Sintilimab, bevacizumab biosimilar, and HAIC for unresectable hepatocellular carcinoma conversion therapy: a prospective, single-arm phase II trial.

We assessed the efficacy and safety of sintilimab [an anti-programmed death (PD-1)] plus bevacizumab biosimilar (IBI305), and hepatic arterial infusion chemotherapy (HAIC) in patients with unresectable hepatocellular carcinoma (HCC). The patients received sintilimab (200 mg) plus IBI305 (7.5 mg/kg) and HAIC (FOLFOX for 23 h) and were treated every 3 weeks. The primary endpoint was the objective response rate (ORR) assessed by an independent review committee (IRC) per mRECIST v1.1. Twenty-nine patients were enrolled in our clinical trial (1 patient voluntarily withdrew due to adverse events after the initial treatment). Objective response was reached in 17/29 (58.6%) patients per mRECIST. A total of 19/29 (65.5%) patients became eligible for further treatment; 14 of them completed surgical resection; 1 (5.3%) achieved pathological complete response (pCR); and 5 (26.3%) reached major partial response (mPR). The 1-year OS rate was better in the PR or pCR+mPR+PR group than in the PD+SD group by either mRECIST or pathological assessment (p=0.039 and 0.006). The 1-year EFS rate was better in the PR group than in the PD+SD group by pathological assessment (p=0.007). The most common treatment-related adverse events (TEAEs) in 30 HCC patients included thrombocytopenia (40.0%), hypertension (23.3%), and leukopenia (23.3%). The grade 3-5 TEAEs that were observed were hypertension (10%), diarrhea (6.7%), asthenia (3.3%), and ascites (3.3%). Sintilimab plus IBI305 and HAIC showed promising efficacy and manageable safety in patients with unresectable HCC. It might represent a novel treatment option for these patients.