Inflammatory Bowel DiseasesPhase 2ICON-2NCT03829475
ICON-2: FMT and Bezlotoxumab Compared to FMT and Placebo for Patients With IBD and CDI
A Phase 2 study testing Bezlotoxumab and Fecal Microbiota Transplantation in people with Inflammatory Bowel Diseases and Clostridium Difficile Infection, run by Brigham and Women's Hospital at 1 site in United States.
Trial summary
This is a randomized controlled trial to assess the clinical and microbiological impacts of FMT in combination with Bezlotoxumab (bezlo) compared to FMT in combination with placebo in patients with both inflammatory bowel disease (IBD) a and clostridium difficile infection (CDI). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Inflammatory Bowel Diseases, Clostridium Difficile Infection
- What is being tested?
- Bezlotoxumab and Fecal Microbiota Transplantation
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 61 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jan 2020to 1 Jun 2025
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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
- Adults age 18 or greater
- History of ≥ 2 episodes of recurrent CDI. CDI is defined as the presence of diarrhea ( Bristol 6 or 7 for 48 hours and a confirmatory test for CDI). Preferred testing will be a two-step method using GDH/EIA toxin, though PCR will be accepted based on hospital availability with confirmation of the most recent episode occurring within the prior 3 months
- Confirmed diagnosis of IBD (ulcerative colitis, Crohn's disease or indeterminate colitis)
- Undergoing FMT via colonoscopy for CDI as part of standard medical care
Who cannot join
- Unable or unwilling to undergo a colonoscopy
- Inpatient status, though patients can be screened while inpatients, the must be outpatient for the planned colonoscopy.
- Anticipated immediate or upcoming surgery within 30 days
- Need for continued non-anti-CDI antibiotic therapy
- History of total proctocolectomy
- Female patients who are pregnant or breastfeeding or plan to become pregnant in the next 6 months.
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- Patients who are unable to give informed consent
- Participation in a clinical trial in the preceding 30 days or simultaneously during this trial
- Severe food allergy (anaphylaxis or anaphylactoid-like reaction)
- Life expectancy < 6 months
- Unable to adhere to protocol requirements
- Patient who have received an FMT in the past year
- Any condition that the physician investigators deems unsafe, including other conditions or medications that the investigator determines that it will put the subject at greater risk from FMT
- Patient who is diagnosed with NYHA class 3 or 4 Heart Failure
- Lab value of WBC <3.0 x 103/mm3 , Platelets <100 x 103/mm3 , ALT or AST > 1.5 x institutional ULN
- EBV or CMV negative if a patient is severely immunosuppressed ( defined as 3 or more immunosuppressing agents)
Trial locations and contacts
1 site in 1 country.
United States1 site
Brigham and Women's Hospital
Boston, Massachusetts, 02115
About this study
Official title: A Randomized Controlled Trial to Compare the Effectiveness of Fecal Microbiota Transplantation (FMT) in Combination With Bezlotoxumab Compared to FMT and Placebo for the Prevention of CDI Recurrence in Patients With Inflammatory Bowel Disease and Recurrent Clostridium Difficile Infection
This is a randomized controlled trial to assess the clinical and microbiological impacts of FMT in combination with Bezlotoxumab (bezlo) compared to FMT in combination with placebo in patients with both inflammatory bowel disease (IBD) a and clostridium difficile infection (CDI). The investigators will prospectively enroll up to 150 IBD-CDI patients from 4 tertiary care FMT referral centers. Patients will be randomized 1:1 to either receive FMT in combination with Bezlo of FMT and a placebo infusion. Donor stool from healthy donors will be obtained from OpenBiome. OpenBiome is a nonprofit 501(c)(3) organization that provides hospitals with screened, filtered, and frozen material ready for clinical use. Patients will be enrolled and followed prospectively for 3 months post therapy. Stool and blood samples as well as clinical data will be collected at baseline, week 1, 8 and 12.
- Being tested
- Bezlotoxumab, Placebo, Fecal Microbiota Transplantation
- Keywords
- Crohn's DIsease, Ulcerative Colitis
- Medical subject headings
- Inflammatory Bowel Diseases, Clostridium Infections, Crohn Disease, Colitis, Ulcerative
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
BezlotoxumabDrug
Also called Zinplava
This is a a fully human monoclonal antibody that binds to C. difficile toxin B, and is indicated to prevent recurrence of CDI in adults at risk for recurrent CDI (rCDI).
PlaceboDrug
Also called Saline
placebo is an infusion of normal saline.
