Muscle targeting complexes and uses thereof for treating facioscapulohumeral muscular 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 DUX4. In some embodiments, the molecular payload is an oligonucleotide, such as an antisense oligonucleotide or RNAi oligonucleotide.
1. A composition comprising complexes comprising an anti-transferrin receptor (TfR) antibody covalently linked to at least one siRNA, wherein the antibody is a Fab and comprises a heavy chain comprising the amino acid sequence of SEQ ID NO: 101 and a light chain comprising the amino acid sequence of SEQ ID NO: 90, and wherein each anti-TfR antibody of the complexes is on average covalently linked to 1 to 3 siRNAs, and wherein the siRNA targets a DUX4 RNA.
2. The composition of claim 1 , wherein the heavy chain of the antibody comprises an N-terminal pyroglutamate.
3. The composition of claim 2 , 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.
4. The composition of claim 1 , wherein the siRNA comprises an antisense strand comprising a region of complementarity to SEQ ID NO: 158, wherein the region of complementarity is 12-35 nucleotides in length.
5. The composition of claim 4 , wherein the antisense strand is 15-35 nucleotides in length.
6. The composition of claim 4 , wherein the antisense strand is 20-30 nucleotides in length.
7. The composition of claim 4 , wherein the siRNA comprises one or more modified nucleosides.
8. The composition of claim 7 , wherein the one or more modified nucleosides comprise 2′-modified nucleosides.
9. The composition of claim 1 , wherein the siRNA comprises one or more modified internucleoside linkages.
10. The composition of claim 1 , wherein the siRNA comprises one or more phosphorothioate internucleoside linkages.
11. The composition of claim 1 , wherein the antibody and the molecular payload are covalently linked via a linker.
12. The composition of claim 11 , wherein the linker comprises a cleavable linker.
13. The composition of claim 11 , wherein the linker comprises a valine-citrulline sequence.
14. The composition of claim 1 , wherein the complex comprises a structure of:
wherein n is 3 and m is 4, wherein L1 comprises a spacer that is a substituted or unsubstituted aliphatic, substituted or unsubstituted heteroaliphatic, substituted or unsubstituted carbocyclylene, substituted or unsubstituted heterocyclylene, substituted or unsubstituted arylene, substituted or unsubstituted heteroarylene, —O—, —N(R A )—, —S—, —C(═O)—, —C(═O)O—, —C(═O)NR A —, —NR A C(═O)—, —NR A C(═O)R A —, —C(═O)R A —, —NR A C(═O)O—, —NR A C(═O)N(R A )—, —OC(═O)—, —OC(═O)O—, —OC(═O)N(R A )—, —S(O) 2 NR A —, —NRAS(O) 2 —, or a combination thereof, wherein each R A is independently hydrogen or substituted or unsubstituted alkyl.
15. The composition of claim 14 , wherein L1 comprises
16. A method of reducing DUX4 expression in muscle cells of a subject, the method comprising administering to the subject the composition of claim 1 .
17. The method of claim 16 , wherein the subject is human.
18. The method of claim 16 , wherein the subject is a cynomolgus.
19. The method of claim 16 , wherein the subject has one or more deletions of a D4Z4 repeat in chromosome 4.
20. The method of claim 16 , wherein the complex is intravenously administered to the subject.
21. The method of claim 16 , wherein the subject has facioscapulohumeral muscular dystrophy (FSHD).
22. The method of claim 16 , wherein the heavy chain of the antibody comprises an N-terminal pyroglutamate.