Compound and method for treating myotonic dystrophy

1. An antisense compound, comprising:

an antisense oligonucleotide having 8-30 bases, with at least 8 contiguous bases being complementary to the polyCUG or polyCCUG repeats in the 3′UTR region of dystrophia myotonica protein kinase (DMPK) mRNA in DM1 or DM2, respectively, and

conjugated to the oligonucleotide, a cell-penetrating peptide having the sequence (RXRRBR) 2 XB, where R is arginine; B is β-alanine; and each X is independently —C(O)—(CH 2 ) n —NH—, where n is 4-6 (SEQ ID NO: 67),

where the compound is effective to selectively block the sequestration of at least one of muscleblind-like 1 protein (MBNL1) and CUG-binding protein CUGBP in heart and quadricep muscle in a myotonic dystrophy animal model.

2. The antisense compound of claim 1 , wherein the cell penetrating peptide has the sequence (RXRRBR) 2 XB (SEQ ID NO: 19) where X is —C(O)—(CH 2 ) 6 —NH—.

3. The antisense compound of claim 2 , wherein the oligonucleotide is a phosphorodiamidate oligonucleotide (PMO) having between 12-30 bases, and at least 12 contiguous bases that are complementary to the polyCUG repeats in the 3′UTR region of dystrophia myotonica protein kinase (DMPK) mRNA in DM1.

4. The antisense compound of claim 2 , wherein the oligonucleotide is a phosphorodiamidate oligonucleotide (PMO) having between 12-30 bases, and at least 12 contiguous bases that are complementary to the polyCCUG repeats in the 3′UTR region of dystrophia myotonica protein kinase (DMPK) mRNA in DM2.

5. A method of targeting a systemically administered antisense oligonucleotide to heart muscle tissue in a mammalian subject, where the oligonucleotide is directed against the polyCUG or polyCCUG repeats in the 3′UTR region of dystrophia myotonica protein kinase (DMPK) mRNA in DM1 or DM2, respectively, the method comprising

conjugating to the oligonucleotide, a cell-penetrating peptide having the sequence (RXRRBR) 2 XB, where R is arginine; B is β-alanine; and each X is independently —C(O)—(CH 2 ) n —NH—, where n is 4-6 (SEQ ID NO: 67).

6. The method of claim 5 , wherein the selective targeting of the oligonucleotide to heart muscle tissue is evidenced by the reversal of sequestration of muscleblind-like 1 protein (MBNL1) in the heart muscle tissue in a PMO-treated animal model having known MBNL1 sequestration.

7. The method of claim 5 , wherein the cell penetrating peptide has the sequence(RXRRBR) 2 XB (SEQ ID NO: 19) where X is —C(O)—(CH 2 ) 6 —NH—.

8. The method of claim 7 , wherein the oligonucleotide is a phosphorodiamidate oligonucleotide (PMO) having between 12-30 bases, and at least 12 contiguous bases that are complementary to (i) the polyCUG repeats in the 3′UTR region of dystrophia myotonica protein kinase (DMPK) mRNA in DM1, or (ii) the polyCCUG repeats in the 3′UTR region of dystrophia myotonica protein kinase (DMPK) mRNA in DM2.

9. A method of treating mytonic dystrophy DM1 or DM2 in a mammalian subject, the method comprising

administering to the subject, an antisense compound comprising an antisense oligonucleotide having 8-30 bases, with at least 8 contiguous bases being complementary to the polyCUG or polyCCUG repeats in the 3′UTR region of dystrophia myotonica protein kinase (DMPK) mRNA in DM1 or DM2, respectively, and conjugated to the oligonucleotide, a cell-penetrating peptide having the sequence RXRRBR) 2 XB, where R is arginine; B is β-alanine; and each X is independently —C(O)—(CH 2 ) n —NH—, where n is 4-6 (SEQ ID NO: 67), and

repeating said administering at least once every one week to 3 months.

10. The method of claim 9 , for treating DM1 in a mammalian subject, wherein the cell penetrating peptide has the form (RXRRBR) 2 XB (SEQ ID NO: 19), where X is —C(O)—(CH 2 ) 6 —NH—, and the oligonucleotide is a phosphorodiamidate oligonucleotide (PMO) having between 12-30 bases, and at least 12 contiguous bases that are complementary to the polyCUG repeats in the 3′UTR region of dystrophia myotonica protein kinase (DMPK) mRNA in DM1.

11. The method of claim 9 , for treating DM2 in a mammalian subject, wherein the cell penetrating peptide has the form (RXRRBR) 2 XB (SEQ ID NO: 19), where X is —C(O)—(CH 2 ) 6 —NH—, and the oligonucleotide is a phosphorodiamidate oligonucleotide (PMO) having between 12-30 bases, and at least 12 contiguous bases that are complementary to the polyCCUG repeats in the 3′UTR region of dystrophia myotonica protein kinase (DMPK) mRNA in DM2.

12. The method of claim 9 , wherein said administering is by intravenous or subcutaneous injection to the subject, at a dose between 1-5 mg/kg body weight antisense compound.

13. The method of claim 9 , wherein said administering is repeated at regular intervals of every one to three months, and further includes monitoring the patient during the treatment period for improvement in skeletal or heart muscle performance.

14. The method of claim 9 , wherein said administering is repeated at regular intervals of every one to three months, and further includes monitoring the patient during the treatment period for improvement in heart conduction properties.

15. The method of claim 9 , wherein said administering is repeated at regular intervals of every one to three months, and further includes monitoring the patient during the treatment period for reduction in serum creatine kinase.