Therapeutic efficacy of dendritic cell vaccine combined with programmed death 1 inhibitor for hepatocellular carcinoma

Background and Aim Hepatocellular carcinoma (HCC) remains a serious cause of cancer‐related deaths worldwide. Developing new therapeutic strategies is urgently needed to improve the outcomes of HCC patients. Dendritic cell (DC)‐based vaccines and programmed death 1 (PD‐1) immune checkpoint inhibitors have been regarded as potential immunotherapeutics for HCC. However, the therapeutic efficacy of combining these two treatments for HCC remains to be evaluated. Methods In this study, DCs were derived from mouse bone marrow and pulsed with mouse HCC cell lysates to generate a DC vaccine. A monoclonal antibody that blocks the interaction of mouse PD‐1 with its ligands was used as a PD‐1 inhibitor. An orthotopic HCC mouse model was established to assess the effect of a DC vaccine in combination with a PD‐1 inhibitor on overall survival and tumor volume. Results Compared with the untreated control, single treatment with a DC vaccine or PD‐1 inhibitor prolonged the overall survival and reduced the tumor volume of HCC mice. Further, compared with the single treatment with the DC vaccine or the PD‐1 inhibitor, a combination treatment using both agents elicited a higher cytotoxicity of T cells against HCC cells and resulted in a better overall survival, smaller tumor volume, and greater tumor cell apoptosis in HCC mice. Conclusions Our results suggest that a combination treatment with DC vaccine and PD‐1 inhibitor may be a promising therapeutic strategy for HCC.