MUSCLE TARGETING COMPLEXES AND USES THEREOF FOR TREATING MYOTONIC DYSTROPHY

1 . A composition comprising a plurality of complexes comprising an antibody covalently linked to one or more oligonucleotides, each oligonucleotide being covalently linked at a linkage site represented by a lysine (K) residue of the antibody,

wherein the antibody comprises a heavy chain comprising a heavy chain variable region (VH) and a heavy chain constant region, and a light chain comprising a light chain variable region (VL) and a light chain constant region,

wherein the oligonucleotide comprises a region of complementarity to a DMPK RNA,

and wherein at least 80% of the light chain constant regions of the antibodies of the complexes in the composition are independently covalently linked to an oligonucleotide at a linkage site represented by K188 (based on Kabat numbering) and/or a linkage site represented by K190 (based on Kabat numbering) of the light chain constant regions of the antibodies.

2 . A composition comprising a plurality of complexes comprising an antibody covalently linked to one or more oligonucleotides, each oligonucleotide being covalently linked at a linkage site represented by a lysine (K) residue of the antibody,

wherein the antibody comprises a heavy chain comprising a heavy chain variable region (VH) and a heavy chain constant region, and a light chain comprising a light chain variable region (VL) and a light chain constant region,

wherein the oligonucleotide comprises a 5′-X—Y—Z-3′ configuration, wherein X and Z are flanking regions comprising one or more modified nucleosides and Y is a gap region comprising one or more 2′-deoxyribonucleosides,

and wherein at least 80% of the light chain constant regions of the antibodies of the complexes in the composition are independently covalently linked to an oligonucleotide at a linkage site represented by K188 (based on Kabat numbering) and/or a linkage site represented by K190 (based on Kabat numbering) of the light chain constant regions of the antibodies.

3 . The composition of claim 1 or claim 2 , wherein about 1%-15% of the heavy chain constant regions of the antibodies of the complexes in the composition are independently covalently linked to an oligonucleotide at a linkage site represented by K213 (based on Kabat numbering) of the heavy chain constant regions of the antibodies.

4 . The composition of any one of claims 1-3 , wherein the antibody is an anti-transferrin receptor (TfR1) antibody comprising: a heavy chain complementarity determining region 1 (CDR-H1) comprising a sequence as set forth in SEQ ID NOs: 1, 7, or 12, a heavy chain complementarity determining region 2 (CDR-H2) comprising a sequence as set forth in SEQ ID NOs: 2, 8, or 13, a heavy chain complementarity determining region 3 (CDR-H3) comprising a sequence as set forth in SEQ ID NOs: 3, 9, or 14, a light chain complementarity determining region 1 (CDR-L1) comprising a sequence as set forth in SEQ ID NOs: 4, 10, or 15, a light chain complementarity determining region 2 (CDR-L2) comprising a sequence as set forth in SEQ ID NOs: 5 or 11, and a light chain complementarity determining region 3 (CDR-L3) comprising a sequence as set forth in SEQ ID NOs: 6 or 16.

5 . The composition of any one of claims 1-4 , wherein the oligonucleotide comprises a 5′-X—Y—Z-3′ configuration wherein X and Z each comprise 4 linked nucleosides and Y comprises 8 linked nucleosides, optionally wherein the oligonucleotide comprises a 5′-X—Y—Z-3′ configuration of LLEE-D8-EELL, wherein “L” represents an LNA nucleoside, “E” represents a 2′-MOE modified ribonucleoside, and “D” represents a 2′-deoxyribonucleoside.

6 . The composition of any one of claims 1-5 , wherein the oligonucleotide comprises a nucleobase sequence of CAGCGCCCACCAGUCA (SEQ ID NO: 21), optionally wherein the oligonucleotide comprises the structure +C*+A*OG*oC*dG*dC*dC*dC*dA*dC*dC*dA*OG*OU*+C*+A (SEQ ID NO: 21), wherein +N represents an LNA (2′-4′ methylene bridge) ribonucleoside, dN represents a 2′-deoxyribonucleoside, oN represents a 2′-MOE modified ribonucleoside, oC represents a 5-methyl-2′-MOE-cytidine, +C represents a 5-methyl-2′-4′-bicyclic-cytidine (2′-4′ methylene bridge), oU represents a 5-methyl-2′-MOE-uridine, and * represents a phosphorothioate internucleoside linkage.

