences, over the full-length of a protein, or a portion thereof. A portion may be at least about 5 amino acids or 24 nucleotides, respectively, in length, and may be up to about 700 amino acids or 2100 nucleotides, respectively. Generally, when referring to “identity”, “homology”, or “similarity” between two different adeno-associated viruses, “identity”, “homology” or “similarity” is determined in reference to “aligned” sequences. “Aligned” sequences or “alignments” refer to multiple nucleic acid sequences or protein (amino acids) sequences, often containing corrections for missing or additional bases or amino acids as compared to a reference sequence.

[0058] Alignments may be performed using any of a variety of publicly or commercially available Multiple Sequence Alignment Programs. Sequence alignment programs arc available for amino acid sequences, e.g., the “Clustal X”, “MAP”, “PIMA”, “MSA”, “BLOCKMAKER”, “MEME”, and “Match-Box” programs. Generally, any of these programs are used at default settings, although one of skill in the art can alter these settings as needed. Alternatively, one of skill in the art can utilize another algorithm or computer program which provides at least the level of identity or alignment as that provided by the referenced algorithms and programs. See, e.g., J. D. Thomson et al, Nucl. Acids. Res., “A comprehensive comparison of multiple sequence alignments”, 27(13):2682-2690 (1999).

[0059] “Retargeting” or “redirecting” may include a scenario in which a wildtype particle targets several cells within a tissue and / or several organs within an organism, and general targeting of the tissue or organs is reduced or abolished by insertion of the heterologous amino acid, and retargeting to more a specific cell in the tissue or a specific organ in the organism is achieved with the targeting ligand (e.g., via a targeting ligand) that binds a marker expressed by the specific cell. Such retargeting or redirecting may also include a scenario in which the wildtype particle targets a tissue, and targeting of the tissue is reduced to or abolished by insertion of the heterologous amino acid, and retargeting to a completely different tissue is achieved with the targeting ligand.

[0060] “Specific binding pair,” “binding pair,” “protein:protein binding pair” and the like includes two members (e.g., a first member (e.g., a first polypeptide) and a second cognate member (e.g., a second polypeptide)) that interact to form a bond (e.g., a non-covalent bond between a first member epitope and a second member antigen-binding portion of an antibody that recognizes the epitope; a covalent bond between e.g., proteins capable of forming isopeptide bonds; split inteins that recognize each other and, through the process of protein trans-splicing, mediate ligation of the flanking proteins and their own removal, etc.). In some embodiments, the term “cognate” refers to components that typically function together, e.g., biomolecules that typically interact (e.g., a receptor and its ligand). Epitopes and cognate antibodies thereto, particularly epitopes that may also act as a detectable label (e.g., c-myc) are well-known in the art. Specific protein:protein binding pairs that typically interact to form a covalent isopeptide bond are reviewed in Veggiani et al. (2014) Trends Biotechnol. 32:506, and include peptide:peptide binding pairs such as SpyTag:SpyCatcher, SpyTag002:SpyCatcher002;SpyTag:KTag; isopeptag:pilin C, SnoopTag: SnoopCatcher, etc., and variants thereof, e.g., SpyTag003:SpyCatcher003. Generally, a first member of a protcin:protcin binding pair refers to member of a protein:protein binding pair, which is generally less than 30 amino acids in length, and which typically interacts (e.g., forms a spontaneous bond, e.g., a covalent isopeptide, a non- covalent bond, etc.) with the second cognate protein, typically wherein the second cognate protein is generally larger, but may also be less than 30 amino acids in length such as in the SpyTag:KTag system.

[0061] The term “isopeptide bond” refers to an amide bond between a carboxyl or carboxamide group and an amino group at least one of which is not derived from a protein main chain or alternatively viewed is not part of the protein backbone. An isopeptide bond may form within a single protein or may occur between two peptides or a peptide and a protein. Thus, an isopeptide bond may form intramolecularly within a single protein or intermolecularly i.e., between two peptide / protein molecules, e.g. between two peptide linkers. Typically, an isopeptide bond may occur between a lysine residue and an asparagine, aspartic acid, glutamine, or glutamic acid residue or the terminal carboxyl group of the protein or peptide chain or may occur between the alpha-amino terminus of the protein or peptide chain and an asparagine, aspartic acid, glutamine or glutamic acid. Each residue of the pair involved in the isopeptide bond is referred to herein as a reactive residue. In preferred embodiments, an isopeptide bond may form between a lysine residue and an asparagine residue or between a lysine residue and an aspartic acid residue. Particularly, isopeptide bonds can occur between the side chain amine of lysine and carboxamide group of asparagine or carboxyl group of an aspartate.

[0062] The SpyTag:SpyCatcher system is described in U.S. Patent No. 9,547,003 and Zaveri et al. (2012) PNAS 109:E690-E697, each of which is incorporated herein in its entirety by reference, and is derived from the CnaB2 domain of the Streptococcus pyogenes fibronectin- binding protein FbaB. By splitting the domain, Zakeri et al. obtained a peptide “SpyTag” having the sequence AHIVMVDAYKPTK (SEQ ID NO: 1449) which forms an amide bond to its cognate protein “SpyCatcher,” an 112 amino acid polypeptide having the amino acid sequence set forth in SEQ ID NO: 1450. (Zakeri (2012), supra). An additional specific binding pair derived from CnaB2 domain is SpyTag:KTag, which forms an isopeptide bond in the presence of SpyLigase (SEQ ID NO: 1459). (Fierer (2014) PNAS 111:E1176-1181) SpyLigase was engineered by excising the β strand from SpyCatcher that contains a reactive lysine,resulting in KTag, 10-residue first member of a protein :protein binding pair having the amino acid sequence ATHIKFSKRD (SEQ ID NO: 1451). The SpyTag002:SpyCatchcr002 system is described in Keeble et al (2017) Angew Chem Int Ed Engl 56:16521-25, incorporated herein in its entirety by reference. SpyTag002 has the amino acid sequence VPTIVMVDAYKRYK, as set forth in SEQ ID NO: 1453, and binds SpyCatcher002 (SEQ ID NO: 1454). SpyTag003 has the amino acid sequence RGVPHIVMVDAYKRYK, as set forth in SEQ ID NO: 1455, and binds SpyCatcher003 (SEQ ID NO: 1456).

[0063] The SnoopTag:SnoopCatcher system is described in Veggiani (2016) PNAS 113: 1202-07. The D4 Ig-like domain of RrgA, an adhesion from Streptococcus pneumoniae, was split to form SnoopTag (residues 734-745; SEQ ID NO: 1457) and SnoopCatcher (residues 749-860; SEQ ID NO: 1458). Incubation of SnoopTag and SnoopCatcher results in a spontaneous isopeptide bond that is specific between the complementary proteins. Veggiani (2016)), supra.

[0064] The isopeptag :pilin-C specific binding pair was derived from the major pilin protein Spy0128 from Streptococcus pyogenes. (Zakeir and Howarth (2010) J. Am. Chem. Soc. 132:4526-27). Isopeptag has the amino acid sequence TDKDMTITFTNKKDAE, as set forth in SEQ ID NO: 1452, and binds pilin-C (residues 18-299 of Spy0128). Incubation of Isopeptag and pilin-C results in a spontaneous isopeptide bond that is specific between the complementary proteins. Zakeir and Howarth (2010), supra.

[0065] Other systems to facilitate retargeting can be based upon the splitting and engineering of RegA domain 4. These have led to SnoopTagJnSnoopCatcher, DogTag:DogCatcher and Snoop Ligase. Other systems include Isopeptag :Pilin-N, SdyTg:SdyCatcher, Jo:In, 3kptTag:3kptCatcher, 4oqlTag:4oqlCatcher, NGTag:NgCatcher, Rumtrunk:Mooncake, GalacTag:GalacDock, Cpe0147, Ececo, Corio and all others based upon isopeptide bond-forming binding pairs. , see e.g., WO2021224451, US20240168018, and Protein Nanotechnology: Protocols, Instrumentation and Applications [3rded 2020] 978-1-4939-9868-5, 978-1-4939-9869-2, available at dokumen.pub / protein-nanotechnology-protocols- instrumentation-and-applications-3rd-ed-2020-978-l-4939-9868-5-978-l-4939-9869-2.html, each incorporated herein in its entirety by reference. Also encompassed by the first and / or second members of the protein:protein binding pairs as described herein are functional portionsor fragments of known isopeptide bond-forming pairs, i.e., portions or fragments of binding pairs that retain the ability to form an isopcptidc bond.

[0066] The term “target cell” includes any cells in which expression of a nucleotide is desired. Preferably, target cells exhibit a receptor on their surface that allows the cell to be targeted with a targeting ligand, as described below.

[0067] As used herein, “therapeutically effective amount” means an amount, concentration or dose of a therapeutic agent (e.g., a nucleic acid, expression cassette, or AAV particle as described herein), or a pharmaceutical composition thereof, upon single or multiple dose administration to an individual in need thereof, provides a desired effect in such an individual under diagnosis or treatment (i.e., may produce a clinically measurable difference in a condition of the individual or may prevent a worsening in the individual). An effective amount can be readily determined by one of skill in the art by using known techniques and by observing results obtained under analogous circumstances. In determining the effective amount for an individual, a number of factors are considered, including, but not limited to, the species of subject, its size, age and general health, the specific disease, disorder, condition or symptom involved, the degree of or involvement or the severity of the disease, disorder, condition or symptom, the response of the individual, the therapeutic agent administered, the mode of administration, the bioavailability characteristics of the preparation administered, the dose regimen selected, the use of concomitant medication, and other relevant circumstances.

[0068] The term “transduction” or “infection” or the like refers to the introduction of a nucleic acid into a target cell nucleus by a viral, e.g., AAV, particle. The term efficiency in relation to transduction or the like, e.g., “transduction efficiency” refers to the fraction (e.g., percentage) of cells expressing a nucleotide after incubation with a set number of viral particles comprising the nucleotide. Well-known methods of determining transduction efficiency include flow cytometry of cells transduced with a fluorescent reporter gene, RT-PCR for expression of the nucleotide, etc.

[0069] “Wildtype”, as used herein in reference to a nucleotide sequence, refers to a nucleotide sequence that can be found in nature and has not been altered by the hand of man. For example, a wildtype human MTMT1 gene sequence is an MTM1 gene sequence that can be found naturally occurring in the human genome. By contrast, a “modified” nucleotide sequence, asused herein, refers to a nucleotide sequence that has been altered from the wildtype sequence in some manner, such that the two sequences arc no longer identical.

[0070] While the subject matter of the disclosure has been particularly shown and described with reference to a number of embodiments, it would be understood by those skilled in the art that changes in the form and details may be made to the various embodiments disclosed herein without departing from the spirit and scope of the subject matter of the disclosure and that the various embodiments disclosed herein are not intended to act as limitations on the scope of the claims.

[0071] As used herein, short gene names which are italicized refer to the gene whereas short, non-italicized gene names refer to the protein.Modified nucleic acids

[0072] Described herein are nucleic acids that have been modified to comprise or improve a desirable characteristic, or that eliminate or diminish an undesirable characteristic. Generally, a modified nucleic acid disclosed herein maintains at least one function of an unmodified, e.g., wildtype, nucleic acid. Non-limiting examples of nucleic acid modifications disclosed herein include codon alteration and CpG depletion. Codon alteration may be used, for example, to improve expression of a coding sequence in a target cell. CpG depletion may be used, for example, to reduce the immunogenicity of a nucleotide sequence, e.g., an AAV vector genome.

[0073] In some embodiments, a modified nucleic acid of the disclosure comprises a modified MTM1 gene sequence. The human MTM1 gene is located at band 28 of the long arm of the X chromosome, has 19 annotated exons, and encodes myotubularin. A representative wildtype human MTM1 coding sequence is contained within NCBI Reference Sequence No. NM_000252.3 or as set forth in SEQ ID NO: 1400. An alternative wildtype human MTM1 coding sequence is as set forth in SEQ ID NO: 1399. A representative wildtype human myotubularin polypeptide, e.g., myotubularin isoform 1, is as set forth in NCBI Reference Sequence No. NP_000243.1 or SEQ ID NO: 1398.

[0074] In some embodiments, the modified MTM1 gene sequence disclosed herein comprises a substitution of a codon of a wildtype MTM1 gene with a degenerate codon, whereinthe modified MTM1 gene sequence encodes myotubularin as set forth in SEQ ID NO: 1398. Accordingly, the modified MTM1 gene sequence encodes wildtypc MTM1 polypeptide.

[0075] In some embodiments, the modified MTM1 gene sequence disclosed herein exhibits reduced immunogenicity in a mammalian subject as compared to the wildtype MTM1 gene sequence and / or exhibits increased expression of myotubularin in a mammalian cell as compared to the wildtype MTM1 gene sequence.

[0076] Various methods of measuring immunogenicity and / or protein expression of a protein-coding nucleotide sequence are known in the art. For example, a plasmacytoid dendritic cell (pDC) assay may be used to evaluate TLR9-mediated immunogenicity in vitro. Moreover, expression of protein-coding sequences can be measured by several methods, including RNA sequencing of mRNA transcripts, quantitative PCR (qPCR) detection of mRNA transcripts, luminescence assays, and western blotting for expressed polypeptide. Accordingly, one may perform an assay as described herein, or otherwise known in the art, to quantify immunogenicity and / or expression of a modified protein-coding nucleotide sequence, e.g., MTM1 gene sequence, as compared to an unmodified, e.g., wildtype, protein-coding nucleotide sequence, wildtype MTM1 gene sequence, to determine if immunogenicity is reduced and / or expression is increased.

[0077] In some embodiments, the modified MTM1 gene sequence disclosed herein is CpG depleted, i.e., to reduce TLR9-mediated immunogenicity in a mammalian, e.g., human, subject. In some embodiments, the modified MTM1 gene sequence is CpG depleted via an algorithm selected from the group consisting of: DNA Chisel, IDT, and GeneArt.

[0078] In some embodiments, the modified MTM1 gene sequence disclosed herein comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence as set forth in SEQ ID NO: 1383 or SEQ ID NO: 1384.

[0079] In some embodiments, the modified MTM1 gene sequence disclosed herein is codon altered to, for example, improve protein expression in a mammalian, e.g., human, cell. In some embodiments, the modified MTM1 gene sequence has a codon adaptation index of at least 0.7, or at least 0.75, or at least 0.8 or at least 0.85 or at least 0.87 or at least 0.89, or at least 0.90, or at least 0.91, or at least 0.92, or at least 0.93, or at least 0.94, or at least 0.95, or at least 0.96, or at least 0.97, or at least 0.98, or at least 0.99. In some embodiments, the modified MTM1 gene sequence has a codon adaptation index of at least 0.74. In some embodiments, the modifiedMTM1 gene sequence has a codon adaptation index of at least 0.89. Various methods for codon alteration arc known in the art and could be readily employed by a skilled artisan. In some embodiments, the modified MTM1 gene sequence is codon altered via an algorithm selected from the group consisting of: DNA Chisel, GenScript, IDT, GeneArt, NovoPro, TwistBio, andVector Builder.

[0080] In some embodiments, the mammalian cell is a mammalian muscle, e.g., skeletal muscle, cell. In some embodiments, the mammalian muscle cell is a human muscle cell. In some embodiments, the human muscle cell is in vitro. In some embodiments, the human muscle cell is in vivo in a subject.

[0081] In some embodiments, the modified MTM1 gene sequence disclosed herein comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence as set forth in any one of SEQ ID NOs: 1401-1409 and / or as set forth in Table 1 below.Table 1. Modified MTM1 gene sequences and corresponding sequence identifiers.

[0082] In some embodiments, a modified nucleic acid as described herein comprises a modified muscle cell-specific promoter. In some embodiments, the muscle cell-specific promoter is selected from the group consisting of: MHCK7, Desmin, CK1, CK8, Des.invi, skCRM4_Des,CK8e, CK7, unc45b_SCP1, skCRMl_Des, HSA1.5, MHCK1, MCK1.35, SP985, 2R5S_c5-12, c5-12, SP-301, tMCK, 0.7 DES, 1.0 DES, 1.7 DES, SCP, 1.0 DES(v2), or biologically equivalent variants thereof. In some embodiments, the muscle cell- specific promoter comprises amodified MHCK7 promoter sequence. In some embodiments, the MHCK7 promoter sequence comprises a substitution of at least one nucleotide of a wildtypc MHCK7 promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, wherein the modified MHCK7 promoter sequence binds to transcriptional proteins and initiates transcription in muscle cells. Thus, the modified MHCK7 promoter sequence comprises a CpG depleted MHCK7 promoter sequence that maintains the ability of the promoter to initiate transcription.

[0083] In some embodiments, the modified MHCK7 promoter sequence disclosed herein exhibits reduced immunogenicity in a mammalian subject as compared to the wildtype MHCK7 promoter sequence. In some embodiments, the modified MHCK7 promoter sequence operably linked to a protein coding sequence exhibits reduced immunogenicity in a mammalian subject and comparable expression of the protein in a mammalian cell as compared to the wildtype MHCK7 promoter sequence operably linked to the protein coding sequence. In some embodiments, the wildtype MHCK7 promoter sequence comprises a nucleotide sequence as set forth in SEQ ID NO: 1410. In some embodiments, the modified MHCK7 promoter sequence comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence as set forth in SEQ ID NO: 1411 or SEQ ID NO: 1412.

[0084] Also described herein is a nucleic acid comprising, in operable linkage: (a) a promoter sequence, wherein the promoter sequence does not comprise an MTM1 promoter sequence, and (b) a modified MTM1 gene sequence comprising a substitution of a codon of a wildtype MTM1 gene as set forth in SEQ ID NO: 1399 or SEQ ID NO: 1400 with a degenerate codon. In some embodiments, the promoter sequence comprises a muscle cell-specific promoter, as described herein. In some embodiments, the promoter sequence comprises a wildtype MHCK7 promoter sequence. In some embodiments, the wildtype MHCK7 promoter sequence comprises a nucleotide sequence as set forth in SEQ ID NO: 1410. In some embodiments, the promoter sequence comprises a modified MHCK7 promoter sequence, as described herein. In some embodiments, the modified MTM1 gene sequence comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence set forth in SEQ ID NOs: 1401-1409.

[0085] In some embodiments, the modified nucleic acid as described herein comprises an expression cassette, i.e., for expressing MTM1 in a mammalian, e.g., human, cell. In someembodiments, the expression cassette comprises a nucleic acid comprising a modified MTM1 gene sequence, as described herein, operably linked to an expression control sequence. In some embodiments, the expression control sequence comprises a muscle cell-specific promoter sequence, as described herein. In some embodiments, the muscle cell-specific promoter sequence comprises a modified muscle cell-specific promoter sequence that exhibits reduced immunogenicity in a mammalian subject as compared to the wildtype muscle cell-specific promoter sequence. In some embodiments, the modified muscle cell-specific promoter sequence comprises a substitution of at least one nucleotide of the wildtype muscle cell-specific promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, wherein the modified muscle cell-specific promoter sequence binds to transcriptional proteins and initiates transcription in muscle cells. In some embodiments, the modified muscle cellspecific promoter sequence is an MHCK7 promoter sequence, e.g., a modified MHCK7 promoter sequence as described herein. In some embodiments, the expression cassette comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to a sequence set forth in any one of SEQ ID NOs: 1414-1427.

[0086] Also encompassed by the present disclosure are methods of making the modified nucleic acids and expression cassettes as described herein. Any known methods of making nucleic acids, which would be familiar and readily available to a skilled artisan, can be employed to make a modified nucleic acid or expression cassette as described herein.

[0087] Also described herein is a method of making a nucleic acid comprising a modified MTM1 gene sequence, the method comprising substituting a codon of a wildtype MTM1 gene with a degenerate codon, wherein the modified MTM1 gene sequence encodes myotubularin as set forth in SEQ ID NO: 1398.

[0088] Also described herein is a method of making a nucleic acid comprising a modified MHCK7 promoter sequence, the method comprising substituting at least one nucleotide of a wildtype MHCK7 promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, wherein the modified MHCK7 promoter sequence binds to transcriptional proteins and initiates transcription.

