Immune Checkpoint Inhibitors: An Innovative Direction in Cancer Immunotherapy

Abstract

Immune checkpoint inhibitors (ICIs) are a type of immunotherapy. They work by blocking certain inhibitory pathways in the body, like PD-1/PD-L1 and CTLA-4, which helps reactivate the immune system’s T cells to find and attack cancer cells. Current studies primarily focus on key targets, including PD-1, PD-L1, and CTLA-4. These treatments are used for various cancers, including melanoma, non-small-cell lung cancer, kidney cancer, and Hodgkin lymphoma, and researchers are also testing them on other types like triple-negative breast cancer and brain tumors. There have been significant advances: several ICIs, such as pembrolizumab, nivolumab, and ipilimumab, have been approved for use, becoming standard treatments for many advanced cancers and helping patients live longer, even achieving long-term remission in some cases. However, there are problems: some tumors resist ICIs from the start or develop resistance later, making the treatments less effective. Additionally, ICIs can cause immune-related side effects because they overactivate the immune system, which can affect the skin, digestive system, or hormone-producing glands, with rare but serious issues, such as heart inflammation. Future research will aim to find ways to overcome resistance and manage these side effects better, so ICIs can be safer and more effective.