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Clostridia Difficile ColitisPhase 3TAPER-V2NCT07328971

Vancomycin Taper to Prevent Recurrent Clostridioides Difficile

A Phase 3 study testing Fidaxomicin and Vancomycin capsule in people with Clostridia Difficile Colitis, run by McGill University Health Centre/Research Institute of the McGill University Health Centre at 2 sites in Canada.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

Indirect evidence from network meta-analyses of randomized controlled trials (RCTs) suggest that a pulse and taper (P-T) of vancomycin may be non-inferior to 10-days of fidaxomicin for the prevention of recurrent Clostridioides difficile infections (rCDI). Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Clostridia Difficile Colitis
What is being tested?
Fidaxomicin and Vancomycin capsule
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
500 participants
Where
2 sitesCanada
Study dates
24 Apr 2026to 1 Nov 2030
Phase
Phase 3
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

  • Inpatient or outpatient adults (≥18 years old) treated at the participating institutions.
  • First episode or first recurrence of CDI (i.e., second episode within 120 days) defined by a positive C. difficile assay (including PCR toxin gene detection, toxin enzyme immunoassay, and/or cell cytotoxicity neutralization assay) and the presence of either ≥3 unformed stools in <24 hours with a duration >24 hours, endoscopic/histologic evidence of pseudomembranous colitis, or ileus. For eligibility, CDI will be considered a first recurrence if the patient experiences 2 episodes within a 120-day timeframe; those with a first ever episode, or 2 episodes separated by more than 120 days, will be categorized as a first-episode.
  • Clinical Exclusion Criteria
  • Treatment with CDI-active antibiotics that will be continued throughout the trial (i.e., rifaximin for hepatic encephalopathy).
  • Planned or current treatment of the present episode of CDI with FMT, intravenous immunoglobulins, or other microbiome therapies (i.e., VOWST or REBYOTA).
  • Inability to take medications orally.
Show all 22Show fewer
  • Ileostomy, colostomy, or total colectomy with ileorectal anastomosis.
  • Severe intolerance or allergy to oral vancomycin or fidaxomicin.
  • The patient is being admitted to a palliative care ward or is anticipated to die within 3 months of enrollment from another illness.
  • Fulminant CDI, defined according to the IDSA definition of CDI with the presence of hypotension, shock, ileus, and/or toxic megacolon.
  • Receipt of more than 72 hours of off-study fidaxomicin or vancomycin CDI therapy for the current episode of CDI.
  • Pregnancy or planning to become pregnant during the study period because minimal data on fidaxomicin in pregnancy are available.
  • Active breastfeeding because minimal data on fidaxomicin in breastfeeding are available.
  • Patients who have had ≥3 episodes of CDI in the last 1 year.
  • Treating team declined participation.
  • Prior enrolment in TAPER-V2.
  • Administrative Exclusion Criteria
  • Prior enrollment in this trial.
  • Inability to consent without a healthcare proxy.
  • Lack of health insurance.
  • Anticipated transfer to a site not involved in this trial, or to a palliative care ward
  • Patient-declared anticipated inability to participate in study follow-up or lack of means for contact in the outpatient setting.

Who cannot join

None listed.

Trial locations and contacts

2 sites in 1 country. Contact the study team or a site near you to ask about taking part.

Canada2 sites, 2 recruiting
  • University of Alberta

    Edmonton, Alberta, T6G 2R3

    Dina Kao, MD, FRCPC, dkao@ualberta.ca

    Dina Kao, MD

    Recruiting
  • McGill University Health Centre

    Montreal, Quebec, H4A0B1

    Connor Prosty, MD, 514-934-1934 ext. x53333, connor.prosty@mail.mcgill.ca

    Emily McDonald, MD MSc

    Recruiting

Other trials in Canada

About this study

Official title: Initial Vancomycin Taper for the Prevention of Recurrent Clostridioides Difficile Infection 2: A Randomized Controlled Trial

Indirect evidence from network meta-analyses of randomized controlled trials (RCTs) suggest that a pulse and taper (P-T) of vancomycin may be non-inferior to 10-days of fidaxomicin for the prevention of recurrent Clostridioides difficile infections (rCDI). The aim of this trial is:

