953P Tislelizumab plus regorafenib as second-line therapy for unresectable hepatocellular carcinoma (uHCC): A single-arm, phase II trial

Second-line treatment options for patients with unresectable hepatocellular carcinoma (uHCC) are limited. Monotherapy with regorafenib or tislelizumab (an anti-PD-1 antibody) has shown clinical benefit for uHCC in the second-line setting. The present study explored the safety and efficacy of the tislelizumab plus regorafenib as second-line therapy for uHCC. This was a single-arm, investigator-initiated phase II trial. Patients with confirmed uHCC were enrolled to receive tislelizumab (200mg, q3w) plus regorafenib (80mg-160mg, daily, 3 weeks on/1 week off, every 4 weeks). The primary endpoint was safety and tolerability; Secondary endpoints included overall response rates (ORR), progression-free survival (PFS), and disease control rate (DCR) per mRECIST. A total of 28 patients were enrolled with median age of 59 years (range: 40-76) and 96% were men. Most common etiology of HCC was hepatitis B (n=26, 93%). 54% of patients were Barcelona Clinic Liver Cancer stage C. 67.9% of patients received prior treatment with tyrosine kinase inhibitors (TKIs; sorafenib [50%] or lenvatinib [17.9%]), and 21.4% received TKIs plus PD-1 antibody. ORR was 28.6% and DCR was 71.4%, with 3 pts having CR, 5 PR, and 12 SD. At the data cut-off date, the median PFS of the 28 pts was 6.4 months (95%Cl 90%, NA)), and the median OS was not reached. The most common treatment-related adverse events at any grade were rash (6/28;21%), hypertension (9/28;32%), hand-foot syndrome (18/28;64%) and fatigue (7/28;25%), which were mostly grade 1 or 2 in severity. This study indicated that tislelizumab plus regorafenib is an effective and well-tolerated therapeutic option for patients with uHCC.