Sarepta shares mixed results from Duchenne gene therapy trial

Oct. 31, 2023

Sarepta Therapeutics' recently-approved gene therapy, Elevidys, failed to meet the primary endpoint in a phase 3 pivotal study, but the drugmaker is still optimistic about a label expansion.

Sarepta announced topline results from the EMBARK study of patients with Duchenne muscular dystrophy between the ages of 4-7 years, revealing that 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.

Despite this, according to Sarepta, "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."

The FDA had granted accelerated approval for Elevidys back in June, for the treatment of a segment of pediatric patients with Duchenne muscular dystrophy. Specifically, Elevidys was approved for ambulatory pediatric patients aged 4-5 years with Duchenne who have a confirmed mutation in the DMD gene. 

Now, relying on the data from the trial's secondary endpoints, Sarepta plans to request an update to expand the labeled indication for Elevidys to treat all patients. 

“Importantly, we have shared the EMBARK topline results with FDA leadership and they have confirmed that, based on the totality of the evidence, they are open to such label expansion if supported by review of the data, and that they intend to proceed rapidly with consideration of the submission,” said Doug Ingram, Sarepta CEO.

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.