---
schema_version: "secwatch.filing_event.v1"
accession: "0001599298-26-000074"
form_type: "8-K"
ticker: "SMMT"
cik: "0001599298"
company_name: "Summit Therapeutics Inc."
filed_at: "2026-08-26T13:17:16+00:00"
generated_at: "2026-08-26T13:18:33.779783+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 Phase III HARMONi-GI1 results for ivonescimab in biliary tract cancer

## Summary
- Akeso announced ivonescimab plus chemo showed statistically significant overall survival benefit vs durvalumab plus chemo in first-line advanced BTC.
- HARMONi-GI1, a Phase III study in China sponsored by Akeso, also met key secondary endpoints of progression-free survival and objective response rate.
- This is the first known Phase III study in advanced BTC to show OS superiority against an anti-PD-(L)1 plus chemotherapy regimen.
- Detailed safety and efficacy results will be presented at an upcoming medical congress and published in a peer-reviewed journal.
- Ivonescimab remains investigational in Summit's territories including U.S. and Europe; it is approved for NSCLC in China.

## SEC filing metadata
- accession: 0001599298-26-000074
- form_type: 8-K
- ticker: SMMT
- cik: 0001599298
- company_name: Summit Therapeutics Inc.
- filed_at: 2026-08-26T13:17:16+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/1599298/000159929826000074/0001599298-26-000074-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1599298/000159929826000074/smmt-20260825.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001599298-26-000074
- JSON: https://secwatch.observer/filing/0001599298-26-000074.json
- Plain text: https://secwatch.observer/filing/0001599298-26-000074.txt

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