Inflammatory Bowel Disease (IBD)Phase 4NCT06794944
Use of Fidaxomicin Compared to Vancomycin for Decolonization of C. Difficile in Patients With Inflammatory Bowel Disease
A Phase 4 study testing Vancomycin (POC) and Fidaxomicin in people with Inflammatory Bowel Disease (IBD) and Clostridioides Difficile Infection, run by Brigham and Women's Hospital at 1 site in United States.
Trial summary
This is a randomized, double-blind study to assess the safety and efficacy of fidaxomicin compared to vancomycin for decolonization of C. difficile in IBD patients. A total of 60 patients who meet eligibility criteria will be randomized 1:1 to either the fidaxomicin or vancomycin arm. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Inflammatory Bowel Disease (IBD), Clostridioides Difficile Infection
- What is being tested?
- Vancomycin (POC) and Fidaxomicin
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteUnited States
- Study dates
- Sep 2026to Sep 2031
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Signed informed consent.
- Male or female > 18 years of age.
- IBD diagnosis (CD, UC or indeterminant Colitis will be permitted.)
- Presenting for outpatient colonoscopy for any indication.
Who cannot join
- Unable to provide consent.
- Patients with previous colectomy, ostomy, J-pouch, or previous colon surgery (excluding appendectomy.)
- Unable to complete study procedures.
- Chronic use of antibiotics.
- Inability or unwillingness to swallow capsules.
- Allergy or sensitivity to vancomycin, fidaxomicin, or microcrystalline cellulose.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
Brigham and Women's Hospital
Boston, Massachusetts, 02115
Alexander Carlin, 6175257322, acarlin@bwh.harvard.edu
About this study
This is a randomized, double-blind study to assess the safety and efficacy of fidaxomicin compared to vancomycin for decolonization of C. difficile in IBD patients. A total of 60 patients who meet eligibility criteria will be randomized 1:1 to either the fidaxomicin or vancomycin arm. The vancomycin arm will receive a dose of 125 mg PO q 6 hours for 10 days. The fidaxomicin arm will receive 200 mg PO BID for 10 days. In order to ensure blinding, both antibiotics will be concealed in opaque 00 capsule shells. In addition, those in the fidaxomicin arm will receive 2 placebo capsules so that all participants will receive 4 capsules daily for 10 days. Microbiome assessment and C. difficile testing will be performed at baseline, day 5, day 10, and weeks 4, 8, and 26.
Read the detailed description
This randomized, double-blind trial will assess the ability of fidaxomicin compared to vancomycin to decolonize C. difficile in the IBD patient population.
Participants who meet eligibility criteria will be randomized 1:1 to either vancomycin or fidaxomicin treatment. The vancomycin arm will receive a dose of 125 mg PO q 6 hours for 10 days. The fidaxomicin arm will receive 200 mg PO BID for 10 days. In order to ensure blinding both antibiotics will be concealed in opaque 00 capsule shells. In addition, those in the fidaxomicin arm will receive 2 placebo capsules so that all participants will receive 4 capsules daily for 10 days. Participants will end dosing after 10 days, but monitoring will continue to week 8. Both participants and study team will be blinded to treatment arm allocation.
Participants will be assessed through week 8 for the primary outcome, decolonization. Safety and tolerability outcomes will be assessed through week 8. In addition, secondary efficacy outcomes including IBD disease activity and development of CDI will be evaluated at week 8 and week 26. Participants will also be followed through week 26 for long-term safety, efficacy, and clinical outcomes. Disease activity and symptoms will be recorded from time of informed consent through to the week 26 trial visit. Stool samples for biomarker assessments and C. difficile testing will be collected at scheduled trial visits per Schedule of Assessments.
The primary outcome, decolonization of C. Difficile at week 8, will be confirmed via stool sampling. Additional C. difficile testing will be done at week 26.
Participants that experience intolerable adverse events will be withdrawn from the study and will be considered treatment failures. Additional subjects may be enrolled to obtain 60 patients with week 8 data.
The study will enroll approximately 60 adult participants at a single center.
- Being tested
- Vancomycin (POC), Fidaxomicin
- Keywords
- C. difficile, Crohn's Disease, Ulcerative Colitis
- Medical subject headings
- Inflammatory Bowel Diseases, Clostridium Infections, Colitis, Ulcerative
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Vancomycin (POC)Drug
Vancomycin is glycopeptide antibiotic that has broad gram-positive coverage. Patients will receive 125mg PO every 6 hours for 10 days.
