U.S. regulators asked Sarepta Therapeutics on Friday to voluntarily halt shipments of its Elevidys gene therapy after a muscular dystrophy patient who received a different, experimental treatment died,

The Food and Drug Administration plans to ask Sarepta Therapeutics Inc. to pause shipments of its Elevidys treatment after three deaths were linked to the company’s gene therapies, according to a person familiar with the matter.

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.