Akeso-Summit Ivonescimab Phase 3 HARMONi-2 Hits Overall Survival Endpoint Versus Keytruda in First-Line PD-L1-Positive NSCLC; First OS Win vs Keytruda in This Setting
Akeso (HKEX: 9926) and Summit Therapeutics (NASDAQ: SMMT) announced Thursday September 3, 2026 that the pre-specified interim overall survival analysis in the Phase 3 HARMONi-2 trial of ivonescimab (a first-in-class PD-1/VEGF bispecific antibody) met the key secondary endpoint of OS versus Merck's Keytruda (pembrolizumab) in first-line PD-L1-positive metastatic non-small cell lung cancer in China. Ivonescimab demonstrated statistically significant and clinically substantive improvement over pembrolizumab; specific hazard ratio and median OS numbers will be released at an upcoming medical meeting. The primary progression-free survival analysis reported earlier had shown ivonescimab reduced the risk of disease progression or death by 49% with median PFS of 11.14 months versus 5.82 months on pembrolizumab. HARMONi-2 is the fourth Phase 3 trial for ivonescimab to meet its OS endpoint (following biliary tract cancer and two other tumor types). The readout is the first head-to-head Phase 3 OS win for any drug versus Keytruda in first-line NSCLC and reshapes the competitive framing for the emerging PD-1/VEGF bispecific class.