Chinese biopharmaceutical company Akeso Inc (HK:9926) announced on Sunday the presentation of positive overall survival (OS) results from the randomised, double-blind, multicentre, registrational Phase III HARMONi-2 study (AK112-303) at the 2026 World Conference on Lung Cancer (WCLC), organised by the International Association for the Study of Lung Cancer (IASLC).

The study evaluated the company's first-in-class next-generation immuno-oncology therapy, ivonescimab, versus pembrolizumab as first-line treatment for patients with PD-L1-positive (PD-L1 TPS greater than 1%) locally advanced or metastatic non-small cell lung cancer (NSCLC).

As of the data cutoff on 20 August 2026, the median follow-up was 36 months, and a total of 234 overall survival (OS) events had occurred. For this OS analysis, a prespecified O'Brien-Fleming spending function was used, with a one-sided alpha of 0.0141.

According to Akeso, results showed that, compared with pembrolizumab, first-line treatment with ivonescimab significantly prolonged OS in patients with PD-L1-positive advanced NSCLC. This finding met the prespecified statistical significance threshold and demonstrated clear clinical benefit. The overall survival benefit was generally consistent across prespecified subgroups, with particularly pronounced benefit observed in the PD-L1-high population.

In May 2024, a prespecified interim analysis of progression-free survival (PFS) confirmed that HARMONi-2 met its primary PFS endpoint with statistically significant and clinically meaningful results. Median PFS was 11.14 months with ivonescimab versus 5.82 months with pembrolizumab.

HARMONi-2 is the first randomised, double-blind, controlled Phase III clinical study to demonstrate statistically significant positive OS and PFS results versus pembrolizumab, the company said.