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 move follows the death of two teenagers who were administered the treatment, as well as the death of a 51-year-old man who received a similar product in a clinical trial for a different form of muscular dystrophy.

Sarepta Therapeutics (NASDAQ:SRPT) shares plummeted on Friday following reports of a third patient death linked to its gene therapy pipeline this year, further clouding investor confidence despite the company’s recent efforts to provide clarity on its restructuring and FDA label plans.