Durvalumab Plus Gemcitabine and Cisplatin Versus Gemcitabine and Cisplatin in Biliary Tract Cancer: a Real-World Retrospective, Multicenter Study

Background: The TOPAZ-1 phase III trial reported a survival benefit with the anti-programmed cell death ligand 1 (anti-PD-L1) durvalumab in combination with gemcitabine and cisplatin in patients with advanced biliary tract cancer (BTC). Objective: The present study investigated for the first time the impact on survival of adding durvalumab to cisplatin/gemcitabine compared with cisplatin/gemcitabine in a real-world setting. Patients and methods: The analyzed population included patients with unresectable, locally advanced, or metastatic BTC treated with durvalumab in combination with cisplatin/gemcitabine or with cisplatin/gemcitabine alone. The impact of adding durvalumab to chemotherapy in terms of overall survival (OS) and progression free survival (PFS) was investigated with univariate and multivariate analysis. Results: Overall, 563 patients were included in the analysis: 213 received cisplatin/gemcitabine alone, 350 received cisplatin/gemcitabine plus durvalumab. At the univariate analysis, the addition of durvalumab was found to have an impact on survival, with a median OS of 14.8 months versus 11.2 months [hazard ratio (HR) 0.63, 95% confidence interval (CI) 0.50-0.80, p = 0.0002] in patients who received cisplatin/gemcitabine plus durvalumab compared to those who received cisplatin/gemcitabine alone. At the univariate analysis for PFS, the addition of durvalumab to cisplatin/gemcitabine demonstrated a survival impact, with a median PFS of 8.3 months and 6.0 months (HR 0.57, 95% CI 0.47-0.70, p < 0.0001) in patients who received cisplatin/gemcitabine plus durvalumab and cisplatin/gemcitabine alone, respectively. The multivariate analysis confirmed that adding durvalumab to cisplatin/gemcitabine is an independent prognostic factor for OS and PFS, with patients > 70 years old and those affected by locally advanced disease experiencing the highest survival benefit. Finally, an exploratory analysis of prognostic factors was performed in the cohort of patients who received durvalumab: neutrophil-lymphocyte ratio (NLR) and disease stage were to be independent prognostic factors in terms of OS. The interaction test highlighted NLR ≤ 3, Eastern Cooperative Oncology Group Performance Status (ECOG PS) = 0, and locally advanced disease as positive predictive factors for OS on cisplatin/gemcitabine plus durvalumab. Conclusion: In line with the results of the TOPAZ-1 trial, adding durvalumab to cisplatin/gemcitabine has been confirmed to confer a survival benefit in terms of OS and PFS in a real-world setting of patients with advanced BTC.