Cogent Biosciences Announces Positive Top-line Results Achieving Statistical Significance Across All Primary and Key Secondary Endpoints from the SUMMIT Trial of Bezuclastinib in Patients with Non-Advanced Systemic Mastocytosis

Core Insights - Bezuclastinib has shown significant clinical benefits in treating patients with non-advanced systemic mastocytosis (NonAdvSM), achieving a statistically significant mean change in total symptom score (TSS) at 24 weeks compared to placebo [1][2][3] - The drug demonstrated a substantial reduction in serum tryptase levels, with 87.4% of patients experiencing at least a 50% reduction, contrasting with 0% in the placebo group [1][2] - Bezuclastinib is expected to submit a New Drug Application (NDA) to the FDA by the end of 2025, supported by a strong financial position with $237 million in cash and access to an additional $350 million [1][2][6] Clinical Trial Results - The SUMMIT trial achieved its primary endpoint with a mean reduction of 24.3 points in TSS for the bezuclastinib group versus 15.4 points for placebo, resulting in a placebo-adjusted improvement of 8.91 points (p=0.0002) [2][3] - All key secondary endpoints also showed statistically significant improvements, including a ≥50% reduction in serum tryptase (p<0.0001) and other measures of mast cell burden [3][4] Safety and Tolerability - Bezuclastinib exhibited a favorable safety profile, with the majority of treatment-emergent adverse events (TEAEs) being low grade; 98.3% in the bezuclastinib arm compared to 88.3% in the placebo arm [4][5] - Common TEAEs included hair color change (69.5% vs. 5.0% placebo), altered taste (23.7% vs. 0%), and nausea (22.0% vs. 13.3%) [4][5] Future Plans - Cogent plans to present detailed results from the SUMMIT trial at an upcoming medical meeting later this year and is on track to share pivotal trial results from the PEAK and APEX trials in the second half of 2025 [1][6][5]