---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-405776"
form_type: "8-K"
ticker: "SMMT"
cik: "0001599298"
company_name: "Summit Therapeutics Inc."
filed_at: "2026-09-29T01:39:22+00:00"
generated_at: "2026-10-12T13:40:23.533936+00:00"
event_type: "m_and_a"
sentiment: "positive"
materiality_score: 0.88
calibrated_materiality_score: 0.88
confidence: "high"
source: SEC EDGAR
---

# AstraZeneca to invest $2B in Summit at $18.36/share, a 10% premium, plus clinical collaboration

## Summary
- AstraZeneca Holdings B.V. buys 108,955.3686 Class A Convertible Preferred shares at $18,356.14 each for $2.0B; each converts into 1,000 common shares.
- Effective common price of $18.36 equals VWAP of the five trading days from the prior week plus 10%, a premium to Summit's closing price; closing expected by end of this week.
- Conversion is blocked until the HSR waiting period ends and a charter amendment authorizing enough common shares is effective; Summit must redeem for cash if the amendment misses an 18-month deadline.
- Summit also signed a clinical collaboration with AstraZeneca to test sonesitatug vedotin (sone-ve) plus ivonescimab in gastrointestinal cancers, AstraZeneca-sponsored with shared costs.
- A non-binding MOU covers combining ivonescimab with AstraZeneca's ADC portfolio; no milestones, royalties, revenue-sharing or profit-sharing; resale registration due within 60 days of closing.

## SEC filing metadata
- accession: 0001193125-26-405776
- form_type: 8-K
- ticker: SMMT
- cik: 0001599298
- company_name: Summit Therapeutics Inc.
- filed_at: 2026-09-29T01:39:22+00:00
- event_type: m_and_a
- sentiment: positive
- materiality_score: 0.88
- calibrated_materiality_score: 0.88
- confidence: high
- sec_items: 1.01, 5.03, 3.02, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1599298/000119312526405776/0001193125-26-405776-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1599298/000119312526405776/d178892d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-405776
- JSON: https://secwatch.observer/filing/0001193125-26-405776.json
- Plain text: https://secwatch.observer/filing/0001193125-26-405776.txt

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