A Pilot Study Testing the Safety and Feasibility of Restorative Microbiota Therapy (RMT) in Patients With Refractory Immune-checkpoint Inhibitor-related Colitis

Immune-related colitis from immune checkpoint inhibitors (ICI) is a common adverse effect causing significant morbidity and impairment of quality of life (QoL). Steroids are the first line of treatment for severe ICI induced Immune- mediated diarrhea and colitis (IMDC). If there is no improvement in 48 to 72 hours, other immunosuppressive agents (infliximab, vedolizumab) are recommended. However, efficacy data supporting the use of immunosuppressives for steroid refractory IMDC is limited by case reports/series. Clinical trials focusing on steroid-refractory colitis are sparse. Novel treatments for IMDC outside of blanket immunosuppression are needed. There is robust evidence to suggest that gut microbial diversity and composition is associated with both ICI efficacy and toxicity. Preliminary studies have shown that pathophysiology of immune mediated colitis may be related to loss of gut microbial diversity. Recently, multiple case series have shown the utility of fecal microbiota transplant for treatment of refractory IMDC providing the proof of concept. This is a pilot randomized placebo controlled study to assess the safety and feasibility of oral restorative microbiota therapy (RMT) in patients with steroid- refractory IMDC.