Update on Immune Checkpoint Inhibitor Enterocolitis

PURPOSE OF REVIEW: Immune checkpoint inhibitor (ICI) therapy revolutionized the treatment of multiple solid and hematologic malignancies. Yet, with it came profound inflammatory toxicities that mimic autoimmune diseases, termed immune-related adverse events (irAEs). Prominent among these is gastrointestinal inflammation, including a spectrum of gastritis, enteritis, and colitis. Here we synthesize an approach to immune checkpoint related enterocolitis (irEC) – including diagnostics and therapeutics – underpinned by new insights into the mechanism behind these phenomena. RECENT FINDINGS: This review presents updated insights on how to approach irEC, including novel approaches to selective immunosuppressive therapy, the role of fecal microbiota transplant, and the underlying cellular mechanisms of irEC. SUMMARY: This review provides an update on irEC diagnosis and therapy, with considerations of new therapies and special patient populations. The field of gastrointestinal irAEs requires additional investigation, which will ultimately provide the tools required for patients to continue to receive life-saving ICI therapy.