Cogent's Bezuclastinib Hits 65% Response Rate in Advanced Mastocytosis Trial — Cogent Biosciences, Inc.

Event summary

Bezuclastinib achieved 65% objective response rate in advanced systemic mastocytosis (AdvSM) patients per mIWG criteria, 81% per PPR criteria.
91% of patients saw ≥50% reduction in KIT D816V variant allele frequency, 89% had ≥50% reduction in bone marrow mast cells.
NDA submission for AdvSM planned for June 2026, with commercial launch expected later this year pending FDA approval.
Safety profile showed low-grade, reversible adverse events with no dose discontinuations for transaminase elevations.

The big picture

Cogent's data positions bezuclastinib as a potential standard of care for AdvSM, leveraging its selective KIT D816V inhibition. The results reinforce the growing trend of precision therapies targeting genetically defined cancers, particularly in rare diseases with high unmet need. The company's ability to secure FDA approval and scale commercial operations will determine its long-term competitive position in oncology.

What we're watching

Regulatory Timing: Whether the June 2026 NDA submission will meet FDA expectations for accelerated approval in rare diseases.
Market Positioning: How Cogent positions bezuclastinib against existing treatments for systemic mastocytosis and GIST.
Commercial Execution: The pace at which Cogent can establish expanded access programs and commercial infrastructure for dual indications.