Ivonescimab Shows Survival Advantage Over Keytruda in Lung Cancer Trial

Akeso and Summit Therapeutics reported that ivonescimab significantly improved overall survival versus Merck’s Keytruda (pembrolizumab) in the phase 3 HARMONi-2 trial.

Among previously untreated patients with PD-L1-positive advanced non-small-cell lung cancer, median overall survival was 30.8 months with ivonescimab versus 22.6 months with Keytruda. The hazard ratio was 0.73, indicating about a 27% lower risk of death.

The benefit was strongest in patients with PD-L1 tumor proportion scores of at least 50%:
the overall-survival hazard ratio was 0.58, equivalent to an approximately 42% lower risk of death. In PD-L1 1–49% disease, the hazard ratio was 0.85 and the confidence interval crossed 1.

The trial had previously shown a major progression-free-survival advantage:
11.14 months with ivonescimab versus 5.82 months with Keytruda, with a hazard ratio of 0.51.

The results are important because Keytruda monotherapy is an established first-line option for PD-L1-high NSCLC. However, HARMONi-2 was conducted in China, so the findings will need confirmation in broader international populations.

Ivonescimab is a bispecific antibody designed to target PD-1 and VEGF-related pathways, aiming to combine immune activation with tumor-vessel inhibition. Further regulatory and global-trial results will determine whether it can challenge Keytruda internationally.