[0089] Also described herein is a method of making a modified MTM1 expression cassette, the method comprising operably linking a nucleic acid comprising a modified MTM1gene sequence, as described herein, to a nucleic acid comprising a modified MHCK7 promoter sequence, as described herein.Adeno-associated viruses (AAV)

[0090] “AAV” is an abbreviation for adeno-associated virus and may be used to refer to the virus itself or derivatives thereof. AAVs are small, non-enveloped, single-stranded DNA viruses. Generally, a wildtype AAV genome is 4.7 kb and is characterized by two inverted terminal repeats (ITR) and two open reading frames (ORFs), rep and cap. The wildtype rep reading frame encodes four proteins of molecular weight 78 kD (“Rep78”), 68 kD (“Rep68”), 52 kD (“Rep52”) and 40 kD (“Rep 40”). Rep78 and Rep68 are transcribed from the p5 promoter, and Rep52 and Rep40 are transcribed from the pl9 promoter. These proteins function mainly in regulating the transcription and replication of the AAV genome. The wildtype cap reading frame encodes three structural (capsid) viral proteins (VPs) having molecular weights of 83-85 kD (VP1), 72-73 kD (VP2), and 61-62 kD (VP3). More than 80% of total proteins in an AAV virion (capsid) comprise VP3; in mature virions VP1, VP2, and VP3 are found at relative abundance of approximately 1:1:10, although ratios of 1:1:8 have been reported. Padron et al. (2005) J. Virology 79:5047-58.

[0091] The genomic sequences of various serotypes of AAV, as well as the sequences of the native inverted terminal repeats (ITRs), Rep proteins, and capsid subunits are known in the art. Such sequences may be found in the literature or in public databases such as GenBank. See, e.g., GenBank Accession Numbers NC .002077 (AAV1), AF063497 (AAV1), NC001401 (AAV-2), AF043303 (AAV2), NC_001729 (AAV3), NC_001829 (AAV4), U89790 (AAV4), NC_006152 (AAV5), AF513851 (AAV7), AF513852 (AAV8), and NC_006261 (AAV8); the disclosures of which are incorporated by reference herein for teaching AAV nucleic acid and amino acid sequences. See also, e.g., Srivistava et al. (1983) J. Virology 45:555; Chiorini et al. (1998) J. Virology 71:6823; Chiorini et al. (1999) J. Virology 73: 1309; Bantel-Schaal et al. (1999) J. Virology 73:939; Xiao et al. (1999) J. Virology 73:3994; Muramatsu et al. (1996) Virology 221:208; Shade et al., (1986) J. Virol. 58:921; Gao et al. (2002) Proc. Nat. Acad. Sci. USA 99: 11854; Moris et al. (2004) Virology 33:375-383; US Patent Publication 20170130245; international patent publications WO 00 / 28061, WO 99 / 61601, WO 98 / 11244; and U.S. Pat. No.6,156,303, each of which is incorporated by reference in its entirety by reference. Table 7 herein provides sequences of various non-primatc AAV.

[0092] “AAV” encompasses all subtypes and both naturally occurring and modified forms. AAV includes primate AAV (e.g., AAV type 1 (AAV1), primate AAV type 2 (AAV2), primate AAV type 3 (AAV3B), primate AAV type 4 (AAV4), primate AAV type 5 (AAV5), primate AAV type 6 (AAV6), primate AAV type 7 (AAV7), primate AAV type 8 (AAV8), primate AAV type 9 (AAV9), AAV10, AAV11, AAV12, AAV13, AAVDJ, Anc80L65, AAV2G9, AAV-LK03, primate AAV type rh10 (AAV rh10), AAV type h10 (AAV h10), AAV type hull (AAV hull), AAV type rh32.33 (AAV rh32.33), AAV retro (AAV retro), AAV PHP.B, AAV PHP.eB, AAV PHP.S, AAV2 / 8, etc., non-primate animal AAV (e.g., avian AAV (AAAV)) and other non-primate animal AAV such as mammalian AAV (e.g., bat AAV, sea lion AAV, bovine AAV, canine AAV, equine AAV, caprine AAV, and ovine AAV etc.), squamate AAV (e.g., snake AAV, bearded dragon AAV), and engineered variants thereof, etc. “Primate AAV” refers to AAV generally isolated from primates. Similarly, “non-primate animal AAV” refers to AAV isolated from non-primate animals.

[0093] As used herein, “of a [specified] AAV” in relation to a gene (e.g., rep, cap, etc.), capsid protein (e.g., a VP1 capsid protein, a VP2 capsid protein, a VP3 capsid protein, etc.), region of a capsid protein of a specified AAV (e.g., PLA2region, VP1-u region, VP1 / VP2 common region, VP3 region), nucleotide sequence (e.g., ITR sequence), e.g., a cap gene or capsid protein of AAV etc., encompasses, in addition to the gene or the polypeptide respectively comprising a nucleic acid sequence or amino acid sequence set forth herein for the specified AAV, also variants of the gene or polypeptide, including variants comprising the least number of nucleotides or amino acids required to retain one or more biological functions. As used herein, a variant gene or a variant polypeptide comprises a nucleic acid sequence or amino acid sequence that differs from the nucleic acid sequence or amino acid sequence set forth herein for the gene or polypeptide of a specified AAV, wherein the difference(s) does not generally alter at least one biological function of the gene or polypeptide, and / or the phylogenetic characterization of the gene or polypeptide, e.g., where the difference(s) may be due to degeneracy of the genetic code, isolate variations, length of the sequence, etc. For example, rep gene and the cap gene as used here may encompass rep and cap genes that differ from the wildtype gene in that the genes may encode one or more Rep proteins and Cap proteins, respectively. In some embodiments, a Repgene encodes at least Rep78 and / or Rep68. In some embodiments, a cap gene includes those that may differ from the wildtypc in that one or more alternative start codons or sequences between one or more alternative start codons are removed such that the cap gene encodes only a single Cap protein, e.g., wherein the VP2 and / or VP3 start codons are removed or substituted such that the cap gene encodes a functional VP1 capsid protein but not a VP2 capsid protein or a VP3 capsid protein. Accordingly, as used herein, a rep gene encompasses any sequence that encodes a functional Rep protein. A cap gene encompasses any sequence that encodes at least one functional cap gene.

[0094] It is well-known that the wildtype cap gene expresses all three VP1, VP2, and VP3 capsid proteins from a single open reading frame of the cap gene under control of the p40 promoter found in the rep ORF. The term “capsid protein,” “Cap protein” and the like includes a protein that is part of the capsid of the virus. For adeno-associated viruses, the capsid proteins are generally referred to as VP1, VP2, and / or VP3, and may be encoded by the single cap gene. For AAV, the three AAV capsid proteins are produced in an overlapping fashion from the cap ORF alternative translational start codon usage, although all three proteins use a common stop codon. The ORF of a wildtype cap gene encodes from 5’ to 3’ three alternative start codons: “the VP1 start codon,” “the VP2 start codon,” and “the VP3 start codon”; and one “common stop codon”. The largest viral protein, VP1, is generally encoded from the VP1 start codon to the “common stop codon.” VP2 is generally encoded from the VP2 start codon to the common stop codon. VP3 is generally encoded from the VP3 start codon to the common stop codon.Accordingly, VP1 comprises at its N-terminus a sequence that it does not share with the VP2 or VP3, referred to as the VP1-unique region (VP1-u). The VP1-u region is generally encoded by the sequence of a wildtype cap gene starting from the VP1 start codon to the “VP2 start codon.” VP1-u comprises a phospholipase A2 domain (PLA2), which may be important for infection, as well as nuclear localization signals which may aid the virus in targeting to the nucleus for uncoating and genome release. The VP1, VP2, and VP3 capsid proteins share the same C- terminal sequence that makes up the entirety of VP3, which may also be referred to herein as the VP3 region. The VP3 region is encoded from the VP3 start codon to the common stop codon. VP2 has an additional - 60 amino acids that it shares with the VP1. This region is called the VP1 / VP2 common region.

[0095] In some embodiments, one or more of the Cap proteins disclosed herein may be encoded by one or more cap genes having one or more ORFs. In some embodiments, the VP proteins disclosed herein may be expressed from more than one ORF comprising nucleotide sequence encoding any combination of VP1, VP2, and / or VP3 by use of separate nucleotide sequences operably linked to at least one expression control sequence for expression in packaging cell, each producing one or more of VP1, VP2, and / or VP3 capsid proteins disclosed herein. In some embodiments, a VP capsid protein disclosed herein may be expressed individually from an ORF comprising nucleotide sequence encoding any one of VP1, VP2, or VP3 by use of separate nucleotide sequences operably linked to one expression control sequence for expression in a viral replication cell, each producing only one of VP1, VP2, or VP3 capsid protein. In another embodiment, VP proteins may be expressed from one ORF comprising nucleotide sequences encoding VP1, VP2, and VP3 capsid proteins operably linked to at least one expression control sequence for expression in a viral replication cell, each producing VP1, VP2, and VP3 capsid protein. Accordingly, although amino acid positions provided herein may be provided in relation to the VP1 capsid protein of the referenced AAV, a skilled artisan would be able to respectively and readily determine the position of that same amino acid within the VP2 and / or VP3 capsid protein of the AAV, and the corresponding position of amino acids among different AAV.

[0096] The phrase “Inverted terminal repeat” or “ITR” includes symmetrical nucleic acid sequences in the genome of adeno-associated viruses required for efficient replication. ITR sequences are located at each end of the AAV DNA genome. The ITRs serve as the origins of replication for viral DNA synthesis and are essential cis components for generating AAV particles, e.g., packaging into AAV particles.

[0097] AAV ITR comprise recognition sites for replication proteins Rep78 or Rep68. A “D” region of the ITR comprises the DNA nick site where DNA replication initiates and provides directionality to the nucleic acid replication step. An AAV replicating in a mammalian cell typically comprises two ITR sequences.

[0098] A single ITR may be engineered with Rep binding sites on both strands of the “A” regions and two symmetrical D regions on each side of the ITR palindrome. Such an engineered construct on a double- stranded circular DNA template allows Rep78 or Rep68 initiated nucleic acid replication that proceeds in both directions. A single ITR is sufficient forAAV replication of a circular particle. In methods of producing an AAV viral particle disclosed herein, the rep encoding sequence encodes a Rep protein or Rep protein equivalent that is capable of binding an ITR on the transfer plasmid.

[0099] The Cap proteins disclosed herein, when expressed with appropriate Rep proteins by a packaging cell, may encapsidate a transfer plasmid comprising a nucleotide and an even number of two or more ITR sequences. In some embodiments, a transfer plasmid disclosed herein comprises one ITR sequence. In some embodiments, a transfer plasmid disclosed herein comprises two ITR sequences.

[0100] Either Rep78 and / or Rep68 bind to unique and known sites on the sequence of the ITR hairpin, and act to break and unwind the hairpin structures on the end of an AAV genome, thereby providing access to replication machinery of the viral replication cell. Rep proteins may be expressed from more than one ORF comprising nucleotide sequence encoding any combination of Rep78, Rep68, Rep 52 and / or Rep40 by use of separate nucleotide sequences operably linked to at least one expression control sequence for expression in a viral replication cell, each producing one or more of Rep78, Rep68, Rep 52 and / or Rep40 Rep proteins.Alternatively, Rep proteins may be expressed individually from an ORF comprising a nucleotide sequence encoding any one of Rep78, Rep68, Rep 52, or Rep40 by use of separate nucleotide sequences operably linked to one expression control sequence for expression in a packaging cell, each producing only one Rep78, Rep68, Rep 52, or Rep40 Rep protein. In another embodiment, Rep proteins disclosed herein may be expressed from one ORF comprising nucleotide sequences encoding Rep78 and Rep52 Rep proteins operably linked to at least one expression control sequence for expression in a viral replication cell each producing Rep78 and Rep52 protein.

[0101] In a method of producing an AAV virion, e.g., viral particle, disclosed herein, a rep encoding sequence and a cap gene disclosed herein may be provided as a single packaging plasmid. Such viral particles may or may not include a genome.

[0102] A “chimeric AAV capsid protein” includes an AAV capsid protein that comprises amino acid sequences, e.g., portions, from two or more different AAV and that is capable of forming and / or forms an AAV viral capsid / viral particle. A chimeric AAV capsid protein is encoded by a chimeric AAV capsid gene, e.g., a chimeric nucleotide comprising a plurality, e.g., at least two, nucleic acid sequences, each of which plurality is identical to a portion of a capsid gene encoding a capsid protein of distinct AAV, and which plurality together encodes afunctional chimeric AAV capsid protein. Association of a chimeric capsid protein to a specific AAV indicates that the capsid protein comprises one or more portions from a capsid protein of that AAV and one or more portions from a capsid protein of a different AAV. For example, a chimeric AAV2 capsid protein includes a capsid protein comprising one or more portions of a VP1, VP2, and / or VP3 capsid protein of AAV2 and one or more portions of a VP1, VP2, and / or VP3 capsid protein of a different AAV.

[0103] A “portion”, as used herein in reference to AAV, encompasses any contiguous segment of amino acids or nucleotides sufficient to determine that the polypeptide or nucleic acid molecule from which the portion is derived is “of a [specified] AAV” or has “significant identity” to a particular AAV, e.g., a non-primate animal AAV or remote AAV. In some embodiments, a portion comprises at least 5 amino acids or 15 nucleotides with 100% identity to a sequence associated with the specified AAV. In some embodiments, a portion comprises at least 10 amino acids or 30 nucleotides with 100% identity to a sequence associated with the specified AAV. In some embodiments, a portion comprises at least 15 amino acids or 45 nucleotides with 100% identity to a sequence associated with the specified AAV. In some embodiments, a portion comprises at least 20 amino acids or 60 nucleotides with 100% identity to a sequence associated with the specified AAV. In some embodiments, a portion comprises at least 25 amino acids or 75 nucleotides with 100% identity to a sequence associated with the specified AAV. In some embodiments, a portion comprises at least 30 amino acids or 90 nucleotides with 100% identity to a sequence associated with the specified AAV. In some embodiments, a portion comprises at least 35 amino acids or 105 nucleotides with 100% identity to a sequence associated with the specified AAV. In some embodiments, a portion comprises at least 40 amino acids or 120 nucleotides with 100% identity to a sequence associated with the specified AAV. In some embodiments, a portion comprises at least 45 amino acids or 135 nucleotides with 100% identity to a sequence associated with the specified AAV. In some embodiments, a portion comprises at least 50 amino acids or 150 nucleotides with 100% identity to a sequence associated with the specified AAV. In some embodiments, a portion comprises at least 60 amino acids or 180 nucleotides with 100% identity to a sequence associated with the specified AAV. In some embodiments, a portion comprises at least 70 amino acids or 210 nucleotides with 100% identity to a sequence associated with the specified AAV. In some embodiments, a portion comprises at least 80 amino acids or 240 nucleotides with 100% identityto a sequence associated with the specified AAV. In some embodiments, a portion comprises at least 90 amino acids or 270 nucleotides with 100% identity to a sequence associated with the specified AAV. In some embodiments, a portion comprises at least 100 amino acids or 300 nucleotides with 100% identity to a sequence associated with the specified AAV.

[0104] Provided herein are AAV vector genomes comprising a nucleic acid of the present disclosure for packaging into AAV capsids to form an AAV particle. An “AAV vector genome”, as used herein, refers to protein-coding sequence operably linked to an expression control sequence and flanked by 5’ and 3’ AAV ITRs.

[0105] In some embodiments, an AAV vector genome as described herein comprises from 5’ to 3’ and in operable linkage: (a) a 5’ AAV inverted terminal repeat (ITR); (b) a promoter sequence; (c) a nucleic acid comprising a modified MTM1 gene sequence as described herein; and (d) a 3’ AAV ITR.

[0106] In some embodiments, an AAV vector genome as described herein comprises from 5’ to 3’ and in operable linkage: (a) a 5’ AAV ITR; (b) a nucleic acid comprising a modified MHCK7 promoter sequence as described herein; (c) a nucleic acid comprising a modified MTM1 gene sequence as described herein; and (d) a 3’ AAV ITR.

[0107] In some embodiments, an AAV vector genome as described herein comprises from 5’ to 3’ and in operable linkage: (a) a 5’ AAV ITR; (b) a nucleic acid comprising a promoter sequence operably linked to a modified MTM1 gene sequence as described herein; and (c) a 3’ AAV ITR.

[0108] In some embodiments, an AAV vector genome as described herein comprises from 5’ to 3’ and in operable linkage: (a) a 5’ AAV ITR; (b) an expression cassette comprising a modified MTM1 gene sequence as described herein operably linked to an expression control sequence, e.g., a modified MHCK7 promoter sequence as described herein; and (c) a 3’ AAV ITR.

[0109] In some embodiments, the 5’ and 3’ AAV ITRs disclosed herein are AAV2 ITRs. In some embodiments, the 5’ AAV ITR comprises a sequence as set forth in SEQ ID NO: 1442 or 1443. In some embodiments, the 3’ ITR comprises a sequence as set forth in SEQ ID NO: 1444 or 1445.

[0110] In some embodiments, the AAV vector genome disclosed herein comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, atleast 97%, at least 98%, or at least 99% identical to a sequence set forth in any one of SEQ ID NOs: 1428-1441.

[0111] Also described are AAV particles comprising an AAV vector genome as described herein encapsidated by an AAV capsid as described herein. In some embodiments, the AAV capsid is a modified AAV capsid.

[0112] In some embodiments, the modified AAV capsid disclosed herein comprises a first member of a protein :protein binding pair, wherein the first member of the protein:protein binding pair is associated with the second member of the protein:protein binding pair. In some embodiments, the second member of the protein:protein binding pair comprises a targeting ligand the specifically binds a mammalian muscle cell-specific surface protein. In some embodiments, the targeting ligand is an antibody or an antigen-binding fragment thereof. In some embodiments, the mammalian muscle cell-specific surface protein is mammalian Calcium Voltage-Gaged Auxiliary Subunit Gamma 1 (CACNG1). In some embodiments, the mammalian muscle cell-specific surface protein is human CACNG1.

[0113] In some embodiments, the first member of the protein:protein binding pair disclosed herein comprises an epitope, wherein the second member of the protein:protein binding pair comprises an antibody paratope that specifically binds the epitope. In some embodiments, the epitope comprises an AAV amino acid sequence. In some embodiments, the epitope comprises an amino acid sequence heterologous to the AAV capsid, optionally wherein the epitope comprises a c-myc amino acid sequence, optionally wherein the c-myc amino acid sequence comprises a sequence as set forth in SEQ ID NO: 1466. In some embodiments, the second member of the protein:protein binding protein binds both the epitope and the mammalian muscle cell-specific surface protein. In some embodiments, the second member of the protein:protein binding protein binds both the epitope and the mammalian muscle cell-specific surface protein. In some embodiments, the second member of the protein:protein binding pair is bispecific targeting ligand, e.g., bispecific antibody, as described herein.

[0114] In some embodiments, the first member of the protein:protein binding pair disclosed herein and the second member of the protein:protein binding pair disclosed herein form an isopeptide bond. Various protein:protein binding pairs that form isopeptide bonds are known in the art, including but not limited to SpyTag:SpyCatcher, SpyTag002:SpyCatcher002; SpyTag:KTag; isopeptag:pilin C, SnoopTag: SnoopCatcher, SpyTag003:SpyCatcher003,SnoopTag Jr: SnoopCatcher, DogTag:SnoopTagJr, Isopeptag:Pilin-N, SdyTg:SdyCatcher, Jo:In, 3kptTag: 3kptCatchcr, 4oqlTag:4oqlCatchcr, NGTag:NgCatchcr, Rumtrunk:Mooncakc, GalacTag:GalacDock, Cpe0147, Ececo, Corio, etc.Modified virus capsid proteins, viral particles, viral nucleic acids

[0115] In some embodiments, a Cap protein, e.g., a VP1 capsid protein as described herein, a VP2 capsid protein as described herein, and / or a VP3 capsid protein as described herein, is modified to comprise any one or combination of e.g., insertion of a targeting ligand, a chemical modification, a first member of a binding pair, a detectable label, point mutation, etc.

