Immune Checkpoint Inhibitor-Associated Colitis and Hepatitis

Abstract

Immune checkpoint inhibitors (ICPIs) are monoclonal antibodies that target downregulators of the anti-cancer immune response: cytotoxic T-lymphocyte antigen-4, programmed cell death protein-1, and its ligand PD-L1. ICPIs are now approved for the treatment of a wide array of malignancies, with rates of durable responses in the metastatic setting far exceeding what would be expected from conventional chemotherapy. ICPIs have also been associated with rare but serious immune-related adverse events due to over-activation of the immune system that can affect any organ, including the gastrointestinal tract and liver. As the use of ICPIs in oncology continues to increase, ICPI-associated colitis and hepatitis will be encountered frequently by gastroenterologists and hepatologists. This review will focus on the diagnosis and management of ICPI-associated colitis and hepatitis. We will also compare these ICPI-related toxicities with sporadic inflammatory bowel disease and autoimmune liver disease.

Fig. 1

This flow diagram depicts a basic approach for evaluation and management of a patient with suspected ICPI colitis based on the severity of their symptoms as defined by Common Terminology Criteria for Adverse Events v5.0

Fig. 2

This flow diagram depicts a basic approach for evaluation and management of a patient with suspected ICPI hepatitis based on the severity of their symptoms as defined by Common Terminology Criteria for Adverse Events v5.0