  1. For first episodes and first recurrences of CDI, to test whether a vancomycin P-T is non-inferior to 10-days of fidaxomicin for the prevention of rCDI at 56 days
Read the detailed description
  1. difficile is a gram positive spore-forming anaerobic bacterium that can cause severe diarrhea through colitis. While the incidence of CDI is decreasing in Canada it remains a major cause of both nosocomial and community-acquired diarrhea. The annual incidence of CDI in Canada is 16,000 cases with 1,300 (8.1%) associated deaths. Estimates suggest that CDI is associated with annual economic losses of ~$150 million in Canada and that 23% of these losses are attributable to recurrent cases. Despite appropriate treatment, approximately 20-30% of CDI cases experience a recurrence (rCDI) and recurrent cases are substantially more costly and deadly. Fidaxomicin reduces the absolute recurrence rate of CDI by ~10% relative to 10 days of vancomycin; however, cost and availability prohibit widespread use. At the current price in Canada, fidaxomicin is not cost-effective. Thus, rCDI is associated with significant morbidity, mortality, and economic cost, and prevention is a substantially unmet clinical need.

International CDI guidelines conflict on the recommended treatments for first episodes and first recurrences. The IDSA and ESCMID favor fidaxomicin for both, the ACG recommends fidaxomicin or vancomycin (P-T for first recurrences) for both, whereas the Association of Medical Microbiology and Infectious Disease (AMMI) Canada favors vancomycin for both. These heterogeneous guidelines are mirrored by significant global practice heterogeneity in the use of fidaxomicin or oral vancomycin (10-14 days or as a P-T) for CDI. Since the publication of these guidelines, the TAPER-V trial (NCT04138706) found a 99.0% probability of superiority of a 4-week vancomycin P-T vs. 14 days of vancomycin for first CDI episodes and recurrences for the rCDI outcome at 38 days. Incorporating TAPER-V into a network meta-analysis of RCTs of treatments for first episodes and recurrences revealed that for the prevention of rCDI at day 38, vancomycin P-T was not significantly different from 10 days of fidaxomicin (Adjusted relative risk=0.73, favouring vancomycin P-T, 95% Confidence Interval (95%CI)=0.33, 1.61). However, only indirect evidence was available for this comparison because vancomycin P-T and fidaxomicin have never been compared head-to-head in an RCT.

Although the probability of superiority for vancomycin P-T vs. 14 days of vancomycin in TAPER-V for rCDI was 99.0% at 38 days, this probability fell to 73.8% at 56 days (i.e., the IDSA timeframe for rCDI), and 62.1% at 90 days. All the available RCT evidence for 10 days of fidaxomicin in the prevention of rCDI is within a 40 day timeframe. Thus, it is unknown whether the benefit of fidaxomicin also wanes over time.

By contrast to fidaxomicin, vancomycin P-T has greater worldwide availability and markedly reduced cost. If it is non-inferior or superior to fidaxomicin in terms of preventing rCDI over the long term (e.g., at least 56 days), it will represent a very important addition to international treatment algorithms.

To determine whether vancomycin P-T is an alternative to fidaxomicin, the investigators propose a non-inferiority RCT comparing vancomycin P-T to 10 days of fidaxomicin for the treatment of first episodes and first recurrences of CDI. Indeed, 68.2% of respondents to a recent clinician survey on CDI supported a trial on this comparison. The proposed trial will directly inform clinical practice on the potential of vancomycin P-T as a non-inferior and a lower-cost first-line therapy for CDI. This trial will also be the first to provide data on the longer term rCDI rate (beyond days 38-40) for fidaxomicin.

