Sarepta Therapeutics is pausing shipments of its gene therapy for muscular dystrophy following several patient deaths that have attracted attention from regulators.

Sarepta stock tanked Friday after a new patient death was uncovered, spurring an FDA request to halt shipments of an unrelated drug.

After the FDA request, Cambridge, Massachusetts-based Sarepta said in a statement that it will continue to ship the therapy to ambulatory people but maintain a halt it implemented June 15 for non-ambulatory patients after reporting to the FDA a case of acute liver failure in a patient who could not walk.

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,

Sarepta would need to conduct new analyses to validate the safety of Elevidys—which has had U.S. shipments paused by the company over a mounting string of controversies—to the FDA, Endpoints News reported Thursday, citing an unnamed senior FDA official.

The company refused the FDA’s request and will continue shipping its therapy, Elevidys, to Duchenne patients who can still walk. A pause on shipments to older, non-ambulatory patients remains in place.

Roche Holding AG said on Tuesday it has paused shipments of muscular disorder gene therapy Elevidys in some countries outside the U.S., echoing a similar decision by U.S. partner Sarepta Therapeutics .

As the controversy over the safety of Sarepta Therapeutics’ gene therapies comes to a head, the biotech is standing firm behind its approved Duchenne muscular dystrophy (DMD) treatment. | As the controversy over the safety of Sarepta Therapeutics’ gene therapies comes to a head,

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.