Shares of Sarepta Therapeutics (SRPT) closed the day up 22.43% after announcing additional positive phase 2b data for its Duchenne Muscular Dystrophy drug. The company stated that their drug Eteplirsen allowed patients to gain an advantage of 151 meters in the 6 minute walk test — 6MWT — compared to an external control drug study. 

In addition the positive efficacy continued with the company performing a biopsy on the patients to determine if they were producing new dystrophin proteins. The biopsy showed that patients were achieving the ability of producing new dystrophin proteins in the body to help with muscle movement. That is meaningful because patients with DMD have muscles that continue to lose function over time, in addition these patients’ bodies are unable to produce new dystrophin proteins to keep the muscles strong. 

DMD is a devastating disease in which children end up in a wheelchair for most of their lives and could end up dying at an early age. There are currently no treatments approved for DMD so these patients desperately need this drug to be approved. This is why the current CEO Edward Kaye is appealing to the FDA to allow for Accelerated approval for this drug.

That means that he would like to see the drug approved early, and then continue large studies thereafter to prove to the FDA that the efficacy can be reproduced in a larger patient population. If the FDA does agree to grant Eteplirsen with Accelerated Approval it could end up being approved in early February of 2016. The drug has an excellent safety profile so there is no trouble there.

All that remains is if the FDA will like a phase 2b study with only 12 patients total. That may be the only risk now, and there is no way of knowing which way the FDA will go. Still the data looks appealing, and considering there are no drugs approved to treat this indication, it could be possible that the FDA might be more lenient than normal for approval.