Summit Therapeutics said the U.S. Food and Drug Administration rejected its ivonescimab application, leaving the proposed chemotherapy combination without U.S. approval for a defined group of advanced lung cancer patients.
The company said the Complete Response Letter found that the application had not established a statistically significant overall-survival benefit. Summit also said the FDA concluded that the progression-free-survival result alone did not support a favorable benefit-risk profile.
The application covered patients with locally advanced or metastatic, epidermal growth factor receptor (EGFR)-mutated, non-squamous non-small cell lung cancer whose disease progressed after treatment with a third-generation EGFR tyrosine kinase inhibitor. It proposed ivonescimab alongside platinum-containing chemotherapy, based on the global Phase III HARMONi trial.
In HARMONi, median progression-free survival was 6.8 months with ivonescimab plus chemotherapy and 4.4 months with placebo plus chemotherapy. Median overall survival was 16.8 months and 14.0 months, respectively. The primary overall-survival analysis had a hazard ratio of 0.79, with a 95% confidence interval of 0.62 to 1.01; Summit reported a p-value of 0.057, which did not meet the threshold for statistical significance.
Summit later reported a post-hoc analysis using data through June 2026. That analysis showed a global overall-survival hazard ratio of 0.76 and a nominal p-value of 0.0151. It was separate from the trial’s primary analysis.
Summit said Akeso Inc. invented ivonescimab and that the drug received its first marketing authorization in China in May 2024. EconoTimes previously covered a separate ivonescimab trial in biliary tract cancer.
Robert W. Duggan, Summit’s chairman and co-CEO, said the company was “disappointed for patients and their families awaiting additional treatment options.” Summit also listed ongoing Phase III studies in first-line lung cancer and colorectal cancer. Its Nov. 15 announcement gave no dates for results from those trials.
