Summit Therapeutics Inc. shares advanced 4.8% in premarket trading after the company reported positive survival data from a Phase III trial of its lung cancer drug ivonescimab.
The HARMONi-2 study, a randomized, double-blind Phase III trial conducted by partner Akeso Inc. in China, enrolled 398 patients with locally advanced or metastatic non-small cell lung cancer and positive PD-L1 expression. Ivonescimab monotherapy demonstrated a statistically significant improvement in progression-free survival versus Merck & Co.'s pembrolizumab monotherapy, achieving a hazard ratio of 0.51.
The company also reported a statistically significant overall survival benefit for ivonescimab, a secondary endpoint in the trial. However, Summit did not disclose specific hazard ratios, median survival times, or event counts for the overall survival analysis. Full results are slated for presentation at an upcoming medical conference.
Akeso received marketing authorization for ivonescimab from China's National Medical Products Administration in April 2025 based on HARMONi-2 data. The drug is approved and commercially available in China for non-small cell lung cancer indications but remains investigational in Summit's license territories, including the United States and Europe.
Analyst Mitchell S. Kapoor of H.C. Wainwright maintained a neutral rating on Summit, noting that while the interim overall survival result reduces the risk of a negative outcome, the lack of detailed data prevents a change in his view. Kapoor also highlighted that Summit does not derive economic benefits from ivonescimab in China.
