Sarepta Offers Results of Phase IIb Open-Label Extension Study of Eteplirsen Which Show Continued Benefit

Sarepta Therapeutics SRPT, a developer of innovative RNA-based therapeutics, today announced updated data from Study 202, its open-label, Phase IIb extension study of eteplirsen for the treatment of Duchenne muscular dystrophy (DMD). Patients treated with eteplirsen for 62 weeks and evaluable on ambulatory measures (modified Intent-to-Treat population) maintained a statistically significant clinical benefit on the primary clinical outcome measure, the 6-minute walk test (6MWT), compared to patients who received placebo for 24 weeks followed by 38 weeks of eteplirsen treatment. As reported previously, Study 202 met its primary endpoint of increased novel dystrophin as assessed in muscle biopsies at week 48 and is now in the long-term extension phase in which patients continue to be followed for safety and clinical outcomes. In the modified Intent-to-Treat (mITT) population, which includes evaluable patients from both the 30mg/kg and 50mg/kg dose cohorts, patients treated with eteplirsen for 62 weeks demonstrated a statistically significant benefit of 62 meters over the placebo/delayed-treatment cohort using a mixed-model repeated measure statistical test. The mITT consisted of 10 of the enrolled 12 patients (4 eteplirsen-treated patients receiving 50 mg/kg weekly, 2 eteplirsen-treated patients receiving 30 mg/kg weekly, and 4 placebo/delayed-treatment patients), and excludes two patients who showed signs of rapid disease progression and lost ambulation by week 24. The eteplirsen treatment cohort (n=6) continued to show disease stabilization and the cohort has shown less than a 5% decline in walking distance on the 6-minute walk test from baseline. The placebo/delayed-treatment cohort (n=4) also demonstrated stability in walking distance from week 36 through week 62 with a less than 10 meter change over this timeframe, the period in which dystrophin was likely produced, with confirmation of significant dystrophin levels at week 48 through analysis of muscle biopsies in these pat ients.