Ivonescimab Plus Chemotherapy Demonstrates Consistent Global Benefit: HARMONi Data Update Shows OS HR=0.78, Nominal P=0.0332
- The overall survival (OS) hazard ratio (HR) in the HARMONi trial was 0.78, with a nominal p-value of 0.0332
- In the North American patients, the OS HR was 0.70
- The HARMONi trial has already demonstrated clinically meaningful and statistically significant progression-free survival (PFS) outcomes
- In the HARMONi trial, clinical endpoint benefits, including OS and PFS, were consistent across Western and Asian patient populations, and these results were also in alignment with the clinical data from the HARMONi-A trial conducted in China
HONG KONG, Sept. 7, 2025 /PRNewswire/ -- Akeso, Inc. (HKEX: 9926.HK) is pleased to share today that its global partner, Summit Therapeutics Inc. (NASDAQ: SMMT), announced the updated overall survival (OS) results from the global Phase III HARMONi clinical trial of ivonescimab, a novel PD-1/VEGF bispecific antibody, at the Presidential Symposium in the 2025 World Conference on Lung Cancer (WCLC).
Longer-term follow-up of western patients showed improving, favorable trend in OS, yielding a hazard ratio (HR) of 0.78 and a nominal p-value of 0.0332.
Meanwhile, Akeso recently announced that the HARMONi-A study conducted in China has also recently reached the OS clinical endpoint, achieving clinically meaningful and statistically significant OS benefit. The OS data from this study will be presented at upcoming academic conferences.
The results from the first international multi-center Phase III HARMONi study of ivonescimab, along with those from the Phase III HARMONi-A study conducted in China, demonstrated consistent and robust clinical efficacy in both progression-free survival (PFS) and OS. These findings provide strong evidence that ivonescimab not only offers significant advantages in terms of rapid onset of action and effective disease control in cancer treatments but also provide survival benefits to patients. The data further support ivonescimab's consistent efficacy and safety across diverse global populations, including both international and Chinese cohorts, reinforcing its potential for broad therapeutic benefit for cancer patients worldwide.
Approximately 38% of patients were recruited from western countries.
The trial results were presented by Jonathan Goldman, MD, Professor of Medicine at UCLA in the Hematology/Oncology Division, UCLA Director of Clinical Trials in Thoracic Oncology, Associate Director of Early Drug Development, and Chair of University of California Lung Cancer Consortium.
Clinically Meaningful Efficacy
As previously disclosed, ivonescimab in combination with chemotherapy showed a positive trend in OS in the primary analysis without achieving a statistically significant benefit with a hazard ratio of 0.79 (95% CI: 0.62 – 1.01; p=0.057). The statistical analysis plan for the study required a p-value of 0.0448 in order to achieve statistical significance at the time of the primary analysis of overall survival. Median overall survival was 16.8 months for those patients administered ivonescimab plus chemotherapy vs. 14.0 months for those receiving placebo plus chemotherapy. It was noted at the time of the primary analysis that the median follow-up time for western patients was 9.2 months and less than the median overall survival at the time of the primary analysis, and these patients may continue to be followed for long-term outcomes.
In September 2025, an additional analysis was performed, whereby the western patients were followed to increase their time on study (Asian patients were locked at the time of the primary analysis). In this analysis that included longer-term follow-up of western patients (median follow-up time of western patients of 13.7 months), a hazard ratio consistent with the primary analysis was observed with an improved nominal p-value (HR=0.78; 95% CI: 0.62 – 0.98; nominal p=0.0332). Median OS for this analysis remained the same in both arms from the primary analysis. Median OS in western patients receiving ivonescimab was 17.0 months compared to 14.0 months for those receiving placebo (HR=0.84); median OS in North American patients, specifically, had not yet been reached in the ivonescimab arm compared to 14.0 months in the placebo arm (HR=0.70). The hazard ratios for western patients in totality, as well as patients from the North American and European regions individually, improved from the primary OS analysis to the analysis with longer-term follow-up of western patients. Consistent benefit was observed across pre-defined subgroups.
As previously disclosed at the prespecified primary data analysis for PFS, ivonescimab in combination with chemotherapy demonstrated a statistically significant and clinically meaningful improvement with a hazard ratio of 0.52 (95% CI: 0.41 – 0.66; p
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