FDA Expands Approval of Sarepta’s Duchenne Muscular Dystrophy Gene Therapy

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Editor's note: second paragraph of this story was updated to clarify details.

FDA has expanded the approval of Elevidys (delandistrogene moxeparvovec-rokl), Sarepta Therapeutics’ gene therapy for treating Duchenne muscular dystrophy (DMD). With the expanded approval, Elevidys can be used to treat ambulatory and non-ambulatory individuals four years of age and older with DMD with a confirmed mutation in the DMD gene.

Elevidys was first approved in June 2023 (1) under accelerated approval for ambulatory individuals four through five years of age with DMD with a confirmed mutation in the DMD gene. The accelerated approval was converted to traditional approval for ambulatory patients aged four and up. Additionally, FDA granted accelerated approval to non-ambulatory patients aged four and up.

The efficacy of Elevidys was evaluated in two double-blind, placebo-controlled studies and two open-label studies. The expanded approval was based on the evaluation of data that showed compelling secondary endpoints and exploratory endpoints, which indicated clinical benefit compared to placebo, despite Elevidys failing to meet its statistical primary endpoint of improvement versus placebo. FDA’s decision took into account the totality of evidence, including the potential risks associated with the product, the life-threatening and debilitating nature of the disease, and the urgent unmet medical need, according to a June 20, 2024 press release.

“Today’s approval broadens the spectrum of patients with Duchenne muscular dystrophy eligible for this therapy, helping to address the ongoing, urgent treatment need for patients with this devastating and life-threatening disease,” said Peter Marks, MD, PhD., director of FDA’s Center for Biologics Evaluation and Research, in the press release. “We remain steadfast in our commitment to help advance safe and effective treatments for patients who desperately need them.”

Elevidys, a recombinant gene therapy, is the first gene therapy to be approved for treating this specific population of DMD patients, according to FDA (1). It is designed to deliver a gene that enables production of Elevidys micro-dystrophin, a shortened protein containing selected domains of the dystrophin protein present in normal muscle cells. Elevidys is administered as a single intravenous dose.

DMD is a rare and serious genetic condition that worsens over time. It leads to weakness and wasting away of muscles. The disease is caused by a defective gene that leads to abnormalities in, or absence of, the dystrophin protein, which helps keep muscle cells intact, according to the press release. Symptoms of DMD may include trouble walking and running, falling frequently, fatigue, and learning disabilities/difficulties. Patients may also experience heart issues and breathing problems. Muscle weakness associated with DMD typically begins in childhood between the ages of three and six. The condition mainly affects males, although females can be affected in rare cases. FDA estimates that approximately one in every 3300 boys are affected by DMD.

Reference

1. FDA, FDA Approves First Gene Therapy for Treatment of Certain Patients with Duchenne Muscular Dystrophy. Press Release, June 22, 2023.

Source: Food and Drug Administration