---
schema_version: "secwatch.filing_event.v1"
accession: "0001599298-24-000043"
form_type: "8-K"
ticker: "SMMT"
cik: "0001599298"
company_name: "Summit Therapeutics Inc."
filed_at: "2024-03-22T23:59:59+00:00"
generated_at: "2026-06-04T09:03:03.992098+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Ivonescimab shows 34% intracranial response in NSCLC brain mets; median PFS 19.3 months

## Summary
- Intracranial response rate 34% (23% complete) in NSCLC patients with brain metastases; median PFS 19.3 months.
- Ivonescimab + chemo in 1L squamous NSCLC: median PFS 11.1 months; non-squamous: 13.3 months; OS not reached at 22.1 months.
- No intracranial bleeding observed across cohorts; safety profile manageable with 11.1% discontinuation in squamous group.
- Two Phase III trials ongoing: HARMONi (EGFR-mutant post-TKI) and HARMONi-3 (1L squamous NSCLC).
- Data presented at ELCC 2024; posters available on company website.

## SEC filing metadata
- accession: 0001599298-24-000043
- form_type: 8-K
- ticker: SMMT
- cik: 0001599298
- company_name: Summit Therapeutics Inc.
- filed_at: 2024-03-22T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1599298/000159929824000043/0001599298-24-000043-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1599298/000159929824000043/smmt-20240322.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001599298-24-000043
- JSON: https://secwatch.observer/filing/0001599298-24-000043.json
- Plain text: https://secwatch.observer/filing/0001599298-24-000043.txt

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