The U.S. FDA has approved a label expansion for Sarepta Therapeutics' Elevidys to include all individuals, regardless of ambulatory status, with Duchenne muscular dystrophy (DMD) with a confirmed mutation in the DMD gene who are at least 4 years of age.
The FDA had granted accelerated approval for Elevidys last June, but only for a segment of pediatric patients with DMD — specifically, ambulatory pediatric patients aged 4-5 years who have a confirmed mutation in the DMD gene.
Now, the FDA has granted traditional approval for ambulatory patients and accelerated approval for non-ambulatory patients. Continued approval for non-ambulatory Duchenne patients may be contingent upon a confirmatory trial. The phase 3 global ENVISION study of Elevidys in non-ambulatory and older ambulatory individuals with Duchenne is underway and intended to serve as this postmarketing requirement.
The label expansion comes despite Elevidys' failure to meet the primary endpoint in the phase 3 EMBARK study of Duchenne patients between the ages of 4-7 years, revaled last October. In the trial, Elevidys-treated patients improved 2.6 points on their North Star Ambulatory Assessment (NSAA) total score 52 weeks after treatment compared to 1.9 points in placebo-treated patients. The difference of 0.65-points between treated and placebo groups did not reach statistical significance, which means the trial did not meet its primary endpoint.
Sarepta had remained optimistic about the label expansion, pointing out that "all key pre-specified functional secondary endpoints demonstrated robust evidence for a clinically meaningful treatment benefit that was consistent across age groups in Elevidys-treated patients."
Developed in collaboration with Roche, Elevidys facilitates the specific generation of functional parts of dystrophin, a protein crucial for DMD, genetic mutations affect the protein's structure, impairing its normal function and leading to various musculoskeletal symptoms. Although the disease is rare, it is life-threatening and affects around 1 in every 3,500-5,000 newborn boys annually.