[0116] Generally, modification of a gene or a polypeptide of a specified AAV, or a variant thereof, results in a nucleic acid sequence or an amino acid sequence that differs from the nucleic acid sequence or amino acid sequence set forth herein for the specified AAV, wherein the modification alters, confers, or removes one or more biological functions, but does not change the phylogenetic characterization of, the gene or polypeptide as an AAV gene or AAV polypeptide. Modifications may include any one or a combination of: substitution of sequences of a first AAV serotype with sequences of a second AAV serotype to create chimerism; chemical modification; an insertion of: a first member of a binding pair, and / or a point mutation; etc., such that the natural tropism of the capsid protein is reduced to abolished, the tropism of the capsid protein may be more easily redirected, and / or such that the capsid protein comprises a detectable label. Modifications as described herein generally do not alter and preferably decrease the low to no recognition of the modified capsid by pre-existing antibodies found in the general population that were produced during the course of infection with another AAV, e.g., infection with serotypes such as AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAV13, AAVDJ, Anc80L65, AAV2G9, AAV-LK03, virions based on such serotypes, virions from currently used AAV gene therapy modalities, or a combination thereof.Targeting ligands

[0117] Modifications described herein may pertain to the association (e.g., display, operable linkage, binding, etc.) of a targeting ligand to a modified capsid protein and / or capsid comprising a modified capsid protein. Generally, a targeting ligand as described herein binds a surface protein expressed by a mammalian muscle cell, e.g., a mammalian muscle cell-specificsurface protein. In certain embodiments, the mammalian muscle cell-specific surface protein comprises CACNG1, e.g., human CACNG1.

[0118] Table 2 provides a summary of the amino acid SEQ ID NOs for each binding portion (e.g., heavy chain variable domain (HCVR), light chain variable domain (LCVR), and CDR1, CDR2, and CDR3) of non-limiting and example anti-human-CACNG1 monoclonal antibodies that may be used to redirect an AAV capsid as described herein. Table 2 provides a summary of the nucleotide SEQ ID NOs encoding each binding portion (e.g., heavy chain variable domain (HCVR), light chain variable domain (LCVR), and CDR1, CDR2, and CDR3) amino acid sequences disclosed in Table 2. In some embodiments, an AAV capsid as described herein comprises a targeting ligand that binds human CACNG1, wherein the targeting ligand comprises a heavy chain variable domain, light chain variable domain, heavy chain variable domain / light chain variable domain pair, HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, LCDR3, and / or set of HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3 amino acid sequence(s) at least 90% identical to, respectively, an amino acid sequence of a heavy chain variable domain, light chain variable domain, heavy chain variable domain / light chain variable domain pair, HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, LCDR3, and / or set of HCDR1-HCDR2-HCDR3-LCDR1- LCDR2-LCDR3 as set forth in Table 2. In some embodiments, an AAV capsid as described herein comprises a targeting ligand that binds human CACNG1, wherein the targeting ligand comprises a heavy chain variable domain, light chain variable domain, heavy chain variable domain / light chain variable domain pair, HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, LCDR3, and / or set of HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3 amino acid sequence at least 95% identical to, respectively, amino acid sequence(s) of a heavy chain variable domain, light chain variable domain, heavy chain variable domain / light chain variable domain pair, HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, LCDR3, and / or set of HCDR1-HCDR2-HCDR3-LCDR1- LCDR2-LCDR3 as set forth in Table 2. In some embodiments, an AAV capsid as described herein comprises a targeting ligand that binds human CACNG1, wherein the targeting ligand comprises a heavy chain variable domain, light chain variable domain, heavy chain variable domain / light chain variable domain pair, HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, LCDR3, and / or set of HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3 amino acid sequence at least 97% identical to amino acid sequence(s) of a heavy chain variable domain, light chain variable domain, heavy chain variable domain / light chain variable domain pair, HCDR1, HCDR2,HCDR3, LCDR1, LCDR2, LCDR3, and / or set of HCDR1-HCDR2-HCDR3-LCDR1-LCDR2- LCDR3 as set forth in Table 2. In some embodiments, an AAV capsid as described herein comprises a targeting ligand that binds human CACNG1, wherein the targeting ligand comprises a heavy chain variable domain, light chain variable domain, heavy chain variable domain / light chain variable domain pair, HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, LCDR3, and / or set of HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3 amino acid sequence(s) at least 98% identical to amino acid sequence(s) of a heavy chain variable domain, light chain variable domain, heavy chain variable domain / light chain variable domain pair, HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, LCDR3, and / or set of HCDR1-HCDR2-HCDR3-LCDR1-LCDR2- LCDR3 as set forth in Table 2. In some embodiments, an AAV capsid as described herein comprises a targeting ligand that binds human CACNG1, wherein the targeting ligand comprises a heavy chain variable domain, light chain variable domain, heavy chain variable domain / light chain variable domain pair, HCDR1, HCDR2, CDR3, LCDR1, LCDR2, LCDR3, and / or set of HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3 amino acid sequences 99% identical to amino acid sequences of a heavy chain variable domain, light chain variable domain, heavy chain variable domain / light chain variable domain pair, HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, LCDR3, and / or set of HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3 as set forth in Table 2. Also described herein are antibodies, or antigen-binding fragments thereof, comprising a set of six CDRs (i.e., HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3) contained within an HCVR / LCVR amino acid sequence pair as defined by any of the example anti-CACNG1 antibodies listed in Table 2. In some embodiments, an AAV capsid as described herein comprises a targeting ligand that binds human CACNG1, wherein the targeting ligand comprises a heavy chain variable domain, light chain variable domain, heavy chain variable domain / light chain variable domain pair, HCDR1, HCDR2, CDR3, LCDR1, LCDR2, LCDR3, and / or set of HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3 encoded by a nucleic acid that is at least 90%, at least 95%, at least 97%, at least 98%, or at least 99% identical to a nucleotide sequence as set forth in Table 3.Table 2. Amino Acid Sequence Identifiers for Anti-CACNG1 AntibodiesTable 3. Nucleic Acid Sequence Identifiers for Anti-CACNG1 Antibodies

[0119] Non-limiting examples of targeting ligands that bind CACNG1 include: (i) Fab fragments; (ii) F(ab')2 fragments; (iii) Fd fragments; (iv) Fv fragments; (v) single-chain Fv (scFv) molecules; (vi) dAb fragments; and (vii) minimal recognition units consisting of the amino acid residues that mimic the hypervariable region of an antibody (e.g., an isolated complementarity determining region (CDR) such as a CDR3 peptide), or a constrained FR3- CDR3-FR4 peptide. Other engineered molecules, such as domain- specific antibodies, single domain antibodies, domain-deleted antibodies, chimeric antibodies, CDR-grafted antibodies, diabodies, triabodies, tetrabodies, minibodies, nanobodies (e.g. monovalent nanobodies, bivalent nanobodies, etc.), small modular immunopharmaceuticals (SMIPs), and shark variable IgNAR domains, are also encompassed within the expression “targeting ligand,” as used herein. In non-limiting embodiments, an anti-CACNG1 targeting ligand that binds CACNG1 useful for retargeting viral capsids as described herein comprise comprises an scFv. As a non-limiting example, an scFv sequence in VL-(Gly4Ser)3-VH format useful for retargeting viral capsids as described herein may comprise a heavy chain variable domain, light chain variable domain, heavy chain variable domain / light chain variable domain pair, HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, LCDR3, and / or set of HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3 that is 90%, 95%, 97%, 98%, 99% or 100% identical, respectively, to any one of the amino acid sequences of a heavy chain variable domain, light chain variable domain, heavy chain variable domain / light chain variable domain pair, HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, LCDR3, and / or set of HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3 as set forth in Table 2.

[0120] A targeting ligand that binds a mammalian muscle cell-specific surface protein disclosed herein may be associated with (e.g., displayed by, operably linked to, bound to) amodified AAV capsid protein and resulting AAV capsids according to well-known methods, e.g., a direct approach in which the targeting ligand is directly inserted into (e.g., using recombinatorial methods) according to well-known methods. See, e.g., Stachler et al. (2006), supra; White et al. (2004), supra; Girod et al. (1999), supra; Grifman et al. (2001), supra; Shi et al. (2001), supra; Shi and Bartlett (2003), supra. A targeting ligand that binds a mammalian muscle cell-specific surface protein may be coupled to a modified AAV capsid protein and resulting AAV capsids using well-known chemical linkers, e.g., wherein the AAV capsid protein may be chemically modified to comprise a dibenzocycootyne group or an azide group, and optionally wherein a targeting ligand as described herein is attached to the dibenzocycootyne group or the azide group, see, e.g., U.S. 2022 / 028234, incorporated herein by reference in its entirety; wherein targeting ligand is covalently linked to a primary amino acid group of an AAV capsid protein, e.g., via a -CSNH- bond, etc. In some embodiments, a modified capsid as described herein comprises a targeting ligand, e.g., an anti-CACNG1 antibody or binding portion thereof, directly inserted into or coupled to it according to well-known direct recombinatorial methods.Multispecific Targeting Ligands

[0121] In some embodiments, the targeting ligand disclosed herein comprises a multispecific binding molecule, e.g., a bispecific antigen-binding molecule, e.g., a bispecific antibody. In some embodiments, the multispecific antigen-binding molecule comprises a first antigen-binding domain and a second antigen-binding domain.

[0122] In some embodiments, the first antigen-binding domain binds to a surface protein expressed by a mammalian muscle cell, e.g., human CACNG1, as described herein.

[0123] In some embodiments, the second antigen-binding domain binds to a first member of a protein:protein binding pair, e.g., a detectable label, comprised within, displayed by, etc., an AAV capsid protein, e.g., at a variable loop of an AAV capsid.

[0124] In some embodiments, the second antigen-binding domain of a multispecific targeting ligand described herein binds to a first member of a protein:protein binding pair, wherein the first member of the protein:protein binding pair is heterologous to the AAV capsid protein. “Heterologous” in this context means heterologous as compared to the AAV serotype from which the capsid protein is derived. In some embodiments, the second antigen-bindingdomain specifically binds to a c-myc epitope, e.g., comprising an amino acid sequence as set forth in SEQ ID NO: 1466. In some embodiments, the second antigen-binding domain comprises an antibody paratope that specifically binds to a c-myc epitope, e.g., comprising an amino acid sequence as set forth in SEQ ID NO: 1466. Thus, the present disclosure includes bispecific antigen-binding molecules, e.g., antibodies, wherein one domain of antigen-binding domain binds to a heterologous detectable label displayed by an AAV capsid (e.g., c-myc, Bl, etc.), and the other antigen-binding domain binds to a surface protein expressed by a mammalian muscle cell, e.g., CACNG1. Accordingly, in some embodiments, the multispecific antigen-binding domain comprising the first and second antigen-binding domains retargets an AAV particle comprising an AAV capsid protein comprising the heterologous epitope to a mammalian muscle cell.

[0125] In some embodiments, the second antigen-binding domain of a multispecific targeting ligand described herein binds to a first member of a protein:protein binding pair, wherein the first member of a protein:protein binding pair comprises one or more epitopes of a capsid of an AAV particle. Thus, the present disclosure includes multispecific, e.g., bispecific, antigen-binding molecules, e.g., antibodies, wherein one domain of antigen-binding domain binds to a capsid of an AAV particle (e.g., a capsid comprising a wild-type and / or non-wild-type AAV capsid protein(s)), and the other antigen-binding domain binds to a surface protein expressed by a mammalian muscle cell, e.g., CACNG1. Such multispecific antigen-binding molecules may be referred to herein as anti-AAV / anti-CACNG1 multispecific antigen-binding molecules, e.g., antibodies. Accordingly, in some embodiments, the multispecific antigenbinding domain comprising the first and second antigen-binding domains as described herein retargets an AAV particle (i.e., comprising an AAV capsid protein comprising one or more epitopes, e.g., epitopes comprised within a wildtype AAV capsid protein, recognized by at least one of the antigen-binding domains) to a cell expressing CACNG1, e.g., mammalian muscle cell.

[0126] In some embodiments, the epitope of the capsid of the AAV particle disclosed herein may comprise any of various serotype- specific or serotype-non-specific (i.e., “universal”) epitopes understood by one of ordinary skill in the art.

[0127] In some embodiments, the one or more epitope(s) of the capsid of the AAV particle disclosed herein comprises any amino acid residues of a capsid protein VP1, VP2 or VP3, or a combination thereof. The AAV particle can be derived from any AAV serotypedescribed herein. In some embodiments, the one or more epitope(s) comprise any variable region of a capsid, or any combination thereof, e.g., a variable region comprised of a capsid protein VP1, VP2 or VP3, or a combination thereof (e.g., variable region I, II, III, IV, V, VI, VII, VIII, IX, or a combination thereof, as described in Emmanuel, et al., Journal of Virology, 2022, 96, 3).

[0128] As a non-limiting example, one or more epitope(s) of an AAV1 capsid disclosed herein may comprise any amino acid residue or combination thereof of a variable region I, II, III, IV, V, VI, VII, VIII, IX, or combination thereof. In some embodiments, the one or more AAV1 epitope(s) comprise any of residues 456-459, 492-499, 582, 583, 588-591, 593-595, 597, or any combination thereof, as described in Tseng, et al., Front Immunol. 2014, 5: 9.

[0129] As a non-limiting example, one or more epitope(s) of an AAV2 capsid disclosed herein may comprise any amino acid residue or combination thereof of a variable region I, II, HI, IV, V, VI, VII, VIII, IX, or combination thereof. In some embodiments, the one or more AAV2 epitope(s) comprise any of residues 253, 254, 258, 261-264, 272-281, 369-378, 381, 384, 385, 474—483, 492-502, 534, 548, 556, 560-573, 585-589, 601-610, 658-660, 708, 717, or any combination thereof, as described in Tseng, et al., Front Immunol. 2014, 5: 9.

[0130] As a non-limiting example, one or more epitope(s) of an AAV5 capsid disclosed herein may comprise any amino acid residue or combination thereof of a variable region I, II, III, IV, V, VI, VII, VIII, IX, or combination thereof. In some embodiments, the one or more AAV5 epitope(s) comprise any of residues 246, 254—261, 374, 375, 483, 485-492, 494, 496, 499-501, 530, 532-538, 653, 654, 656, 657, 704—708, or any combination thereof as described in Tseng, et al., Front Immunol. 2014, 5: 9.

[0131] As a non-limiting example, one or more epitope(s) of an AAV8 capsid disclosed herein may comprise any amino acid residue or combination thereof of a variable region I, II, III, IV, V, VI, VII, VIII, IX, or combination thereof. In some embodiments, the one or more AAV8 epitope(s) comprise any of residues 586-591 or any combination thereof as described in Tseng, et al., Front Immunol. 2014, 5: 9.

[0132] As a non-limiting example, one or more epitope(s) of an AAV9 capsid disclosed herein may comprise any amino acid residue or combination thereof of a variable region I, II, III, IV, V, VI, VII, VIII, IX, or combination thereof. In some embodiments, the one or more AAV8 epitope(s) comprise any of residues 221, 228, 246-248, 250-256, 258-260, any of residues 262- 273 of variable region I, any of residues 274, 275, 278, 291, 293, 324, 325, any of residues 327-333 of variable region IT, any of residues 334, 335, 338, 341 , 363-365, 369-373, 375, 376, any of residues 382-387, 389, 391 of variable region III, any of residues 438-441, 443, any of residues 446, 448, 449, 451-460, 462, 464-473 of variable region IV, any of residues 488, 491-501, 503- 506, 510-515 of variable region V, any of residues 528-534, 545 of variable region VI, any of residues 547-560 of variable region VII, residue 572, any of residues 579, 584, 587-590 of variable region VIII, any of residues 651-653, 655-676, 678, any of residues 701-720, 722, 724- 728 of variable region IX, or any of residues 730, 731, or any combination thereof, as described in Emmanuel, et al., Journal of Virology, 2022, 96, 3.

[0133] Sequence identifiers corresponding to exemplary anti-AAV antibodies provided herein are listed in Table 4 and Table 5. Table 4 sets forth the amino acid sequence identifiers of the heavy chain variable regions (HCVRs) and light chain variable regions (LCVRs), heavy chain complementarity determining regions (HCDR1, HCDR2 and HCDR3), and light chain complementarity determining regions (LCDR1, LCDR2 and LCDR3), as well as heavy chain (HC) and light chain (LC) of the exemplary anti-AAV antibodies and antigen-binding fragments. Table 4 sets forth the sequence identifiers of the nucleic acid molecules encoding the HCVRs, LCVRs, HCDR1, HCDR2, HCDR3, LCDR1, LCDR2 LCDR3, HC and LC of the exemplary anti-AAV antibodies and antigen-binding fragments described herein. Corresponding Fab and “standard mAb” (i.e., mAb comprising a constant region derived from IgG4 subclass) pairs are listed consecutively within Table 4 and Table 5. Non-limiting examples of amino acid sequences and nucleotide sequences of the anti-AAV antibodies are also listed below.Table 4. Amino Acid Sequence Identifiers for Anti- AAV AntibodiesTable 5. Nucleic Acid Sequence Identifiers for Anti-AAV Antibodies

[0134] Provided herein are anti- AAV antibodies, or antigen-binding fragments thereof, comprising an HCVR comprising an amino acid sequence selected from any of the HCVR amino acid sequences listed in Table 4, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

[0135] Also provided herein are anti-AAV antibodies, or antigen-binding fragments thereof, comprising an LCVR comprising an amino acid sequence selected from any of theLCVR amino acid sequences listed in Table 4, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

[0136] Provided herein are anti- AAV antibodies, or antigen-binding fragments thereof, comprising an HCVR and an LCVR amino acid sequence pair (HCVR / LCVR) comprising any of the HCVR amino acid sequences listed in Table 4 paired with any of the LCVR amino acid sequences listed in Table 4. According to certain embodiments, the present disclosure provides antibodies, or antigen-binding fragments thereof, comprising an HCVR / LCVR amino acid sequence pair contained within any of the exemplary anti- AAV antibodies listed in Table 4. In certain embodiments, the HCVR / LCVR amino acid sequence pair is selected from SEQ ID NOs: 2 / 10 (e.g., REGN13876); 22 / 10 (e.g., REGN13877); 32 / 10 (e.g., REGN13878); 42 / 10 (e.g., REGN13879); 52 or 1159 / 10 or 1157 (e.g., REGN13880); 62 / 10 (e.g., REGN13881); 71 / 10 (e.g., REGN13882); 81 / 10 (e.g., REGN13883); 91 / 10 (e.g., REGN13884); 101 / 10 (e.g., REGN13885); 111 / 119 (e.g., REGN13070); 131 / 119 (e.g., REGN13071); 141 / 119 (e.g., REGN13072); 151 / 119 (e.g., REGN13073); 161 / 119 (e.g., REGN13074); 171 / 119 (e.g., REGN13075); 180 / 119 (e.g., REGN13076); 190 / 119 (e.g., REGN13220); 200 / 119 (e.g., REGN13221); and, 210 / 119 (e.g., REGN13284).

[0137] Provided herein are anti- AAV antibodies, or antigen-binding fragments thereof, comprising a heavy chain CDR1 (HCDR1) comprising an amino acid sequence selected from any of the HCDR1 amino acid sequences listed in Table 4 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

[0138] Provided herein are anti- AAV antibodies, or antigen-binding fragments thereof, comprising a heavy chain CDR2 (HCDR2) comprising an amino acid sequence selected from any of the HCDR2 amino acid sequences listed in Table 4 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

[0139] Provided herein are anti- AAV antibodies, or antigen-binding fragments thereof, comprising a heavy chain CDR3 (HCDR3) comprising an amino acid sequence selected from any of the HCDR3 amino acid sequences listed in Table 4 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

[0140] Provided herein are anti- AAV antibodies, or antigen-binding fragments thereof, comprising a light chain CDR1 (LCDR1) comprising an amino acid sequence selected from anyof the LCDR1 amino acid sequences listed in Table 4 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

[0141] Provided herein are anti- AAV antibodies, or antigen-binding fragments thereof, comprising a light chain CDR2 (LCDR2) comprising an amino acid sequence selected from any of the LCDR2 amino acid sequences listed in Table 4 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

[0142] Provided herein are anti- AAV antibodies, or antigen-binding fragments thereof, comprising a light chain CDR3 (LCDR3) comprising an amino acid sequence selected from any of the LCDR3 amino acid sequences listed in Table 4 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

[0143] Provided herein are antibodies, or antigen-binding fragments thereof, comprising a set of six CDRs (i.e., HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3) contained within any of the exemplary anti-AAV antibodies listed in Table 4. In certain embodiments, the HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3 amino acid sequences set is selected from SEQ ID NOs: 4-6-8-12-14-16 (e.g., REGN13876); 24-26-28-12-14-16 (e.g.-REGN13877); 34- 36-38-12-14-16 (e.g., REGN13878); 44-46-48-12-14-16 (e.g., REGN13879; 54-56-58-12-14-16 (e.g., REGN13880); 64-56-67-12-14-16 (e.g., REGN13881); 73-75-77-12-14-16 (e.g., REGN13882); 83-85-87-12-14-16 (e.g., REGN13883); 93-95-97-12-14-16 (e.g.-REGN13884); 103-105-107-12-14-16 (e.g., REGN13885); 113-115-117-121-123-125 (e.g.-REGN13070); 133- 135-137-121-123-125 (e.g., REGN13071); 143-145-147-121-123-125 (e.g.-REGN13072); 153- 155-157-121-123-125 (e.g., REGN13073); 163-165-167-121-123-125 (e.g.-REGN13074); 173- 145-176-121-123-125 (e.g., REGN13075); 182-184-186-121-123-125 (e.g.-REGN13076); 192- 194-196-121-123-125 (e.g., REGN13220); 202-204-206-121-123-125 (e.g.-REGN13221); and- 212-214-216-121-123-125 (e.g.-REGN13284).

