The drisapersen failure eliminates Sarepta's only competitor for an effective DMD treatment. That's a big positive for Sarepta. It's premature to write off drisapersen completely, but the drug has suffered a major setback, no doubt. This eliminates a lot of competitive pressure from Sarepta, even if a pre-approval phase III study of eteplirsen is required, delaying its approval.
Eteplirsen is a more potent, effective drug than drisapersen. I still believe this because eteplirsen can be dosed higher and has demonstrated a more profound effect on dystrophin production than drisapersen in previous studies. The ability to produce functional dystrophin is still key, in my mind.