---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-311217"
form_type: "8-K"
ticker: "COGT"
cik: "0001622229"
company_name: "Cogent Biosciences, Inc."
filed_at: "2025-12-08T23:59:59+00:00"
generated_at: "2026-05-16T13:58:33.644520+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# Cogent reports positive SUMMIT and APEX trial results for bezuclastinib in mastocytosis

## Summary
- SUMMIT Part 2: mean TSS change -24.3 (-43%) vs placebo -15.4 (-29%), p<0.001; 34.3% vs 18.1% had >=50% TSS reduction (p=0.01).
- SUMMIT: 87.4% had >=50% serum tryptase reduction; 75.6% had >=50% bone marrow mast cell reduction (p<0.001 vs placebo).
- APEX Part 2 top-line: 57% ORR (CR+CRh+PR+CI) per mIWG criteria; 80% ORR per pure pathological response.
- APEX: 89% had >=50% serum tryptase reduction; 91% had >=50% KIT D816V VAF reduction; no discontinuations due to TRAEs.
- Cogent expects to submit NDA for bezuclastinib in AdvSM to FDA in H1 2026; detailed APEX data at scientific meeting H1 2026.

## SEC filing metadata
- accession: 0001193125-25-311217
- form_type: 8-K
- ticker: COGT
- cik: 0001622229
- company_name: Cogent Biosciences, Inc.
- filed_at: 2025-12-08T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1622229/000119312525311217/0001193125-25-311217-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1622229/000119312525311217/d81277d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-311217
- JSON: https://secwatch.observer/filing/0001193125-25-311217.json
- Plain text: https://secwatch.observer/filing/0001193125-25-311217.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.