Summit reports updated HARMONi overall survival data at WCLC 2026
Longer follow-up in western patients on ivonescimab plus chemotherapy matched survival gains seen earlier in Asian patients, with no new safety signals.
Summit Therapeutics announced on September 15, 2026 that updated overall survival results from the global Phase III HARMONi trial were presented at the IASLC 2026 World Conference on Lung Cancer in Seoul. Summit had previously reported on July 22, 2026 that ivonescimab plus platinum-doublet chemotherapy in HARMONi continued to show a positive OS trend and consistent efficacy and safety compared with placebo plus chemotherapy in both Asian and western patients.1
The trial enrolls patients with EGFR-mutated, locally advanced or metastatic non-squamous NSCLC previously treated with a third-generation EGFR TKI. At the primary OS analysis in April 2025, ivonescimab plus chemotherapy showed a hazard ratio of 0.79 (95% CI: 0.62-1.01; p=0.057), with median OS of 16.8 months versus 14.0 months for placebo plus chemotherapy.1 A newer analysis, with a June 2026 data cutoff, came after most western patients had discontinued or completed two years of treatment, giving a median follow-up of 23.2 months in that subgroup.1
In the updated June 2026 analysis, the global intention-to-treat hazard ratio improved to 0.76, with a 95% confidence interval of 0.61 to 0.95 and a nominal p-value of 0.0151.1 The western patient subgroup showed a matching hazard ratio of 0.76 (95% CI: 0.52-1.10), described as consistent with both the overall population and the Asian subgroup.1 The company said ivonescimab's safety profile remained acceptable and manageable and consistent with prior Phase III data, with no additional safety signals in this data cut.1
Separately, Akeso Inc., Summit's partner, presented full results from its China-only HARMONi-2 trial at the same conference. In that study, ivonescimab monotherapy showed a statistically significant improvement over pembrolizumab monotherapy in a secondary OS analysis, with a hazard ratio of 0.73 (95% CI: 0.57-0.95; p=0.009).1
Summit's BLA for ivonescimab, based on HARMONi data, has an FDA PDUFA goal action date of November 14, 2026.1
Written by readthrough’s AI from the linked primary sources and fact-checked against them automatically before publishing. Not investment advice.