Phase 2 trial of first-line cadonilimab plus chemotherapy for unresectable locally advanced or metastatic biliary tract cancer

The phase 2 BicureX trial, at West China Hospital of Sichuan University (Chengdu, China) evaluated cadonilimab (anti-PD-1/CTLA-4 bispecific antibody) plus gemcitabine-cisplatin (GC) chemotherapy as first-line treatment for unresectable locally advanced or metastatic biliary tract cancer (BTC). Patients received up to eight combination cycles followed by cadonilimab maintenance. The primary endpoint was objective response rate (ORR). Sixty-one patients were enrolled. At a median follow-up of 23.5 months, ORR was 55.7% (95% CI 42.4-68.5), meeting the prespecified efficacy criterion. Disease control rate was 85.2%, median duration of response 6.1 months, median progression-free survival 8.0 months, and median overall survival 15.6 months. Grade ≥ 3 adverse events occurred in 68.9% and grade ≥ 3 immune-related adverse events in 18.0%; no deaths were adjudicated as treatment-related. The authors conclude that these findings support further randomized evaluation.