Different interventional time of hepatic arterial infusion with PD-1 inhibitor for advanced biliary tract cancer: a multicenter retrospective study.

This study investigated the efficacy and safety of hepatic artery infusion chemotherapy (HAIC) combined with PD-1 immunotherapy for advanced biliary tract cancer (BTC) and evaluated the optimal timing of HAIC. A total of 36 unresectable BTC patients treated with HAIC and PD-1 inhibitors between September 2019 and July 2021 were included in this study. Overall survival (OS), progression-free survival (PFS), tumor response, and adverse events (AEs) were investigated. Overall, 52.8% patients with advanced BTC were in stage IV, 23 patients who progressed after receiving PD-1 inhibitor had undergone HAIC, and 23 patients have received 2 or more lines of therapy. The median OS was 8.8 months (range: 4.0-24.0 months), and the median PFS was 3.7 months. The objective response rate and disease control rate were 11.5% and 76.9%, respectively. In the subgroup analysis, patients who treated with HAIC early without progression after immunotherapy were associated with a trend toward better OS (median 13.0 vs. 7.6 months; P = 0.004) and PFS (median 7.9 vs. 3.6 months; P = 0.09) compared to with HAIC with progression after PD-1 treatment. No treatment-related deaths occurred. A total of 44.4% of the patients experienced grade 3 or 4 AEs. We conclude that the combination of HAIC and PD-1 inhibitors is safe and effective. Early HAIC combined with immunotherapy can effectively prolong the overall survival of patients with advanced BTC.