[0144] In a related embodiment, provided herein are antibodies, or antigen-binding fragments thereof, comprising a set of six CDRs (i.e., HCDR1-HCDR2-HCDR3-LCDR1- LCDR2-LCDR3) contained within an HCVR / LCVR amino acid sequence pair as defined by any of the exemplary anti-AAV antibodies listed in Table 4. For example, provided herein are antibodies, or antigen-binding fragments thereof, comprising the HCDR1-HCDR2-HCDR3- LCDR1-LCDR2-LCDR3 amino acid sequences set contained within an HCVR / LCVR amino acid sequence pair selected from SEQ ID NOs: 2 / 10 (e.g., REGN13876); 22 / 10 (e.g.,REGN13877); 32 / 10 (e.g., REGN13878); 42 / 10 (e.g., REGN13879); 52 or 1159 / 10 or 1157 (e.g., REGN13880); 62 / 10 (e.g., REGN13881); 71 / 10 (e.g., REGN13882); 81 / 10 (e.g., REGN13883); 91 / 10 (e.g., REGN13884); 101 / 10 (e.g., REGN13885); 111 / 119 (e.g., REGN13070); 131 / 119 (e.g., REGN13071); 141 / 119 (e.g., REGN13072); 151 / 119 (e.g., REGN13073); 161 / 119 (e.g., REGN13074); 171 / 119 (e.g., REGN13075); 180 / 119 (e.g., REGN13076); 190 / 119 (e.g., REGN13220); 200 / 119 (e.g., REGN13221); and, 210 / 119 (e.g., REGN13284).

[0145] In an embodiment provided herein, the anti- AAV antibody or antigen-binding fragment thereof can include: a) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 2, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; b) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 22, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; c) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 32, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; d) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 42, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; e) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 52 or 1159, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10 or 1157;f) a heavy chain variable region (HCVR) that comprises a HCDR1 , HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 62, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; g) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 71, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; h) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 81, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; i) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 91, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; j) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 101, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; k) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 111, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 119; l) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 131, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 119; m) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 141,and / or a light chain variable region (LCVR) that comprises a LCDR1 , LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 119; n) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 151, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 119; o) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 161, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 119; p) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 171, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 119; q) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 180, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 119; r) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 190, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 119; s) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 200, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 119; and / or t) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 210, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 119.

[0146] In an embodiment provided herein, the anti-AAV antibody or antigen-binding fragment thereof can include: a) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 4, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 6, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 8; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; b) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 24, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 26, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 28; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; c) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 34, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 36, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 38; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; d) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 44, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 46, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 48; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; e) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 54, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 56, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 58; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; f) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 64, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 56, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 67; and / or a LCDR1 comprising the amino acid sequence of SEQID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; g) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 73, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 75, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 77; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; h) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 83, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 85, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 87; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; i) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 93, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 95, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 97; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; j) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 103, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 105, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 107; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; k) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 113, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 115, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 117; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 121, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 123, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 125; l) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 133, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 135, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 137; and / or a LCDR1 comprising the amino acid sequence ofSEQ ID NO: 121 , a LCDR2 comprising the amino acid sequence of SEQ ID NO: 123, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 125; m) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 143, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 145, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 147; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 121, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 123, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 125; n) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 153, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 155, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 157; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 121, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 123, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 125; o) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 163, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 165, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 167; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 121, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 123, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 125; p) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 173, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 145, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 176; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 121, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 123, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 125; q) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 182, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 184, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 186; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 121, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 123, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 125; r) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 192, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 194, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 196; and / or a LCDR1 comprising the amino acid sequence ofSEQ ID NO: 121 , a LCDR2 comprising the amino acid sequence of SEQ ID NO: 123, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 125; s) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 202, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 204, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 206; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 121, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 123, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 125; and / or t) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 212, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 214, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 216; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 121, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 123, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 125.

[0147] In an embodiment provided herein, the anti- AAV antibody or antigen-binding fragment thereof can include: a) a HCVR comprising the amino acid sequence of SEQ ID NO: 2, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; b) a HCVR comprising the amino acid sequence of SEQ ID NO: 22, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; c) a HCVR comprising the amino acid sequence of SEQ ID NO: 32, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; d) a HCVR comprising the amino acid sequence of SEQ ID NO: 42, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; e) a HCVR comprising the amino acid sequence of SEQ ID NO: 52 or 1159, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10 or 1157; f) a HCVR comprising the amino acid sequence of SEQ ID NO: 62, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; g) a HCVR comprising the amino acid sequence of SEQ ID NO: 71, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; h) a HCVR comprising the amino acid sequence of SEQ ID NO: 81, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10;i) a HCVR comprising the amino acid sequence of SEQ ID NO: 91 , and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; j) a HCVR comprising the amino acid sequence of SEQ ID NO: 101, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; k) a HCVR comprising the amino acid sequence of SEQ ID NO: 111, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 119; l) a HCVR comprising the amino acid sequence of SEQ ID NO: 131, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 119; m) a HCVR comprising the amino acid sequence of SEQ ID NO: 141, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 119; n) a HCVR comprising the amino acid sequence of SEQ ID NO: 151, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 119; o) a HCVR comprising the amino acid sequence of SEQ ID NO: 161, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 119; p) a HCVR comprising the amino acid sequence of SEQ ID NO: 171, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 119; q) a HCVR comprising the amino acid sequence of SEQ ID NO: 180, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 119; r) a HCVR comprising the amino acid sequence of SEQ ID NO: 190, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 119; s) a HCVR comprising the amino acid sequence of SEQ ID NO: 200, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 119; and / or t) a HCVR comprising the amino acid sequence of SEQ ID NO: 210, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 119.

[0148] In an embodiment provided herein, the anti- AAV antigen-binding fragment is anFab. In some embodiments, an anti-AAV Fab of the present disclosure includes: a) an HC that comprises the amino acid sequence of SEQ ID NO: 18, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 20, or a variant thereof; b) an HC that comprises the amino acid sequence of SEQ ID NO: 30, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 20, or a variant thereof;c) an HC that comprises the amino acid sequence of SEQ ID NO: 40, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 20, or a variant thereof; d) an HC that comprises the amino acid sequence of SEQ ID NO: 50, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 20, or a variant thereof; e) an HC that comprises the amino acid sequence of SEQ ID NO: 60 or 1108, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 20, or a variant thereof; f) an HC that comprises the amino acid sequence of SEQ ID NO: 69, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 20, or a variant thereof; g) an HC that comprises the amino acid sequence of SEQ ID NO: 79, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 20, or a variant thereof; h) an HC that comprises the amino acid sequence of SEQ ID NO: 89, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 20, or a variant thereof; i) an HC that comprises the amino acid sequence of SEQ ID NO: 99, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 20, or a variant thereof; or j) an HC that comprises the amino acid sequence of SEQ ID NO: 109, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 20, or a variant thereof.

[0149] In an embodiment provided herein, the anti- AAV antibody comprises a constant region derived from IgG4 subclass. In some embodiments, an anti-AAV Fab of the present disclosure includes: k) an HC that comprises the amino acid sequence of SEQ ID NO: 127, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 129, or a variant thereof; l) an HC that comprises the amino acid sequence of SEQ ID NO: 139, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 129, or a variant thereof; m) an HC that comprises the amino acid sequence of SEQ ID NO: 149, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 129, or a variant thereof;n) an HC that comprises the amino acid sequence of SEQ ID NO: 159, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 129, or a variant thereof; o) an HC that comprises the amino acid sequence of SEQ ID NO: 169, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 129, or a variant thereof; p) an HC that comprises the amino acid sequence of SEQ ID NO: 178, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 129, or a variant thereof; q) an HC that comprises the amino acid sequence of SEQ ID NO: 188, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 129, or a variant thereof; r) an HC that comprises the amino acid sequence of SEQ ID NO: 198, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 129, or a variant thereof; s) an HC that comprises the amino acid sequence of SEQ ID NO: 208, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 129, or a variant thereof; and / or t) an HC that comprises the amino acid sequence of SEQ ID NO: 218, or a variant thereof; and / or an LC that comprises the amino acid sequence of SEQ ID NO: 129, or a variant thereof.

[0150] The anti- AAV antibodies or antigen-binding fragments thereof described herein may bind to a capsid of an AAV particle with a KDvalue of about 5x10-6M or less, such as about 10-7M or less, about 10-8M or less, such as about 10-9M or less when determined by, for instance, surface plasmon resonance (SPR) technology in a BIAcore instrument using the antigen as the ligand and the antibody, Ig, antibody-binding fragment, or Fc-containing protein as the analyte (or antiligand). Cell-based binding strategies, such as fluorescent-activated cell sorting (FACS) binding assays, are also routinely used, and FACS data correlates well with other methods such as radioligand competition binding and SPR (Benedict, CA, J Immunol Methods. 1997, 201(2):223-31; Geuijen, CA, et al. J Immunol Methods. 2005, 302(l-2):68-77). In some embodiments, an anti-AAV antibody or antigen-binding fragment thereof described herein maybind to a capsid of an AAV particle with a KDvalue of about 5x10-6M to 1x10-6M (e.g., 1x10-6M, 1.5x10-6M, 2x10-6M, 3x10-6M, 4x10-6M, 5x10-6M), about 1x10-6M to 1x10-7M (e.g., 1x10-7M, 2x10-7M, 3x10-7M, 4x10-7M, 5x10-7M, 6x10-7M, 7x10-7M, 8x10-7M, 9x10-7M), about 1x10-7M to 1x10-8M (e.g., 1x10-8M, 2x10-8M, 3x10-8M, 4x10-8M, 5x10-8M, 6x10-8M, 7x10-8M, 8x10-8M, 9x10-8M), about 1x10-8M to 1x10-9M (e.g., 1x10-9M, 2x10-9M, 3x10-9M, 4x10-9M, 5x10-9M, 6x10-9M, 7x10-9M, 8x10-9M, 9x10-9M), or about 1x10-9M to 1x10-10M (e.g., 1x10-10M, 2x10-10M, 3x10-10M, 4x10-10M, 5x10-10M, 6x10-10M, 7x10-10M, 8x10-10M, 9x10-loM).

[0151] The antibody or antigen-binding protein of the disclosure may bind to the predetermined antigen or cell surface molecule (receptor) having an affinity corresponding to a KDvalue that is at least ten-fold lower than its affinity for binding to a non-specific antigen (e.g., BSA). According to the present disclosure, the affinity of an antibody corresponding to a KDvalue that is equal to or less than ten-fold lower than a non-specific antigen may be considered non-detectable binding, however such an antibody may be paired with a second antigen-binding domain for the production of a multispecific antibody of the disclosure.

[0152] The term “KD” (M) can refer to the dissociation equilibrium constant of a particular antibody-antigen interaction, or the dissociation equilibrium constant of an antibody or antibody-binding fragment binding to an antigen. There is an inverse relationship between KDand binding affinity, therefore the smaller the KDvalue, the higher, i.e. stronger, the affinity. Thus, the terms “higher affinity” or “stronger affinity” relate to a higher ability to form an interaction and therefore a smaller KDvalue, and conversely the terms “lower affinity” or “weaker affinity” relate to a lower ability to form an interaction and therefore a larger KDvalue. In some circumstances, a higher binding affinity (or KD) of a particular molecule (e.g. antibody) to its interactive partner molecule (e.g. antigen X) compared to the binding affinity of the molecule (e.g. antibody) to another interactive partner molecule (e.g. antigen Y) may be expressed as a binding ratio determined by dividing the larger KDvalue (lower, or weaker, affinity) by the smaller KD(higher, or stronger, affinity), for example expressed as 5-fold or 10- fold greater binding affinity, as the case may be.

[0153] The term “kd” (sec -1 or 1 / s) refers to the dissociation rate constant of a particular antibody-antigen interaction, or the dissociation rate constant of an antibody or antibody-binding fragment. Said value is also referred to as the koffvalue.

[0154] The term “ka” (M-1 x sec-1 or 1 / M / s) can refer to the association rate constant of a particular antibody-antigen interaction, or the association rate constant of an antibody or antibody-binding fragment.

[0155] The term “KA” (M-1 or 1 / M) can refer to the association equilibrium constant of a particular antibody-antigen interaction, or the association equilibrium constant of an antibody or antibody-binding fragment. The association equilibrium constant is obtained by dividing the kaby the kd.

[0156] The term “EC50” or “EC50” can refer to the half maximal effective concentration, which includes the concentration of an antibody which induces a response halfway between the baseline and maximum after a specified exposure time. The EC50essentially represents the concentration of an antibody where 50% of its maximal effect is observed. In certain embodiments, the EC50value equals the concentration of an antibody of the disclosure that gives half-maximal binding to a capsid protein of an AAV particle (e.g., a wild-type or a non-wild-type AAV capsid protein(s) or to cells expressing a molecule on a cell surface described herein, as determined by e.g., a FACS binding assay. Thus, reduced or weaker binding is observed with an increased EC50, or half maximal effective concentration value.

[0157] Also provided herein are nucleic acid molecules encoding anti- AAV antibodies or antigen-binding fragments thereof.

[0158] Provided herein are nucleic acid molecules encoding any of the HCVR amino acid sequences listed in Table 4; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the HCVR nucleic acid sequences listed in Table4, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

[0159] Provided herein are nucleic acid molecules encoding any of the HCDR1 amino acid sequences listed in Table 4; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the HCDR1 nucleic acid sequences listed in Table5, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

[0160] Provided herein are nucleic acid molecules encoding any of the HCDR2 amino acid sequences listed in Table 4; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the HCDR2 nucleic acid sequences listed in Table5, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

[0161] Provided herein are nucleic acid molecules encoding any of the HCDR3 amino acid sequences listed in Table 4; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the HCDR3 nucleic acid sequences listed in Table 5, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

[0162] Provided herein are nucleic acid molecules encoding any of the LCVR amino acid sequences listed in Table 4; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the LCVR nucleic acid sequences listed in Table 5, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

[0163] Provided herein are nucleic acid molecules encoding any of the LCDR1 amino acid sequences listed in Table 4; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the LCDR1 nucleic acid sequences listed in Table 5, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

[0164] Provided herein are nucleic acid molecules encoding any of the LCDR2 amino acid sequences listed in Table 4; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the LCDR2 nucleic acid sequences listed in Table 5, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

[0165] Provided herein are nucleic acid molecules encoding any of the LCDR3 amino acid sequences listed in Table 4; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the LCDR3 nucleic acid sequences listed in Table 5, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

[0166] Provided herein are nucleic acid molecules encoding an HCVR, wherein the HCVR comprises a set of three CDRs (i.e., HCDR1-HCDR2-HCDR3), wherein the HCDR1- HCDR2-HCDR3 amino acid sequence set is as defined by any of the exemplary anti- AAV antibodies listed in Table 4.

[0167] Provided herein are nucleic acid molecules encoding an LCVR, wherein the LCVR comprises a set of three CDRs (i.c., LCDR1-LCDR2-LCDR3), wherein the LCDR1- LCDR2-LCDR3 amino acid sequence set is as defined by any of the exemplary anti- AAV antibodies listed in Table 4.

[0168] Provided herein are nucleic acid molecules encoding both an HCVR and an LCVR, wherein the HCVR comprises an amino acid sequence of any of the HCVR amino acid sequences listed in Table 4, and wherein the LCVR comprises an amino acid sequence of any of the LCVR amino acid sequences listed in Table 4. In certain embodiments, the nucleic acid molecule comprises a polynucleotide sequence selected from any of the HCVR nucleic acid sequences listed in Table 5, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto, and a polynucleotide sequence selected from any of the LCVR nucleic acid sequences listed in Table 5, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto. In certain embodiments according to this aspect of the disclosure, the nucleic acid molecule encodes an HCVR and LCVR, wherein the HCVR and LCVR are both derived from the same anti- AAV antibody listed in Table 4.

[0169] Also provided herein are nucleic acid molecules encoding any of the HC amino acid sequences listed in Table 4; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the HC nucleic acid sequences listed in Table 5, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto. As another example, the present disclosure provides nucleic acid molecules encoding any of the LC amino acid sequences listed in Table 4; in certain embodiments the nucleic acid molecule comprises a polynucleotide sequence selected from any of the LC nucleic acid sequences listed in Table 5, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity thereto.

[0170] Provided herein are recombinant expression vectors capable of expressing one or more polypeptides of an anti- AAV antibody or antigen-binding fragment thereof. For example, provided herein are recombinant expression vectors comprising any of the nucleic acid molecules mentioned above, i.e., nucleic acid molecules encoding any of the HCVR, LCVR, and / or CDR sequences as set forth in Table 4. Also included within the scope of the present disclosure are host cells into which such vectors have been introduced, as well as methods ofproducing the antibodies or portions thereof by culturing the host cells under conditions permitting production of the antibodies or antibody fragments and recovering the antibodies and antibody fragments so produced. The term “host cell” as used herein can refer to cells into which a nucleic acid of the disclosure has been introduced. The terms “host cell” and “recombinant host cell” are used interchangeably herein. It is understood that such terms can refer to the particular subject cell and to the progeny or potential progeny of such a cell. Because certain modifications may occur in succeeding generations due to either mutation or environmental influences, such progeny may not, in fact, be identical to the parent cell, but are still included within the scope of the term as used herein. Typical host cells are eukaryotic host cells, such as mammalian host cells. Exemplary eukaryotic host cells include yeast and mammalian cells, for example vertebrate cells such as a mouse, rat, monkey or human cell line, for example HKB11 cells, PER.C6 cells, HEK cells or CHO cells.

[0171] According to certain embodiments, an anti-AAV / anti-CACNG1 multispecific antibody disclosed herein may comprise a second antigen-binding domain that binds to CACNG1, wherein the second antigen-binding domain comprises any of the heavy chain variable region (HCVR) amino acid sequences as set forth in Table 2. The second antigenbinding domain that binds to CACNG1 may also comprise any of the light chain variable region (LCVR) amino acid sequences as set forth in Table 2. In some embodiments, the second antigen-binding domain that binds to CACNG1 may comprise any of the HCVR / LCVR amino acid sequence pairs as set forth in Table 2. The present disclosure also provides anti-AAV / anti- CACNG1 multispecific antibodies, wherein the second antigen-binding domain that binds to CACNG1 comprises any of the heavy chain CDR1-CDR2-CDR3 amino acid sequences as set forth in Table 2, and / or any of the light chain CDR1-CDR2-CDR3 amino acid sequences as set forth in Table 2.

[0172] In another aspect, provided herein are nucleic acid molecules encoding any of the CDR, HCVR, LCVR, HC, or LC sequences of the anti-AAV / anti-CACNG1 multispecific antigen-binding molecules disclosed herein, or variants thereof, including nucleic acid molecules comprising any of the polynucleotide sequences as set forth in Table 3 herein, as well as nucleic acid molecules comprising any of the polynucleotide sequences as set forth in Table 5 herein, in any combination thereof. In some embodiments, the nucleic acid molecules described herein may comprise one or more polynucleotide sequence(s) in Table 3 that encode a pair of HCVR / LCVRamino acid sequences, and one or more polynucleotide sequence(s) selected from Table 5 that encode a pair of HCVR / LCVR amino acid sequences. In some embodiments, the nucleic acid molecules described herein may comprise one or more polynucleotide sequence(s) selected from Table 3 that encode a set of six CDRs (i.e„ HCDR1-HCDR2-HCDR3-LCDR1-LCDR2- LCDR3), and one or more polynucleotide sequence(s) selected from Table 5 that encode a set of six CDRs (i.e., HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3).

