News Release | sareptatherapeutics.com

News Release | sareptatherapeutics.com: Sarepta Therapeutics Announces Eteplirsen Demonstrates Continued Stability on Walking Test Through 96 Weeks in Phase IIb Study in Duchenne Muscular Dystrophy

Sarepta Therapeutics, Inc. (NASDAQ: SRPT), a developer of innovative RNA-based therapeutics, today announced data through Week 96 from Study 202, a Phase IIb open-label extension study of eteplirsen in patients with Duchenne muscular dystrophy (DMD). Results through nearly two years showed a continued stabilization of walking ability in eteplirsen-treated patients evaluable on the 6-minute walk test (6MWT). As previously reported, Study 202 met its primary endpoint of increased novel dystrophin as assessed by muscle biopsy at Week 48 and is now in the long-term extension phase in which patients continue to be followed for safety and clinical outcomes.

After 96 weeks, patients in the 30 mg/kg and 50 mg/kg eteplirsen cohorts who were able to perform the 6MWT (modified Intent-to-Treat or mITT population; n=6) experienced less than a 5 percent decline (17.5 meters) from baseline in walking ability. A statistically significant treatment benefit of 70.8 meters (p ≤0.001) was observed for the mITT population compared with the placebo/delayed-treatment cohort (n=4), which initiated treatment at Week 25 following 24 weeks of placebo. After experiencing a substantial decline earlier in the study, the placebo/delayed-treatment cohort also demonstrated stabilization in walking ability from Week 36 through 96, the period from which meaningful levels of dystrophin were likely produced, with a decline of 18.5 meters over this timeframe. These analyses were based on the maximum 6MWT score when the test was performed on two consecutive days.

"We are very encouraged the study has demonstrated walking stability in patients for more than a year since confirming that eteplirsen treatment produced dystrophin in their muscles," said Chris Garabedian, president and chief executive officer of Sarepta Therapeutics. "We look forward to sharing these updated data with the FDA as part of our New Drug Application for eteplirsen, which we plan to submit in the first half of 2014."