Pd-1 inhibitors plus nab-paclitaxel with S1 (AS) as first line in patients with advanced biliary tract cancer.

Abstract

e15195 Background: The way to treat advanced biliary tract cancers (BTCs) including Intrahepatic cholangiocarcinoma, extrahepatic bile duct cancer, gallbladder cancer was disappointing. Hence, we explore the efficacy and safety of pd-1 inhibitors plus chemotherapy (nab-paclitaxel with S1, AS) as first line in patients with BTC. Methods: BTC patients from oncology department of Chinese PLA general hospital receiving PD-1 inhibitors with AS or AS alone were retrospectively analyzed. The primary endpoint was progression-free survival (PFS). The second endpoint was objective response rate (ORR), disease control rate (DCR) and safety. Results: 32 patients given pd-1 inhibitors (Pembrolizumab, Nivolumab, Sintilimab, Toripalimab) plus AS and 26 patients used AS alone were included in the study. The median PFS was 5.43m in combined group, significantly longer than the 2.82m with monotherapy alone group (HR 0.46, 95% CI 0.25–0.84, P = 0.01). OS was not matured in the pd-1 inhibitors group. PFS of Intrahepatic cholangiocarcinoma subgroup seemed better than extrahepatic group in the AS group (5.54m VS 2.57m, P = 0.004).however, there was no evidence of difference in intrahepatic group compared the other group in the pd-1 inhibitor group (5.07m vs 5.43m, P = 0.453). liver metastatic was poor predictor of PFS in both Pd-1 combined or not group (2.43m vs 7.63m, P = 0.01; 2.14m vs 5.54m, P = 0.04 ).ORR was 25% and DCR were 84.3% in Pd-1 inhibitor group and ORR was 15.3% and DCR was 69.2% in chemotherapy alone group respectively. No significant difference was seen for ORR and DCR compared between two groups (P = 0.364, P = 0.169). Grade 3 or 4 treatment-related adverse events(AE) in pd-1 inhibitor group were hypothyroidism (n = 3), rash (n = 2), hepatitis (n = 1). No AE related death. Myelosuppression was similar between the anti-PD-1 combination group and the chemotherapy alone group (12.5% and15.3 %, respectively). Conclusions: Anti-PD-1 therapy plus nab-paclitaxel with S1 prolonged the PFS and improved the ORR, DCR compared the nab-paclitaxel with S1 alone in advanced BTC with controllable AE. Further clinical trials were needed and we conduct the phrase II clinic trail of Toripalimab with AS (TSA-01 study) is ongoing (clinical registration number: NCT04027764).