7 . A composition comprising a plurality of complexes comprising a structure of formula (I): [R 1 ] n1 —R 2 , wherein each R 1 independently comprises a group of the formula (Ia):

wherein R 2 comprises an anti-transferrin receptor (TfR1) antibody comprising a heavy chain comprising a heavy chain variable region (VH) and a heavy chain constant region, and a light chain comprising a light chain variable region (VL) and a light chain constant region; and wherein the anti-TfR1 antibody comprises: a heavy chain complementarity determining region 1 (CDR-H1) comprising a sequence as set forth in SEQ ID NOs: 1, 7, or 12, a heavy chain complementarity determining region 2 (CDR-H2) comprising a sequence as set forth in SEQ ID NOs: 2, 8, or 13, a heavy chain complementarity determining region 3 (CDR-H3) comprising a sequence as set forth in SEQ ID NOs: 3, 9, or 14, a light chain complementarity determining region 1 (CDR-L1) comprising a sequence as set forth in SEQ ID NOs: 4, 10, or 15, a light chain complementarity determining region 2 (CDR-L2) comprising a sequence as set forth in SEQ ID NOs: 5 or 11, and a light chain complementarity determining region 3 (CDR-L3) comprising a sequence as set forth in SEQ ID NOs: 6 or 16;

wherein R 3 comprises a structure of +C*+A*OG*oC*dG*dC*dC*dC*dA*dC*dC*dA*G*OU*+C*+A (SEQ ID NO: 21), wherein +N represents an LNA (2′-4′ methylene bridge) ribonucleoside, dN represents a 2′-deoxyribonucleoside, oN represents a 2′-MOE modified ribonucleoside, oC represents a 5-methyl-2′-MOE-cytidine, +C represents a 5-methyl-2′-4′-bicyclic-cytidine (2′-4′ methylene bridge), oU represents a 5-methyl-2′-MOE-uridine, and * represents a phosphorothioate internucleoside linkage;

wherein each R 1 is covalently linked at attachment point A to R 2 via a linkage site represented by a lysine (K) residue of the anti-TfR1 antibody, and wherein, at least 80% of the light chain constant regions of the anti-TfR1 antibodies of the complexes in the composition are independently covalently linked to R 1 at a linkage site represented by K188 (based on Kabat numbering) and/or a linkage site represented by K190 (based on Kabat numbering) of the light chain constant regions of the anti-TfR1 antibodies; and

wherein in each complex of the plurality of complexes, n1 is independently an integer of one or greater representing the number of instances of R 1 .

8 . A composition comprising a plurality of complexes comprising a structure of formula (I): [R 1 ] n1 —R 2 , wherein each R 1 independently comprises a group of the formula (Ib):

in which +N represents an LNA (2′-4′ methylene bridge) ribonucleoside, dN represents a 2′-deoxyribonucleoside, oN represents a 2′-MOE modified ribonucleoside, oC represents a 5-methyl-2′-MOE-cytidine, +C represents a 5-methyl-2′-4′-bicyclic-cytidine (2′-4′ methylene bridge), oU represents a 5-methyl-2′-MOE-uridine, and * represents a phosphorothioate internucleoside linkage, and the oligonucleotide of R 1 comprises a nucleobase sequence of CAGCGCCCACCAGUCA (SEQ ID NO: 21);

wherein R 2 comprises an anti-transferrin receptor (TfR1) antibody comprising a heavy chain comprising a heavy chain variable region (VH) and a heavy chain constant region, and a light chain comprising a light chain variable region (VL) and a light chain constant region; and wherein the anti-TfR1 antibody comprises: a heavy chain complementarity determining region 1 (CDR-H1) comprising a sequence as set forth in SEQ ID NOs: 1, 7, or 12, a heavy chain complementarity determining region 2 (CDR-H2) comprising a sequence as set forth in SEQ ID NOs: 2, 8, or 13, a heavy chain complementarity determining region 3 (CDR-H3) comprising a sequence as set forth in SEQ ID NOs: 3, 9, or 14, a light chain complementarity determining region 1 (CDR-L1) comprising a sequence as set forth in SEQ ID NOs: 4, 10, or 15, a light chain complementarity determining region 2 (CDR-L2) comprising a sequence as set forth in SEQ ID NOs: 5 or 11, and a light chain complementarity determining region 3 (CDR-L3) comprising a sequence as set forth in SEQ ID NOs: 6 or 16; and

wherein each R 1 is covalently linked at attachment point A to R 2 via a linkage site represented by a lysine (K) residue of the anti-TfR1 antibody, and wherein, at least 80% of the light chain constant regions of the anti-TfR1 antibodies of the complexes in the composition are independently covalently linked to R 1 at a linkage site represented by K188 (based on Kabat numbering) and/or a linkage site represented by K190 (based on Kabat numbering) of the light chain constant regions of the anti-TfR1 antibodies; and

wherein in each complex of the plurality of complexes, n1 is independently an integer of one or greater representing the number of instances of R 1 .

