S2093 Long-Term Safety of Fecal Microbiota, Live-jslm Administered via Colonoscopy to Adults With Recurrent Clostridioides difficile Infection: 6-Month Safety Data From CDI-SCOPE, a Single-Arm, Phase 3b Trial

Introduction: Fecal microbiota, live-jslm (RBL) is a microbiota-based product to prevent recurrent Clostridioides difficile infection (rCDI) in adults after standard-of-care antibiotic treatment. In CDI-SCOPE (NCT05831189), a multicenter, single-arm, phase 3b trial assessing the safety and efficacy of RBL when administered by colonoscopy to adults with rCDI, interim results through 8 weeks showed 9.8% of participants had RBL-related treatment-emergent adverse events (TEAEs) and 95.1% experienced treatment success (no CDI recurrence; PMID 40321366). This analysis presents long-term safety and efficacy through 6 months of follow-up in CDI-SCOPE. Methods: Adults with documented rCDI who had completed standard-of-care antibiotics were eligible to participate in the trial. Participants received 1 dose of RBL by colonoscopy after a 24- to 72-hour antibiotic washout period and bowel preparation. Secondary endpoints included safety up to 6 months after RBL administration and assessment of CDI recurrence. Results: Of the 41 participants, 39 completed follow-up through 6 months. From 8 weeks through 6 months after RBL administration, 36 additional TEAEs in 15 participants (36.6%) were reported, 1 of which (irritable bowel syndrome) was RBL-related. During this period, most TEAEs (97.2%) were of mild or moderate severity, and 1 serious, potentially life-threatening TEAE (worsening abdominal pain) unrelated to RBL was observed. Over the full trial period, 6 RBL-related TEAEs occurred in 4 participants (9.8%), all of which were mild in severity and gastrointestinal in nature. Overall, 23 participants (56.1%) experienced 69 TEAEs; 94.2% were of mild or moderate severity. Serious TEAEs occurred in 3 participants (7.3%), none of which were related to RBL or its administration. TEAEs of special interest were reported in 2 participants (4.9%) and were not related to RBL. During the full trial period, 38 participants (92.7%) did not experience CDI recurrence, 1 (2.4%) did between 8 weeks and 6 months, and 2 (4.9%) had an indeterminate outcome due to study withdrawal before 8 weeks. Conclusion: RBL administered via colonoscopy was safe and effective for the prevention of CDI recurrence in adults with rCDI in CDI-SCOPE. Long-term safety findings through 6 months were consistent with results from previous RBL trials.