secwatch.observer — SEC 8-K summary
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Issuer:     Summit Therapeutics Inc. (SMMT)
CIK:        0001599298
Form:       8-K
Filed at:   2025-09-08T23:59:59+00:00
Accession:  0001599298-25-000137
Event type: other_material
Sentiment:  positive
Materiality: 0.85
Item codes: 8.01, 9.01
LLM model:  deepseek-v4-flash:cloud@v2

Ivonescimab HARMONi trial shows improved OS trend in longer follow-up; North American HR=0.70
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- Longer-term follow-up of Western patients: OS HR=0.78 (nominal p=0.0332); median OS 16.8 vs 14.0 months.
- North American patients: median OS not reached for ivonescimab vs 14.0 months for placebo (HR=0.70).
- Primary PFS analysis showed HR=0.52 (p<0.00001); median PFS 6.8 vs 4.4 months.
- Overall response rate higher with ivonescimab (45% vs 34%); median duration of response 7.6 vs 4.2 months.
- Safety profile manageable; TRAEs leading to discontinuation 7.3% (ivonescimab) vs 5.0% (placebo).

Source:
  EDGAR index:    https://www.sec.gov/Archives/edgar/data/1599298/000159929825000137/0001599298-25-000137-index.htm
  Primary doc:    https://www.sec.gov/Archives/edgar/data/1599298/000159929825000137/smmt-20250907.htm
  HTML page:      https://secwatch.observer/filing/0001599298-25-000137

License: Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer