Cogent Biosciences reported a Phase 3 success for bezuclastinib in advanced systemic mastocytosis, meeting its primary endpoint and demonstrating benefit in sicker patient cohorts. The company plans to use the data to support a regulatory submission in 2026. Results build on earlier positive readouts and strengthen Cogent's case for market access in a rare, high‑need indication where treatment options are limited. The company highlighted safety and durability data as part of its regulatory dossier preparation.