Use of Fecal Microbial Transplantation for Immune Checkpoint Inhibitor Colitis.

Immune checkpoint inhibitors (ICIs) can result in immune-related adverse events which require rapid identification and treatment. Gastrointestinal immune-related adverse events are among the most frequent and severe of these events. ICI colitis can be refractory to current therapies such as corticosteroids and biologic therapy. Fecal microbiota transplantation (FMT) is currently used in cases of recurrent Clostridioides difficile colitis. Many investigations are underway to test the utility of FMT for additional indications, including inflammatory bowel disease (IBD). We present a 71-year-old man with ICI colitis that was nonresponsive to currently defined management options and treated with benefit from FMT.