Edgewise Therapeutics (NASDAQ:EWTX), a clinical-stage biopharmaceutical company developing orally bioavailable small molecules for rare muscle disorders, announced positive long-term results from its MESA open-label extension study of sevasemten.
The data suggests that sevasemten, a first-in-class selective fast myofiber myosin inhibitor, may fundamentally alter the disease trajectory for individuals living with Becker muscular dystrophy (BMD).
The updated results highlight a significant divergence from the expected natural history of the disease.
In the CANYON cohort, patients treated with sevasemten showed a functional score improvement of +0.1 on the North Star Ambulatory Assessment (NSAA) at the two-year mark, compared to a predicted natural history decline of -2.9 points.
Even more striking were the results from the ARCH cohort, which demonstrated stabilization at +0.1 points over 3.5 years, contrasting sharply with a predicted decline of -5.3 points.
The study also reflected high patient confidence and commitment, with nearly 99% of all eligible participants from previous trials electing to enroll in the MESA extension.
Beyond the functional metrics, sevasemten maintained a favorable long-term safety and tolerability profile, with no treatment-related serious adverse events reported during the extended observation period.
All eyes in the rare disease community are now turning toward the company's pivotal Phase 2/3 GRAND CANYON trial.
This placebo-controlled cohort is expected to provide a topline readout in the fourth quarter of 2026.
If the results are positive and reflect the stabilization seen in the open-label data, Edgewise intends to move forward with a marketing application to the FDA and global regulatory bodies.