The U.S. Food and Drug Administration ( FDA) has placed an immediate clinical hold on Sarepta Therapeutics' investigational gene therapy trials for limb girdle muscular dystrophy following three patient deaths potentially linked to the company's treatments.

Shares of Sarepta Therapeutics SRPT nosedived 35.9% on Friday following the death of a patient dosed with one of its experimental gene therapies. The company confirmed that a 51-year-old, non-ambulant (unable to walk) limb-girdle muscular dystrophy (LGMD) patient died due to acute liver failure (ALF).

Sarepta rebuffed a call from the Food and Drug Administration to halt all shipments of its gene therapy for Duchenne muscular dystrophy over safety issues, even as patients and investors expressed growing concern about the company’s decision-making.

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.

As mothers of children with this disease, we have wept helplessly in recent months as friends — fellow members of a club we never asked to join — said goodbye to their sons, the babies they once held in their arms, whose dreams they held in their hearts until Duchenne robbed them of working muscles or a healthy future.

Sarepta says it will continue to ship Elevidys despite FDA requests that it stop shipments of the Duchenne muscular dystrophy gene therapy, while Wall Street awaits earnings Monday from Verizon.

New research has identified the enzyme glutamate dehydrogenase 1 (GLUD1) as a new therapeutic target for Duchenne muscular dystrophy (DMD).