Sarepta's shares more than halve after FDA staff question data supporting eteplirsen filing

Shares in Sarepta Therapeutics plunged as much as 58 percent Friday after briefing documents released by FDA staff suggested that the company had not provided enough evidence to support the effectiveness of eteplirsen for patients with Duchenne muscular dystrophy (DMD). The documents were posted ahead of an advisory committee meeting on January 22.

"Although FDA 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," the agency stated. Specifically, FDAreviewers questioned the validity of the "small" clinical study used to establish the efficacy of eteplirsen, describing the trial as "exploratory" because of its design. Meanwhile, Sarepta has initiated a Phase III study of eteplirsen, with final results expected in 2018.

The FDA advisory panel is scheduled to consider eteplirsen next week, while a final decision on the therapy is expected next month. In addition, the FDA previously awarded the drug rare paediatric disease designation for patients with DMD who are amenable to exon 51-skipping therapy.

Earlier this week, the FDA declined to approve BioMarin Pharmaceutical's DMD therapy Kyndrisa (drisapersen). For related analysis, see ViewPoints: BioMarin’s rough ride at an FDA AdComm may be good news for Sarepta, PTC Therapeutics.

To read more Top Story articles, click here.