A Wall Street Darling No More: FDA Sends Sarepta Plunging

One of the hottest biotech stories over the past year went ice cold today when Sarepta Therapeutics revealed the FDA decided it would be “premature” to proceed with paperwork for its eteplirsen drug to treat Duchenne muscular dystrophy, or DMD. The disclosure sent Sarepta shares plunging nearly 60 percent this morning and appears to have ended its run as a Wall Street darling, at least for now. In explaining the setback, Sarepta was told the FDA believes there is “considerable doubt” about a proposed biomarker – an increased production of dystrophin, which is a protein that Duchenne patients are lacking. The agency also raised questions about data in a Phase IIb study that relied on results of what is known as a six-minute walk test, which is used to measure ambulatory ability. Finally, the FDA cited the recent failure of a Phase III study for a rival drug called drisapersen that is being developed by Prosensa Holding (RNA) and GlaxoSmithKline (GSK) (back story). The outcome had not been expected and set off a debate about whether Sarepta may fare differently. “The disconnect between increased expression of dystrophin and clinical efficacy for drisapersen, combined with previous negative reports for (another DMD drug) thought to act by increasing dystrophin, raises considerable doubt about the biomarker and, consequently, its ability to reasonably likely predict clinical benefit,” according to FDA comments released by Sarepta. DMD is a rare and fatal disease tha...
Source: Pharmalot - Category: Pharma Commentators Authors: Source Type: blogs