[0173] According to certain exemplary embodiments, provided herein are anti-AAV / anti-CACNG1 multispecific antibodies, wherein the second antigen-binding domain that binds to CACNG1 comprises a heavy chain variable region (HCVR) having an amino acid sequence selected from SEQ ID NOs: 615, 635, 655, 675, 695, 715, 735, 755, 775, 795, 815, 835, 855, 875, 895, 915, 935, 955, 1181, or 1205 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

[0174] In some embodiments, provided herein are anti-AAV / anti-CACNG1 multispecific antibodies, wherein the second antigen-binding domain that binds to CACNG1 comprises a light chain variable region (LCVR) having an amino acid sequence selected from SEQ ID NOs: 623, 643, 663, 683, 703, 723, 743, 763, 783, 803, 823, 843, 863, 883, 903, 923, 943, 963, 1189, or 1213 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

[0175] In some embodiments, provided herein are anti-AAV / anti-CACNG1 multispecific antibodies, wherein the second antigen-binding domain that binds to CACNG1 comprises a HCVR and LCVR (HCVR / LCVR) amino acid sequence pair selected from SEQ ID NOs: 615 / 623 (e.g., H2aM31929N / REGN10728), SEQ ID NOs: 635 / 643 (e.g., H2aM31944N), SEQ ID NOs: 655 / 663 (e.g., H4H31265P2 / REGN5972), SEQ ID NOs: 675 / 683 (e.g., H2aM31941N), SEQ ID NOs: 695 / 703 (e.g., REGN7660), SEQ ID NOs: 715 / 723 (e.g., REGN9909), SEQ ID NOs: 735 / 743 (e.g., REGN10713), SEQ ID NOs: 755 / 763 (e.g., REGN10715), SEQ ID NOs: 775 / 783 (e.g., REGN10716), SEQ ID NOs: 795 / 803 (e.g., REGN10717), SEQ ID NOs: 815 / 823 (e.g., REGN10783), SEQ ID NOs: 835 / 843 (e.g., REGN7854), SEQ ID NOs: 855 / 863 (e.g., REGN14570), SEQ ID NOs: 875 / 883 (e.g., REGN14571), SEQ ID NOs: 895 / 903 (e.g., REGN14572), SEQ ID NOs: 915 / 923 (e.g., REGN14573), SEQ ID NOs: 935 / 943 (e.g., REGN14574), SEQ ID NOs: 955 / 963 (e.g., REGN14647), SEQ ID NOs: 1181 / 1189 (e.g., REGN10712), and SEQ ID NOs: 1205 / 1213 (e.g., REGN9908).

[0176] In some embodiments, provided herein are anti-AAV / anti-CACNGl multispecific antibodies, wherein the second antigen-binding domain that binds to CACNG1 comprises a heavy chain CDR1 (HCDR1) domain having an amino acid sequence selected from SEQ ID NOs: 617, 637, 657, 677, 697, 717, 737, 757, 777, 797, 817, 837, 857, 877, 897, 917, 937, 957, 1183, or 1207 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity; a heavy chain CDR2 (HCDR2) domain having an amino acid sequence selected from SEQ ID NOs: 619, 639, 659, 679, 699, 719, 739, 759, 779, 799, 819, 839, 859, 879, 899, 919, 939, 959, 1185, or 1209 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity; a heavy chain CDR3 (HCDR3) domain having an amino acid sequence selected from SEQ ID NOs: 621, 641, 661, 681, 701, 721, 741, 761, 781, 801, 821, 841, 861, 881, 901, 921, 941, 961, 1187, or 1211 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity; a light chain CDR1 (LCDR1) domain having an amino acid sequence of SEQ ID NOs: 625, 645, 665, 685, 705, 725, 745, 765, 785, 805, 825, 845, 865, 885, 905, 925, 945, 965, 1191, or 1215 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity; a light chain CDR2 (LCDR2) domain having an amino acid sequence of SEQ ID NOs: 627, 647, 667, 687, 707, 727, 747, 767, 787, 807, 827, 847, 867, 887, 907, 927, 947, 967, 1193, or 1217 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity; and a light chain CDR3 (LCDR3) domain having an amino acid sequence of SEQ ID NOs: 629, 649, 669, 689, 709, 729, 749, 769, 789, 809, 829, 849, 869, 889, 909, 929, 949, 969, 1195, or 1219 or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

[0177] Certain non-limiting, exemplary anti-AAV / anti-CACNG1 multispecific antibodies provided herein include a second antigen-binding domain that binds to CACNG1 comprising a set of six CDRs (i.e., HCDR1-HCDR2-HCDR3-LCDR1-LCDR2-LCDR3), respectively, having the amino acid sequences selected from SEQ ID NOs: 617- 619- 621- 625- 627- 629 (e.g., H2aM31929N / REGN 10728), SEQ ID NOs: 637- 639- 641- 645- 647- 649 (e.g., H2aM31944N), SEQ ID NOs: 657- 659- 661- 665- 667- 669 (e.g., H4H31265P2 / REGN5972), SEQ ID NOs: 677- 679- 681- 685- 687- 689 (e.g., H2aM31941N), SEQ ID NOs: 697- 699- 701- 705- 707- 709 (e.g., REGN7660), SEQ ID NOs: 717- 719- 721- 725- 727- 729 (e.g.,REGN9909), SEQ ID NOs: 737- 739- 741- 745- 747- 749 (e.g., REGN10713), SEQ ID NOs: 757- 759- 761- 765- 767- 769 (e.g., REGN10715), SEQ ID NOs: 777- 779- 781- 785- 787- 789 (e.g., REGN10716), SEQ ID NOs: 797- 799- 801- 805- 807- 809 (e.g., REGN10717), SEQ ID NOs: 817- 819- 821- 825- 827- 829 (e.g., REGN10783), SEQ ID NOs: 837- 839- 841- 845- 847- 849 (e.g., REGN7854), SEQ ID NOs: 857- 859- 861- 865- 867- 869 (e.g., REGN14570), SEQ ID NOs: 877- 879- 881- 885- 887- 889 (e.g., REGN14571), SEQ ID NOs: 897- 899- 901- 905- 907- 909 (e.g., REGN14572), SEQ ID NOs: 917- 919- 921- 925- 927- 929 (e.g., REGN14573), SEQ ID NOs: 937- 939- 941- 945- 947- 949 (e.g., REGN14574), SEQ ID NOs: 957- 959- 961- 965- 967- 969 (e.g., REGN14647), SEQ ID NOs: 1183- 1185- 1187- 1191- 1193- 1195 (e.g., REGN10712), and SEQ ID NOs: 1207- 1209- 1211- 1215- 1217- 1219 (e.g., REGN9908).

[0178] In an embodiment provided herein, an anti-AAV / anti-CACNG1 multispecific antibody herein can comprise an anti-CACNG1 antibody, or antigen-binding fragment thereof, wherein the anti-CACNG1 antibody or antigen-binding fragment thereof can include: a) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 615, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 623; b) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 635, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 643; c) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 655, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 663; d) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 675, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 683; e) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 695,and / or a light chain variable region (LCVR) that comprises a LCDR1 , LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 703; f) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 715, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 723; g) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 735, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 743; h) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 755, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 763; i) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 775, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 783; j) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 795, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 803; k) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 815, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 823; l) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 835, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 843; m) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, andHCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 855, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 863; n) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 875, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 883; o) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 895, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 903; p) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 915, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 923; q) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 935, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 943; r) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 955, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 963; s) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 1181, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 1189; and / or t) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within a HCVR comprising the amino acid sequence of SEQ ID NO: 1205, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 1213.

[0179] In an embodiment provided herein, an anti-AAV / anti-CACNG1 multispecific antibody herein can comprise an anti-CACNG1 antibody or antigen-binding fragment thereof, wherein the anti-CACNG1 antibody or antigen-binding fragment thereof, can include: a) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 617, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 619, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 621; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 625, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 627, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 629; b) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 637, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 639, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 641; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 645, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 647, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 649; c) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 657, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 659, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 661; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 665, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 667, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 669; d) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 677, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 679, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 681; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 685, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 687, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 689; e) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 697, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 699, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 701; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 705, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 707, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 709; f) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 717, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 719, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 721; and / or a LCDR1 comprising the amino acid sequence ofSEQ ID NO: 725, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 727, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 729; g) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 737, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 739, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 741; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 745, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 747, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 749; h) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 757, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 759, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 761; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 765, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 767, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 769; i) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 777, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 779, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 781; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 785, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 787, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 789; j) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 797, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 799, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 801; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 805, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 807, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 809; k) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 817, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 819, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 821; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 825, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 827, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 829; l) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 837, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 839, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 841; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 845, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 847, and aLCDR3 comprising the amino acid sequence of SEQ ID NO: 849; m) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 857, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 859, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 861; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 865, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 867, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 869; n) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 877, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 879, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 881; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 885, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 887, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 889; o) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 897, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 899, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 901; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 905, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 907, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 909; p) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 917, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 919, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 921; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 925, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 927, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 929; q) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 937, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 939, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 941; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 945, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 947, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 949; r) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 957, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 959, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 961; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 965, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 967, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 969;s) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 1183, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 1185, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 1187; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 1191, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 1193, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 1195; and / or t) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 1207, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 1209, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 1211; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 1215, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 1217, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 1219.

[0180] In an embodiment provided herein, an anti-AAV / anti-CACNG1 multispecific antibody herein can comprise an anti-CACNG1 antibody, or antigen-binding fragment thereof, wherein the anti-CACNG1 antibody or antigen-binding fragment thereof can include: a) a HCVR comprising the amino acid sequence of SEQ ID NO: 615, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 623; b) a HCVR comprising the amino acid sequence of SEQ ID NO: 635, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 643; c) a HCVR comprising the amino acid sequence of SEQ ID NO: 655, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 663; d) a HCVR comprising the amino acid sequence of SEQ ID NO: 675, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 683; e) a HCVR comprising the amino acid sequence of SEQ ID NO: 695, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 703; f) a HCVR comprising the amino acid sequence of SEQ ID NO: 715, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 723; g) a HCVR comprising the amino acid sequence of SEQ ID NO: 735, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 743; h) a HCVR comprising the amino acid sequence of SEQ ID NO: 755, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 763; i) a HCVR comprising the amino acid sequence of SEQ ID NO: 775, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 783;j) a HCVR comprising the amino acid sequence of SEQ ID NO: 795, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 803; k) a HCVR comprising the amino acid sequence of SEQ ID NO: 815, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 823; l) a HCVR comprising the amino acid sequence of SEQ ID NO: 835, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 843; m) a HCVR comprising the amino acid sequence of SEQ ID NO: 855, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 863; n) a HCVR comprising the amino acid sequence of SEQ ID NO: 875, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 883; o) a HCVR comprising the amino acid sequence of SEQ ID NO: 895, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 903; p) a HCVR comprising the amino acid sequence of SEQ ID NO: 915, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 923; q) a HCVR comprising the amino acid sequence of SEQ ID NO: 935, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 943; r) a HCVR comprising the amino acid sequence of SEQ ID NO: 955, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 963; s) a HCVR comprising the amino acid sequence of SEQ ID NO: 1181, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 1189; and / or t) a HCVR comprising the amino acid sequence of SEQ ID NO: 1205, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 1213.

[0181] In an embodiment provided herein, an anti-AAV / anti-CACNG1 multispecific antibody herein can comprise an anti-CACNG1 antigen-binding fragment comprising an anti- CACNG1 Fab, wherein the anti-CACNG1 Fab can include: a) a HC region that comprises the amino acid sequence of SEQ ID NO: 631, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 633, or a variant thereof; b) a HC region that comprises the amino acid sequence of SEQ ID NO: 651, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 653, or a variant thereof;c) a HC region that comprises the amino acid sequence of SEQ ID NO: 671 , or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 673, or a variant thereof; d) a HC region that comprises the amino acid sequence of SEQ ID NO: 691, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 693, or a variant thereof; e) a HC region that comprises the amino acid sequence of SEQ ID NO: 711, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 713, or a variant thereof; f) a HC region that comprises the amino acid sequence of SEQ ID NO: 731, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 733, or a variant thereof; g) a HC region that comprises the amino acid sequence of SEQ ID NO: 751, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 753, or a variant thereof; h) a HC region that comprises the amino acid sequence of SEQ ID NO: 771, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 773, or a variant thereof; i) a HC region that comprises the amino acid sequence of SEQ ID NO: 791, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 793, or a variant thereof; j) a HC region that comprises the amino acid sequence of SEQ ID NO: 811 or 1173, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 813, or a variant thereof; k) a HC region that comprises the amino acid sequence of SEQ ID NO: 831, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 833, or a variant thereof; l) a HC region that comprises the amino acid sequence of SEQ ID NO: 851, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 853, or a variant thereof; m) a HC region that comprises the amino acid sequence of SEQ ID NO: 871, or a variantthereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 873, or a variant thereof; n) a HC region that comprises the amino acid sequence of SEQ ID NO: 891, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 893, or a variant thereof; o) a HC region that comprises the amino acid sequence of SEQ ID NO: 911, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 913, or a variant thereof; p) a HC region that comprises the amino acid sequence of SEQ ID NO: 931, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 933, or a variant thereof; q) a HC region that comprises the amino acid sequence of SEQ ID NO: 951, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 953, or a variant thereof; and / or r) a HC region that comprises the amino acid sequence of SEQ ID NO: 971, or a variant thereof; and / or a LC region that comprises the amino acid sequence of SEQ ID NO: 973, or a variant thereof.

[0182] Any of the HCVR and / or LCVR of the anti-CACNG1 antibodies, or variants thereof, disclosed herein can be contained within an antigen-binding fragment such as but not limited to (i) Fab fragment; (ii) F(ab')2 fragment; (iii) Fd fragment; (iv) Fv fragment; (v) singlechain Fv (scFv) molecules; and (vi) dAb fragments.

[0183] In various embodiments disclosed herein, for example, when a HCVR and a LCVR of an anti-CACNG1 antibody, or variant thereof, are contained within an antigen binding fragment (e.g., an scFv or a Fab), the HCVR and the LCVR can be in either orientation (HCVR- LCVR or LCVR-HCVR). In some embodiments, the HCVR and LCVR are optionally linked by a linker, e.g., that comprises an amino acid sequence, e.g., about 10 amino acids in length, for example: (Gly4Ser)n (SEQ ID NO: 241) wherein n is 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0184] In some embodiments, the scFv disclosed herein comprises (i) a heavy chain variable region that comprises the HCDR1, HCDR2 and HCDR3 of a HCVR comprising the amino acid sequence of SEQ ID NO: 615, 635, 655, 675, 695, 715, 735, 755, 775, 795, 815, 835, 855, 875, 895, 915, 935, 955, 1181, or 1205;and / or (ii) a light chain variable region that comprises the LCDR1 , LCDR2 and LCDR3 of a LCVR comprising the amino acid sequence of SEQ ID NO: 623, 643, 663, 683, 703, 723, 743, 763, 783, 803, 823, 843, 863, 883, 903, 923, 943, 963, 1189, or 1213; or the scFv comprises:(1) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 615, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 623, or a variant thereof;(2) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 635, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 643, or a variant thereof;(3) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 655, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 663, or a variant thereof;(4) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 675, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 683, or a variant thereof;(5) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 695, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 703, or a variant thereof;(6) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 715, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 723, or a variant thereof;(7) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 735, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ IDNO: 743, or a variant thereof;(8) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 755, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 763, or a variant thereof;(9) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 775, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 783, or a variant thereof;(10) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 795, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 803, or a variant thereof;(11) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 815, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 823, or a variant thereof;(12) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 835, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 843, or a variant thereof;(13) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 855, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 863, or a variant thereof;(14) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 875, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 883, or a variant thereof;(15) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 895, or a variant thereof; and a LCVR comprising theLCDR1 , LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 903, or a variant thereof;(16) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 915, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 923, or a variant thereof;(17) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 935, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 943, or a variant thereof;(18) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 955, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 963, or a variant thereof;(19) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 1181, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 1189, or a variant thereof;(20) a HCVR comprising the HCDR1, HCDR2 and HCDR3 of a HCVR that comprises the amino acid sequence of SEQ ID NO: 1205, or a variant thereof; and a LCVR comprising the LCDR1, LCDR2 and LCDR3 of a LCVR that comprises the amino acid sequence of SEQ ID NO: 1213, or a variant thereof; or the scFv comprises:(a) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 617, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 619, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 621, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 625, or a variant thereof,an LCDR2 comprising the amino acid sequence of SEQ ID NO: 627, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 629, or a variant thereof;(b) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 637, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 639, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 641, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 645, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 647, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 649, or a variant thereof;(c) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 657, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 659, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 661, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 665, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 667, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 669, or a variant thereof;(d) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 677, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 679, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 681, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 685, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 687, or a variant thereof, andan LCDR3 comprising the amino acid sequence of SEQ ID NO: 689, or a variant thereof;(c) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 697, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 699, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 701, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 705, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 707, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 709, or a variant thereof;(f) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 717, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 719, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 721, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 725, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 727, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 729, or a variant thereof;(g) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 737, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 739, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 741, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 745, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 747, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 749, or a variant thereof;(h) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 757, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 759, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 761, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 765, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 767, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 769, or a variant thereof;(i) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 777, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 779, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 781, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 785, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 787, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 789, or a variant thereof;(j) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 797, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 799, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 801, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 805, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 807, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 809, or a variant thereof;(k) a HCVR that comprises:an HCDR1 comprising the amino acid sequence of SEQ ID NO: 817, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 819, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 821, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 825, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 827, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 829, or a variant thereof;(1) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 837, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 839, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 841, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 845, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 847, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 849, or a variant thereof;(m) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 857, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 859, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 861, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 865, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 867, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 869, or a variant thereof;(n) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 877, or a variant thereof,an HCDR2 comprising the amino acid sequence of SEQ ID NO: 879, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 881, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 885, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 887, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 889, or a variant thereof;(o) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 897, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 899, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 901, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 905, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 907, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 909, or a variant thereof;(p) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 917, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 919, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 921, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 925, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 927, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 929, or a variant thereof;(q) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 937, or a variant thereof,an HCDR2 comprising the amino acid sequence of SEQ ID NO: 939, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 941, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 945, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 947, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 949, or a variant thereof;(r) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 957, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 959, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 961, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 965, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 967, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 969, or a variant thereof;(s) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 1183, or a variant thereof, an HCDR2 comprising the amino acid sequence of SEQ ID NO: 1185, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 1187, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 1191, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 1193, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 1195, or a variant thereof;(t) a HCVR that comprises: an HCDR1 comprising the amino acid sequence of SEQ ID NO: 1207, or a variant thereof,an HCDR2 comprising the amino acid sequence of SEQ ID NO: 1209, or a variant thereof, and an HCDR3 comprising the amino acid sequence of SEQ ID NO: 1211, or a variant thereof; and a LCVR that comprises: an LCDR1 comprising the amino acid sequence of SEQ ID NO: 1215, or a variant thereof, an LCDR2 comprising the amino acid sequence of SEQ ID NO: 1217, or a variant thereof, and an LCDR3 comprising the amino acid sequence of SEQ ID NO: 1219, or a variant thereof; or the scFv comprises:(i) a HCVR that comprises the amino acid sequence of SEQ ID NO: 615, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 623, or a variant thereof;(ii) a HCVR that comprises the amino acid sequence of SEQ ID NO: 635, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 643, or a variant thereof;(iii) a HCVR that comprises the amino acid sequence of SEQ ID NO: 655, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 663, or a variant thereof;(iv) a HCVR that comprises the amino acid sequence of SEQ ID NO: 675, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 683, or a variant thereof;(v) a HCVR that comprises the amino acid sequence of SEQ ID NO: 695, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 703, or a variant thereof;(vi) a HCVR that comprises the amino acid sequence of SEQ ID NO: 715, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 723, or a variant thereof;(vii) a HCVR that comprises the amino acid sequence of SEQ ID NO: 735, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 743, or a variant thereof;(viii) a HCVR that comprises the amino acid sequence of SEQ ID NO: 755, or a variantthereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 763, or a variant thereof;(ix) a HCVR that comprises the amino acid sequence of SEQ ID NO: 775, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 783, or a variant thereof;(x) a HCVR that comprises the amino acid sequence of SEQ ID NO: 795, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 803, or a variant thereof;(xi) a HCVR that comprises the amino acid sequence of SEQ ID NO: 815, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 823, or a variant thereof;(xii) a HCVR that comprises the amino acid sequence of SEQ ID NO: 835, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 843, or a variant thereof;(xiii) a HCVR that comprises the amino acid sequence of SEQ ID NO: 855, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 863, or a variant thereof;(xiv) a HCVR that comprises the amino acid sequence of SEQ ID NO: 875, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 883, or a variant thereof;(xv) a HCVR that comprises the amino acid sequence of SEQ ID NO: 895, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 903, or a variant thereof;(xvi) a HCVR that comprises the amino acid sequence of SEQ ID NO: 915, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 923, or a variant thereof;(xvii) a HCVR that comprises the amino acid sequence of SEQ ID NO: 935, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 943, or a variant thereof;(xviii) a HCVR that comprises the amino acid sequence of SEQ ID NO: 955, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 963, or a variantthereof;(xix) a HCVR that comprises the amino acid sequence of SEQ ID NO: 1181, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 1189, or a variant thereof;(xx) a HCVR that comprises the amino acid sequence of SEQ ID NO: 1205, or a variant thereof; and a LCVR that comprises the amino acid sequence of SEQ ID NO: 1213, or a variant thereof; e.g., wherein the HCVR and LCVR are in either orientation (HCVR-LCVR or LCVR- HCVR), optionally, wherein the HCVR and LCVR are linked by a linker, e.g., that comprises an amino acid sequence, e.g., about 10 amino acids in length, for example:(Gly4Ser)n (SEQ ID NO: 241) wherein n is 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.

