Sarepta Therapeutics (NASDAQ:SRPT) plummeted on Friday after the U.S. Food and Drug Administration implied it may not approve the company’s treatment for Duchenne muscular dystrophy, a disease for which there is currently no treatment.
Shares fell 55% to $14.17 at 1:38 p.m. in New York.
The FDA released briefing documents for Sarepta’s drug candidate, called eteplirsen, on Friday, ahead of a meeting of its advisory committee on January 22.
The documents said the agency has not reached a final decision on the application but hinted at doubts about the findings of two clinical trials, dampening investor expectations.
The FDA said it “is prepared to be flexible with respect to a devastating illness with no treatment options, we cannot approve drugs for which substantial evidence of effectiveness has not been established.”
Effects patients may have seen while on the drug, called eteplirsen, are “too small and variable, in the context of a poorly-controlled trial, to be reliably attributed to drug treatment,” FDA staff wrote in the report on Friday.
A competing drug from BioMarin Pharmaceutical (NASDAQ:BMRN) was formally rejected by the FDA earlier this week. Shares of BioMarin fell 3.2% to $81.75.
The FDA is scheduled to give a final decision on Sarepta’s drug by February 26.