First Gene Therapy for Duchenne Priced at $3.2 Million

The first FDA-approved gene therapy to treat Duchenne muscular dystrophy (DMD), Sarepta Therapeutics’ Elevidys (delandistrogene moxeparvovec-rokl), will have a wholesale acquisition cost (WAC) of $3.2 million. The FDA granted accelerated approval of Elevidys to treat ambulatory pediatric patients aged 4 through 5 years with a confirmed mutation in the DMD gene. This follows a positive vote by an advisory committee in May.

Duchenne is a rare genetic disease that is characterized by a mutation in the dystrophin gene. This results in the lack of dystrophin, which acts as a shock absorber for muscle at the membrane. Duchenne causes the muscles in the body to become weak and damaged over time and is eventually fatal. Duchenne affects about 1 in 3,500 to 5,000 males born worldwide.

Elevidys is a one-time therapy that delivers to muscle a gene that codes for a shortened, functional form of dystrophin. It uses an adeno-associated virus (AAV) vector and a promoter that helps to drive gene expression.

Peter Marks, M.D., Ph.D.

“The 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,” Peter Marks, M.D., Ph.D., director of the FDA’s Center for Biologics Evaluation and Research, said in a press release.

A cost-effectiveness analysis shows the value of Elevidys in treating Duchenne at between $5 million and $13 million compared with standard of care alone, Sarepta said in an investor presentation.

The WAC price is similar to other gene therapies, which range from $2.1 million to $3.5 million, Arash Sadeghi, clinical pharmacist for Optum Rx, told FormularyWatch.

The FDA is requiring the company to complete a clinical study to confirm the drug’s clinical benefit. Sarepta’s EMBARK placebo-controlled phase 3 trial for Elevidys will serve as the confirmatory trial and is fully enrolled with top-line results expected in late 2023.

“If EMBARK confirms the benefits seen in our prior trials, Sarepta will move rapidly to submit a BLA supplement to expand the approved label as broadly as good science will permit,” Doug Ingram, president and chief executive officer, Sarepta, said in a press release.

This accelerated approval is based on an increase in Elevidys micro-dystrophin protein expression in skeletal muscle. Sarepta submitted the BLA for Elevidys in September 2022 based on efficacy and safety data from Study SRP-9001-103 (ENDEAVOR), Studies SRP-9001-101 and SRP-9001-102, and an integrated analysis across these three clinical studies. In clinical results from more than 80 treated patients, SRP-9001 has demonstrated positive results at multiple time points, including one-, two- and up to four-years after treatment, in addition to demonstrating a consistent safety profile.

Acute serious liver injury, immune-mediated myositis and myocarditis have occurred in patients treated with Elevidys. The most common adverse reactions in clinical studies were vomiting, nausea, liver function test increased, pyrexia and thrombocytopenia.