---
schema_version: "secwatch.filing_event.v1"
accession: "0001599298-26-000076"
form_type: "8-K"
ticker: "SMMT"
cik: "0001599298"
company_name: "Summit Therapeutics Inc."
filed_at: "2026-09-03T13:21:44+00:00"
generated_at: "2026-09-03T13:23:26.792508+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# Summit partner Akeso reports positive OS for ivonescimab in HARMONi-2 vs pembrolizumab

## Summary
- Akeso's HARMONi-2: statistically significant OS improvement for ivonescimab vs pembrolizumab in PD-L1-positive advanced NSCLC.
- Primary PFS analysis earlier: HR 0.51 (95% CI 0.38-0.69; p<0.0001) by IRRC; OS data to be presented at upcoming medical conference.
- Ivonescimab was approved by China's NMPA in April 2025 based on HARMONi-2; Summit holds license rights in US/Europe where it remains investigational.
- Summit is conducting HARMONi-7 in PD-L1 high-expressing NSCLC.

## SEC filing metadata
- accession: 0001599298-26-000076
- form_type: 8-K
- ticker: SMMT
- cik: 0001599298
- company_name: Summit Therapeutics Inc.
- filed_at: 2026-09-03T13:21:44+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1599298/000159929826000076/0001599298-26-000076-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1599298/000159929826000076/smmt-20260902.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001599298-26-000076
- JSON: https://secwatch.observer/filing/0001599298-26-000076.json
- Plain text: https://secwatch.observer/filing/0001599298-26-000076.txt

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