FidaxomicinDrug
Fidaxomicin is a macrolide antibiotic. It is narrow spectrum with potent bactericidal activity specifically against C. difficile. Patients will receive 200mg PO twice daily for 10 days.
| Study group | Role | What they receive |
|---|---|---|
| Vancomycin | Active comparator | Vancomycin is glycopeptide antibiotic that has broad gram-positive coverage. The current approved dose is 125mg PO every 6 hours for 10 days. Appropriate dosing and tolerance of vancomycin is well defined in both healthy and hospitalized populations, as it is already approved and indicated by the FDA for use in treating C. difficile infection. Receives: Drug: Vancomycin (POC) |
| Fidaxomicin | Active comparator | Fidaxomicin is a macrolide antibiotic. It is narrow spectrum with potent bactericidal activity specifically against C. difficile. The approved dose is 200mg PO twice daily for 10 days. Appropriate dosing and tolerance of fidaxomicin is well defined in both healthy and hospitalized populations, as it is already approved and indicated by the FDA for use in treating C. difficile infection. Receives: Drug: Fidaxomicin |
What is being measured
The primary outcome is the main question the study is designed to answer.
C. difficile decolonization
Absence of C. difficile via PCR in Week 8 stool sample
Measured: 8 weeks
Safety and tolerability
Subject incidence of treatment-emergent adverse events (including treatment-emergent adverse events for clinically significant changes in laboratory parameters and vital signs)
Measured: 8 weeks
Secondary outcomes (3)
Biomass of C. difficile
Change in stool C. difficile biomass in patients at week 8 by quantitative culture and qPCR
Measured: 8 weeks
Long-term effect of C. difficile decolonization on IBD clinical outcomes
Change in IBD clinical scores from baseline at week 8 and week 26. IBD clinical scores are used to assess IBD patient symptoms. The assessments are separated between scores for Ulcerative Colitis (UC) and Crohn's Disease (CD). The Harvey Bradshaw Index (HBI) is a clinical assessment for IBD patients with Crohn's disease while Partial Mayo Score is a clinical assessment for Ulcerative Colitis. The scores will be collected at study visit in form of a survey. The HBI score can vary but a score above 8 or 9 is considered severe disease activity. The Partial Mayo Score can range from 0 to 9 and a score above 7 is considered severe disease activity. A decrease in score from baseline to follow-up timepoints is indicative of improved IBD patient symptoms. A decrease in score from baseline to follow-up timepoints is indicative of improved IBD patient symptoms.
Measured: 26 weeks
C. difficile infection surveillance
Incidence of patients developing CDI through Week 26
Measured: 26 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Jan 2025
- Study startSep 2026 (estimated)
- Primary completion1 Sep 2030 (estimated)
- Study completionSep 2031 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Inflammatory Bowel Disease (IBD)Studies of the same condition, open and under way.
- More trials run by Brigham and Women's HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Brigham and Women's Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jessica Ravikoff Allegretti, Brigham and Women's Hospital
- Investigators
- Jessica Allegretti, MD, MPH, Principal investigator, Brigham and Women's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06794944
- Sponsor's protocol ID
- 2025P000187
- Status last verified
- Oct 2025
- First submitted
- 21 Jan 2025
- Last updated
- 3 Nov 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Use of Fidaxomicin Compared to Vancomycin for Decolonization of C. Difficile in Patients With Inflammatory Bowel Disease
- ClinicalTrials.gov ID
- NCT06794944
- Acronym / sponsor ID
- 2025P000187
- Keywords
- C. difficile, Crohn's Disease, Ulcerative Colitis
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Brigham and Women's HospitalUniversity, hospital or other
- Study start
- Sep 2026 (estimated)
- Primary completion
- 1 Sep 2030 (estimated)
- Study completion
- Sep 2031 (estimated)
- First posted
- 27 Jan 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a randomized, double-blind study to assess the safety and efficacy of fidaxomicin compared to vancomycin for decolonization of C. difficile in IBD patients. A total of 60 patients who meet eligibility criteria will be randomized 1:1 to either the fidaxomicin or vancomycin arm. The vancomycin arm will receive a dose of 125 mg PO q 6 hours for 10 days. The fidaxomicin arm will receive 200 mg PO BID for 10 days. In order to ensure blinding, both antibiotics will be concealed in opaque 00 capsule shells. In addition, those in the fidaxomicin arm will receive 2 placebo capsules so that all participants will receive 4 capsules daily for 10 days. Microbiome assessment and C. difficile testing will be performed at baseline, day 5, day 10, and weeks 4, 8, and 26.
