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 (TfR) antibody covalently linked to a molecular payload configured to reduce expression or activity of a pro-atrophy gene, wherein the antibody comprises:
a heavy chain variable region (VH) comprising an amino acid sequence at least 95% identical to SEQ ID NO: 77; and/or a light chain variable region (VL) comprising an amino acid sequence at least 95% identical to SEQ ID NO: 78.
2 . The complex of claim 1 , wherein the antibody comprises:
a VH comprising the amino acid sequence of SEQ ID NO: 77 and a VL comprising the amino acid sequence of SEQ ID NO: 78.
3 . The complex of claim 1 , wherein the antibody is selected from the group consisting of a Fab fragment, a Fab′ fragment, a F(ab′)2 fragment, a scFv, a Fv, and a full-length IgG,.
4 . The complex of claim 3 , wherein the antibody is a Fab fragment.
5 . The complex of claim 4 , wherein the antibody comprises:
a heavy chain comprising an amino acid sequence at least 85% identical to SEQ ID NO: 102; and/or a light chain comprising an amino acid sequence at least 85% identical to SEQ ID NO: 93.
6 . The complex of claim 4 , wherein the antibody comprises:
a heavy chain comprising the amino acid sequence of SEQ ID NO: 102; and a light chain comprising the amino acid sequence of SEQ ID NO: 93.
7 . The complex of claim 1 , wherein the antibody does not specifically bind to the transferrin binding site of the transferrin receptor and/or wherein the antibody does not inhibit binding of transferrin to the transferrin receptor.
8 . The complex of claim 1 , wherein the antibody is cross-reactive with extracellular epitopes of two or more of a human, non-human primate and rodent transferrin receptor.
9 . The complex of claim 1 , wherein the molecular payload is an oligonucleotide.
10 . The complex of claim 9 , wherein the oligonucleotide comprises a region of complementarity to the pro-atrophy gene, optionally wherein the pro-atrophy gene is INHBA, MSTN, TRIM63 or FBXO32.
11 . The complex of claim 1 , wherein the pro-atrophy gene encodes a non-secreted product that functions within muscle cells.
12 . The complex of claim 9 , wherein the oligonucleotide comprises at least one modified internucleoside linkage.
13 . The complex of claim 9 , wherein the oligonucleotide comprises one or more modified nucleosides.
14 . (canceled)
15 . The complex of claim 9 , wherein the oligonucleotide is a gapmer oligonucleotide that directs RNAse H-mediated cleavage of an mRNA transcript encoded by the pro-atrophy gene in a cell.
16 . (canceled)
17 . The complex of claim 9 , wherein the oligonucleotide is an RNAi oligonucleotide that promotes RNAi-mediated cleavage of a mRNA transcript encoded by the pro-atrophy gene.
18 - 20 . (canceled)
21 . The complex of claim 1 , wherein the antibody is covalently linked to the molecular payload via a cleavable linker, optionally wherein the cleavable linker comprises a valine citrulline sequence.
22 . (canceled)
23 . The complex of claim 1 , wherein the antibody is covalently linked to the molecular payload via conjugation to a lysine residue or a cysteine residue of the antibody.
24 . A method of reducing 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.
25 . The method of claim 24 , wherein the pro-atrophy gene is INHBA, MSTN, TRIM63 or FBXO32.
26 . 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 , optionally wherein the muscle disease is a disease listed in Table 1.