MUSCLE TARGETING COMPLEXES AND USES THEREOF FOR TREATING DYSTROPHINOPATHIES
Aspects of the disclosure relate to complexes comprising a muscle-targeting agent covalently linked to a molecular payload. In some embodiments, the muscle-targeting agent specifically binds to an internalizing cell surface receptor on muscle cells. In some embodiments, the molecular payload promotes the expression or activity of a functional dystrophin protein. In some embodiments, the molecular payload is an oligonucleotide, such as an antisense oligonucleotide, e.g., an oligonucleotide that causes exon skipping in a mRNA expressed from a mutant DMD allele.
1 . A complex comprising an anti-transferrin receptor antibody covalently linked to a molecular payload configured for inducing skipping of an exon in a dystrophin (DMD) mRNA, wherein the antibody comprises a heavy chain complementarity determining region 1 (CDR-H1), a heavy chain complementarity determining region 2 (CDR-H2), a heavy chain complementarity determining region 3 (CDR-H3) of a heavy chain variable region (VH) comprising the amino acid sequence of SEQ ID NO: 54, and a light chain complementarity determining region 1 (CDR-L1), a light chain complementarity determining region 2 (CDR-L2), a light chain complementarity determining region 3 (CDR-L3) of a light chain variable region (VL) comprising the amino acid sequence of SEQ ID NO: 55.
2 . The complex of claim 1 , wherein the antibody comprises a CDR-H1 of SEQ ID NO: 49, a CDR-H2 of SEQ ID NO: 50, a CDR-H3 of SEQ ID NO: 51, a CDR-L1 of SEQ ID NO: 52, a CDR-L2 of SEQ ID NO: 29, and a CDR-L3 of SEQ ID NO: 53.
3 . The complex of claim 1 , wherein the antibody comprises human or humanized framework regions with the CDR-H1, the CDR-H2, the CDR-H3 of a VH as set forth in SEO ID NO: 54, and the CDR-L1, the CDR-L2, the CDR-L3 of a VL as set forth in SEO ID NO: 55.
4 . The complex of claim 1 , wherein the antibody comprises a VH comprising an amino acid sequence at least 80% identical to SEQ ID NO: 54, and a VL comprising an amino acid sequence at least 80% identical to SEQ ID NO: 55.
5 . The complex of claim 1 , wherein the equilibrium dissociation constant (K D ) of binding of the antibody to the transferrin receptor is in a range from 10 −11 to 10 −6 M.
6 . The complex of claim 1 , wherein the antibody is selected from a full-length IgG, a Fab fragment, a F(ab′) fragment, a F(ab′)2 fragment, a scFv, and a Fv.
7 . The complex of claim 1 , wherein the molecular payload is an oligonucleotide.
8 . The complex of claim 7 , wherein the oligonucleotide comprises a region of complementarity of at least 15 nucleotides to a DMD mRNA.
9 . The complex of claim 7 , wherein the oligonucleotide comprises at least 15 consecutive nucleotides any one of SEQ ID NOs: 257-508.
10 . The complex of claim 7 , wherein the oligonucleotide comprises one or more modified nucleosides.
11 . The complex of claim 10 , wherein the oligonucleotide is phosphorodiamidite morpholino oligomer.
12 . The complex of claim 1 , wherein the molecular payload induces skipping of exon 8, exon 23, exon 44, exon 45, exon 50, exon 51, exon 52, exon 53, or exon 55.
13 . The complex of claim 1 , wherein the antibody is covalently linked to the molecular payload via
(i) a cleavable linker,
(ii) a non-cleavable linker.
14 . The complex of claim 1 , wherein the molecular payload is linked to the antibody via conjugation to a lysine residue or a cysteine residue of the antibody.
15 . The complex of claim 1 , wherein the molecular payload promotes the expression or activity of a functional dystrophin protein.
16 . A method of inducing skipping of an exon in a DMD mRNA in a muscle cell, the method comprising contacting the muscle cell with the complex of claim 1 in an amount effective for promoting internalization of the molecular payload to the cell.
17 . The method of claim 16 , wherein the cell comprises a DMD mRNA transcript comprising one or more frameshift mutations.
18 . A method of promoting the expression or activity of a DMD protein in a cell, the method comprising contacting the cell with the complex of claim 1 in an amount effective for promoting internalization of the molecular payload to the cell.
19 . A method of treating a subject with DMD, the method comprising administering to the subject an effective amount of the complex of claim 1 , wherein the subject has a mutated DMD mRNA allele that is associated with dystrophinopathy.
20 . The method of claim 19 , wherein the administration is via intravenous infusion.