Muscle targeting complexes and uses thereof for treating facioscapulohumeral muscular dystrophy

Abstract

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 .- 94 . (canceled) 
     
     
         95 . An anti-transferrin receptor antibody, wherein the antibody comprises a lysine residue covalently linked via a linker comprising a cleavable valine-citrulline sequence to a molecular payload configured for modulating DUX4 activity, wherein the antibody binds in the range of C89 to F760 of human transferrin receptor protein 1 (TfR1) having an amino acid sequence as set forth in SEQ ID NO: 1, and wherein the antibody comprises:
 a heavy chain variable region (VH) comprising a heavy chain complementarity determining region 1 (CDR-H1), a heavy chain complementarity determining region 2 (CDR-H2), and a heavy chain complementarity determining region 3 (CDR-H3); and   a light chain variable region (VL) comprising a light chain complementarity determining region 1 (CDR-L1), a light chain complementarity determining region 2 (CDR-L2), and a light chain complementarity determining region 3 (CDR-L3).   
     
     
         96 . The anti-transferrin receptor antibody of  claim 95 , wherein the molecular payload is a small molecule or a peptide. 
     
     
         97 . The anti-transferrin receptor antibody of  claim 95 , wherein the anti-transferrin receptor antibody is in the form of a Fab fragment, Fab′ fragment, F(ab′)2 fragment, ScFv, or Fv fragment. 
     
     
         98 . A complex comprising an anti-transferrin receptor antibody covalently linked to an oligonucleotide that targets a DUX4 RNA,
 wherein the oligonucleotide is 15 to 35 nucleotides in length and comprises a region of complementarity to a DUX4 RNA sequence as set forth in Genbank Accession No. NM_001293798.1, wherein the region of complementarity is at least 12 nucleotides in length; and   wherein the anti-transferrin receptor antibody binds in the range of C89 to F760 of human transferrin receptor protein 1 (TfR1) having an amino acid sequence as set forth in SEQ ID NO: 1.   
     
     
         99 . The complex of  claim 98 , wherein the anti-transferrin receptor antibody is in the form of a ScFv, Fab fragment, Fab′ fragment, F(ab′)2 fragment, or Fv fragment. 
     
     
         100 . The complex of  claim 98 , wherein the anti-transferrin receptor antibody binds human TfR1 with a K D  of 10 −11  M to 10 −6  M. 
     
     
         101 . The complex of  claim 98 , wherein the anti-transferrin receptor antibody is a humanized antibody. 
     
     
         102 . The complex of  claim 98 , wherein the oligonucleotide targets a 3′ UTR region of the DUX4 RNA. 
     
     
         103 . The complex of  claim 98 , wherein the anti-transferrin receptor is covalently linked to the oligonucleotide via a cleavable linker. 
     
     
         104 . The complex of  claim 102 , wherein the cleavable linker comprises a valine-citrulline sequence. 
     
     
         105 . The complex of  claim 98 , wherein the anti-transferrin receptor antibody is covalently linked to the oligonucleotide via conjugation to a lysine residue or a cysteine residue of the anti-transferrin receptor antibody. 
     
     
         106 . The complex of  claim 98 , wherein the complex is configured to promote transferrin receptor mediated internalization of the oligonucleotide into a muscle cell. 
     
     
         107 . A method of reducing expression level of DUX4 in a muscle cell, the method comprising contacting the muscle cell with the complex of  claim 98 . 
     
     
         108 . A method of treating facioscapulohumeral muscular dystrophy (FSHD) in a subject having one or more deletions of D4Z4 repeats in chromosome 4, the method comprising administering to the subject a complex comprising an anti-transferrin receptor antibody covalently linked to an oligonucleotide that targets a DUX4 RNA,
 wherein the oligonucleotide is 15 to 35 nucleotides in length and comprises a region of complementarity to the DUX4 RNA, wherein the region of complementarity is at least 12 nucleotides in length; and   wherein the anti-transferrin receptor antibody in the range of C89 to F760 of human transferrin receptor protein 1 (TfR1) having an amino acid sequence as set forth in SEQ ID NO: 1.