To compare the efficacy and safety of immunotherapy plus regorafenib versus regorafenib only in patients with pretreated hepatocellular carcinoma (HCC).

Immunotherapy plus regorafenib or regorafenib alone was analyzed in patients with advanced HCC with documented tumor progression on front-line therapy. Progression-free survival (PFS), overall survival (OS), disease control rate (DCR), and treatment-related adverse events (TRAEs) were assessed.

Of the 125 patients enrolled in this study, 50 patients received combination (pCOM) treatment as front-line treatment, and 60 patients received monotherapy (pMONO) as front-line treatment. In the pCOM cohort, median OS was significantly longer with for patients regorafenib plus immunotherapy than regorafenib alone treatment (15.0 vs. 2.0 months; P = 0.035). The DCR numerically increased in the regorafenib plus immunotherapy treatment in both cohorts (40.6 % vs. 22.2 %, 72.7 % vs. 54.7 %, respectively). There were no differences in PFS with regorafenib according to whether or not regorafenib was combined with immunotherapy in the pCOM and pMONO cohorts (PFS, P = 0.17, P = 0.91, respectively). Regarding the number of TRAEs occurred, regorafenib plus immunotherapy group was comparable to regorafenib group in the pCOM cohort (65.6 % vs. 72.2 %). In the pMONO cohort, TRAEs occurred in fewer patients receiving regorafenib than regorafenib plus immunotherapy (69.8 % vs. 95.5 %).

Immunotherapy plus regorafenib may significantly improve clinical outcomes and have a manageable safety profile compared with regorafenib monotherapy in advanced HCC after front-line therapy failure. The efficacy of combination therapy needs to be validated in prospective studies with large samples.