A review of cancer immunotherapy: immune checkpoint inhibitors

Abstract

Immunotherapy is a method of treating malignant diseases that aims to stimulate the immune system to destroy tumor cells. For this purpose, immune checkpoint inhibitors are mainly used. These drugs block coin-hibitory signaling pathways in T-cells and thus induce antitumor immune responses. The most common targets for immune checkpoint inhibitors are programmed cell death receptor-1 (PD-1), programmed death ligand-1 (PD-L1), and cytotoxic T-lymphocyte-associated protein-4 (CTLA-4). PD-1/PD-L1 inhibitors and CTLA-4 inhibitors are widely used in the treatment of various types of cancer, for instance, melanoma, non-small cell lung cancer, colorectal carcinoma, esophageal carcinoma, urothelial carcinoma, and others. In comparison to other approaches to cancer treatment such as chemotherapy and radiotherapy, immunotherapy has been shown to improve patients' quality of life and survival and is generally better tolerated. In conclusion, while immunotherapy with immune checkpoint inhibitors has seen rapid development in recent years, further clinical studies are necessary to enhance the safety and efficacy of PD-1/PD-L1 and CTLA-4 inhibitors, whether administered alone or in combination.