European Society for Medical Oncology (ESMO) shared on LinkedIn:
“Promising phase III data were presented in a Presidential Symposium at ESMO 2026 with the PD-1/VEGF bispecific antibody ivonescimab in treatment-naïve patients with biliary tract cancer in the HARMONi-GI1 Clinical Trial.
At a preplanned interim analysis, median overall survival was significantly improved with ivonescimab compared with durvalumab (14.9 months versus 12.1 months; p=0.0031), both added to chemotherapy.
Significant improvements were also seen with ivonescimab for progression-free survival and objective response rate. No new safety signals were identified.
About the HARMONi-GI1 trial
The Phase III HARMONi-GI1 trial demonstrated that ivonescimab (a PD-1/VEGF bispecific antibody) combined with chemotherapy significantly improves outcomes compared to standard durvalumab plus chemotherapy in first-line advanced biliary tract cancer. The trial successfully met its primary endpoint, extending median overall survival to 14.9 months versus 12.1 months with durvalumab, alongside substantial improvements in progression-free survival and objective response rate (53.8% versus 32.5%), with no new safety signals observed.
Commenting on the results presented at ESMO 2026, Dr. James J. Harding emphasized that this represents the fourth randomized Phase III trial in this setting to meet its primary overall survival endpoint. He noted that while the trial was conducted exclusively in a Chinese population with higher baseline Hepatitis B rates, global testing will help determine broader applicability across diverse patient populations.
These findings reflect a major shift toward bispecific antibodies in biliary tract cancers. Up to 50% of these tumors harbor actionable genomic alterations, with KRAS variants, MTAP deletions, and MET amplifications expanding the list of precision targets.
Additional agents such as rilvegostomig (PD-1/TIGIT) and tovecimig (DLL-4/VEGF), as well as novel combination regimens pairing ivonescimab with RAS inhibitors or antibody-drug conjugates (ADCs), are currently advancing clinical development.
You can also read: HARMONi-GI1 at ESMO 2026: Ivonescimab Plus Chemotherapy in Advanced Biliary Tract Cancer
