Trial Outcomes & Findings for A Multi-center, Single-arm Trial Exploring the Safety and Clinical Effectiveness of RBX2660 Administered by Colonoscopy to Adults With Recurrent Clostridioides Difficile Infection (NCT NCT05831189)

NCT ID: NCT05831189

Last Updated: 2026-04-24

Results Overview

Recruitment status

COMPLETED

Study phase

PHASE3

Target enrollment

41 participants

Primary outcome timeframe

8 weeks after RBX2660 treatment delivered by colonoscopy

Results posted on

2026-04-24

Participant Flow

Participant milestones

Participant milestones
Measure	RBX2660 RBX2660: RBX2660 should be administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
Overall Study STARTED	41
Overall Study COMPLETED	39
Overall Study NOT COMPLETED	2

Reasons for withdrawal

Reasons for withdrawal
Measure	RBX2660 RBX2660: RBX2660 should be administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
Overall Study Withdrawal by Subject	2

Baseline Characteristics

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

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	RBX2660 n=41 Participants RBX2660: RBX2660 was administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
Age, Continuous	61.2 Years STANDARD_DEVIATION 14.9 • n=2 Participants
Sex: Female, Male Female	36 Participants n=2 Participants
Sex: Female, Male Male	5 Participants n=2 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	1 Participants n=2 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	40 Participants n=2 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=2 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=2 Participants
Race (NIH/OMB) Asian	0 Participants n=2 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=2 Participants
Race (NIH/OMB) Black or African American	2 Participants n=2 Participants
Race (NIH/OMB) White	39 Participants n=2 Participants
Race (NIH/OMB) More than one race	0 Participants n=2 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=2 Participants
Number of Previous CDI Episodes	3.2 Episodes STANDARD_DEVIATION 1.8 • n=2 Participants

PRIMARY outcome

Timeframe: 8 weeks after RBX2660 treatment delivered by colonoscopy

Outcome measures

Outcome measures
Measure	RBX2660 n=41 Participants RBX2660: RBX2660 was administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
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

SECONDARY outcome

Timeframe: Within 8 weeks after RBX2660 treatment delivered by colonoscopy

Outcome measures

Outcome measures
Measure	RBX2660 n=41 Participants RBX2660: RBX2660 was administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
Number of Participants With Recurrence of Clostridioides Difficile Infection (CDI) Within 8 Weeks After RBX2660 Treatment Delivered by Colonoscopy.	2 Participants

SECONDARY outcome

Timeframe: 8 weeks after RBX2660 treatment delivered by colonoscopy

Outcome measures

Outcome measures
Measure	RBX2660 n=41 Participants RBX2660: RBX2660 was administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
Time to CDI Recurrence From Baseline Through 8 Weeks After RBX2660 Treatment Delivered by Colonoscopy	0 Weeks

SECONDARY outcome

Timeframe: At Day 1 (baseline visit)

Outcome measures

Outcome measures
Measure	RBX2660 n=41 Participants RBX2660: RBX2660 was administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Ease of administration · Positive experience	17 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Ease of administration · Very positive experience	21 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Ease of administration · Somewhat negative experience	1 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Ease of administration · Neutral experience	2 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Activities following administration · Somewhat positive	1 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Activities following administration · Positive experience	16 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Activities following administration · Very positive experience	21 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Activities following administration · Somewhat negative experience	0 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Activities following administration · Neutral experience	3 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Overall experience using RBX2660 · Somewhat positive	1 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Overall experience using RBX2660 · Positive experience	23 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Overall experience using RBX2660 · Very positive experience	14 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Overall experience using RBX2660 · Somewhat negative experience	1 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Overall experience using RBX2660 · Neutral experience	2 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Preparations before administration · Positive experience	20 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Preparations before administration · Very positive experience	19 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Preparations before administration · Somewhat negative experience	0 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Preparations before administration · Neutral experience	0 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Ease of administration · Somewhat positive	0 Participants
Physician-experience, as Determined by Questionnaire, Documenting Subjective Experience of Investigators on Usability of RBX2660 in Clinical Practice When Delivered by Colonoscopy Preparations before administration · Somewhat positive	2 Participants

