Real-world efficacy and safety of durvalumab combined with various chemotherapy regimens in advanced biliary tract cancer: Insights from a large single-center study.

e16221 Background: The TOPAZ-1 study established durvalumab plus chemotherapy as a new standard of care for advanced biliary tract cancer (BTC). We present the largest single-center real-world data on durvalumab in advanced BTC, providing critical insights into its efficacy and safety when combined with different chemotherapy regimens, with a particular focus on DurGAP (durvalumab, gemcitabine, albumin-bound paclitaxel, and cisplatin). Methods: In this retrospective study from Tianjin Cancer Hospital Airport Hospital, we analyzed patients with advanced BTC treated with DurGC (durvalumab, gemcitabine and cisplatin), DurGAP, or DurHAIC (durvalumab plus hepatic arterial infusion chemotherapy). Primary endpoint was overall survival (OS). Secondary endpoints included objective response rate (ORR), disease control rate (DCR), safety profile. Results: Between Feb, 2023 to Sep, 2024, a total of 67 patients were included (median age: 65 years; 58.2% ECOG 0). Tumor subtypes were intrahepatic (iCCA 46.2%), perihilar(pCCA17.9%), distal cholangiocarcinoma (dCCA 8.9%), and gallbladder cancer (GBC 26.8%). 76.1% had lymph node involvement and 7.4% had distant metastases. Overall ORR was 40%, with DCR at 81.7%. ORR for DurGAP, DurGC were 41.6% and 44.4% respectively. Grade 3/4 adverse events occurred in 6(8.9)% patients. After a median follow-up of 13 months (95% CI, 9.3-16.7), median OS for the entire cohort reached 18.0 months (95% CI, 14.0-NR), with 1-year OS rates of 70.1% (95%CI 57.6% - 85.4%). Median OS varied by subtype: iCCA 18.0months, pCCA 13.4 months, dCCA Not reached, and GBC Not reached (p = 0.43). Notably, median OS for DurGAP, DurGC and DurHAIC were 18.0, 7.2, and 6.5 months (p = 0.04), respectively. Conclusions: This comprehensive real-world study provides compelling evidence on the efficacy and safety of durvalumab combined with various chemotherapy regimens in advanced BTC. Our findings offer valuable insights into treatment outcomes across different BTC subtypes and chemotherapy combinations. Notably, DurGAP regimen emerges as a particularly promising strategy, warranting further investigation in prospective clinical trials.