Shares of Sarepta Therapeutics plunged more than 30% on Friday as the future of its key gene therapy treatment appeared at risk. The Food and Drug Administration will request that the company voluntarily stop all shipments of the treatment, Elevidys, a person familiar with the matter told CNBC.

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

The head of the US Food and Drug Administration said the agency will “take a hard look” at a gene therapy from Sarepta Therapeutics Inc. after two patient deaths, adding pressure to the biotech company which also announced a third patient had recently died on a similar treatment.