Patients with underlying inflammatory bowel disease (IBD) have an increased risk of developing potentially severe gastrointestinal (GI) adverse events during immune checkpoint inhibitor therapy compared with patients without IBD, according to the results of an international, multicenter, retrospective study. The findings were published in the Journal of Clinical Oncology.1

The study included 102 retrospectively identified patients with IBD who were treated with an immune checkpoint inhibitor between January 2010 and February 2019 as a well as 11,377 patients without IBD to serve as a comparator group.

Most patients with IBD (83%) were treated with a PD-1 or PD-L1 inhibitor, and the remaining patients were treated with a CTLA-4 inhibitor (7%) or a combination of the immune checkpoint inhibitors (10%). Patients with IBD had either stage III (5%) or stage IV disease (95%), and the most common cancer types were melanoma (44%), lung cancer (23%), and GI cancer (17%). Patients with IBD had Crohn disease (48%), ulcerative colitis (48%), or unclassified IBD (4%).

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Overall, a significantly higher proportion of patients with IBD developed a GI adverse event during immune checkpoint inhibitor therapy than patients without IBD (41% vs 11%; P <.001). Nearly all patients with IBD who developed a GI adverse event had diarrhea (41 of 42 patients), approximately half of whom (21 patients) had grade 3/4 severity. Four patients had colonic perforation, and no deaths related to a GI adverse event were seen.

If patients had active IBD within the 3 months before initiating immune checkpoint inhibitor therapy, a higher grade of diarrhea was seen compared with patients who had IBD that was not active (P =.027).

The most common reasons for stopping immune checkpoint inhibitor therapy included disease progression (30%), the completion of treatment course (25%), or because of a GI-related adverse event (23%).

The study authors described the clinical benefit rate seen as “similar” to that reported in clinical trials. “The rate of GI adverse events was high in the current study, yet the benefits of immunotherapy in this population likely outweighed the risks.”

Disclosure: Some of the authors of the study reported financial relationships with pharmaceutical or medical device companies. For a full list of disclosures, please refer to the original study.

Editor’s Note: The original version of this article incorrectly defined IBD as irritable bowel disease, this article was corrected to reflect that the study included patients with inflammatory bowel disease.


Abu-Sbeih H, Faleck DM, Ricciuti B, et al. Immune checkpoint inhibitor therapy in patients with preexisting inflammatory bowel disease [published online December 4, 2019]. J Clin Oncol. doi: 10.1200/JCO.19.01674