Cogent Biosciences, Inc. has announced positive top-line results from the registration-directed part 2 of the summit clinical trial of bezuclastinib in patients with non-advanced systemic mastocytosis (nonadvsm). The trial achieved statistical significance across all primary and key secondary endpoints, showcasing the drug's effectiveness in treating this patient population.
In the summit trial, patients treated with bezuclastinib demonstrated a superior mean change in total symptom score at 24 weeks compared to those treated with placebo. The bezuclastinib arm had a mean reduction of 24.3 points in total symptom score, versus the placebo arm which had a mean reduction of 15.4 points. This resulted in a placebo-adjusted total symptom score improvement of 8.91 points, with a p-value of 0.0002.
Furthermore, bezuclastinib showed a powerful effect on mast cell burden, with 87.4% of patients treated with bezuclastinib achieving at least a 50% reduction in serum tryptase, compared to 0% of patients treated with placebo, with a p-value of <0.0001.
The trial also demonstrated highly statistically significant benefit across all key secondary endpoints, including the reduction of kit D816V VAF, reduction in bone marrow mast cell aggregates, and mean change in the most severe symptom at baseline.
Regarding safety and tolerability, the majority of treatment emergent adverse events (TEAEs) were of low grade, with hair color change, altered taste, and nausea being the most frequently reported TEAEs on bezuclastinib treatment. Serious adverse events occurred in 4.2% of patients treated with bezuclastinib, compared to 5.0% of patients treated with placebo.
Cogent Biosciences plans to submit its first new drug application (NDA) to the U.S. Food and Drug Administration (FDA) for bezuclastinib in nonadvsm by the end of 2025, and detailed results from the summit trial will be presented at an upcoming medical meeting later this year.
In addition to the positive results from the summit trial, Cogent Biosciences remains on track to provide top-line results from both the peak, a phase 3 trial of bezuclastinib in combination with sunitinib in patients with gastrointestinal stromal tumors (GIST), and the apex, a registration-directed trial of bezuclastinib in advanced systemic mastocytosis (advsm) patients, during the second half of 2025.
The company also highlighted its strong financial position, with a current cash balance of $237 million and access to up to an additional $350 million via a recently announced debt facility with SLR Capital Partners.
The market has reacted to these announcements by moving the company's shares 5.53% to a price of $10.975. For more information, read the company's full 8-K submission here.
