Summit Therapeutics Partner's Monotherapy Beats Pembrolizumab on Overall Survival

By Tamara Parker • Thursday, September 03 10:51 • Permanent Link

Summit Therapeutics said its partner Akeso reported that ivonescimab monotherapy beat pembrolizumab monotherapy on overall survival in the phase 3 HARMONI-2 study in patients with locally advanced or metastatic non-small cell lung cancer whose tumors were PD-L1-positive.

The result comes from a preplanned overall survival analysis in HARMONI-2, a randomized, double-blind study conducted in China. Summit said the overall survival finding was statistically significant, though it did not provide the hazard ratio, median survival figures, or p-value in the release.

The company pointed back to the study’s earlier primary analysis, which showed progression-free survival of 0.51 versus pembrolizumab, with a 95% confidence interval of 0.38 to 0.69 and p-value below 0.0001. That earlier readout also showed benefit across PD-L1 low and high expression, squamous and non-squamous disease.

Akeso received Chinese marketing authorization for ivonescimab in April 2025 based on HARMONI-2. Summit said the latest overall survival data will be presented at an upcoming medical conference.

Summit’s own HARMONI-7 trial is still enrolling. That study is testing ivonescimab monotherapy against pembrolizumab monotherapy in first-line metastatic NSCLC with high PD-L1 expression.

The company said five phase 3 ivonescimab studies have reported results so far, and all five have been positive. Four of those are in NSCLC and one is in biliary tract cancer. In addition to HARMONI-2, Akeso has reported positive phase 3 readouts in HARMONI-A, HARMONI-6 and HARMONI-GI1, with overall survival benefit reported in all three NSCLC studies from China and in the biliary tract cancer study.

Summit said more than 4,000 patients have received ivonescimab in clinical studies globally, and more than 70,000 patients have been treated in China in the commercial setting. The drug is now in 16 phase 3 studies, including five sponsored by Summit, one by a cooperative group, and 10 run by Akeso in China. The market has reacted to these announcements by moving the company's shares 8.4% to a price of $15.8261. For more information, read the company's full 8-K submission here.

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