Why Is Summit Therapeutics Stock Gaining Monday?

Summit Therapeutics Inc. (NASDAQ: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 Benzinga Pro data.

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