Endocrine sequelae of immune checkpoint inhibitors

Cancer immunotherapy has introduced a novel class of drugs known as immune checkpoint inhibitors (ICIs). They enhance antitumour immunity by blocking negative regulators (checkpoints) of T cell function that exist on both immune and tumour cells. ICIs targeting CTLA-4 and PD-1/PDL-1 have dramatically changed the outcome of patients with several advanced-stage malignancies but they may lead to a variety of inflammatory toxicities and autoimmune consequences. The main endocrine immune-related adverse events (IRAEs) include hypophysitis, primary thyroid dysfunction, adrenalitis and type 1 diabetes mellitus. In general, the management of endocrine IRAEs requires assessment of their severity, in moderate or severe cases interruption of the checkpoint inhibitor and use of corticosteroid or alternative immunosuppression and appropriate hormone replacement or treatment when necessary.