9 . A composition comprising a plurality of complexes comprising a structure of formula (I): [R 1 ] n1 —R 2 , wherein: each R 1 comprises a group of the formula (Ic):

wherein R 2 comprises an anti-transferrin receptor (TfR1) antibody comprising a heavy chain comprising a heavy chain variable region (VH) and a heavy chain constant region, and a light chain comprising a light chain variable region (VL) and a light chain constant region; and wherein the anti-TfR1 antibody comprises: a heavy chain complementarity determining region 1 (CDR-H1) comprising a sequence as set forth in SEQ ID NOs: 1, 7, or 12, a heavy chain complementarity determining region 2 (CDR-H2) comprising a sequence as set forth in SEQ ID NOs: 2, 8, or 13, a heavy chain complementarity determining region 3 (CDR-H3) comprising a sequence as set forth in SEQ ID NOs: 3, 9, or 14, a light chain complementarity determining region 1 (CDR-L1) comprising a sequence as set forth in SEQ ID NOs: 4, 10, or 15, a light chain complementarity determining region 2 (CDR-L2) comprising a sequence as set forth in SEQ ID NOs: 5 or 11, and a light chain complementarity determining region 3 (CDR-L3) comprising a sequence as set forth in SEQ ID NOs: 6 or 16; and

wherein each R 1 is covalently linked at attachment point A to R 2 via a linkage site represented by a lysine (K) residue of the anti-TfR1 antibody, and wherein, at least 80% of the light chain constant regions of the anti-TfR1 antibodies of the complexes in the composition are independently covalently linked to R 1 at a linkage site represented by K188 (based on Kabat numbering) and/or a linkage site represented by K190 (based on Kabat numbering) of the light chain constant regions of the anti-TfR1 antibodies; and

wherein in each complex of the plurality of complexes, n1 is independently an integer of one or greater representing the number of instances of R 1 .

10 . The composition of any one of claims 7-9 , wherein:

(a) 85%-98% of the light chain constant regions of the anti-TfR1 antibodies of the complexes in the composition are independently covalently linked to R 1 at a linkage site represented by K188 (based on Kabat numbering) and/or a linkage site represented by K190 (based on Kabat numbering) of the light chain constant regions of the anti-TfR1 antibodies; or

(b) 95%-97% of the light chain constant regions of the anti-TfR1 antibodies of the complexes in the composition are independently covalently linked to R 1 at a linkage site represented by K188 (based on Kabat numbering) and/or a linkage site represented by K190 (based on Kabat numbering) of the light chain constant regions of the anti-TfR1 antibodies.

11 . The composition of any one of claims 7-10 , wherein:

(a) 1%-15% of the heavy chain constant regions of the anti-TfR1 antibodies of the complexes in the composition are independently covalently linked to R 1 at a linkage site represented by K213 (based on Kabat numbering) of the heavy chain constant regions of the anti-TfR1 antibodies; or

(b) 4%-8% of the heavy chain constant regions of the anti-TfR1 antibodies of the complexes in the composition are independently covalently linked to R 1 at a linkage site represented by K213 (based on Kabat numbering) of the heavy chain constant regions of the anti-TfR1 antibodies.

12 . The composition of any one of claims 1-11 , wherein the antibody is a Fab fragment, a full-length IgG, a Fab′ fragment, or a F(ab′) 2 fragment.

13 . The composition of any one of claims 1-12 , wherein the antibody is a Fab fragment.

14 . The composition of any one of claims 1-13 , wherein the VH comprises an amino acid sequence at least 85% identical to SEQ ID NO: 17; and/or wherein the VL comprises an amino acid sequence at least 85% identical to SEQ ID NO: 18, optionally wherein the antibody comprises a heavy chain variable region (VH) comprising the amino acid sequence of SEQ ID NO: 17 and a light chain variable region (VL) comprising the amino acid sequence of SEQ ID NO: 18.

15 . The composition of any one of claims 1-14 , wherein the heavy chain comprises the amino acid sequence of SEQ ID NO: 19 and the light chain comprises the amino acid sequence of SEQ ID NO: 20.

16 . The composition of any one of claims 1-15 , further comprising one or more antibodies that are not covalently linked to an oligonucleotide.

17 . The composition of claim 16 , wherein the average value of n1 of complexes in the composition is in the range of 0.5 to 5.

18 . A method of reducing DMPK expression and/or treating myotonic dystrophy in a subject, the method comprising administering to the subject an effective amount of the composition of any one of claims 1-17 .

19 . The method of claim 18 , wherein the subject has an expansion of a disease-associated-repeat of a DMPK allele that is associated with myotonic dystrophy, optionally wherein the disease-associated-repeat comprises repeating units of a CTG trinucleotide sequence.

20 . The method of claim 18 or claim 19 , wherein the complexes reduce DMPK expression in the subject, optionally wherein reducing DMPK expression comprises reducing the level of a DMPK mRNA in the muscle cell, further optionally wherein the DMPK mRNA is a mutant DMPK mRNA.