Being tested
Fidaxomicin, Vancomycin capsule
Keywords
Clostridoides difficile, Recurrent Clostridioides difficile, C. difficile, Clostridium difficile
Medical subject headings
Enterocolitis, Pseudomembranous

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • FidaxomicinDrug

    Fidaxomicin 200mg PO BID x 10 days

  • Vancomycin capsuleDrug

    Vancomycin 125mg PO QID x2 weeks, then 125mg PO BID x2 weeks, then 125mg PO daily x2 weeks

Study groups in NCT07328971
Study groupRoleWhat they receive
FidaxomicinActive comparatorFidaxomicin 200mg PO BID x 10 days
Receives: Drug: Fidaxomicin
Vancomycin T-PExperimentalVancomycin 125mg PO QID x2 weeks, then 125mg PO BID x2 weeks, then 125mg PO daily x2 weeks
Receives: Drug: Vancomycin capsule

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. CDI Recurrence

    Recurrence will be assessed by clinical record review (chart, laboratory, pharmacy records) and any direct patient interview. CDI recurrence will be defined by 1) three or more unformed stools in a 24-hour period, 2) a positive PCR for toxin gene or and/or detection of toxin by enzyme immunoassay or cell cytotoxicity neutralization assay, and 3) administration of CDI treatment. To avoid missing severe recurrences for cases of ileus, toxic megacolon, or pseudomembranous colitis on colonoscopy the test result and administration of treatment will fulfill criteria for a recurrence in the absence of three or more unformed stools.

    Measured: 56 days

Secondary outcomes (5)
  1. All-Cause Mortality

    All-cause mortality

    Measured: 56 days

  2. All-Cause Mortality

    All-cause mortality

    Measured: 120 days

  3. Discontinuation of study drug due to adverse events

    Discontinuation of the study drug due to any patient-reported adverse event

    Measured: 56 days

  4. ER Visit or Hospital (Re)Admission

    All-cause ER visits and hospital (re)admission

    Measured: 56 days

  5. ER Visit or Hospital (Re)Admission

    All-cause ER visits and hospital (re)admission

    Measured: 120 days

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted9 Jan 2026
  2. Study start24 Apr 2026
  3. Primary completion1 Jun 2030 (estimated)
  4. Study completion1 Nov 2030 (estimated)

Resources

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 3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Outcomes assessor
Enrolment
500 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07328971
Sponsor's protocol ID
2026-12121
Acronym
TAPER-V2
Status last verified
Sep 2026
First submitted
25 Nov 2025
Last updated
23 Sep 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Louie TJ, Miller MA, Mullane KM, Weiss K, Lentnek A, Golan Y, Gorbach S, Sears P, Shue YK; OPT-80-003 Clinical Study Group. Fidaxomicin versus vancomycin for Clostridium difficile infection. N Engl J Med. 2011 Feb 3;364(5):422-31. doi: 10.1056/NEJMoa0910812.

    PubMed 21288078
  • Johnson S, Lavergne V, Skinner AM, Gonzales-Luna AJ, Garey KW, Kelly CP, Wilcox MH. Clinical Practice Guideline by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA): 2021 Focused Update Guidelines on Management of Clostridioides difficile Infection in Adults. Clin Infect Dis. 2021 Sep 7;73(5):e1029-e1044. doi: 10.1093/cid/ciab549.

    PubMed 34164674
  • McDonald LC, Gerding DN, Johnson S, Bakken JS, Carroll KC, Coffin SE, Dubberke ER, Garey KW, Gould CV, Kelly C, Loo V, Shaklee Sammons J, Sandora TJ, Wilcox MH. Clinical Practice Guidelines for Clostridium difficile Infection in Adults and Children: 2017 Update by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA). Clin Infect Dis. 2018 Mar 19;66(7):e1-e48. doi: 10.1093/cid/cix1085.

    PubMed 29462280

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Fidaxomicin and Vancomycin capsule in people with Clostridia Difficile Colitis, run by McGill University Health Centre/Research Institute of the McGill University Health Centre at 2 sites in Canada.

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 22 inclusion and 0 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: looking for participants now, as of the sponsor's last update on 23 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites in Canada. 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 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

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 Connor Prosty, MD (514-934-1934 ext. 53333, connor.prosty@mail.mcgill.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

CDI Recurrence (time frame: 56 days). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07328971, which also lists 3 linked publications.

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 23 Sep 2026.

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