Sarepta snags priority review status to keep pace with BioMarin in DMD race

The FDA has awarded priority review status to Sarepta Therapeutics' ($SRPT) eteplirsen. The regulatory go sign means Sarepta is still tucked in just behind BioMarin ($BMRN) in the race to bring a therapy for Duchenne muscular dystrophy (DMD) to market, with analysts tipping the agency to make a decision on both drugs by the end of the year.

Sarepta received the priority review status after the FDA gave its application the once over and deemed it complete enough to advance. The FDA awards the status to treatments for indications for which no adequate drugs are already available, a description that fits DMD, for now. That could change before the end of the year, by which time BioMarin should have heard from the agency about the fate of its DMD drug, drisapersen. Yet while BioMarin is marginally ahead of Sarepta--there's a two-month gap between their PDUFA dates--the proximity of the two filings means the FDA may rule on both at about the same time.

"We would not be surprised if accelerated approval is granted [to Sarepta's eteplirsen] around December 27," Roth Capital analyst Debjit Chattopadhyay wrote in a note to investors. In this scenario, a regulatory advisory committee would look at both treatments at a joint meeting in November, setting up FDA to make a decision on eteplirsen and drisapersen before BioMarin's PDUFA date in the final days of 2015. A lot is resting on the decision, for both companies, the patient community they are trying to treat and FDA itself.

The mood in DMD R&D has swung wildly over the past couple of years as the drugs have stumbled through clinical trials and into the regulatory decision process. BioMarin bought its way into the race through the $840 million deal to acquire Prosensa Therapeutics, and since then it has ratcheted up the drama in an already feverish field by bickering with its rival over the strength of their respective datasets. Sarepta, having dealt with its internal squabbles, has added to the din by talking up how it plans to "own DMD."

Now, finally, after all the inter and intra-company squabbling, R&D stumbles and regulatory shifts, there is a clear line of sight to a FDA decision on whether either firm will get a marketing nod and an accompanying priority review voucher.

Shares of Sarepta were up about 5% in pre-market trading on Wednesday.

- read the release
- and Boston Business Journal's take