Patient Dies Following Gene Therapy Treatment for Duchenne Muscular Dystrophy

A patient suffered acute liver failure after Elevidys treatment, with Sarepta Therapeutics citing a preexisting infection as a possible contributing factor.

A mobile phone with the logo of Sarepta Therapeutics on screen in front of a web page in Stuttgart, Germany, on July 16, 2022. Shutterstock

A patient with Duchenne muscular dystrophy has died following treatment with Elevidys, a gene therapy developed by Sarepta Therapeutics, the company announced in a safety update. The news sent the company’s stock down about 23 percent in morning trading on March 18.

“We are profoundly saddened to share that a young man with Duchenne muscular dystrophy has passed away following treatment with ELEVIDYS, having suffered acute liver failure,” a company report read.

“Patient safety and well-being are Sarepta’s top priority. We continue to gather and analyze the information from this event,” the company added.

Sarepta Therapeutics, a major player in genetic medicine, stated that while acute liver injury is a known risk associated with Elevidys and other “AAV-mediated gene therapies,” acute liver failure leading to death had not previously been reported among the more than 800 patients treated with the therapy.

In its statement, Sarepta noted that the patient had also recently contracted cytomegalovirus (CMV), which the treating physician identified as a possible contributing factor to his condition. CMV can affect the liver and lead to CMV hepatitis, the company said, potentially compounding the risks associated with gene therapy.

Sarepta has reported the incident to relevant health authorities and intends to update Elevidys’ prescribing information to reflect the severity of the adverse event. Sarepta has also notified clinical study investigators and prescribing physicians about the case.

Elevidys, also known as delandistrogene moxeparvovec-rokl, is the only approved gene therapy for Duchenne muscular dystrophy (DMD), a progressive, genetic neuromuscular disorder that primarily affects young boys and leads to severe muscle degeneration and weakness.

The treatment uses a disabled virus to insert a replacement gene for producing dystrophin into patient cells. It costs around $3.2 million for a one-time treatment, making it one of the most expensive drugs in the world.

The therapy is currently approved for patients at least four years of age with a confirmed mutation in the DMD gene, according to the company. It was first approved by the U.S. Food and Drug Administration (FDA) in 2023 following several delays.

Sarepta has urged physicians to closely monitor liver function in patients receiving Elevidys for at least three months after the infusion. The company also reiterated its recommendation for systemic corticosteroid treatment before and after therapy to mitigate liver-related risks.

The FDA has not issued any new regulatory action related to Elevidys following the report.

The Associated Press contributed to this report.