CTLA-4 Inhibitors for the Treatment of Lung Cancer

One of the most prevalent malignancies and the main reason for cancer-related deaths globally is lung cancer. The majority of these non-small-cell lung cancer (NSCLC) patients are diagnosed at an advanced stage of the illness, lowering the 5-year survival rate to around 5%. Immune checkpoint inhibitors (ICIs) can restore and sustain anti-tumour immunity by inhibiting the cancer immune response’s inhibitory pathway. Programmed cell death 1 (PD-1), programmed cell death ligand 1 (PD-L1), and cytotoxic T lymphocyte antigen 4 (CTLA-4) pathway are just a few of the routes that have already been the target of ICIs. A receptor protein with high expression on the surface of T cells, B lymphocytes, and fibroblasts is the CTLA-4, also known as CD152. The CTLA-4 protein suppresses the immune system and disrupts the Cancer-Immunity Cycle (CIC) by preventing T cells from removing tumour cells, which advances lung cancer. The US FDA has approved ipilimumab and tremelimumab, immune checkpoint inhibitors that target CTLA4, as therapeutic options for people with metastatic melanoma. Additionally, several randomised clinical studies utilising CTLA4-related checkpoint inhibitors, either alone or in combination with other NSCLC therapy modalities, are now being conducted and are anticipated to improve survival results with manageable toxicity levels. This chapter gives a general review of CTLA-4’s function in the pathogenesis of lung tumours and how CTLA-4 inhibitors are used to treat patients with lung cancer, including NSCLC and SCLC.