Summit Therapeutics Inc. (NASDAQ: SMMT) shares are trading higher following news from its development partner, Akeso Inc., regarding a late-stage clinical trial for ivonescimab. The Phase 3 HARMONi-2 study evaluated ivonescimab as a standalone treatment against Merck & Co Inc.’s (NYSE: MRK) Keytruda (pembrolizumab) for locally advanced or metastatic non-small cell lung cancer (NSCLC) with positive PD-L1 expression.
The trial, conducted exclusively in China, reported that ivonescimab monotherapy provided a statistically significant improvement in overall survival compared to pembrolizumab. While overall survival was a secondary endpoint, the company plans to present the comprehensive findings at an upcoming medical conference.
In the primary analysis, the Independent Radiologic Review Committee determined that ivonescimab showed a significant enhancement in progression-free survival. The treatment achieved a hazard ratio of 0.51. The data demonstrated a clinically meaningful benefit across various patient subgroups, including those with high and low PD-L1 expression, as well as those with squamous and non-squamous tumor histologies.
China’s National Medical Products Administration previously granted marketing authorization for ivonescimab in April 2025, driven by the initial HARMONi-2 results. However, the therapy remains strictly investigational within Summit Therapeutics’ licensed territories outside of China.
At the time of publication, Summit Therapeutics shares were up 10.79% at $15.55.
