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 has refused to suspend all dosing of its gene therapy for Duchenne muscular dystrophy, Elevidys, defying a clinical hold request from the FDA.

Drugmaker Sarepta Therapeutics says it won’t comply with a request from U.S. regulators to halt all shipments of its gene therapy.