S726 Fecal Transplantation Improved Patients’ Reported Outcome After Immune Checkpoint Inhibitor Colitis

Abstract

Introduction: Immune checkpoint inhibitors (ICIs) have become standard treatment for cancers poorly responsive to traditional chemotherapy. The most common GI toxicity of this class of drugs is ICIs colitis (IMC) associated with difficulty to treat chronic diarrhea and risk of fatality. We have previously demonstrated that fecal microbiota transplantation (FMT) was effective in the treatment of a small number of refractory cases suggesting the gut microbiome is involved in the pathogenesis of ICIs colitis. Further large studies are needed to determine its efficacy. Methods: The present study summarizes our experience with FMT treatment of 37 patients with refractory ICIs colitis. We measured the efficacy of FMT and patients’ reported outcome (PRO) via established MD Anderson Symptom Inventory (MDASI). Among them, 9 patients had concurrent CDI as well at the time of diagnosis. (Table) Results: Thirty-seven patients included in our study, with a median age of 59 years and mostly had genitourinary cancers (35.1%) followed by melanoma (27.0%). Most patients had a peak CTCAE diarrhea grade ≥ 3 (91.9%) and colitis grade ≥ 2 (89.1%). Ulcerous (18, 48.6%) and non-ulcerous (12, 32.4%) inflammation was predominant endoscopic findings. 36 (97.3%) patients received corticosteroids, and 33 (89.1%) received add-on infliximab or vedolizumab. IMC symptom response was 83.7% after FMT with median time to response of 5 days. The rate of complications is 16.2% at 7 days and 5.4% at 30 days, and mostly were transient and mild. Response rate among 28 patients without concurrent CDI was 85.7%. Thirty-five (94.6%) patients demonstrated colitis remission at the last follow up. On the PRO analysis, we observed a favorable trend of significant patient-reported symptom reduction on diarrhea during 12 weeks after FMT, along with improved daily physical functioning on working. (Figure) Conclusion: Evidence is accumulating to suggest that efficacy and prevention of ICI related toxicities is dependent upon a healthy diverse microbiome. In the present study, we have shown that FMT achieved 83.7% success rate in patients with IMC with a favorable safety profile. FMT could become a preferred treatment option for the IMC in the future practice.Figure 1.: Patients Reported Outcome Summary Table 1. - Characteristic before FMT No. (%) (n=37) Concurrent CDI# 9 (24.3%) Highest grade of diarrhea of initial IMC onset – no. (%) 1 or 2 3 (8.1%) 3 or 4 34 (91.9%) Highest grade of colitis of initial IMC onset – no. (%) 1 4 (10.8%) 2- 4 33 (89.2%) Initial endoscopic findings – no (%), n=36 Ulcers 18 (48.6%) Non-ulcer inflammation 12 (32.4%) Normal 6 (16.2%) Hospitalizations – no. (%) 29 (78.3%) Median duration of hospitalization – days (IQR) 8 (5-13) Treatment of GI adverse events – no. (%) Steroid 36 (97.3%) Infliximab/vedolizumab added 33 (89.1%) FMT characteristic and outcome Symptom improvement after FMT, all patients – no (%) 31 (83.7%) Symptom improvement after FMT (no concurrent CDI, n=28) – no (%) 24 (85.7%) Median time from FMT to symptom improvement– days (IQR), n=37 5 (2-10) FMT-related complications within 7 days –no (%) 6 (16.2%) FMT-related complications within 30 days –no (%) 2 (5.4%) Colitis status at the end of the study period Clinical remission – no (%) 35 (94.6%) Persistent symptoms – no (%) 2 (5.4%)