Edgewise Therapeutics announces results from sevasemten program

Edgewise Therapeutics (EWTX) unveiled results in its sevasemten program for Becker and Duchenne muscular dystrophies. The company announced data from MESA, an open label extension trial that is providing continued access to sevasemten to participants with Becker who were previously enrolled in ARCH, or completed CANYON, GRAND CANYON, or DUNE. As of the March data cut, 99% of eligible participants are enrolled in MESA. The MESA data demonstrated sustained disease stabilization, reinforcing prior ARCH and CANYON findings. Importantly, CANYON participants who rolled over to MESA showed increased North Star Ambulatory Assessment scores over 18 months, with a trend toward improvement in placebo participants switching to sevasemten. During the 18 months of sevasemten treatment, participants’ NSAA scores continued to diverge relative to the expected functional declines seen in multiple Becker natural history studies. Further, NSAA scores for ARCH participants who rolled over to MESA remained stable after three years of treatment. Sevasemten continues to demonstrate a favorable safety profile after up to three years of treatment. Edgewise recently completed a successful Type C meeting with the FDA, which provided a clear path to registration of sevasemten as the first ever therapy for Becker. While the FDA deemed the CANYON data alone insufficient for an accelerated approval, the Agency reiterated that NSAA is a clinically meaningful endpoint for traditional approval. The FDA encouraged Edgewise to continue to share MESA data and natural history prospective modeling ahead of GRAND CANYON completion. Further, the FDA emphasized their support for GRAND CANYON, the ongoing global pivotal placebo-controlled cohort, and its potential as a single adequate well-controlled study to support registration. GRAND CANYON is highly powered to show a statistically significant difference in NSAA versus placebo over 18 months and is on track for topline data in the fourth quarter of 2026. The company also announced encouraging topline data from its Phase 2 Duchenne trials, LYNX and FOX. The goals were to explore a range of doses to assess safety and identify a potentially beneficial dose for Phase 3. The trial’s dose escalation paradigm provided a three-month placebo-controlled period to evaluate biomarkers for dose selection, followed by an open label period. Across both studies, at target doses, sevasemten was well-tolerated. The company plans to meet with the FDA in the fourth quarter to discuss a Phase 3 design including input on the patient population and endpoints, with plans to initiate the pivotal study in 2026. In addition, the company plans to continue to collect longer-term open label extension data, which will provide further access to the drug to trial participants.