FDA Approves First Gene Therapy to Treat Duchenne Muscular Dystrophy

The U.S. Food and Drug Administration on Thursday approved the drug Elevidys, the first gene therapy for the treatment of children with Duchenne muscular dystrophy (DMD).

The groundbreaking treatment will not be cheap: Drugmaker Sarepta Therapeutics Inc. said it would charge $3.2 million for the one-time IV treatment, the Associated Press reported. Like most medicines in the United States, the cost would be mostly paid by insurers.

The drug will be used to treat children ages 4 through 5 who have a mutation in the DMD gene.

“Today’s approval addresses an urgent unmet medical need and is an important advancement in the treatment of Duchenne muscular dystrophy, a devastating condition with limited treatment options, that leads to a progressive deterioration of an individual’s health over time,” Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said in an agency news release.

“The approval of Elevidys is a watershed moment for the treatment of Duchenne. Elevidys is the first and only gene therapy approved for Duchenne, and this approval brings us closer to our goal of bringing forward a treatment that provides the potential to alter the trajectory of this degenerative disease,” Sarepta President and CEO Doug Ingram said in a company statement.

Advocates welcomed the approval.

“Today’s decision marks an important moment in gene therapy for patients living with Duchenne,” said Pat Furlong, founding president and CEO of Parent Project Muscular Dystrophy. “It’s been the lifelong work of so many in the Duchenne community. Our work continues until all patients in our community have access to therapy.”

Duchenne muscular dystrophy is a rare, genetic condition that worsens over time, leading to weakness and wasting away of the body’s muscles. A defective gene that results in the absence of dystrophin causes the condition.

As a result, children with DMD can have trouble walking and running, falling frequently, fatigue, learning disabilities and difficulties, heart issues and breathing problems.

Symptoms of DMD usually begin in childhood, often between 3 to 6 years of age. DMD mainly affects boys, and patients often die in their 20s or 30s due to heart and/or respiratory failure, the FDA said.

Most treatments target symptoms, not the underlying genetic cause of the debilitating condition.

But Elevidys is a recombinant gene therapy that delivers a gene that boosted production of Elevidys micro-dystrophin, a protein that contains a dystrophin protein seen in normal muscle cells. The product is given in a single intravenous dose.

In approving the drug, the FDA considered the risks associated with the drug, the life-threatening and debilitating nature of the disease for children, and the urgent unmet medical need, the agency said

A clinical benefit of Elevidys, including improved motor function, has not been established. As a condition of approval, the FDA has required the company to complete a study to confirm the drug’s clinical benefit.

The most commonly reported side effects were vomiting, nausea, acute liver injury, fever and an abnormally low platelet count in the blood. Patients may also be at risk for severe muscle inflammation. Inflammation of heart muscle and elevations of a heart protein found in the blood after heart muscle injury has also been seen following the use of Elevidys in clinical trials, the FDA said.

More information

For more on DMD, head to the Muscular Dystrophy Association.

SOURCES: U.S. Food and Drug Administration, news release, June 22, 2023; Sarepta Therapeutics Inc., news release, June 22, 2023; Associated Press