Compositions and methods of treating muscle atrophy and myotonic dystrophy

1. A small interfering RNA (siRNA) conjugate comprising an anti-transferrin receptor antibody or antigen-binding fragment thereof conjugated to an siRNA that hybridizes to a target sequence in exons 1-13 of human DMPK mRNA excluding CUG repeats and mediates RNA interference against the human DMPK mRNA preferentially in a muscle cell in a subject, wherein the siRNA is a double stranded RNA comprising a guide strand and a passenger strand.

2. The siRNA conjugate of claim 1 , wherein the siRNA comprises at least one 2′ modified nucleotide, at least one modified internucleotide linkage, or at least one inverted abasic moiety.

3. The siRNA conjugate of claim 1 , wherein mediation of RNA interference against the human DMPK mRNA modulates muscle atrophy or myotonic dystrophy in the subject.

4. The siRNA conjugate of claim 1 , wherein the anti-transferrin receptor antibody or antigen binding fragment thereof binds to a transferrin receptor on cell surface of the muscle cell.

5. The siRNA conjugate of claim 1 , wherein each of the guide strand and the passenger strand of the siRNA is 8 to 30 nucleotides in length.

6. The siRNA conjugate of claim 1 , wherein the siRNA hybridizes to at least 8 contiguous nucleotides of the target sequence in the exons 1-13 of the human DMPK mRNA.

7. The siRNA conjugate of claim 1 , wherein the siRNA conjugate comprises a linker connecting the anti-transferrin receptor antibody or antigen binding fragment thereof to the siRNA.

8. The siRNA conjugate of claim 2 , wherein the at least one 2′ modified nucleotide:

comprises 2′-O-methyl, 2′-O-methoxyethyl (2′-O-MOE), 2′-O-aminopropyl, 2′-deoxy, 2′-deoxy-2′-fluoro, 2′-O-aminopropyl (2′-O-AP), 2′-O-dimethylaminoethyl (2′-O-DMAOE), 2′-O-dimethylaminopropyl (2′-O-DMAP), 2′-O-dimethylaminoethyloxyethyl (2′-O-DMAEOE), or 2′-O—N-methylacetamido (2′-O—NMA) modified nucleotide;

comprises locked nucleic acid (LNA) or ethylene nucleic acid (ENA); or

comprises a combination thereof.

9. The siRNA conjugate of claim 2 , wherein the at least one modified internucleotide linkage comprises a phosphorothioate linkage or a phosphorodithioate linkage.

10. The siRNA conjugate of claim 2 , wherein the siRNA comprises 3 or more 2′ modified nucleotides selected from 2′-O-methyl and 2′-deoxy-2′-fluoro.

11. The siRNA conjugate of claim 1 , wherein the siRNA conjugate has a drug to antibody ratio of from about 1 to about 4.

12. The siRNA conjugate of claim 1 , wherein the siRNA comprises a 5′-terminal vinylphosphonate modified nucleotide.

13. The siRNA conjugate of claim 1 , wherein the anti-transferrin receptor antibody or antigen-binding fragment thereof comprises a humanized antibody or antigen-binding fragment thereof, chimeric antibody or antigen-binding fragment thereof, monoclonal antibody or antigen-binding fragment thereof, monovalent Fab′, divalent Fab2, single-chain variable fragment (scFv), diabody, minibody, nanobody, single-domain antibody (sdAb), or camelid antibody or antigen-binding fragment thereof.

14. The siRNA conjugate of claim 3 , wherein the muscle atrophy is associated with myotonic dystrophy type 1 (DM1).

15. The siRNA conjugate of claim 3 , wherein the myotonic dystrophy is DM1.

16. The siRNA conjugate of claim 1 , wherein the siRNA conjugate is formulated for parenteral administration.

17. The siRNA conjugate of claim 1 , wherein the guide strand of the siRNA is selected from a group consisting of SEQ ID NOs: 6111-8814, 11519-14222.

18. The siRNA conjugate of claim 1 , wherein the passenger strand of the siRNA is selected from a group consisting of SEQ ID NOs: 3407-6110, 8815-11518.

