Immune Checkpoint Blockade Therapy for Cancer

Abstract

The expression of immune checkpoint molecules such as programmed cell death ligand 1 (PD-L1) on the surface of cancer cells and programmed cell death 1 (PD-1) and cytotoxic T-lymphocyte associated protein 4 (CTLA-4) on the surface of T-cells results in immune tolerance. Despite the unprecedented success of checkpoint inhibitors in cancer therapy, only a minority of patients respond durably. This review focuses on the role of immune checkpoint blockade in cancer therapy highlighting clinical trials with the best results, mechanisms of resistance, combination therapies and future directions in this interesting field.