Sarepta Stock Tumbles 34% After Earnings Report. Why Shares Crashed.

Sarepta reported an adjusted third-quarter loss of 13 cents a share, narrower than the loss of 32 cents that analysts polled by FactSet were expecting. (Dreamstime)

Sarepta Therapeutics stock plummeted on Tuesday despite reporting a smaller-than-expected loss.

It came after the biotechnology company disclosed disappointing trial data for two treatments for Duchenne muscular dystrophy, raising questions about how long it will take regulators to approve a key drug.

Shares crashed 34% to $16.20. The S&P 500 was 1.2% lower.

Created with Highcharts 9.0.1Sarepta TherapeuticsSource: FactSet

Created with Highcharts 9.0.12025Nov.020406080100120$140

The move came after Sarepta said the results of a trial for two of its drugs targeting Duchenne muscular dystrophy, a rare muscle-wasting illness, hadn’t reached statistical significance.

The company separately reported an adjusted third-quarter loss of 13 cents a share, narrower than the loss of 32 cents that analysts polled by FactSet were expecting.

Sarepta stock already had declined 80% for the year before Tuesday’s selloff. It has tumbled amid a Food and Drug Administration inquiry into Elevidys, one of the gene therapies targeting Duchenne muscular dystrophy, after two people who took the treatment died from liver failure. Another patient died after taking an unrelated treatment in a trial for the inherited muscular dystrophy LGMD Type 2D.

Write to George Glover at george.glover@dowjones.com