Efficacy of Fecal Microbiota, Live-jslm (REBYOTA®), Among Patients Exposed to Non–Clostridioides difficile Infection Antibiotics: Post Hoc Subgroup Analysis of a Phase 2 Open-Label Study

Background. Antibiotic use is a major risk factor for recurrent Clostridioides difficile infection (CDI) due to the associated disruption in gut microbiota. Fecal microbiota, live-jslm (REBYOTA®; RBL, previously RBX2660), is the first microbiota-based live biotherapeutic approved by the US Food and Drug Administration to prevent recurrent CDI in adults following standard-of-care antibiotic treatment. To investigate the impact of non-CDI antibiotics on the durability of RBL, a subgroup analysis was conducted on PUNCH™ Open-Label study participants who received non-CDI antibiotics during the period between RBL administration and up to 2 years after. Methods. Participants in PUNCH™ Open-Label who received non-CDI antibiotics after RBL administration were included in this subgroup analysis. Treatment response was defined as the absence of CDI diarrhea needing retreatment at the last evaluable time point (8 weeks, 6 months, 1 year, or 2 years) after RBL administration. Results. Among participants from PUNCH™ Open-Label, 43 received non-CDI antibiotics after RBL administration but before CDI recurrence as evaluated over a 2-year period. Across all evaluable time points, 86% (37/43) of participants had a treatment response regardless of when non-CDI antibiotic exposure occurred. Treatment response was sustained for a median 470 days (IQR, 212–648) from the first day of non-CDI antibiotic use. Most participants (5/6) with CDI recurrences received a high-risk antibiotic. Conclusions. RBL remained efficacious in participants with a history of recurrent CDI after subsequent non-CDI antibiotic exposure.