[0185] In some embodiments, an scFv fragment that binds specifically to CACNG1 comprises the amino acid sequence as set forth in SEQ ID NO: 1355, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

[0186] In some embodiments, an scFv fragment that binds specifically to CACNG1 disclosed herein comprises the amino acid sequence as set forth in SEQ ID NO: 1350, or a substantially similar sequence thereof having at least 90%, at least 95%, at least 98% or at least 99% sequence identity.

[0187] Fab fragments that bind specifically to CACNG1 form part of the present disclosure. Fab fragments typically contain one complete light chain, VL and a constant light (CL) domain, e.g., kappa (e.g., the amino acid sequence as set forth in SEQ ID NO: 1147); and the VH and IgG1 CH1 portion (e.g., the amino acid sequence as set forth in SEQ ID NO: 1179 or SEQ ID NO: 1112); or IgG4 CH1 (e.g., the amino acid sequence as set forth in SEQ ID NO: 1171, SEQ ID NO: 1135, SEQ ID NO: 1344, or SEQ ID NO: 1367) of one heavy chain. Fab fragment antibodies can be generated by papain digestion of whole IgG antibodies to remove the entire Fc fragment, including the hinge region. For example, the present disclosure includes Fab proteins comprising:(1) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 615, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 ofsuch a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 623, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(2) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 635, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 643, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(3) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 655, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 663, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(4) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 675, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 683, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(5) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 695, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 703, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(6) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 715, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 723, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(7) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 735, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) thatcomprises the amino acid sequence of SEQ ID NO: 743, or LCDR1 , LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(8) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 755, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 763, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(9) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 775, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 783, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(10) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 795, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 803, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(11) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 815, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 823, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(12) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 835, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 843, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(13) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 855, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 863, or LCDR1, LCDR2 and LCDR3 ofsuch a LCVR-linked to the CL domain;(14) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 875, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 883, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(15) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 895, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 903, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(16) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 915, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 923, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(17) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 935, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 943, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(18) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 955, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 963, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain;(19) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 1181, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 1189, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain; and / or(20) a heavy chain variable region (HCVR) that comprises the amino acid sequence of SEQ ID NO: 1205, or a heavy chain variable region that includes HCDR1, HCDR2 and HCDR3 of such a HCVR- linked to the CH1 domain; and a light chain variable region (LCVR) that comprises the amino acid sequence of SEQ ID NO: 1213, or LCDR1, LCDR2 and LCDR3 of such a LCVR-linked to the CL domain; e.g., wherein CH1 is from IgG1 or IgG4; e.g., wherein CH1 is SEQ ID NO: 1147, 1179, 1112, 1171, 1135, 1344, or 1367.

[0188] The heavy and light chains of exemplified anti-CACNG1 Fabs in anti-AAV / anti- CACNG1 multispecific antibodies of the present disclosure are set forth below:(1) REGN10717HC Fab (VH + IgG1 CH1 ) DNA Sequence (SEQ ID NO: 1174)HC Fab (VH + IgG1 CH1 ) Amino Acid Sequence (SEQ ID NO: 1175)HC Fab (VH + IgG4us CH1) Amino Acid Sequence (SEQ ID NO: 1343)HC Fab (VH + IgG4us CH1) Amino Acid Sequence (SEQ ID NO: 1359 or SEQ ID NO: 1370)LC Fab DNA Sequence (SEQ ID NO: 812)LC Fab Amino Acid Sequence (SEQ ID NO: 813)Non-limiting Examples of Alternative Format Antibodies

[0189] The present disclosure provides any of the multispecific antibodies, or antigen binding fragments thereof, described herein in any of various alternative formats described herein. In some embodiments, an alternative format multispecific antibody as disclosed herein comprises a first antigen-binding domain that binds to a mammalian muscle cell- specific surface protein, e.g., CACNG1, and a second antigen-binding domain that binds to a first member of a protein:protein binding pair as disclosed herein. In some embodiments, the first member of the protein:protein binding pair is an epitope that is heterologous to an AAV capsid protein, e.g., a c- myc epitope as disclosed herein, and the second member of the protein:protein binding pair comprises the second antigen-binding domain of the alternative format multispecific antibody. In some embodiments, the first member of the protein:protein binding pair is an AAV capsid protein amino acid sequence as disclosed herein, and the second member of the protein:proteinbinding pair comprises the second antigen-binding domain of the alternative format multi specific antibody.

[0190] In one aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising: a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) an scFv comprising a first antigen-binding domain (“ABD1”) operably linked to (ii) a first heavy chain region of a first Fab (“Fab1”), the first heavy chain region operably linked to (iii) an Fc domain; b) a second polypeptide chain comprising, in an N- to C-terminal orientation, (i) a second heavy chain region of a second Fab (“Fab2”) operably linked to (ii) an Fc domain; c) a third polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a second antigen-binding domain (“ABD2”); and d) a fourth polypeptide chain comprising a second light chain that pairs with the second heavy chain region to form Fab2, wherein Fab2 comprises a third antigen-binding domain (“ABD3”); wherein at least one of ABD1, ABD2, and ABD3 binds to a capsid of an adeno-associated virus (AAV) particle, and the other(s) of ABD1, ABD2, and ABD3 bind to a molecule on a cell surface.

[0191] In some embodiments, two of ABD1, ABD2, and ABD3 bind to a capsid of anAAV particle, and one of ABD1, ABD2, and ABD3 binds to a molecule on a cell surface.

[0192] In some embodiments, ABD2 and ABD3 bind to a capsid of an AAV particle, and ABD1 binds to a molecule on a cell surface.

[0193] In some embodiments, ABD1 and ABD3 bind to a capsid of an AAV particle, and ABD2 binds to a molecule on a cell surface.

[0194] In some embodiments, the scFv is linked to the first heavy chain region via a linker.

[0195] In another aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising: a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) a first heavy chain region of a first Fab (“Fab1”) operably linked to (ii) an Fc domain, the Fc domain operably linked to (iii) an scFv comprising a first antigen-binding domain (“ABD1”);b) a second polypeptide chain comprising, in an N- to C-terminal orientation, (i) a second heavy chain region of a second Fab (“Fab2”) operably linked to (ii) an Fc domain; c) a third polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a second antigen-binding domain (“ABD2”); and d) a fourth polypeptide chain comprising a second light chain that pairs with the second heavy chain region to form Fab2, wherein Fab2 comprises a third antigen-binding domain (“ABD3”); wherein at least one of ABD1, ABD2, and ABD3 binds to a capsid of an adeno-associated virus (AAV) particle, and the other(s) of ABD1, ABD2, and ABD3 bind to a molecule on a cell surface.

[0196] In some embodiments, two of ABD1, ABD2, and ABD3 bind to a capsid of anAAV particle, and one of ABD1, ABD2, and ABD3 binds to a molecule on a cell surface.

[0197] In some embodiments, ABD2 and ABD3 bind to a capsid of an AAV particle, and ABD1 binds to a molecule on a cell surface.

[0198] In some embodiments, ABD1 and ABD2 bind to a capsid of an AAV particle, and ABD3 binds to a molecule on a cell surface.

[0199] In another aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising: a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) a first heavy chain region of a first Fab (“Fab1”) operably linked to (ii) a second heavy chain region of a second Fab (“Fab2”), the second heavy chain region of Fab2 operably linked to (iii) an Fc domain; b) a second polypeptide chain comprising, in an N- to C-terminal orientation, (i) a third heavy chain region of a third Fab (“Fab3”) operably linked to (ii) an Fc domain; c) a third polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a first antigen-binding domain (“ABD1”); d) a fourth polypeptide chain comprising a second light chain that pairs with the second heavy chain region to form Fab2, wherein Fab2 comprises a second antigen-binding domain (“ABD2”); and e) a fifth polypeptide chain comprising a third light chain that pairs with the third heavy chain region to form Fab3, wherein Fab3 comprises a third antigen-binding domain (“ABD3”);wherein at least one of ABD1 , ABD2, and ABD3 binds to a capsid of an adeno-associated virus (AAV) particle, and the othcr(s) of ABD1, ABD2, and ABD3 bind to a molecule on a cell surface.

[0200] In some embodiments, two of ABD1, ABD2, and ABD3 bind to a capsid of an AAV particle, and one of ABD1, ABD2, and ABD3 binds to a molecule on a cell surface.

[0201] In some embodiments, ABD2 and ABD3 bind to a capsid of an AAV particle, and ABD1 binds to a molecule on a cell surface.

[0202] In some embodiments, ABD1 and ABD3 bind to a capsid of an AAV particle, and ABD2 binds to a molecule on a cell surface.

[0203] In some embodiments, the first heavy chain region is linked to the second heavy chain region via a linker.

[0204] In another aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising: a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) a first heavy chain region of a first Fab (“Fab1”) operably linked to (ii) an Fc domain, the Fc domain operably linked to (iii) a second heavy chain region of a second Fab (“Fab2”); b) a second polypeptide chain comprising, in an N- to C-terminal orientation, (i) a third heavy chain region of a third Fab (“Fab3”) operably linked to (ii) an Fc domain; c) a third polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a first antigen-binding domain (“ABD1”); d) a fourth polypeptide chain comprising a second light chain that pairs with the second heavy chain region to form Fab2, wherein Fab2 comprises a second antigen-binding domain (“ABD2”); and e) a fifth polypeptide chain comprising a third light chain that pairs with the third heavy chain region to form Fab3, wherein Fab3 comprises a third antigen-binding domain (“ABD3”); wherein at least one of ABD1, ABD2, and ABD3 binds to a capsid of an adeno-associated virus (AAV) particle, and the other(s) of ABD1, ABD2, and ABD3 bind to a molecule on a cell surface.

[0205] In some embodiments, two of ABD1, ABD2, and ABD3 bind to a capsid of an AAV particle, and one of ABD1, ABD2, and ABD3 binds to a molecule on a cell surface.

[0206] In some embodiments, ABD1 and ABD3 bind to a capsid of an AAV particle, and ABD2 binds to a molecule on a cell surface.

[0207] In some embodiments, ABD1 and ABD2 bind to a capsid of an AAV particle, and ABD3 binds to a molecule on a cell surface.

[0208] In some embodiments, the second heavy chain region is linked to the Fc domain via a linker.

[0209] In another aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising: a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) a first heavy chain region of a first Fab (“Fab1”) operably linked to (ii) an scFv comprising a first antigenbinding domain (“ABD1”), the scFv operably linked to (iii) an Fc domain; b) a second polypeptide chain comprising, in an N- to C-terminal orientation, (i) a second heavy chain region of a second Fab (“Fab2”) operably linked to (ii) an Fc domain; c) a third polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a second antigen-binding domain (“ABD2”); and d) a fourth polypeptide chain comprising a second light chain that pairs with the second heavy chain region to form Fab2, wherein Fab2 comprises a third antigen-binding domain (“ABD3”); wherein at least one of ABD1, ABD2, and ABD3 binds to a capsid of an adeno-associated virus (AAV) particle, and the other(s) of ABD1, ABD2, and ABD3 bind to a molecule on a cell surface.

[0210] In some embodiments, two of ABD1, ABD2, and ABD3 bind to a capsid of an AAV particle, and one of ABD1, ABD2, and ABD3 binds to a molecule on a cell surface.

[0211] In some embodiments, ABD2 and ABD3 bind to a capsid of an AAV particle, and ABD1 binds to a molecule on a cell surface.

[0212] In some embodiments, ABD1 and ABD2 bind to a capsid of an AAV particle, and ABD3 binds to a molecule on a cell surface.

[0213] In some embodiments, the scFv is linked to the first heavy chain region via a linker.

[0214] In another aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising:a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) a first heavy chain region of a first Fab (“Fab1”) operably linked to (ii) an Fc domain, the Fc domain operably linked to (iii) a second heavy chain region of a second Fab (“Fab2”); b) a second polypeptide chain comprising, in an N- to C-terminal orientation, (i) an scFv comprising a first antigen-binding domain (“ABD1”) operably linked to (ii) an Fc domain; c) a third polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a second antigen-binding domain (“ABD2”); d) a fourth polypeptide chain comprising a second light chain that pairs with the second heavy chain region to form Fab2, wherein Fab2 comprises a third antigen-binding domain (“ABD3”); wherein at least one of ABD1, ABD2, and ABD3 binds to a capsid of an adeno-associated virus (AAV) particle, and the other(s) of ABD1, ABD2, and ABD3 bind to a molecule on a cell surface.

[0215] In some embodiments, two of ABD1, ABD2, and ABD3 bind to a capsid of anAAV particle, and one of ABD1, ABD2, and ABD3 binds to a molecule on a cell surface.

[0216] In some embodiments, ABD2 and ABD3 bind to a capsid of an AAV particle, and ABD1 binds to a molecule on a cell surface.

[0217] In some embodiments, ABD1 and ABD2 bind to a capsid of an AAV particle, and ABD3 binds to a molecule on a cell surface.

[0218] In some embodiments, Fab2 is linked to the Fc domain via a linker.

[0219] In some embodiments of any of the above-described multispecific antibodies, or multispecific antigen-binding fragments, the at least one of ABD1, ABD2, and ABD3 which binds to a capsid of an AAV particle comprises: a) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 2, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; b) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 22, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10;c) a heavy chain variable region (HCVR) that comprises a HCDR1 , HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 32, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; d) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 42, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; e) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 52 or 1159, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10 or 1157; f) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 62, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; g) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 71, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; h) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 81, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; i) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 91, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; and / or j) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 101, and / or alight chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10.

[0220] In some embodiments, the at least one of ABD1, ABD2, and ABD3 which binds to a capsid of an AAV particle comprises: a) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 4, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 6, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 8; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; b) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 24, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 26, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 28; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; c) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 34, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 36, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 38; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; d) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 44, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 46, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 48; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; e) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 54, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 56, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 58; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; f) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 64, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 56, and a HCDR3 comprising the amino acid sequenceof SEQ ID NO: 67; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; g) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 73, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 75, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 77; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; h) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 83, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 85, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 87; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; i) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 93, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 95, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 97; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; and / or j) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 103, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 105, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 107; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16.

[0221] In some embodiments, the at least one of ABD1, ABD2, and ABD3 which binds to a capsid of an AAV particle comprises: a) a HCVR comprising the amino acid sequence of SEQ ID NO: 2, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; b) a HCVR comprising the amino acid sequence of SEQ ID NO: 22, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; c) a HCVR comprising the amino acid sequence of SEQ ID NO: 32, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10;d) a HCVR comprising the amino acid sequence of SEQ ID NO: 42, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; e) a HCVR comprising the amino acid sequence of SEQ ID NO: 52 or 1159, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10 or 1157; f) a HCVR comprising the amino acid sequence of SEQ ID NO: 62, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; g) a HCVR comprising the amino acid sequence of SEQ ID NO: 71, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; h) a HCVR comprising the amino acid sequence of SEQ ID NO: 81, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; i) a HCVR comprising the amino acid sequence of SEQ ID NO: 91, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; and / or j) a HCVR comprising the amino acid sequence of SEQ ID NO: 101, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10.

[0222] In some embodiments of the above-described multispecific antibodies, or multispecific antigen-binding fragments, the molecule on the cell surface is calcium voltagegated channel auxiliary subunit gamma 1 (CACNG1).

[0223] In some embodiments, the other(s) of ABD1, ABD2, and ABD3 which binds to CACNG1 comprises:1) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 615, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 623;2) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 635, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 643;3) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 655, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 663;4) a HCVR that comprises the HCDR1 , HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 675, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 683;5) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 695, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 703;6) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 715, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 723;7) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 735, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 743;8) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 755, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 763;9) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 775, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 783;10) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 795, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 803;11) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 815, and / or a LCVR that comprises theLCDR1 , LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 823;12) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 835, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 843;13) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 855, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 863;14) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 875, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 883;15) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 895, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 903;16) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 915, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 923;17) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 935, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 943;18) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 955, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 963;19) a HCVR that comprises the HCDR1 , HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 1181, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 1189; or20) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 1205, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 1213.

[0224] In some embodiments, the other(s) of ABD1, ABD2, and ABD3 which binds to CACNG1 comprises1) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 617, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 619, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 621; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 625, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 627, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 629;2) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 637, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 639, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 641; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 645, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 647, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 649;3) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 657, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 659, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 661; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 665, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 667, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 669;4) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 677, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 679, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 681; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 685, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 687, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 689;5) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 697, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 699, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 701; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 705, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 707, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 709;6) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 717, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 719, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 721; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 725, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 727, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 729;7) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 737, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 739, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 741; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 745, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 747, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 749;8) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 757, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 759, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 761; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 765, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 767, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 769;9) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 777, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 779, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 781; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 785, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 787, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 789;10) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 797, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 799, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 801; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 805, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 807, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 809;11) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 817, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 819, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 821; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 825, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 827, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 829;12) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 837, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 839, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 841; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 845, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 847, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 849;13) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 857, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 859, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 861; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 865, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 867, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 869;14) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 877, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 879, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 881; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 885, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 887, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 889;15) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 897, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 899, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 901; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 905, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 907, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 909;16) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 917, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 919, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 921; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 925, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 927, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 929;17) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 937, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 939, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 941; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 945, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 947, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 949;18) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 957, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 959, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 961; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 965, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 967, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 969;19) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 1183, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 1185, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 1187; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 1191, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 1193, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 1195; or20) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 1207, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 1209, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 1211; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 1215, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 1217, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 1219.

[0225] In some embodiments, the other(s) of ABD1, ABD2, and ABD3 which binds to CACNG1 comprises1) a HCVR comprising the amino acid sequence of SEQ ID NO: 615, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 623;2) a HCVR comprising the amino acid sequence of SEQ ID NO: 635, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 643;3) a HCVR comprising the amino acid sequence of SEQ ID NO: 655, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 663;4) a HCVR comprising the amino acid sequence of SEQ ID NO: 675, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 683;5) a HCVR comprising the amino acid sequence of SEQ ID NO: 695, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 703;6) a HCVR comprising the amino acid sequence of SEQ ID NO: 715, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 723;7) a HCVR comprising the amino acid sequence of SEQ ID NO: 735, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 743;8) a HCVR comprising the amino acid sequence of SEQ ID NO: 755, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 763;9) a HCVR comprising the amino acid sequence of SEQ ID NO: 775, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 783;10) a HCVR comprising the amino acid sequence of SEQ ID NO: 795, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 803;11) a HCVR comprising the amino acid sequence of SEQ ID NO: 815, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 823;12) a HCVR comprising the amino acid sequence of SEQ ID NO: 835, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 843;13) a HCVR comprising the amino acid sequence of SEQ ID NO: 855, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 863;14) a HCVR comprising the amino acid sequence of SEQ ID NO: 875, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 883;15) a HCVR comprising the amino acid sequence of SEQ ID NO: 895, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 903;16) a HCVR comprising the amino acid sequence of SEQ ID NO: 915, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 923;17) a HCVR comprising the amino acid sequence of SEQ ID NO: 935, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 943;18) a HCVR comprising the amino acid sequence of SEQ ID NO: 955, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 963;19) a HCVR comprising the amino acid sequence of SEQ ID NO: 1181, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 1189; or20) a HCVR comprising the amino acid sequence of SEQ ID NO: 1205, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 1213.

