Provided are compositions and methods for determining whether or not an individual who has cancer is likely to develop immune-related adverse events (irAEs) because of treatment with an immune checkpoint inhibitor such as an anti-Programmed cell death protein 1 (anti-PD-1) checkpoint inhibitor, and/or anti-Cytotoxic T-lymphocyte-associated protein 4 (anti-CTLA-4) checkpoint inhibitor. Also provided are methods for treating an individual who has cancer with a checkpoint inhibitor and an agent to reduce the risk of toxicity from the checkpoint inhibitor, as well as administering agents to prevent or reduce the risk of toxicity during treatment.
