Akeso presented the survival data for ivonescimab in biliary tract cancer at the ESMO Presidential Symposium, one of 12 presentations the company gave on the drug at the congress, according to PharmaVoice. In the randomised, double blind Phase 3 HARMONi-GI1 trial in China, ivonescimab plus chemotherapy produced a median overall survival of 14.9 months against 12.1 months for AstraZeneca durvalumab plus chemotherapy as first line treatment for advanced biliary tract cancer. The hazard ratio was 0.75, a 25 percent reduction in the risk of death, and the trial also met its progression free survival and response rate secondary endpoints.
The companies describe it as the first regimen to achieve a statistically significant and clinically meaningful overall survival benefit over an anti PD-L1 antibody combined with chemotherapy in a Phase 3 trial in this disease. The benefit is modest in absolute months, 2.8 months of median survival, in a cancer with few effective options, and it adds a second tumour type to a drug whose reputation rests mainly on lung cancer data.
The limits are geographic and regulatory. HARMONi-GI1 was a single region study conducted in China, sponsored by Akeso, with all data generated, managed and analysed by Akeso. Ivonescimab is approved in China, and more than 100,000 patients have been treated commercially there according to the company, but its United States partner Summit Therapeutics is still awaiting an FDA decision in lung cancer. A United States registration enabling Phase 2/3 study in biliary tract cancer is due to start in the fourth quarter of 2026 through Summit collaboration with the ECOG-ACRIN research group.
Summit holds rights to ivonescimab in the United States, Canada, Europe, the Middle East, Africa, Japan and South America under a deal worth up to 5 billion dollars. Five Phase 3 trials of the drug have now read out with positive data, four in lung cancer and this one in biliary tract cancer, according to Summit. Each additional positive head to head result against an established checkpoint inhibitor strengthens the argument that the bispecific design, blocking PD-1 and VEGF in one molecule, is a class effect rather than a single trial result, and each one also raises the cost of an FDA delay in the lead lung indication.