[0226] In another aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising: a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) a first heavy chain region of a first Fab (“Fab1”) operably linked to (ii) a second heavy chain region of a second Fab (“Fab2”); b) a second polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a first antigen-binding domain (“ABD1”); and c) a third polypeptide chain comprising a second light chain that pairs with the second heavy chain region to form Fab2, wherein Fab2 comprises a second antigen-binding domain (“ABD2”); wherein ABD1 or ABD2 binds to a capsid of an adeno-associated virus (AAV) particle, and the other of ABD1 or ABD2 binds to a molecule on a cell surface.

[0227] In some embodiments, ABD1 binds to a capsid of an adeno-associated virus (AAV) particle and ABD2 binds to a molecule on the cell surface.

[0228] In some embodiments, ABD2 binds to a capsid of an adeno-associated virus (AAV) particle and ABD1 binds to a molecule on the cell surface.

[0229] In some embodiments, the first heavy chain region is linked to the second heavy chain region via a linker.

[0230] In another aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising: a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) a first scFv comprising a first antigen-binding domain (“ABD1”) operably linked to (ii) an Fc domain; b) a second polypeptide chain, in an N- to C-terminal orientation, (i) a first heavy chain region of a first Fab (“Fab1”) operably linked to (ii) an Fc domain; and c) a third polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a second antigen-binding domain (“ABD2”); wherein ABD1 or ABD2 binds to a capsid of an adeno-associated virus (AAV) particle, and the other of ABD1 or ABD2 binds to a molecule on a cell surface.

[0231] In some embodiments, ABD1 binds to a capsid of an adeno-associated virus (AAV) particle and ABD2 binds to a molecule on the cell surface.

[0232] In some embodiments, ABD2 binds to a capsid of an adeno-associated virus (AAV) particle and ABD1 binds to a molecule on the cell surface.

[0233] In some embodiments, the first scFv and / or the first heavy chain region is linked to the Fc domain via a linker.

[0234] In some embodiments, the ABD1 or ABD2 which binds to a capsid of an AAV particle comprises: a) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 2, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; b) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 22, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; c) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 32, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; d) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 42, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; e) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 52 or 1159, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10 or 1157; f) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 62, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10;g) a heavy chain variable region (HCVR) that comprises a HCDR1 , HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 71, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; h) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 81, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; i) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 91, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; and / or j) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 101, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10.

[0235] In some embodiments, the ABD1 or ABD2 which binds to a capsid of an AAV particle comprises: a) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 4, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 6, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 8; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; b) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 24, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 26, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 28; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; c) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 34, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 36, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 38; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, aLCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; d) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 44, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 46, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 48; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; e) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 54, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 56, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 58; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; f) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 64, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 56, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 67; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; g) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 73, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 75, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 77; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; h) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 83, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 85, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 87; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; i) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 93, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 95, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 97; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, aLCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16; and / or j) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 103, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 105, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 107; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 12, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 14, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 16.

[0236] In some embodiments, the ABD1 or ABD2 which binds to a capsid of an AAV particle comprises: a) a HCVR comprising the amino acid sequence of SEQ ID NO: 2, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; b) a HCVR comprising the amino acid sequence of SEQ ID NO: 22, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; c) a HCVR comprising the amino acid sequence of SEQ ID NO: 32, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; d) a HCVR comprising the amino acid sequence of SEQ ID NO: 42, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; e) a HCVR comprising the amino acid sequence of SEQ ID NO: 52 or 1159, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10 or 1157; f) a HCVR comprising the amino acid sequence of SEQ ID NO: 62, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; g) a HCVR comprising the amino acid sequence of SEQ ID NO: 71, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; h) a HCVR comprising the amino acid sequence of SEQ ID NO: 81, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; i) a HCVR comprising the amino acid sequence of SEQ ID NO: 91, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10; and / or j) a HCVR comprising the amino acid sequence of SEQ ID NO: 101, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 10.

[0237] In some embodiments, the molecule on the cell surface disclosed herein is calcium voltage-gated channel auxiliary subunit gamma 1 (CACNG1).

[0238] In some embodiments, the other of ABD1 or ABD2 which binds to CACNG1 comprises:1) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 615, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 623;2) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 635, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 643;3) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 655, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 663;4) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 675, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 683;5) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 695, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 703;6) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 715, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 723;7) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 735, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 743;8) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 755, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 763;9) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 775, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 783;10) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 795, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 803;11) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 815, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 823;12) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 835, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 843;13) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 855, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 863;14) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 875, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 883;15) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 895, and / or a LCVR that comprises theLCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 903;16) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 915, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 923;17) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 935, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 943;18) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 955, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 963;19) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 1181, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 1189; or20) a HCVR that comprises the HCDR1, HCDR2 and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 1205, and / or a LCVR that comprises the LCDR1, LCDR2 and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 1213.

[0239] In some embodiments, the other of ABD1 or ABD2 which binds to CACNG1 comprises:1) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 617, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 619, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 621; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 625, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 627, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 629;2) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 637, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 639, and a HCDR3 comprising the amino acid sequenceof SEQ ID NO: 641 ; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 645, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 647, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 649;3) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 657, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 659, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 661; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 665, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 667, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 669;4) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 677, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 679, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 681; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 685, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 687, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 689;5) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 697, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 699, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 701; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 705, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 707, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 709;6) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 717, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 719, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 721; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 725, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 727, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 729;7) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 737, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 739, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 741; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 745, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 747, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 749;8) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 757, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 759, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 761; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 765, aLCDR2 comprising the amino acid sequence of SEQ ID NO: 767, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 769;9) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 777, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 779, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 781; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 785, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 787, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 789;10) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 797, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 799, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 801; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 805, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 807, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 809;11) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 817, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 819, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 821; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 825, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 827, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 829;12) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 837, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 839, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 841; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 845, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 847, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 849;13) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 857, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 859, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 861; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 865, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 867, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 869;14) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 877, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 879, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 881; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 885, aLCDR2 comprising the amino acid sequence of SEQ ID NO: 887, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 889;15) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 897, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 899, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 901; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 905, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 907, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 909;16) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 917, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 919, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 921; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 925, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 927, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 929;17) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 937, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 939, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 941; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 945, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 947, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 949;18) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 957, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 959, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 961; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 965, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 967, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 969;19) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 1183, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 1185, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 1187; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 1191, a LCDR2 comprising the amino acid sequence of SEQ ID NO: 1193, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 1195; or20) a HCDR1 comprising the amino acid sequence of SEQ ID NO: 1207, a HCDR2 comprising the amino acid sequence of SEQ ID NO: 1209, and a HCDR3 comprising the amino acid sequence of SEQ ID NO: 1211; and / or a LCDR1 comprising the amino acid sequence of SEQ ID NO: 1215,a LCDR2 comprising the amino acid sequence of SEQ ID NO: 1217, and a LCDR3 comprising the amino acid sequence of SEQ ID NO: 1219.

[0240] In some embodiments, the other of ABD1 or ABD2 which binds to CACNG1 comprises:1) a HCVR comprising the amino acid sequence of SEQ ID NO: 615, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 623;2) a HCVR comprising the amino acid sequence of SEQ ID NO: 635, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 643;3) a HCVR comprising the amino acid sequence of SEQ ID NO: 655, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 663;4) a HCVR comprising the amino acid sequence of SEQ ID NO: 675, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 683;5) a HCVR comprising the amino acid sequence of SEQ ID NO: 695, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 703;6) a HCVR comprising the amino acid sequence of SEQ ID NO: 715, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 723;7) a HCVR comprising the amino acid sequence of SEQ ID NO: 735, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 743;8) a HCVR comprising the amino acid sequence of SEQ ID NO: 755, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 763;9) a HCVR comprising the amino acid sequence of SEQ ID NO: 775, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 783;10) a HCVR comprising the amino acid sequence of SEQ ID NO: 795, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 803;11) a HCVR comprising the amino acid sequence of SEQ ID NO: 815, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 823;12) a HCVR comprising the amino acid sequence of SEQ ID NO: 835, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 843;13) a HCVR comprising the amino acid sequence of SEQ ID NO: 855, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 863;14) a HCVR comprising the amino acid sequence of SEQ ID NO: 875, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 883;15) a HCVR comprising the amino acid sequence of SEQ ID NO: 895, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 903;16) a HCVR comprising the amino acid sequence of SEQ ID NO: 915, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 923;17) a HCVR comprising the amino acid sequence of SEQ ID NO: 935, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 943;18) a HCVR comprising the amino acid sequence of SEQ ID NO: 955, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 963;19) a HCVR comprising the amino acid sequence of SEQ ID NO: 1181, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 1189; or20) a HCVR comprising the amino acid sequence of SEQ ID NO: 1205, and / or a LCVR comprising the amino acid sequence of SEQ ID NO: 1213.

[0241] In another aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising: a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) an scFv comprising a first antigen-binding domain (“ABD1”) operably linked to (ii) a first heavy chain region of a first Fab (“Fab1”), said first heavy chain region operably linked to (iii) an Fc domain; b) a second polypeptide chain comprising, in an N- to C-terminal orientation, (i) a second heavy chain region of a second Fab (“Fab2”) operably linked to (ii) an Fc domain; c) a third polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a second antigen-binding domain (“ABD2”); and d) a fourth polypeptide chain comprising a second light chain that pairs with the second heavy chain region to form Fab2, wherein Fab2 comprises a third antigen-binding domain (“ABD3”); wherein at least one of ABD1, ABD2, and ABD3 binds to a capsid of an adeno-associated virus (AAV) particle, and the other(s) of ABD1, ABD2, and ABD3 bind to a molecule on a cell surface.

[0242] In some embodiments, two of ABD1 , ABD2, and ABD3 bind to a capsid of an AAV particle, and one of ABD1, ABD2, and ABD3 binds to a molecule on a cell surface.

[0243] In some embodiments, ABD2 and ABD3 bind to a capsid of an AAV particle, and ABD1 binds to a molecule on a cell surface.

[0244] In some embodiments, ABD1 and ABD3 bind to a capsid of an AAV particle, and ABD2 binds to a molecule on a cell surface.

[0245] In some embodiments, the scFv is linked to the first heavy chain region via a linker.

[0246] In another aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising: a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) a first heavy chain region of a first Fab (“Fab1”) operably linked to (ii) an Fc domain, said Fc domain operably linked to (iii) an scFv comprising a first antigen-binding domain (“ABD1”); b) a second polypeptide chain comprising, in an N- to C-terminal orientation, (i) a second heavy chain region of a second Fab (“Fab2”) operably linked to (ii) an Fc domain; c) a third polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a second antigen-binding domain (“ABD2”); and d) a fourth polypeptide chain comprising a second light chain that pairs with the second heavy chain region to form Fab2, wherein Fab2 comprises a third antigen-binding domain (“ABD3”); wherein at least one of ABD1, ABD2, and ABD3 binds to a capsid of an adeno-associated virus (AAV) particle, and the other(s) of ABD1, ABD2, and ABD3 bind to a molecule on a cell surface.

[0247] In some embodiments, two of ABD1, ABD2, and ABD3 bind to a capsid of anAAV particle, and one of ABD1, ABD2, and ABD3 binds to a molecule on a cell surface.

[0248] In some embodiments, ABD2 and ABD3 bind to a capsid of an AAV particle, and ABD1 binds to a molecule on a cell surface.

[0249] In some embodiments, ABD1 and ABD2 bind to a capsid of an AAV particle, and ABD3 binds to a molecule on a cell surface.

[0250] In some embodiments, the scFv is linked to the Fc domain via a linker.

[0251] In another aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising: a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) a first heavy chain region of a first Fab (“Fab1”) operably linked to (ii) a second heavy chain region of a second Fab (“Fab2”), said second heavy chain region of Fab2 operably linked to (iii) an Fc domain; b) a second polypeptide chain comprising, in an N- to C-terminal orientation, (i) a third heavy chain region of a third Fab (“Fab3”) operably linked to (ii) an Fc domain; c) a third polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a first antigen-binding domain (“ABD1”); d) a fourth polypeptide chain comprising a second light chain that pairs with the second heavy chain region to form Fab2, wherein Fab2 comprises a second antigen-binding domain (“ABD2”); and e) a fifth polypeptide chain comprising a third light chain that pairs with the third heavy chain region to form Fab3, wherein Fab3 comprises a third antigen-binding domain (“ABD3”); wherein at least one of ABD1, ABD2, and ABD3 binds to a capsid of an adeno-associated virus (AAV) particle, and the other(s) of ABD1, ABD2, and ABD3 bind to a molecule on a cell surface.

[0252] In some embodiments, two of ABD1, ABD2, and ABD3 bind to a capsid of anAAV particle, and one of ABD1, ABD2, and ABD3 binds to a molecule on a cell surface.

[0253] In some embodiments, ABD2 and ABD3 bind to a capsid of an AAV particle, and ABD1 binds to a molecule on a cell surface.

[0254] In some embodiments, ABD1 and ABD3 bind to a capsid of an AAV particle, and ABD2 binds to a molecule on a cell surface.

[0255] In some embodiments, the first heavy chain region is linked to the second heavy chain region via a linker.

[0256] In another aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising: a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) a first heavy chain region of a first Fab (“Fab1”) operably linked to (ii) an Fc domain, said Fc domain operably linked to (iii) a second heavy chain region of a second Fab (“Fab2”);b) a second polypeptide chain comprising, in an N- to C-terminal orientation, (i) a third heavy chain region of a third Fab (“Fab3”) operably linked to (ii) an Fc domain; c) a third polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a first antigen-binding domain (“ABD1”); d) a fourth polypeptide chain comprising a second light chain that pairs with the second heavy chain region to form Fab2, wherein Fab2 comprises a second antigen-binding domain (“ABD2”); and e) a fifth polypeptide chain comprising a third light chain that pairs with the third heavy chain region to form Fab3, wherein Fab3 comprises a third antigen-binding domain (“ABD3”); wherein at least one of ABD1, ABD2, and ABD3 binds to a capsid of an adeno-associated virus (AAV) particle, and the other(s) of ABD1, ABD2, and ABD3 bind to a molecule on a cell surface.

[0257] In some embodiments, two of ABD1, ABD2, and ABD3 bind to a capsid of anAAV particle, and one of ABD1, ABD2, and ABD3 binds to a molecule on a cell surface.

[0258] In some embodiments, ABD1 and ABD3 bind to a capsid of an AAV particle, and ABD2 binds to a molecule on a cell surface.

[0259] In some embodiments, ABD1 and ABD2 bind to a capsid of an AAV particle, and ABD3 binds to a molecule on a cell surface.

[0260] In some embodiments, the second heavy chain region is linked to the Fc domain via a linker.

[0261] In another aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising: a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) a first heavy chain region of a first Fab (“Fab1”) operably linked to (ii) an scFv comprising a first antigen-binding domain (“ABD1”), said scFv operably linked to (iii) an Fc domain; b) a second polypeptide chain comprising, in an N- to C-terminal orientation, (i) a second heavy chain region of a second Fab (“Fab2”) operably linked to (ii) an Fc domain; c) a third polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a second antigen-binding domain (“ABD2”); andd) a fourth polypeptide chain comprising a second light chain that pairs with the second heavy chain region to form Fab2, wherein Fab2 comprises a third antigen-binding domain (“ABD3”); wherein at least one of ABD1, ABD2, and ABD3 binds to a capsid of an adeno- associated virus (AAV) particle, and the other(s) of ABD1, ABD2, and ABD3 bind to a molecule on a cell surface.

[0262] In some embodiments, two of ABD1, ABD2, and ABD3 bind to a capsid of anAAV particle, and one of ABD1, ABD2, and ABD3 binds to a molecule on a cell surface.

[0263] In some embodiments, ABD2 and ABD3 bind to a capsid of an AAV particle, and ABD1 binds to a molecule on a cell surface.

[0264] In some embodiments, ABD1 and ABD2 bind to a capsid of an AAV particle, and ABD3 binds to a molecule on a cell surface.

[0265] In some embodiments, the scFv is linked to the first heavy chain region via a linker.

[0266] In another aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising: a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) a first heavy chain region of a first Fab (“Fab1”) operably linked to (ii) an Fc domain, said Fc domain operably linked to (iii) a second heavy chain region of a second Fab (“Fab2”); b) a second polypeptide chain comprising, in an N- to C-terminal orientation, (i) an scFv comprising a first antigen-binding domain (“ABD1”) operably linked to (ii) an Fc domain; c) a third polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a second antigen-binding domain (“ABD2”); and d) a fourth polypeptide chain comprising a second light chain that pairs with the second heavy chain region to form Fab2, wherein Fab2 comprises a third antigen-binding domain (“ABD3”); wherein at least one of ABD1, ABD2, and ABD3 binds to a capsid of an adeno- associated virus (AAV) particle, and the other(s) of ABD1, ABD2, and ABD3 bind to a molecule on a cell surface.

[0267] In some embodiments, two of ABD1 , ABD2, and ABD3 bind to a capsid of an AAV particle, and one of ABD1, ABD2, and ABD3 binds to a molecule on a cell surface.

[0268] In some embodiments, ABD2 and ABD3 bind to a capsid of an AAV particle, and ABD1 binds to a molecule on a cell surface.

[0269] In some embodiments, ABD1 and ABD2 bind to a capsid of an AAV particle, and ABD3 binds to a molecule on a cell surface.

[0270] In some embodiments, the second heavy chain region is linked to the Fc domain via a linker.

[0271] In another aspect, provided herein is a multispecific antibody, or a multispecific antigen-binding fragment thereof, comprising: a) a first polypeptide chain comprising, in an N- to C-terminal orientation, (i) a first heavy chain region of a first Fab (“Fab1”) operably linked to (ii) a second heavy chain region of a second Fab (“Fab2”), said second heavy chain region operably linked to (iii) a third heavy chain region of a third Fab (“Fab3”); b) a second polypeptide chain comprising a first light chain that pairs with the first heavy chain region to form Fab1, wherein Fab1 comprises a first antigen-binding domain (“ABD1”); and c) a third polypeptide chain comprising a second light chain that pairs with the second heavy chain region to form Fab2, wherein Fab2 comprises a second antigen-binding domain (“ABD2”); d) a fourth polypeptide chain comprising a third light chain that pairs with the third heavy chain region to form Fab3, wherein Fab3 comprises a third antigen-binding domain (“ABD3”); wherein at least one of ABD1, ABD2, and ABD3 binds to a capsid of an adeno-associated virus (AAV) particle, and the other(s) of ABD1, ABD2, and ABD3 bind to a molecule on a cell surface.

[0272] In some embodiments, two of ABD1, ABD2, and ABD3 bind to a capsid of an AAV particle, and one of ABD1, ABD2, and ABD3 binds to a molecule on a cell surface.

[0273] In some embodiments, ABD2 and ABD3 bind to a capsid of an AAV particle, and ABD1 binds to a molecule on a cell surface.

[0274] In some embodiments, ABD1 and ABD3 bind to a capsid of an AAV particle, and ABD2 binds to a molecule on a cell surface.

[0275] In some embodiments, the first heavy chain region is operably linked to the second heavy chain region and / or the second heavy chain region is operably linked to the third heavy chain region via a linker.

[0276] In some embodiments, the at least one of ABD1 , ABD2, and ABD3 which binds to a capsid of an AAV particle comprises: a) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 2, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; b) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 22, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained within a LCVR comprising the amino acid sequence of SEQ ID NO: 10; c) a heavy chain variable region (HCVR) that comprises a HCDR1, HCDR2, and HCDR3 contained within an HCVR comprising the amino acid sequence of SEQ ID NO: 32, and / or a light chain variable region (LCVR) that comprises a LCDR1, LCDR2, and LCDR3 contained withi...

Claims

CLAIMSWhat is claimed is:

1. A nucleic acid comprising a modified MTM1 gene sequence, wherein the modified MTM1 gene sequence comprises a substitution of a codon of a wildtype MTM1 gene sequence with a degenerate codon, wherein the modified MTM1 gene sequence encodes myotubularin comprising the amino acid sequence set forth in SEQ ID NO: 1398.

2. The nucleic acid of claim 1, wherein the wildtype MTM1 gene sequence comprises the nucleotide sequence set forth in SEQ ID NO: 1399.

