BackgroundThe TOPAZ-1 phase III trial showed a survival benefit with durvalumab plus gemcitabine and cisplatin in patients with advanced biliary tract cancer (BTC). To understand this combination's real-world efficacy and tolerability, we conducted a global multicenter retrospective analysis of its first-line treatment outcomes. MethodsWe included patients with unresectable, locally advanced, or metastatic BTC treated with durvalumab, gemcitabine, and cisplatin at 39 sites in 11 countries (Europe, the United States, and Asia). The primary endpoint was overall survival (OS). Results666 patients were enrolled. Median OS was 15.1 months and median PFS was 8.2 months. The investigator-assessed overall response rate was 32.7 %, with stable disease in 45.2 % of patients. High baseline CEA levels, ECOG PS > 0, metastatic disease, and NLR > 3 were associated with poor survival. Any grade adverse events (AEs) occurred in 92.9 % of patients (grade >2: 46.6 %). Immune-related AEs (irAEs) occurred in 20.0 % (grade >2: 2.5 %). Three deaths (0.5 %) were deemed treatment-related, none linked to immunotherapy. Common irAEs were rash (8.2 % all grades; 0.3 % grade >2), itching (10.3 % all grades; 0.2 % grade >2), and hypothyroidism (5.1 % all grades; 0.3 % grade >2). Durvalumab discontinuation rate due to AEs was 1.5 %.ESMO-recommended genes were analyzed and no outcome differences were found. A comparative analysis with a historical cohort of patients treated with chemotherapy alone confirmed the positive survival impact of durvalumab in combination with cisplatin/gemcitabine. ConclusionThis first global real-world analysis largely confirmed the TOPAZ-1 findings, supporting gemcitabine, cisplatin, and durvalumab as a first-line standard of care for patients with advanced BTC.