DAY 2 - Infliximab Versus Vedolizumab in Outpatient Treatment of Immune Checkpoint Inhibitor Colitis

Immune checkpoint inhibitors (ICIs) have FDA approval for over 43 indications. However, ICI-induced colitis remains a common and potentially severe immune-related adverse event. While steroids are the recommended first-line therapy, their prolonged use can lead to significant side effects. The optimal management of moderate to severe ICI colitis, particularly the choice between biologic therapies, remains a challenge for clinicians.

At the American College of Gastroenterology (ACG) 2024 Annual Scientific Meeting in Philadelphia, Pennsylvania, Dr. Matthew J. Townsend, senior assistant resident at the Duke University Medical Center, discussed the findings of a retrospective study comparing the efficacy and safety of infliximab and vedolizumab in this setting.

Dr. Townsend explained the research method, which involved a retrospective analysis of adult cancer patients at their institution who received ICIs between 2011 and 2023 and were subsequently treated with infliximab or vedolizumab as outpatients for biopsy-proven ICI-induced colitis.

Out of 55 patients included in the study, 33 were treated with infliximab and 22 with vedolizumab. 91% of patients treated with infliximab and 86% treated with vedolizumab achieved sustained clinical response. The median time to symptom improvement to CTCAE (a system used to assess adverse events severity) Grade 1 for infliximab and vedolizumab was 10 and 18 days, respectively. However, this difference was not statistically significant. 

After biologic initiation, steroids were more rapidly discontinued in patients treated with vedolizumab compared to those treated with infliximab. This finding suggests that vedolizumab may offer an advantage in terms of reducing overall steroid exposure. The data indicates that both infliximab and vedolizumab effectively treat outpatient ICI colitis, with high response rates and similar proportions of patients requiring extended biologic therapy. However, the shorter time to steroid-free remission with vedolizumab may influence treatment decisions, particularly for patients at higher risk of steroid-related complications.

Dr. Townsend noted several research limitations, including the retrospective nature of the analysis, modest cohort size, limited racial/ethnic diversity, and variations in biologic dosing practices. He also noted that the findings may not be generalizable to subsequent episodes of ICI colitis.

Dr. Townsend concluded, "Steroids are recommended as first-line therapy, but biologic therapy with infliximab or vedolizumab has been associated with favorable outcomes in moderate to superior ICI-induced colitis." His research demonstrated that both infliximab and vedolizumab achieve similarly high response rates in outpatient treatment of ICI colitis, but vedolizumab may offer an advantage in terms of faster steroid discontinuation. He proposed that vedolizumab could be considered a first-line treatment for outpatients with ICI colitis if confirmed in prospective clinical trials.