3. The nucleic acid of claim 1, wherein the wildtype MTM1 gene sequence comprises the nucleotide sequence set forth in SEQ ID NO: 1400.

4. The nucleic acid of claim 1, wherein the modified MTM1 gene sequence exhibits reduced immunogenicity in a mammalian subject as compared to the wildtype MTM1 gene sequence.

5. The nucleic acid of claim 4, wherein the mammalian subject is a human subject.

6. The nucleic acid of claim 1, wherein the modified MTM1 gene sequence is CpG depleted.

7. The nucleic acid of claim 5, wherein the modified MTM1 gene sequence is CpG depleted via an algorithm selected from the group consisting of: DNA Chisel, IDT, and GeneArt.

8. The nucleic acid of claim 1, wherein the modified MTM1 gene sequence exhibits increased expression of myotubularin in a mammalian cell as compared to the wildtype MTM1 gene sequence.

9. The nucleic acid of claim 8, wherein the mammalian cell is a mammalian muscle cell.

10. The nucleic acid of claim 9, wherein the mammalian muscle cell is a human muscle cell.

11. The nucleic acid of claim 10, wherein the mammalian muscle cell is in vivo in a subject.

12. The nucleic acid of claim 1, wherein the modified MTM1 gene sequence is codon altered:(a) such that the modified MTM1 gene sequence has a codon adaptation index of at least 0.7, or at least 0.75, or at least 0.8 or at least 0.85 or at least 0.87 or at least 0.89, or at least 0.90, or at least 0.91, or at least 0.92, or at least 0.93, or at least 0.94, or at least 0.95, or at least 0.96, or at least 0.97, or at least 0.98, or at least 0.99; and / or(b) via an algorithm selected from the group consisting of: DNA Chisel, GenScript, IDT, GeneArt, NovoPro, TwistBio, and Vector Builder.

13. The nucleic acid of claim 1, wherein the nucleic acid comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the nucleotide sequence set forth in any one of SEQ ID NOs: 1401-1409.

14. A nucleic acid comprising a modified MHCK7 promoter sequence, wherein the MHCK7 promoter sequence comprises a substitution of at least one nucleotide of a wildtype MHCK7 promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, wherein the modified MHCK7 promoter sequence binds to a transcriptional protein and initiates transcription in muscle cells.

15. The nucleic acid of claim 14, wherein the modified MHCK7 promoter sequence exhibits reduced immunogenicity in a mammalian subject as compared to the wildtype MHCK7 promoter sequence.

16. The nucleic acid of claim 15, wherein the modified MHCK7 promoter sequence operably linked to a protein coding sequence exhibits reduced immunogenicity in a mammalian subject and comparable expression of the protein in a mammalian cell as compared to the wildtype MHCK7 promoter sequence operably linked to the protein coding sequence.

17. The nucleic acid of claim 14, wherein the wildtype MHCK7 promoter sequence comprises the nucleotide sequence set forth in SEQ ID NO: 1410.

18. The nucleic acid of claim 14, wherein the modified MHCK7 promoter sequence comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the nucleotide sequence set forth in SEQ ID NO: 1411 or SEQ ID NO: 1412.

19. A nucleic acid comprising, in operable linkage:(a) a promoter sequence, wherein the promoter sequence does not comprise an MTM1 promoter sequence; and(b) a modified MTM1 gene sequence comprising a substitution of a codon of a wildtype MTM1 gene nucleotide sequence set forth in SEQ ID NO: 1399 or SEQ ID NO: 1400 with a degenerate codon.

20. The nucleic acid of claim 19, wherein the promoter sequence comprises a wildtype MHCK7 promoter sequence.

21. The nucleic acid of claim 20, wherein the wildtype MHCK7 promoter sequence comprises the nucleotide sequence set forth in SEQ ID NO: 1410.

22. The nucleic acid of claim 19, wherein the promoter sequence comprises a modified MHCK7 promoter sequence, wherein the modified MHCK7 promoter sequence comprises a substitution of at least one nucleotide of a wildtype MHCK7 promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, wherein the modified MHCK7 promoter sequence binds to a transcriptional protein and initiates transcription.

23. The nucleic acid of claim 22, wherein the modified MHCK7 promoter sequence comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the nucleotide sequence set forth in SEQ ID NO: 1411 or SEQ ID NO: 1412.

24. The nucleic acid of claim 19, wherein the modified MTM1 gene sequence exhibits reduced immunogenicity in a mammalian subject as compared to the wildtype MTM1 gene sequence.

25. The nucleic acid of claim 19, wherein the modified MTM1 gene sequence is CpG depleted.

26. The nucleic acid of claim 25, wherein the modified MTM1 gene sequence is CpG depleted via an algorithm selected from the group consisting of: DNA Chisel, IDT, and GeneArt.

27. The nucleic acid of claim 19, wherein the modified MTM1 gene sequence exhibits increased expression of myotubularin in a mammalian cell as compared to the wildtype MTM1 gene sequence.

28. The nucleic acid of claim 19, wherein the modified MTM1 gene sequence is codon altered, such that the modified MTM1 gene sequence has a codon adaptation index of at least 0.7, or at least 0.75, or at least 0.8, or at least 0.85, or at least 0.87, or at least 0.89, or at least 0.90, or at least 0.91, or at least 0.92, or at least 0.93, or at least 0.94, or at least 0.95, or at least 0.96, or at least 0.97, or at least 0.98, or at least 0.99.

29. The nucleic acid of claim 28, wherein the modified MTM1 gene sequence is codon altered via an algorithm selected from the group consisting of: DNA Chisel, GenScript, IDT, GeneArt, NovoPro, TwistBio, and Vector Builder.

30. The nucleic acid of claim 19, wherein the modified MTM1 gene sequence comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the nucleotide sequence set forth in any one of SEQ ID NOs: 1401-1409.

31. An expression cassette comprising the nucleic acid of claim 1 operably linked to an expression control sequence.

32. The expression cassette of claim 31, wherein the expression control sequence comprises a muscle cell-specific promoter sequence.

33. The expression cassette of claim 32, wherein the muscle cell-specific promoter sequence is selected from the group consisting of: MHCK7, CK1, CK8, CK8e, CK7, unc45b_SCP1, HSA1.5, MHCK1, MCK1.35, SP985, 2R5S_c5-12, c5-12, SP-301, tMCK, SCP, and a biologically equivalent variant thereof.

34. The expression cassette of claim 32, wherein the muscle cell-specific promoter sequence comprises a modified muscle cell-specific promoter sequence that exhibits reduced immunogenicity in a mammalian subject as compared to a wildtype muscle cell-specific promoter sequence.

35. The expression cassette of claim 34, wherein the modified muscle cell-specific promoter sequence comprises a substitution of at least one nucleotide of the wildtype muscle cell-specific promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, wherein the modified muscle cell-specific promoter sequence binds to transcriptional proteins and initiates transcription in muscle cells.

36. The expression cassette of claim 34, wherein the modified muscle cell-specific promoter sequence is a modified MHCK7 promoter sequence.

37. The expression cassette of claim 36, wherein the modified MHCK7 promoter sequence comprises a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the nucleotide sequence set forth in SEQ ID NO: 1411 or SEQ ID NO: 1412.

38. The expression cassette of claim 36, comprising a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the nucleotide sequence set forth in any one of SEQ ID NOs: 1414-1427.

39. An adeno-associated virus (AAV) vector genome comprising, from 5’ to 3’ and in operable linkage:(a) a 5’ AAV inverted terminal repeat (ITR) sequence;(b) the expression cassette of claim 31; and(c) a 3’ AAV ITR sequence.

40. The AAV vector genome of claim 39, wherein the 5’ AAV ITR sequence and the 3’ AAV ITR sequence are both AAV2 ITR sequences.

41. The AAV vector genome of claim 39, wherein the 5’ AAV ITR sequence comprises the nucleotide sequence as set forth in SEQ ID NO: 1442 or SEQ ID NO: 1443 and / or the 3’ AAV ITR sequence comprises the nucleotide sequence as set forth in SEQ ID NO: 1444 or SEQ ID NO: 1445.

42. The AAV vector genome of claim 39, comprising a nucleotide sequence that is at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the nucleotide sequence set forth in any one of SEQ ID NOs: 1428-1441.

43. An AAV particle comprising the AAV vector genome of claim 39 encapsidated by an AAV capsid.

44. The AAV particle of claim 43, wherein the AAV capsid comprises a first member of a protein:protein binding pair, wherein the first member of the protein:protein binding pair is associated with a second member of the protein :protein binding pair.

45. The AAV particle of claim 44, wherein the second member of the protein:protein binding pair comprises a targeting ligand that specifically binds a mammalian muscle cell- specific surface protein.

46. The AAV particle of claim 45, wherein the mammalian muscle cell-specific surface protein is mammalian Calcium Voltage-Gaged Auxiliary Subunit Gamma 1 (CACNG1).

47. The AAV particle of claim 46, wherein the mammalian muscle cell-specific surface protein is human CACNG1.

48. The AAV particle of claim 45, wherein the targeting ligand is an antibody or an antigenbinding fragment thereof.

49. The AAV particle of claim 48, wherein the targeting ligand comprises a first heavy chain comprising a first heavy chain variable region (VH) and a first heavy chain constant region (CH), wherein the first CHcomprises a first CH3region of a human IgG, wherein the human IgG is IgG1, IgG2, or IgG4.

50. The AAV particle of claim 49, wherein the targeting ligand comprises a second heavy chain comprising a second VHand a second CH, wherein the second CHcomprises (i) a second CH3region of a human IgG, wherein the human IgG is IgG1, IgG2, or IgG4; and (ii) one or more modifications in the second CH3region that reduces or eliminates binding of the second CH3region to Protein A.

51. The AAV particle of claim 50, wherein the one or more modifications in the second CH3region comprises a 435R mutation or a 435R and a 436F mutation, according to the EU numbering system.

52. The AAV particle of claim 50, wherein the first heavy chain further comprises one or more modifications in a first hinge domain, and / or the second heavy chain further comprises one or more modifications in a second hinge domain.

53. The AAV particle of claim 52, wherein the first hinge domain comprises one or more modifications at positions 233-236 and the second hinge domain comprises one or more modifications at positions 233-236, according to the EU numbering system.

54. The AAV particle of claim 53, wherein:(a) the one or more modifications in the first hinge domain and / or the one or more modifications in the second hinge domain are G, G, G and unoccupied; G, G, unoccupied, and unoccupied; G, unoccupied, unoccupied, and unoccupied; or all unoccupied, with positions numbered according to the EU numbering system; and / or(b) positions 226-229 of the first hinge domain are CPPC and positions 226-229 of the second hinge domain are CPPC; and / or(c) the first hinge domain and / or the second hinge domain each comprise the amino acid sequence set forth in: CPPCPAPGGG-GPSVF (SEQ ID NO: 1497), CPPCPAPGG-GPSVF (SEQ ID NO: 1498), CPPCPAPG— GPSVF (SEQ ID NO: 1499), or CPPCPAP — GPSVF (SEQ ID NO: 1500).

55. The AAV particle of claim 49, wherein the first CHcomprises the amino acid sequence set forth in SEQ ID NO: 1480, and / or the second CHcomprises the amino acid sequence set forth in SEQ ID NO: 1486.

56. The AAV particle of claim 44, wherein the first member of the protein:protein binding pair comprises an epitope, and wherein the second member of the protein:protein binding pair comprises an antibody paratope that specifically binds the epitope.

57. The AAV particle of claim 56, wherein the epitope comprises an AAV amino acid sequence.

58. The AAV particle of claim 57, wherein the antibody paratope that specifically binds the epitope comprising the AAV amino acid sequence comprises a set of three heavy chain complementarity determining regions (HCDRs) and a set of three light chain complementaritydetermining regions (LCDRs) of a heavy chain variable region (HCVR) and light chain variable region (LCVR) pair as set forth in SEQ ID NOs: 2 / 10, 22 / 10, 32 / 10, 42 / 10, 52 / 10, 52 / 1157, 1159 / 10, 1159 / 1157, 62 / 10, 71 / 10, 81 / 10, 91 / 10, 101 / 10, 111 / 119, 131 / 119, 141 / 119, 141 / 10, 151 / 119, 161 / 119, 171 / 119, 180 / 119, 180 / 10, 190 / 119, 200 / 119, or 210 / 119, respectively.

59. The AAV particle of claim 57, wherein the second member of the protein:protein binding pair further comprises a second antibody paratope that binds to a mammalian muscle cellspecific surface protein.

60. The AAV particle of claim 59, wherein the mammalian muscle cell-specific surface protein is human CACNG1 and the second antibody paratope that specifically binds to human CACNG1 comprises a set of three HCDRs and a set of three LCDRs of an HCVR / LCVR pair as set forth in SEQ ID NOs: 615 / 623, 635 / 643, 655 / 663, 675 / 683, 695 / 703, 715 / 723, 735 / 743, 755 / 763, 775 / 783, 795 or 1351 / 803, 815 / 823, 835 / 843, 855 / 863, 875 / 883, 895 / 903, 915 / 923, 935 / 943, 955 / 963, 1181 / 1189, or 1205 / 1213, respectively.

61. The AAV particle of claim 59, wherein the second member of the protein:protein binding pair comprises a multispecific binding molecule comprising a first antigen-binding domain that binds to the epitope comprising the AAV amino acid sequence and a second antigen-binding domain that binds to human CACNG1, wherein:(a) the first antigen-binding domain comprises a set of three HCDRs and a set of three LCDRs of an HCVR / LCVR pair as set forth in SEQ ID NOs: 2 / 10, 22 / 10, 32 / 10, 42 / 10, 52 / 10, 52 / 1157, 1159 / 10, 1159 / 1157, 62 / 10, 71 / 10, 81 / 10, 91 / 10, 101 / 10, 111 / 119, 131 / 119, 141 / 119, 141 / 10, 151 / 119, 161 / 119, 171 / 119, 180 / 119, 180 / 10, 190 / 119, 200 / 119, or 210 / 119, respectively; and(b) the second antigen-binding domain comprises a set of three HCDRs and a set of three LCDRs of an HCVR / LCVR pair as set forth in SEQ ID NOs: 615 / 623, 635 / 643, 655 / 663, 675 / 683, 695 / 703, 715 / 723, 735 / 743, 755 / 763, 775 / 783, 795 or 1351 / 803, 815 / 823, 835 / 843, 855 / 863, 875 / 883, 895 / 903, 915 / 923, 935 / 943, 955 / 963, 1181 / 1189, or 1205 / 1213, respectively.

62. The AAV particle of claim 56, wherein the epitope comprises:(a) an amino acid sequence heterologous to the AAV capsid; and / or(b) a c-myc amino acid sequence; and / or(c) the amino acid sequence set forth in SEQ ID NO: 1466.

63. The AAV particle of claim 44, wherein the first member of the protein:protein binding pair and the second member of the protein:protein binding pair form an isopeptide bond.

64. The AAV particle of claim 63, wherein:(a) the first member of the protein:protein binding pair comprises SpyTag, Isopeptag, SnoopTag, SpyTag002, SpyTag003, or any biologically active portion or variant thereof;(b) the second member of the protein:protein binding pair comprises(i) SpyCatcher, KTag, pilin-C, SnoopCatcher, SpyCatcher002,SpyCatcher003, or any biologically active portion or variant thereof, and(ii) a targeting ligand that binds a mammalian muscle cell-specific surface protein; and(c) the first member of the protein:protein binding pair and the second member of the protein:protein binding pair are linked by an isopeptide bond.

65. The AAV particle of claim 64, wherein(a) the first member of the protein:protein binding pair comprises SpyTag,(b) the second member of the protein:protein binding pair comprises:(i) SpyCatcher fused to(ii) a targeting ligand comprising a set of three HCDRs and a set of three LCDRs of an HCVR / LCVR pair as set forth in SEQ ID NOs: 615 / 623, 635 / 643, 655 / 663, 675 / 683, 695 / 703, 715 / 723, 735 / 743, 755 / 763, 775 / 783, 795 or 1351 / 803, 815 / 823, 835 / 843, 855 / 863, 875 / 883, 895 / 903, 915 / 923, 935 / 943, 955 / 963, 1181 / 1189, or 1205 / 1213, respectively; and(c) SpyTag and SpyCatcher are linked via an isopeptide bond.

66. The AAV particle of claim 64, wherein:(a) the first member of the protein:protein binding pair comprises SpyTag,(b) the second member of the protein:protein binding pair comprises:(i) SpyCatchcr fused to(ii) a targeting ligand comprising a first heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 1482, and a second heavy chain comprising the amino acid sequence set forth in SEQ ID NO: 1490; and(c) SpyTag and SpyCatcher are linked via an isopeptide bond.

67. A pharmaceutical composition comprising:(i) the AAV particle of claim 43, and(ii) a pharmaceutically acceptable carrier.

68. The pharmaceutical composition of claim 67, wherein the pharmaceutical composition comprises the AAV particle at a concentration between 2 x 1012vg / kg and 2 x 1014vg / kg.

69. A method of making a nucleic acid comprising a modified MTM1 gene sequence, the method comprising substituting a codon of a wildtype MTM1 gene sequence with a degenerate codon, wherein the modified MTM1 gene sequence encodes myotubularin comprising the amino acid sequence as set forth in SEQ ID NO: 1398.

70. A method of making a nucleic acid comprising a modified MHCK7 promoter sequence, the method comprising substituting at least one nucleotide of a wildtype MHCK7 promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, wherein the modified MHCK7 promoter sequence binds to transcriptional proteins and initiates transcription.

71. A method of making a modified MTM1 expression cassette, the method comprising operably linking a nucleic acid comprising a modified MTM1 gene sequence to a nucleic acid comprising a modified MHCK7 promoter sequence, wherein the modified MTM1 gene sequence comprises a substitution of a codon of a wildtype MTM1 gene sequence with a degenerate codon, and the modified MTM1 gene sequence encodes myotubularin comprising the amino acid sequence as set forth in SEQ ID NO: 1398, andwherein the modified MHCK7 promoter sequence comprises a substitution of at least one nucleotide of a wildtypc MHCK7 promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, and the modified MHCK7 promoter sequence binds to a transcriptional protein and initiates transcription in muscle cells.

72. The method of claim 71, wherein the nucleic acid comprising the modified MTM1 gene sequence comprises the nucleic acid of claim 1.

73. The method of claim 71, wherein the modified MHCK7 promoter sequence comprises the nucleic acid of claim 14.

74. A packaging cell for producing AAV particles, comprising an AAV vector genome comprising, from 5’ to 3’ and in operable linkage:(a) a 5’ AAV ITR sequence;(b) a modified MHCK7 promoter sequence, wherein the modified MHCK7 promoter sequence comprises a substitution of at least one nucleotide of a wildtype MHCK7 promoter sequence CpG site with at least one non-C / G nucleotide, such that the CpG site is removed, and the modified MHCK7 promoter sequence binds to a transcriptional protein and initiates transcription in muscle cells;(c) a modified MTM1 gene sequence, wherein the modified MTM1 gene sequence comprises a substitution of a codon of a wildtype MTM1 gene sequence with a degenerate codon, and the modified MTM1 gene sequence encodes myotubularin comprising the amino acid sequence set forth in SEQ ID NO: 1398; and(d) a 3’ AAV ITR sequence.

75. The packaging cell of claim 74, wherein the modified MHCK7 promoter sequence comprises the nucleic acid of claim 14.

76. The packaging cell of claim 74, wherein the modified MTM1 gene sequence comprises the nucleic acid of claim 1.

77. A method of making an AAV particle, the method comprising culturing the packaging cell of claim 74 in conditions sufficient to produce AAV particles.

78. A method of delivering an MTM1 protein to a mammalian muscle cell, the method comprising contacting the mammalian muscle cell with the pharmaceutical composition of claim 67.

79. The method of claim 78, wherein the mammalian muscle cell is in vitro.

80. The method of claim 78, wherein the mammalian muscle cell is in vivo.

81. The method of claim 78, wherein the mammalian muscle cell is a human muscle cell.

82. A method for treating X-linked Myotubular Myopathy (XLMTM) in a human subject in need thereof, the method comprising administering to the human subject a therapeutically effective amount of the pharmaceutical composition of claim 67.

83. Use of the pharmaceutical composition of claim 67 in the manufacture of a medicament for treating XLMTM in a subject in need thereof.

84. The pharmaceutical composition of claim 67 for use in the treatment of XLMTM in a subject in need thereof.

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