Summit Therapeutics Inc. (SMMT) partner Akeso Inc. on Sunday revealed overall survival data from the Phase 3 HARMONi-2 trial evaluating ivonescimab against pembrolizumab.
The findings showed that ivonescimab significantly extended survival for first-line patients with PD-L1-positive locally advanced or metastatic non-small cell lung cancer.
Following the announcement, the stock gained over 6%.
In the intention-to-treat population, ivonescimab monotherapy achieved a median overall survival of 30.8 months compared to 22.6 months for pembrolizumab.
This represents a statistically significant 27% reduction in the risk of death, based on a 36-month median follow-up with 234 survival events.
Ivonescimab Shows Superior Survival Benefits Over Pembrolizumab
Ivonescimab demonstrated broad clinical benefit across prespecified patient subgroups, showing pronounced efficacy in high PD-L1 expression populations.
Patients with a PD-L1 tumor proportion score of 50% or higher experienced a 42% reduction in mortality risk.
Additionally, treatment reduced death risk by 35% in patients with squamous cell carcinoma and 21% in non-squamous patients.
Broad Efficacy Across Subgroups And Favorable Safety Profile
Squamous NSCLC patients made up 45.5% of the trial, with many presenting high-risk features such as central tumors or major vessel encasement.
Despite traditional anti-VEGF contraindications for these conditions, ivonescimab showed no apparent increase in bleeding risk while maintaining a favorable safety profile.
HARMONi-2 is the first randomized Phase 3 study to prove statistically significant positive overall survival and progression-free survival results against pembrolizumab.
Following approval in China in 2025, ivonescimab's dual immuno-oncology and anti-angiogenesis mechanism continues expanding into major solid tumors worldwide.
Summit Therapeutics Price Action
SMMT Price Action: Summit Therapeutics shares were up 6.25% to $18.65 at the time of publication on Monday, according to market data.
