MUSCLE TARGETING COMPLEXES AND USES THEREOF FOR TREATING MYOTONIC DYSTROPHY
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 expression or activity of a DMPK allele comprising a disease-associated-repeat. 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 inhibiting DMPK expression or activity, 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 a region of complementarity to at least 15 consecutive nucleotides of SEQ ID NO: 727.
9 . The complex of claim 7 , wherein the oligonucleotide comprises a region of complementarity to at least 15 consecutive nucleotides of any one of SEQ ID NO: 482-717.
10 . The complex of claim 7 , wherein the oligonucleotide comprises at least 15 consecutive nucleotides of a sequence comprising any one of SEQ ID NOs: 246-481 and 778-795.
11 . The complex of claim 7 , wherein the oligonucleotide comprises at least one modified internucleoside linkage.
12 . The complex of claim 7 , wherein the oligonucleotide comprises one or more modified nucleosides.
13 . The complex of claim 7 , wherein the oligonucleotide is a gapmer oligonucleotide that directs RNAse H-mediated cleavage of a DMPK mRNA transcript.
14 . The complex of claim 13 , wherein the gapmer oligonucleotide comprises a 5′-X-Y-Z-3′ formula, and wherein:
X comprises 3-5 linked nucleosides, wherein at least one of the nucleosides in X is a 2′-modified nucleoside;
Y comprises 6-10 linked 2′-deoxyribonuclsides, wherein one or more of the nucleosides in the gap region Y is a modified nucleoside, and wherein one or more cytosines in the gap region Y are optionally 5-methyl-cytosines; and
Z comprises 3-5 linked nucleosides, wherein at least one of the nucleosides in Z is a 2′-modified nucleoside.
15 . The complex of claim 14 , wherein each nucleoside in X and Z is a 2′modified nucleoside.
16 . The complex of claim 12 , 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.
17 . The complex of claim 1 , wherein the muscle-targeting agent is covalently linked to the molecular payload via
(i) a cleavable linker; or
(ii) a non-cleavable linker.
18 . 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.
19 . A method of inhibiting activity of DMPK 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 an expansion of a disease-associated-repeat of a DMPK allele that is associated with myotonic dystrophy type 1 (DM1), the method comprising administering to the subject an effective amount of the complex of claim 1 .