Sarepta shares sink as FDA staff stay sour on muscle disorder drug

Sarepta Therapeutics Inc lost more than a third of its market value after U.S. Food and Administration staff maintained their negative outlook on the company's rare muscle wasting disorder drug on Thursday.

Sarepta is looking for accelerated approval for its drug, eteplirsen, which aims to treat a subset of patients with Duchenne muscular dystrophy (DMD).

Staff reviewers on Thursday reiterated their discomfort with the drug raising concerns surrounding the drug's trials, its effectiveness, and the company's statistical analysis.

The scientists in January highlighted similar concerns ahead of a scheduled meeting of an independent panel of experts to the FDA. However, this meeting was postponed due to an inclement weather forecast for Washington DC.

After the original FDA staff review was published in January, Sarepta provided additional information on trial data and pointed toward "key inaccuracies" in the staff analysis.

On Thursday, reviewers disagreed with Sarepta's "characterization of inaccuracies" and said that newer information presented by the company further increased concerns about the reliability of trial data.

The biotechnology company's stock plummeted about 32 percent to $13.40 in premarket trading. (Reporting by Natalie Grover in Bengaluru; Editing by Maju Samuel)