checkpoint inhibitor

Syllable breakdown

Dictionary meaning

a class of cancer immunotherapy drugs that block proteins — checkpoints — that cancer cells exploit to prevent immune T-cells from attacking them; under normal circumstances checkpoint proteins such as PD-1, PD-L1, and CTLA-4 serve to prevent excessive immune responses that would damage healthy tissue, but many cancers hijack these pathways to evade immune surveillance; checkpoint inhibitors such as pembrolizumab, nivolumab, and ipilimumab block these proteins, effectively releasing the brakes on the immune system and allowing T-cells to recognise and destroy cancer cells; the development of checkpoint inhibitors earned James Allison and Tasuku Honjo the 2018 Nobel Prize in Physiology or Medicine and transformed the treatment of melanoma, lung cancer, bladder cancer, and many other tumour types; while many patients achieve durable responses, a significant proportion do not respond, and identifying predictive biomarkers remains a major research priority