Toripalimab Plus Bevacizumab as First-line Treatment for Advanced Hepatocellular Carcinoma: A Prospective, Multicenter, Single-Arm, Phase II Trial

Abstract Purpose: This phase II, multicenter, prospective, single-arm study aimed to evaluate the efficacy and safety of toripalimab plus bevacizumab in treating advanced hepatocellular carcinoma (HCC). Patients and methods: Treatment-naïve patients with advanced HCC received toripalimab 240 mg plus bevacizumab 15 mg/kg every 3 weeks. Primary endpoints included safety and tolerability, and objective response rate (ORR) assessed by the investigator per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Results: Fifty-four patients were enrolled between Apr 17, 2020 and Dec 11, 2020. As assessed by the investigator according to RECIST v1.1, the ORR was 31.5% [95% confidence interval (CI), 19.5-45.6] and the lower bound of the 95% CI was above the pre-specified boundary of 10%. The independent review committee (IRC) assessed ORR according to modified RECIST (mRECIST) was 46.3% (95% CI, 32.6-60.4). The median progression-free survival were 8.5 months (95% CI, 5.5-11.0) and 9.8 months (95% CI, 5.6-not evaluable) assessed by the investigator according to RECIST v1.1 and IRC according to mRECIST criteria, respectively. The median overall survival (OS) was not reached, and the 12- and 24-month OS rates were 77.3% and 63.5%, respectively. Grade 3 or higher treatment-emergent adverse events (TEAEs) occurred in 27 patients (50.0%). The most common TEAEs were proteinuria (59.3%), hypertension (38.9%), aspartate aminotransferase increased (33.3%), amylase increased (29.6%), platelet count decreased (27.8%), and bilirubin increased (27.8%). Conclusions: Toripalimab plus bevacizumab showed a favorable efficacy and safety profile, supporting further studies of this combination regimen as a first-line treatment of advanced HCC.