MUSCLE-TARGETING COMPLEXES AND USES THEREOF IN TREATING MUSCLE ATROPHY
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 inhibits activity of a pro-atrophy gene. In some embodiments, the molecular payload is an oligonucleotide, such as an antisense oligonucleotide or RNAi oligonucleotide.
1 . A complex comprising an anti-transferrin receptor antibody covalently linked to a molecular payload configured for to inhibit expression or activity of a pro-atrophy gene, 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 SEQ ID NO: 54, and the CDR-L1, the CDR-L2, the CDR-L3 of a VL as set forth in SEQ 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 M to 10 −6 M.
6 . The complex of claim 1 , wherein the antibody is selected from the group consisting of 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 at least one modified internucleoside linkage.
9 . The complex of claim 8 , wherein the at least one modified internucleoside linkage is a phosphorothioate linkage.
10 . The complex of claim 7 , wherein the oligonucleotide comprises one or more modified nucleotides.
11 . The complex of claim 10 , wherein the one or more modified nucleotides are 2′-modified nucleotides.
12 . The complex of claim 11 , wherein the 2′ modified nucleotide is selected from the group consisting of: 2′-O-methyl (2′-O-Me), 2′-fluoro (2′-F), 2′-O-methoxyethyl (2′-MOE), and 2′,4′-bicyclic nucleosides.
13 . The complex of claim 7 , wherein the oligonucleotide is a gapmer oligonucleotide that directs RNAse H-mediated cleavage of an mRNA transcript encoded by the muscle disease gene in a cell.
14 . The complex of claim 7 , wherein the oligonucleotide is a mixmer oligonucleotide.
15 . The complex of claim 7 , wherein the oligonucleotide is an RNAi oligonucleotide that promotes RNAi-mediated cleavage of a mRNA transcript encoded by the muscle disease gene.
16 . The complex of claim 7 , wherein the oligonucleotide is a phosphorodiamidate morpholino oligomer (PMO).
17 . The complex of claim 1 , wherein the antibody is covalently linked to the molecular payload via a cleavable linker.
18 . A method of delivering a molecular payload to a cell expressing transferrin receptor, the method comprising contacting the cell with the complex of claim 1 .
19 . A method of inhibiting expression or activity of a pro-atrophy gene 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.
20 . A method of treating a subject having muscle atrophy, the method comprising administering to the subject an effective amount of the complex of claim 1 .