Real-world data of durvalumab plus gemcitabine and cisplatin in patients with advanced biliary tract cancer: A Thailand multicenter observational study.

607 Background: Currently, durvalumab plus gemcitabine and cisplatin is a standard of care for patients with advanced biliary tract cancer (BTC). We aimed to evaluate efficacy and tolerability of durvalumab plus gemcitabine and cisplatin in real world experience in Thailand where there is high incidence of liver-fluke related cholangiocarcinoma (CCA). Methods: This is an observation study of patients with advanced BTC participating in the early access program of durvalumab since August 2023. Data were collected and analyzed for efficacy and toxicity. Results: Fifty patients participated the early access program in 14 centers across Thailand. Median follow-up time was 8.5 months. Median number of treatment cycles was 8.8 (1-16) cycles. Thirty six (72%) patients were alive and 8 (16%) patients were still on treatment. The mean age was 63 years, 60% were male and 92% were ECOG 0-1. There were 68% intrahepatic cholangiocarcinoma (CCA), 28% extrahepatic CCA and 8% gallbladder cancer. There were 29.5% objective response rate and 79.5% disease control rate. Median progression free survival (PFS) was 6.0 (95%CI 4.49-7.50) months. Eight (16%) patients were still on treatment with PFS more than 10 months. Grade 3 or 4 adverse events (AEs) were reported in 50% of patients. Most AEs were related to chemotherapy, there were 10% immune related AEs. Conclusions: In this real-world experience, durvalumab plus gemcitabine and cisplatin was efficacious and tolerable in Thai patients with advanced BTC.