Summit Therapeutics Inc. reported on September 2, 2026, that its partner, Akeso Inc., has announced positive overall survival results from the Phase III HARMONi-2 study. The study evaluated ivonescimab monotherapy against pembrolizumab monotherapy in patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) whose tumors have positive PD-L1 expression.
HARMONi-2 is a randomized, double-blind Phase III study conducted in China and sponsored by Akeso. In a preplanned analysis of OS, a secondary endpoint, Akeso reported that ivonescimab monotherapy demonstrated a statistically significant improvement compared to pembrolizumab monotherapy. Results from this analysis are scheduled to be presented at an upcoming medical conference.
Akeso received marketing authorization for ivonescimab from China’s National Medical Products Administration (NMPA) based on the results of HARMONi-2 in April 2025. In the study's primary analysis, ivonescimab monotherapy demonstrated a statistically significant improvement in progression-free survival (PFS) by the Independent Radiologic Review Committee (IRRC) when compared to pembrolizumab monotherapy, achieving a hazard ratio of 0.51 (95% CI: 0.38, 0.69; p<0.0001).
Ivonescimab, known as SMT112 in Summit’s license territories, is a novel bispecific antibody combining the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects associated with blocking VEGF. The company notes that ivonescimab remains investigational and is not approved by any regulatory authority in Summit’s license territories, including the United States and Europe.