SECONDARY outcome

Timeframe: 8 weeks after RBX2660 treatment delivered by colonoscopy

Outcome measures

Outcome measures
Measure	RBX2660 n=39 Participants RBX2660: RBX2660 was administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
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 Very much improved	26 Participants
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 Much improved	13 Participants

SECONDARY outcome

Timeframe: 8 weeks after RBX2660 treatment delivered by colonoscopy

Outcome measures

Outcome measures
Measure	RBX2660 n=39 Participants RBX2660: RBX2660 was administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
Patient-experience Interview at 8 Weeks, or at Treatment Failure, After RBX2660 Treatment Delivered by Colonoscopy Very Much Improved	26 Participants
Patient-experience Interview at 8 Weeks, or at Treatment Failure, After RBX2660 Treatment Delivered by Colonoscopy Much Improved	13 Participants

SECONDARY outcome

Timeframe: Up to 8 weeks after RBX2660 treatment delivered by colonoscopy

Outcome measures

Outcome measures
Measure	RBX2660 n=41 Participants RBX2660: RBX2660 was administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
Number of Participants With Treatment-emergent Adverse Events up to 8 Weeks or Treatment Failure After RBX2660 Treatment Mild adverse events	14 Participants
Number of Participants With Treatment-emergent Adverse Events up to 8 Weeks or Treatment Failure After RBX2660 Treatment Moderate adverse events	3 Participants
Number of Participants With Treatment-emergent Adverse Events up to 8 Weeks or Treatment Failure After RBX2660 Treatment Severe adverse events	2 Participants
Number of Participants With Treatment-emergent Adverse Events up to 8 Weeks or Treatment Failure After RBX2660 Treatment Potentially Life-threatening	1 Participants
Number of Participants With Treatment-emergent Adverse Events up to 8 Weeks or Treatment Failure After RBX2660 Treatment Adverse events leading to discontinuation	0 Participants
Number of Participants With Treatment-emergent Adverse Events up to 8 Weeks or Treatment Failure After RBX2660 Treatment Serious adverse events	2 Participants
Number of Participants With Treatment-emergent Adverse Events up to 8 Weeks or Treatment Failure After RBX2660 Treatment Adverse events leading to death	0 Participants
Number of Participants With Treatment-emergent Adverse Events up to 8 Weeks or Treatment Failure After RBX2660 Treatment Adverse events	18 Participants

SECONDARY outcome

Timeframe: Up to 8 weeks after RBX2660 treatment delivered by colonoscopy

Outcome measures

Outcome measures
Measure	RBX2660 n=41 Participants RBX2660: RBX2660 was administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
Number of Participants With Serious Adverse Events (SAEs)	2 Participants

SECONDARY outcome

Timeframe: Up to 8 weeks after RBX2660 treatment delivered by colonoscopy

Outcome measures

Outcome measures
Measure	RBX2660 n=41 Participants RBX2660: RBX2660 was administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
Number of Participants With Any Adverse Events of Special Interest (AESIs)	2 Participants

SECONDARY outcome

Timeframe: Up to 8 weeks after RBX2660 treatment delivered by colonoscopy

Outcome measures

Outcome measures
Measure	RBX2660 n=41 Participants RBX2660: RBX2660 was administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
Number of Participants With Adverse Events Leading to Death or Intensive Care Unit (ICU) Admission	2 Participants

Adverse Events

RBX2660

Serious events: 2 serious events

Other events: 6 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	RBX2660 n=41 participants at risk RBX2660: RBX2660 was administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
Gastrointestinal disorders Colitis Ulcerative	2.4% 1/41 • Number of events 1 • 8 weeks
Neoplasms benign, malignant and unspecified (incl cysts and polyps) Brain Neoplasm	2.4% 1/41 • Number of events 1 • 8 weeks

Other adverse events

Other adverse events
Measure	RBX2660 n=41 participants at risk RBX2660: RBX2660 was administered to the right side of the colon (i.e., between the ileocecal valve and the hepatic flexure of the colon).
Gastrointestinal disorders Abdominal Distension	7.3% 3/41 • Number of events 3 • 8 weeks
Gastrointestinal disorders Constipation	7.3% 3/41 • Number of events 4 • 8 weeks

Additional Information

Global Clinical Compliance

Ferring Pharmaceuticals A/S

Phone: 1-888-3377464

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place