Use of CAR-T cell therapy, PD-1 blockade, and their combination for the treatment of hematological malignancies

With the successful treatment of B-cell lymphomas using rituximab, a monoclonal antibody targeting CD20, novel immunotherapies have developed rapidly in recent years. Immune checkpoint blockade and chimeric antigen receptor-T (CAR-T) cell therapy, which are antibody-based therapy and cell-based therapy, respectively, show promising efficacy and have been approved by the Food and Drug Administration for treating hematological malignancies. However, considering severe side effects and short-term clinical remission, the combination of CAR-T cell therapy and programmed cell-death protein-1 (PD-1) blockade has been applied to enhance therapeutic efficacy in preclinical models and clinical trials. Herein, we review the mechanism of the two therapies, show their toxicities and clinical use respectively, address their combined application, and discuss the scope of further investigations of this mechanism-based combination therapy.