19. The siRNA conjugate of claim 1 , wherein the guide strand of the siRNA that hybridizes to a target sequence in exons 2-13 of the human DMPK mRNA is selected from SEQ ID NOs: 11903, 11961, 11962, 11963, 12051, 12052, 12053, 12057, 12058, 12059, 12061, 12062, 12094, 12095, 12099, 12101, 12102, 12208, 12234, 12235, 12303, 12304, 12307, 12544, 12545, 12546, 12547, 12555, 12557, 12559, 12561, 12562, 12565, 12589, 12591, 12780, 12781, 12782, 12783, 12785, 12786, 12787, 12792, 12794, 12801, 12815, 12860, 12861, 12862, 12864, 13343, 13404, 13408, 13416, 13463, 13478, 13644, 13645, 13667, 13668, 13786, 13790, 14046, 14047, 14048, 14049, 14050, 14072, 14076, 14118, 14146, 14147, 14149, 14154, 14157, 14193, 14194, 14197, 14198, 14199, and 14200.

20. The siRNA conjugate of claim 1 , wherein the passenger strand of the siRNA that hybridizes to a target sequence in exons 2-13 of the human DMPK mRNA is selected from SEQ ID NOs: 9199, 9257, 9258, 9259, 9347, 9348, 9349, 9353, 9354, 9355, 9357, 9358, 9390, 9391, 9395, 9397, 9398, 9504, 9530, 9531, 9599, 9600, 9603, 9840, 9841, 9842, 9843, 9851, 9853, 9855, 9857, 9858, 9861, 9885, 9887, 10076, 10077, 10078, 10079, 10081, 10082, 10083, 10088, 10090, 10097, 10111, 10156, 10157, 10158, 10160, 10639, 10700, 10704, 10712, 10759, 10774, 10940, 10941, 10963, 10964, 11082, 11086, 11342, 11343, 11344, 11345, 11346, 11368, 11372, 11414, 11442, 11443, 11445, 11450, 11453, 11489, 11490, 11493, 11494, 11495, and 11496.

21. The siRNA conjugate of claim 19 , wherein guide strand of the siRNA that hybridizes to a target sequence in exons 4, 5, and 6 of the human DMPK mRNA is selected from SEQ ID NOs: 12102, 12234, 12303, 12304, and 12307.

22. The siRNA conjugate of claim 20 , wherein the passenger strand of the siRNA that hybridizes to a target sequence in exons 4, 5, and 6 of the human DMPK mRNA is selected from SEQ ID NOs: 9398, 9530, 9599, 9600, and 9603.

23. The siRNA conjugate of claim 19 , wherein the guide strand of the siRNA that hybridizes to a target sequence in exons 7 and 8 of the human DMPK mRNA is selected from SEQ ID NOs: 12544, 12545, 12546, 12547, 12555, 12557, 12559, 12561, 12562, 12565, 12589, 12783 and 12815.

24. The siRNA conjugate of claim 20 , wherein the passenger strand of the siRNA that hybridizes to a target sequence in exons 7 and 8 of the human DMPK mRNA is selected from SEQ ID NOs: 9840, 9841, 9842, 9843, 9851, 9853, 9855, 9857, 9858, 9861, 9885, 10079 and 10111.

25. The siRNA conjugate of claim 19 , wherein the guide strand of the siRNA that hybridizes to a target sequence in exon 9 of the human DMPK mRNA is selected from SEQ ID NOs: 12860, 12861, 12862, and 12864.

26. The siRNA conjugate of claim 20 , wherein the passenger strand of the siRNA that hybridizes to a target sequence in exon 9 of the human DMPK mRNA is selected from SEQ ID NOs: 10156, 10157, 10158, and 10160.

27. The siRNA conjugate of claim 19 , wherein the guide strand of the siRNA that hybridizes to a target sequence in exon 13 of the human DMPK mRNA is selected from SEQ ID NOs: 13343, 13463, 13478, 14047, 14048, 14049, 14072, 14146, 14147, 14199, and 14200.

28. The siRNA conjugate of claim 20 , wherein the passenger strand of the siRNA that hybridizes to a target sequence in exon 13 of the human DMPK mRNA is selected from SEQ ID NOs: 10639, 10759, 10774, 11343, 11344, 11345, 11368, 11442, 11443, 11495, and 11496.

29. A method of treating myotonic dystrophy in a subject in need thereof, comprising:

administering to said subject a therapeutically effective amount of a small interfering RNA (siRNA) conjugate comprising an anti-transferrin receptor antibody or antigen binding fragment thereof conjugated to an siRNA that hybridizes to a target sequence in exons 1-13 of human DMPK mRNA excluding CUG repeats, wherein the siRNA is 8 to 30 nucleotides in length, thereby treating myotonic dystrophy in said subject.

30. The method of claim 29 , wherein the myotonic dystrophy is myotonic dystrophy type 1 (DM1).