Pre-existing Autoimmune Diseases and Immune Checkpoint Inhibitors for Cancer Treatment: Considerations About Initiation, Flares, Immune-Related Adverse Events, and Cancer Progression

Immune checkpoint inhibitors (ICIs) are increasingly used to treat a variety of cancer types. Patients with preexisting autoimmune diseases may be vulnerable to underlying disease flare as well as immune-related adverse events from ICIs. There has also been concern that immunosuppression needed to control the autoimmune disease may blunt ICI efficacy. Much of the literature is focused on diverse preexisting autoimmune diseases, which may limit conclusions to specific diseases. There is a growing literature of specific diseases, such as preexisting rheumatoid arthritis, investigating outcomes after ICI.