MUSCLE TARGETING COMPLEXES AND USES THEREOF FOR MODULATION OF GENES ASSOCIATED WITH MUSCLE HEALTH
Aspects of the disclosure relate to molecular payloads that modulate the expression or activity of genes involved in muscle growth and maintenance (e.g., MSTN, INHBA, and/or ACVR1B), and complexes comprising a muscle-targeting agent covalently linked to such molecular payloads. In some embodiments, the muscle-targeting agent specifically binds to an internalizing cell surface receptor on a muscle cell (e.g., a cardiac muscle cell). In some embodiments, the molecular payload is an oligonucleotide, such as an antisense oligonucleotide or RNAi oligonucleotide.
1 . A complex comprising a muscle-targeting agent covalently linked to a molecular payload that modulates the expression or activity of myostatin (MSTN), inhibin beta A (INHBA) and/or activin receptor type-1B (ACVR1B), wherein the muscle-targeting agent specifically binds to an internalizing cell surface receptor on a muscle cell.
2 . The complex of claim 1 , wherein the muscle cell is a cardiac muscle cell.
3 . (canceled)
4 . The complex of claim 1 , 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.
5 . 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.
6 . 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.
7 . 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.
8 . 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.
9 . 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.
10 . The complex of claim 1 , wherein the molecular payload is an oligonucleotide comprising an antisense strand comprising a region of complementarity to an MSTN target sequence.
11 . The complex of claim 10 , wherein the antisense strand comprises at least 16 consecutive nucleotides of a nucleotide sequence set forth in any one of SEQ ID NOs: 350-373.
12 . The complex of claim 1 , wherein the molecular payload is an oligonucleotide comprising an antisense strand comprising a region of complementarity to an INHBA target sequence.
13 . The complex of claim 12 , wherein the antisense strand comprises at least 16 consecutive nucleotides of a nucleotide sequence set forth in any one of SEQ ID NOs: 472-495.
14 . The complex of claim 1 , wherein the molecular payload is an oligonucleotide comprising an antisense strand comprising a region of complementarity to an ACVR1B target sequence.
15 . The complex of claim 14 , wherein the antisense strand comprises at least 16 consecutive nucleotides of a nucleotide sequence set forth in any one of SEQ ID NOs: 496-519.
16 . The complex of claim 10 , wherein the oligonucleotide further comprises a sense strand that hybridizes to the antisense strand to form a double stranded siRNA.
17 . The complex of claim 10 , wherein the oligonucleotide comprises one or more modified nucleosides.
18 . The complex of claim 17 , wherein the one or more modified nucleosides are 2′ modified nucleotides.
19 . The complex of claim 10 , wherein the oligonucleotide comprises one or more phosphorothioate internucleoside linkages.
20 .- 23 . (canceled)
24 . A method of reducing MSTN, INHBA, and/or ACVR1B expression in a muscle cell, the method comprising contacting the muscle cell with an effective amount of the complex of any one of claim 1 for promoting internalization of the molecular payload to the muscle cell.
25 . A method of treating muscle atrophy the method comprising administering to a subject in need thereof an effective amount of the complex of any one of claim 1 , wherein the subject has elevated expression or activity of MSTN, INHBA, and/or ACVR1B.
26 . (canceled)