P1915 - Safety of Fecal Microbiota Spores, Live-brpk (Formerly SER-109) in Participants With Recurrent Clostridioides difficile Infection and Comorbidities: Findings From an Integrated Analysis of Phase 3 Trials

Matthew Sims, MD, PhD¹, Charles S.. Berenson, MD², Robert Stevens, PharmD³, Dianne Nguyen, MD, MBA⁴, John R. Pullman, MD^5
1Corewell Health William Beaumont University Hospital, Royal Oak, MI; ²University at Buffalo, VA Western New York Healthcare System, Buffalo, NY; ³Seres Therapeutics, Cambridge, MA; ⁴Nestlé Health Science, Bridgewater, NJ; ⁵Mercury Street Medical Group, PLLC, Butte, MT

Introduction: Clinically relevant comorbid conditions increase risk of recurrent Clostridioides difficile infection (rCDI) with potentially more severe clinical course or consequences. Fecal microbiota spores, live-brpk (VOWST™; formerly SER-109, hereafter referred to as VOS) is an orally administered microbiome therapeutic to prevent future recurrence of CDI in adults after antibiotic treatment for rCDI. This integrated analysis of two Phase 3 trials further describes VOS safety in participants (pts) with select comorbidities.

Methods: The randomized, double-blind, placebo-controlled ECOSPOR III trial enrolled 182 pts with ≥2 CDI recurrences; the open-label, single-arm ECOSPOR IV trial enrolled 263 pts with rCDI. VOS was given orally as 4 capsules daily for 3 consecutive days after completion of antibiotics. Treatment-emergent adverse events (TEAEs) were obtained through Week 8; serious TEAEs/AEs of special interest were obtained through Week 24. Treatment-related adverse events (TRAEs) were TEAEs considered related/possibly related to study drug. VOS data from the integrated analysis and placebo data from ECOSPOR III are reported by comorbidity subgroups.

Results: Pts with comorbidities receiving VOS (n=178/349, 51%) reported numerically higher rates of TEAEs, serious TEAEs, and TEAEs of special interest in renal impairment/failure (80%, 35%, and 26%, respectively), diabetes (70%, 20%, and 9%), cardiac disease (75%, 27%, and 12%), and immunocompromised/immunosuppressed (IC/IS; 77%, 20%, and 14%) subgroups vs the overall population (Table). Pts receiving placebo in ECOSPOR III reported similar rates of TEAEs, serious TEAEs, and TEAEs of special interest in renal impairment/failure (100%, 57%, and 0%, respectively), diabetes (80%, 32%, and 8%), cardiac disease (97%, 41%, and 10%), and IC/IS (93%, 32%, and 4%) subgroups. In pts receiving VOS, TRAE rates were similar between subgroups with comorbidities and the overall population. No serious TEAEs, TEAEs of special interest, or TEAEs leading to study withdrawal were considered related to VOS. TEAE rates leading to death were low across VOS subgroups and the overall integrated population.

Discussion: As expected, TEAE rates were generally higher in vulnerable pts with clinically relevant comorbidities, regardless of VOS or placebo use, vs the overall populations. In pts receiving VOS, TRAE rates were generally low across subgroups and the overall population, indicating similar safety profiles for VOS in all pts.


Disclosures:


Matthew Sims, MD, PhD¹, Charles S.. Berenson, MD², Robert Stevens, PharmD³, Dianne Nguyen, MD, MBA⁴, John R. Pullman, MD⁵. P1915 - Safety of Fecal Microbiota Spores, Live-brpk (Formerly SER-109) in Participants With Recurrent <i>Clostridioides difficile</i> Infection and Comorbidities: Findings From an Integrated Analysis of Phase 3 Trials, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.