CMAJ 2019
Inhibitors against cytotoxic T-lymphocyte--associated protein 4 and programmed cell death 1 immune checkpoints are novel agents that modulate immune pathways and enhance anti-tumor immunity. Their use has set new standards in the treatment of many cancer types. Some patients with tumors previously deemed incurable are now able to achieve long-term remissions. Immune checkpoint inhibitors are increasingly used, either as stand-alone treatments or in combination with chemotherapy, surgery and radiotherapy, not only for patients with refractory metastatic cancer, but also earlier in the cancer cycle as adjuvant and neoadjuvant treatments. Although these treatments are usually well tolerated, severe and, rarely, fatal adverse events have occurred, especially if not promptly recognized and treated. These reactions, called immune-related adverse events, are the consequence of off-target immune attack on the hosts' healthy tissues. Immune checkpoint inhibitors have rapidly established themselves as a new pillar in cancer therapy alongside chemotherapy, radiotherapy and surgery.

Esfahani K, Meti N, Miller WH Jr, Hudson M. Adverse events associated with immune checkpoint inhibitor treatment for cancer. CMAJ. 2019 Jan 14;191(2):E40-E46.