Fecal Microbiota TransplantationDrug
Also called FMT
FMT is an infusion of prescreened donor stool that will be administered via colonoscopy
| Study group | Role | What they receive |
|---|---|---|
| FMT + Bezlo | Experimental | Patients in this arm will received an FMT via colonoscopy ( 250ml) as well as a single IV infusion of bezlotoxumab (10mg/kg) that will take place over 60 mins. Receives: Drug: Bezlotoxumab; Drug: Fecal Microbiota Transplantation |
| FMT + Placebo | Placebo comparator | Patients in this arm will receive a single FMT via colonoscopy (250ml) and a placebo (saline) infusion (250cc) over Receives: Drug: Placebo; Drug: Fecal Microbiota Transplantation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants With Clostridium Difficile Recurrence
positive test for CDI by EIA toxin
Measured: 8 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Feb 2019
- Study start1 Jan 2020
- Primary completion3 Aug 2023
- Study completion1 Jun 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Inflammatory Bowel DiseasesStudies 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 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 61 participants (actual)
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
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03829475
- Sponsor's protocol ID
- 2018
- Acronym
- ICON-2
- Status last verified
- Nov 2025
- First submitted
- 26 Jan 2019
- Last updated
- 9 Dec 2025
- Results posted
- Yes, on ClinicalTrials.gov
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized Controlled Trial to Compare the Effectiveness of Fecal Microbiota Transplantation (FMT) in Combination With Bezlotoxumab Compared to FMT and Placebo for the Prevention of CDI Recurrence in Patients With Inflammatory Bowel Disease and Recurrent Clostridium Difficile Infection
- ClinicalTrials.gov ID
- NCT03829475
- Acronym / sponsor ID
- ICON-2 / 2018
- Keywords
- Crohn's DIsease, Ulcerative Colitis
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 61 participants (actual)
- Lead sponsor
- Brigham and Women's HospitalUniversity, hospital or other
- Study start
- 1 Jan 2020 (actual)
- Primary completion
- 3 Aug 2023 (actual)
- Study completion
- 1 Jun 2025 (actual)
- First posted
- 4 Feb 2019 (actual)
- Results
- Posted 11 Dec 2024
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 controlled trial to assess the clinical and microbiological impacts of FMT in combination with Bezlotoxumab (bezlo) compared to FMT in combination with placebo in patients with both inflammatory bowel disease (IBD) a and clostridium difficile infection (CDI). The investigators will prospectively enroll up to 150 IBD-CDI patients from 4 tertiary care FMT referral centers. Patients will be randomized 1:1 to either receive FMT in combination with Bezlo of FMT and a placebo infusion. Donor stool from healthy donors will be obtained from OpenBiome. OpenBiome is a nonprofit 501(c)(3) organization that provides hospitals with screened, filtered, and frozen material ready for clinical use. Patients will be enrolled and followed prospectively for 3 months post therapy. Stool and blood samples as well as clinical data will be collected at baseline, week 1, 8 and 12.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| FMT + Bezlo | Experimental | Drug: Bezlotoxumab, Drug: Fecal Microbiota TransplantationPatients in this arm will received an FMT via colonoscopy ( 250ml) as well as a single IV infusion of bezlotoxumab (10mg/kg) that will take place over 60 mins. |
| FMT + Placebo | Placebo comparator | Drug: Placebo, Drug: Fecal Microbiota TransplantationPatients in this arm will receive a single FMT via colonoscopy (250ml) and a placebo (saline) infusion (250cc) over |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Adults age 18 or greater
- History of ≥ 2 episodes of recurrent CDI. CDI is defined as the presence of diarrhea ( Bristol 6 or 7 for 48 hours and a confirmatory test for CDI). Preferred testing will be a two-step method using GDH/EIA toxin, though PCR will be accepted based on hospital availability with confirmation of the most recent episode occurring within the prior 3 months
- Confirmed diagnosis of IBD (ulcerative colitis, Crohn's disease or indeterminate colitis)
- Undergoing FMT via colonoscopy for CDI as part of standard medical care
Key exclusion criteria (16 listed)
- Unable or unwilling to undergo a colonoscopy
- Inpatient status, though patients can be screened while inpatients, the must be outpatient for the planned colonoscopy.
- Anticipated immediate or upcoming surgery within 30 days
- Need for continued non-anti-CDI antibiotic therapy
- History of total proctocolectomy
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 |
|---|---|---|
| BezlotoxumabAlso: ZinplavaThis is a a fully human monoclonal antibody that binds to C. difficile toxin B, and is indicated to prevent recurrence of CDI in adults at risk for recurrent CDI (rCDI). | Drug | FMT + Bezlo |
| PlaceboAlso: Salineplacebo is an infusion of normal saline. | Drug | FMT + Placebo |
| Fecal Microbiota TransplantationAlso: FMTFMT is an infusion of prescreened donor stool that will be administered via colonoscopy | Drug | FMT + Bezlo, FMT + Placebo |
Primary outcome
Number of Participants With Clostridium Difficile Recurrence
Time frame: 8 weeks
positive test for CDI by EIA toxin
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Dec 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Bezlotoxumab and Fecal Microbiota Transplantation in people with Inflammatory Bowel Diseases and Clostridium 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 16 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: finished, as of the sponsor's last update on 9 Dec 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. Some participants in this study may receive a placebo. 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 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 11 Dec 2024). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants With Clostridium Difficile Recurrence (time frame: 8 weeks). 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 9 Dec 2025.