Detailed description
This randomized, double-blind trial will assess the ability of fidaxomicin compared to vancomycin to decolonize C. difficile in the IBD patient population.
Participants who meet eligibility criteria will be randomized 1:1 to either vancomycin or fidaxomicin treatment. The vancomycin arm will receive a dose of 125 mg PO q 6 hours for 10 days. The fidaxomicin arm will receive 200 mg PO BID for 10 days. In order to ensure blinding both antibiotics will be concealed in opaque 00 capsule shells. In addition, those in the fidaxomicin arm will receive 2 placebo capsules so that all participants will receive 4 capsules daily for 10 days. Participants will end dosing after 10 days, but monitoring will continue to week 8. Both participants and study team will be blinded to treatment arm allocation.
Participants will be assessed through week 8 for the primary outcome, decolonization. Safety and tolerability outcomes will be assessed through week 8. In addition, secondary efficacy outcomes including IBD disease activity and development of CDI will be evaluated at week 8 and week 26. Participants will also be followed through week 26 for long-term safety, efficacy, and clinical outcomes. Disease activity and symptoms will be recorded from time of informed consent through to the week 26 trial visit. Stool samples for biomarker assessments and C. difficile testing will be collected at scheduled trial visits per Schedule of Assessments.
The primary outcome, decolonization of C. Difficile at week 8, will be confirmed via stool sampling. Additional C. difficile testing will be done at week 26.
Participants that experience intolerable adverse events will be withdrawn from the study and will be considered treatment failures. Additional subjects may be enrolled to obtain 60 patients with week 8 data.
The study will enroll approximately 60 adult participants at a single center.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Vancomycin | Active comparator | Drug: Vancomycin (POC)Vancomycin is glycopeptide antibiotic that has broad gram-positive coverage. The current approved dose is 125mg PO every 6 hours for 10 days. Appropriate dosing and tolerance of vancomycin is well defined in both healthy and hospitalized populations, as it is already approved and indicated by the FDA for use in treating C. difficile infection. |
| Fidaxomicin | Active comparator | Drug: FidaxomicinFidaxomicin is a macrolide antibiotic. It is narrow spectrum with potent bactericidal activity specifically against C. difficile. The approved dose is 200mg PO twice daily for 10 days. Appropriate dosing and tolerance of fidaxomicin is well defined in both healthy and hospitalized populations, as it is already approved and indicated by the FDA for use in treating C. difficile infection. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Signed informed consent.
- Male or female > 18 years of age.
- IBD diagnosis (CD, UC or indeterminant Colitis will be permitted.)
- Presenting for outpatient colonoscopy for any indication.
Key exclusion criteria (6 listed)
- Unable to provide consent.
- Patients with previous colectomy, ostomy, J-pouch, or previous colon surgery (excluding appendectomy.)
- Unable to complete study procedures.
- Chronic use of antibiotics.
- Inability or unwillingness to swallow capsules.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Vancomycin (POC)Vancomycin is glycopeptide antibiotic that has broad gram-positive coverage. Patients will receive 125mg PO every 6 hours for 10 days. | Drug | Vancomycin |
| FidaxomicinFidaxomicin is a macrolide antibiotic. It is narrow spectrum with potent bactericidal activity specifically against C. difficile. Patients will receive 200mg PO twice daily for 10 days. | Drug | Fidaxomicin |
Primary outcome
C. difficile decolonization
Time frame: 8 weeks
Absence of C. difficile via PCR in Week 8 stool sample
Safety and tolerability
Time frame: 8 weeks
Subject incidence of treatment-emergent adverse events (including treatment-emergent adverse events for clinically significant changes in laboratory parameters and vital signs)
3 secondary outcomes
Biomass of C. difficile
Time frame: 8 weeks
Long-term effect of C. difficile decolonization on IBD clinical outcomes
Time frame: 26 weeks
C. difficile infection surveillance
Time frame: 26 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Nov 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Jessica Allegretti, MD, MPH principal investigator
Brigham and Women's Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Vancomycin (POC) and Fidaxomicin in people with Inflammatory Bowel Disease (IBD) and Clostridioides Difficile Infection, run by Brigham and Women's Hospital at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 3 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Alexander Carlin (6175257322, acarlin@bwh.harvard.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
C. difficile decolonization (time frame: 8 weeks). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Nov 2025; AzTrials last refreshed its copy on 8 Nov 2026.