Phase 3 N=41 Treatment

A Multi-center, Single-arm Trial Exploring the Safety and Clinical Effectiveness of RBX2660 Administered by Colonoscopy to Adults With Recurrent Clostridioides Difficile Infection

Clostridium Difficile Infection Recurrence

Bottom Line

View on ClinicalTrials.gov: NCT05831189 ↗

Enrolled (actual)

Serious AEs

4.9%

Results posted

Apr 2026

Primary outcome: Primary: Number of Participants With RBX2660-related Treatment-emergent Adverse Events (TEAEs) After RBX2660 Treatment Delivered by Colonoscopy Through 8 Weeks, or Treatment Failure — 18 Participants

Study Design & Population

Study type: Interventional
Phase: Phase 3
Interventions: RBX2660 (Drug)
Age: Adult, Older Adult · 18+ yrs
Sex: All
Sponsor: Ferring Pharmaceuticals
Primary completion: Jan 2025

Outcome Measures

Outcome	Result	p-value
PRIMARY Number of Participants With RBX2660-related Treatment-emergent Adverse Events (TEAEs) After RBX2660 Treatment Delivered by Colonoscopy Through 8 Weeks, or Treatment Failure	18	—
SECONDARY Number of Participants With Recurrence of Clostridioides Difficile Infection (CDI) Within 8 Weeks After RBX2660 Treatment Delivered by Colonoscopy.	2	—
SECONDARY Time to CDI Recurrence From Baseline Through 8 Weeks After RBX2660 Treatment Delivered by Colonoscopy	—	—
SECONDARY Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy	2; 20; 19; 0; 0; 0	—
SECONDARY Physician Perception of Patient Benefit, as Determined by Number of Participants With Clinician Global Impression of Improvement (CGI-I) at 8 Weeks, or at Treatment Failure, After RBX2660 Treatment Delivered by Colonoscopy	26; 13	—
SECONDARY Patient-experience Interview at 8 Weeks, or at Treatment Failure, After RBX2660 Treatment Delivered by Colonoscopy	26; 13	—
SECONDARY Number of Participants With Treatment-emergent Adverse Events up to 8 Weeks or Treatment Failure After RBX2660 Treatment	18; 14; 3; 2; 1; 0	—
SECONDARY Number of Participants With Serious Adverse Events (SAEs)	2	—
SECONDARY Number of Participants With Any Adverse Events of Special Interest (AESIs)	2	—
SECONDARY Number of Participants With Adverse Events Leading to Death or Intensive Care Unit (ICU) Admission	2	—

Summary

This trial will be initiated to explore whether RBX2660 (REBYOTA®) could be suitable for administration by the practice of colonoscopy. More specifically, the purpose of this trial is to explore the safety and clinical effectiveness of RBX2660 when delivered by colonoscopy to adults with rCDI. The experience of physicians will be documented through a physician-experience questionnaire to explore the usability of RBX2660 in clinical practice for colonoscopic administration. Furthermore, to explore the patient-experience of RBX2660 treatment, each trial participant will be offered to undergo a structured interview.

Eligibility Criteria

Inclusion Criteria

have documented evidence of rCDI (≥1 recurrence after a primary CDI episode)
be undergoing antibiotic treatment for the qualifying rCDI episode that was diagnosed by a stool test for the presence of toxigenic C. difficile or C. difficile toxin
be eligible for FMT as judged by the investigator or current treatment guidelines for rCDI in the US
be a candidate for colonoscopy as judged by the investigator

Exclusion Criteria

Use or planned use of systemic antibiotics for an indication other than the qualifying rCDI episode.
Current uncontrolled chronic diarrhea not related to CDI.
Receipt of CDI vaccine or treatment with CDI monoclonal antibodies within the past 12 months before screening.
Evidence of active, severe, or fulminant colitis, diagnosis of toxic megacolon or have a current colostomy or ileostomy

View full record on ClinicalTrials.gov →

Data sourced from ClinicalTrials.gov (NCT05831189). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.