---
schema_version: "secwatch.filing_event.v1"
accession: "0001599298-24-000128"
form_type: "8-K"
ticker: "SMMT"
cik: "0001599298"
company_name: "Summit Therapeutics Inc."
filed_at: "2024-09-09T23:59:59+00:00"
generated_at: "2026-05-31T05:54:22.498043+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Summit reports ivonescimab beats Keytruda in Phase 3 NSCLC trial; PFS HR=0.51 p<0.0001

## Summary
- Ivonescimab vs pembrolizumab in 1L PD-L1+ advanced NSCLC: mPFS 11.14 vs 5.82 months (HR 0.51, p<0.0001).
- ORR 50.0% vs 38.5%, DCR 89.9% vs 70.5%. OS not yet mature; safety manageable.
- Subgroup benefit consistent: PD-L1 TPS≥50% HR 0.46; squamous HR 0.48; non-squamous HR 0.54.
- Phase II perioperative AK112-205 in resectable NSCLC: MPR 71.8% (cohort 2), pCR 43.6% with ivonescimab+chemo.
- Additional Phase II data in breast, colorectal, head & neck cancers released at ESMO; conference call Sep 9.

## SEC filing metadata
- accession: 0001599298-24-000128
- form_type: 8-K
- ticker: SMMT
- cik: 0001599298
- company_name: Summit Therapeutics Inc.
- filed_at: 2024-09-09T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1599298/000159929824000128/0001599298-24-000128-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1599298/000159929824000128/smmt-20240908.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001599298-24-000128
- JSON: https://secwatch.observer/filing/0001599298-24-000128.json
- Plain text: https://secwatch.observer/filing/0001599298-24-000128.txt

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