What did Elevidys's confirmatory trial show?

The phase 3 EMBARK trial was designed to confirm that Elevidys improves function, as required for its accelerated approval. It enrolled 125 ambulatory boys aged 4 to 7 and measured change in the North Star Ambulatory Assessment motor score at 52 weeks. Treated boys improved by 2.6 points versus 1.9 on placebo, a difference that was not statistically significant, so the trial failed its primary endpoint.

Sarepta announced the miss in October 2023 but called the findings "robust evidence" of clinically meaningful benefit, pointing to secondary measures such as time to rise from the floor. Those measures, however, were also not statistically significant. Despite this, the FDA expanded the label in 2024, which critics saw as a further weakening of the evidentiary standard.