Sevasemten stumbles in pivotal Becker muscular dystrophy trial, leaving patients without a first-ever approved therapy

Hope deferred for Becker muscular dystrophy patients as sevasemten fails its pivotal trial.

Servier announced that sevasemten, once positioned to become the first-ever approved therapy for Becker muscular dystrophy (BMD), failed to meet its primary or secondary endpoints in the pivotal GRAND CANYON trial. The trial randomized ~120 adults with BMD 2:1 to oral sevasemten or placebo over 18 months, using change in the North Star Ambulatory Assessment (NSAA) as the primary endpoint. No statistically significant benefit was observed. The safety profile remained favorable, and Servier is conducting a comprehensive analysis to understand why results diverged from earlier studies.

The miss is a sharp contrast to the phase 2 CANYON trial, which met its primary endpoint in December 2024, and open-label studies that showed encouraging biomarker and functional trends. Servier acquired the BMD program from Edgewise Therapeutics in June 2026 for up to $2.65 billion.

By the Numbers:

• ~120 adults randomized in GRAND CANYON (2:1 sevasemten vs. placebo)
• CANYON showed a 28% greater creatine kinase reduction vs. placebo (P=.02)
• Fast skeletal muscle troponin I fell 77% more than placebo in CANYON (P<.001)
• Acquisition cost: $1.55B upfront + up to $1.1B in milestones

Why it matters: BMD remains without any approved therapy, and this failure sets back what had been the field's most advanced treatment candidate — leaving patients and clinicians back at square one.