When three patients die after taking a cutting-edge drug, most companies hit the brakes. Not Sarepta Therapeutics. The Massachusetts-based biotech company is under fire for refusing a request from the U.

The U.S. Food and Drug Administration is planning to ask Sarepta Therapeutics to voluntarily stop all shipments of its gene therapy Elevidys, a source familiar with the matter told Reuters on Friday.

Shares of Sarepta Therapeutics plunged more than 30% on Friday as the future of its approved gene therapy appeared at risk. Sarepta has reported three patient deaths related to its gene therapies.