Summit Therapeutics has reported updated two-year overall survival (OS) data for Western patients in its HARMONi Phase III trial of ivonescimab plus chemotherapy in EGFR-mutated non–small cell lung cancer (NSCLC). At a June 2026 data cutoff, the Western subgroup showed an OS hazard ratio of 0.76 with a median follow‑up of 23.2 months, indicating a 24% reduction in the risk of death compared with placebo plus chemotherapy. The improvement in the Western HR over earlier analyses (from 0.98 in April 2025 to 0.84 in September 2025 and now 0.76) reflects longer follow‑up that better captures the full survival benefit. Median OS for Western patients treated with ivonescimab plus chemotherapy was approximately 16.8–17.0 months versus 14.0 months in the control arm, though detailed median OS, confidence intervals, and p‑values are reserved for an upcoming medical meeting.
Sources:
UPDATE: Summit Therapeutics (SMMT) - The Western OS Number Just Caught Up
Summit debuts longer-term ivonescimab data as it awaits ...
Summit Therapeutics Announces Updated Phase II Data ...
Summit Lung Cancer Drug Falls Short on Key Survival Goal in ...
Summit Therapeutics (SMMT) FDA Approvals, PDUFA ...
Summit drops as concerns over older patients cloud cancer ...
Summit's Keytruda Challenger Hits Cross-Country Consistency ...
Summit Therapeutics' Bispecific Antibody Shows Positive Survival ...
SUMMIT Meets Primary Endpoint for Safety, Efficacy of Tirzepatide
Summit's Bispecific Misses Survival Endpoint in Global ...
Extended follow-up of a phase II trial in relapsed, refractory ...
Summit's global PD-1xVEGF data show new promising OS ...