Immune Checkpoint Inhibition in Hepatocellular Carcinoma: Basics and Ongoing Clinical Trials

Clinical trials of antibodies targeting the immune checkpoint inhibitors programmed cell death 1 (PD-1), programmed cell death ligand 1 (PD-L1), or cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) for the treatment of advanced hepatocellular carcinoma (HCC) are ongoing. Expansion cohorts of a phase I/II trial of the anti-PD-1 antibody nivolumab in advanced HCC showed favorable results. Two phase III studies are currently ongoing: a comparison of nivolumab and sorafenib in the first-line setting for advanced HCC, and a comparison of the anti-PD-1 antibody pembrolizumab and a placebo in the second-line setting for patients with advanced HCC who progressed on sorafenib therapy. The combination of anti-PD-1/PD-L1 and anti-CTLA-4 antibodies is being evaluated in other phase I/II trials, and the results suggest that an anti-PD-1 antibody combined with locoregional therapy or other molecular targeted agents is an effective treatment strategy for HCC. Immune checkpoint inhibitors may therefore open new doors to the treatment of HCC.