Immunotherapy to treat malignancy in patients with pre-existing autoimmunity

In the past 10 years, immune checkpoint inhibitors (ICIs) have become an additional pillar of cancer therapy by activating the immune system to treat a number of different malignancies. Many patients receiving ICIs develop immune-related adverse events (irAEs) that mimic some features of classical autoimmune diseases. Unfortunately, patients with underlying autoimmune conditions, many of whom have an increased risk for malignancy, have been excluded from clinical trials of ICIs due to a concern that they will have an increased risk of irAEs. Retrospective data from patients with autoimmune diseases and concomitant malignancy treated with ICIs are encouraging and suggest that ICIs may be tolerated safely in patients with specific autoimmune diseases, but there are no prospective data to guide management. In this manuscript, we review the relationship between pre-existing autoimmune disease and irAEs from checkpoint inhibitors. In addition, we assess the likelihood of autoimmune disease exacerbations in patients with pre-existing autoimmunity receiving ICI.