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.

“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.