Sarepta’s stock price plunged in November
Back in November of last year, Sarepta Therapeutics Inc (NASDAQ:SRPT) announced the FDA considered its plans to file for approval of eteplirsen based on existing data premature. The stock price tumbled by 64% in a single day. The selloff was even more pronounced because the announcement came just a few weeks after a clinical study of a competitor drug called drisapersen, being developed by Prosensa Holding NV (NASDAQ:RNA) and GlaxoSmithKline plc (ADR) (NYSE:GSK) (LON:GSK), failed to meet its end points.
Filing for accelerated approval
Given their are no effective treatments for Duchenne MD, a crippling genetic disease that impacts children, Sarepta Therapeutics Inc (NASDAQ:SRPT) can file for accelerated approval, a type of provisional approval granted by the FDA on the condition that the manufacturer will conduct more studies to prove the clinical benefits of the drug. If the trials don’t demonstrate sufficient clinical benefit, then the marketing authorization for the drug is withdrawn.
According to FDA policy, accelerated approval decisions are to be based on an “intermediate measure” of the benefit of a new therapy. A cancer drug might be approved because it shrinks tumors, but additional studies must be performed to prove using the drug leads to longer patient survival or better quality of life. In this case, the FDA is allowing for two options for the approval of eteplirsen, and Sarepta Therapeutics Inc (NASDAQ:SRPT) will submit data on both.
Eteplirsen is an RNA-based therapy that focuses on an abnormality in the dystrophin gene called exon 51. The drug is designed assist the body to “skip over” the abnormal section of the gene in order to produce enough protein to keep muscles functioning. Around 13% of Duchenne MD patients have this particular genetic variation of the disease.
