Sarepta Therapeutics’ treatment Elevidys (delandistrogene moxeparvovec-rokl) received conditional approval from the FDA in June 2023. The designation implies that if the drug is used in accordance with its label, it is deemed safe and reasonably effective. The FDA’s decision relied on results from two clinical trials, SRP 9001-102 and -103. However, in October 2023, Sarepta announced that a late-stage study indicated Elevidys had failed to meet its primary goal. Instead, the treatment was not significantly different from the placebo (2.6 compared to placebo 1.9).
About DMD
DMD is caused by changes in the dystrophin gene, which helps maintain the function and structure of muscle cells. It is one of the largest human genes and serves as the ‘shock absorber’ protecting muscles during contraction or relaxation.
Mutations in the dystrophin gene may alter the size of the dystrophin protein. Duchenne occurs when there is an insufficient amount of the dystrophin protein in muscle cells, resulting in the loss of function and strength. The FDA’s conditional clearance was based on Elevidys’ production of micro-dystrophin, judged as ‘reasonably likely’ to deliver clinical benefits. However, the company’s late-stage study failed to confirm those benefits, changing the scenario.
About Elevidys
Elevidys, a micro dystrophin therapy, is a one-time infusion into a vein. The drug compensates for mutations causing Duchenne and is delivered by an engineered virus providing instructions for the protein that patients lack.
Sarepta defended its position by citing examples of the treatment’s benefits, such as participants being able to walk ten meters. Usually, when a negative primary result occurs, a further study is necessary. However, Sarepta argues that the severity of the disease and Elevidys’ data warrant an expansion of the treatment’s approval.
The company’s application submitted recently requests a six-month priority review instead of the standard ten-month review and a full approval instead of conditional approval. While the FDA could potentially motion to withdraw Elevidys’ trial, analysts familiar with the company consider it an unlikely prospect. Nonetheless, Sarepta recently expressed concerns that the FDA may be unwilling to approve such a wide expansion.
Joseph Schwartz of Leerink Partners, an investment bank, summarized the situation. Schwartz believes that Elevidys will stay on the market through an expanded label with no age restriction for ambulatory patients. However, he acknowledges that the situation is more uncertain for non-ambulatory patients. Roche, Sarepta’s partner, holds responsibility for regulatory discussions outside the United States.
Roche, Sarepta’s partner, holds responsibility for any regulatory discussions outside of the United States.
