Sarepta Therapeutics, Inc., a developer of innovative RNA-based therapeutics, today announced updated data from Study 202, a Phase IIb open-label extension study of eteplirsen in patients with Duchenne muscular dystrophy (DMD). Results at 84 weeks 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. Eteplirsen is Sarepta's lead exon-skipping compound in development for the treatment of patients with DMD who have a genotype amenable to skipping of exon 51.
"We now have demonstrated stability of walking for over a year and a half in the original eteplirsen treatment cohort in boys who are now 11 years old on average, an age when many DMD boys have lost the ability to walk," said Chris Garabedian, president and chief executive officer of Sarepta Therapeutics. "In addition, the placebo/delayed-treatment cohort, which has now received eteplirsen for over a year, has demonstrated a stabilization in walking ability for 48 weeks compared with the precipitous decline observed earlier in the study before dystrophin was confirmed in these patients. Overall, we believe the data across all treatment cohorts are remarkably consistent and continue to support eteplirsen as a potential treatment option in DMD."
Through 84 weeks, eteplirsen was well tolerated and there were no clinically significant treatment-related adverse events, no serious adverse events, hospitalizations or discontinuations.
One boy in the placebo/delayed-treatment cohort was not able to perform the 6MWT at the Week 84 clinic visit due to a physical injury unrelated to treatment, and therefore had no 6MWT data captured at the Week 84 time point. The boy has recovered from the injury, continues to be ambulatory and is expected to be evaluated on the 6MWT at future clinic visits.
Across all patients in the eteplirsen and placebo/delayed-treatment cohorts (Intent-to-Treat or ITT population), there is evidence of continued stabilization on clinical laboratory tests, echocardiograms, pulmonary function tests and measures of muscle strength.