Recent developments with immunotherapy for hepatocellular carcinoma.

INTRODUCTION: Immunotherapy is on the way to become the new standard of care for advanced hepatocellular carcinoma (HCC) worldwide. With higher rates of objective responses, and overall less side effects compared to tyrosine-kinase inhibitors (TKIs) immunotherapeutics will probably replace sorafenib from standard first-line treatment. AREAS COVERED: This review covers recent clinical data on systemic agents and ongoing trials in patients with advanced HCC focusing on immunotherapy. EXPERT OPINION: In unselected patients with advanced HCC immunotherapeutics, namely the programmed cell death-1 (PD-1) antibodies, nivolumab and pembrolizumab have shown promising efficacy in therapy-naïve, as well as pre-treated patients with advanced HCC. However, only 10-20 percent of treated patients show an objective and durable response to the indicated therapeutics. Therefore, combination therapies including different immunotherapeutics, e.g. PD-1/programmed cell death 1 ligand 1 (PD-L1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) antibodies, or combinations of immunotherapeutics and small molecules, or bifunctional antibodies will be needed to improve response rates. ABBREVIATIONS: HCC: hepatocellular carcinoma; TKI: tyrosine-kinase inhibitors; PD-1: programmed death receptor-1; PD-L1: programmed cell death 1 ligand 1; CTLA-4: cytotoxic T-lymphocyte-associated Protein 4; CAR-T: chimeric T cell receptors; TACE: transarterial chemoembolization; SIRT: selective internal radiation therapy; SBRT: stereotactic body radiation therapy; VEGF: vascular endothelial growth factor; MEK: mitogen-activated protein kinase kinase; NK cell: natural killer cell; TGFβ: transforming growth factor-β; OV: Oncolytic viruses; PFU: plaque-forming unit.