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Clostridium Difficile InfectionPhase 1NCT07649096

A Safety Trial to Evaluate an Orally Ingested Yeast Modified to Express a Tetra-specific Anti-toxin for Clostridioides Difficile

A Phase 1 study testing FZ002 in people with Clostridium Difficile Infection, run by National Institute of Allergy and Infectious Diseases (NIAID) at 1 site in United States.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
Search all trials

Trial summary

This is a Phase 1, first-in-human, double-blind, placebo-controlled, adaptive-design, single-site study, involving dose exploration cohorts. During dose escalation, up to 4 cohorts, each consisting of up to 14 healthy adult (18-75 years, inclusive) study participants, will be randomly allocated to receive either FZ002… Read more about this study

Who is it for?
Ages 18 to 75 yearsHealthy volunteers can take part
Conditions the study is for
Clostridium Difficile Infection
What is being tested?
FZ002
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
56 participants
Where
1 siteUnited States
Study dates
29 Oct 2026to 22 Sep 2028
Phase
Phase 1
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 to 75 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • To be eligible to participate in this trial, an individual must meet all of the following criteria:
  • Provides written informed consent prior to the initiation of any trial procedures.
  • Is able to understand and agrees to comply with all planned trial procedures and be available for all study visits, including:
  • Receiving 28 days of blinded oral study product
  • Providing blood and self-collected stool samples
  • Is a non-pregnant individual, aged 18-75 years, inclusive, at the time of enrollment.
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  • Has no more than 1 single Grade 1 screening laboratory abnormality that is not clinically significant. If the participant has more than 1 Grade 1 abnormality, it must be approved by the Division of Microbiology and Infectious Diseases [DMID] Medical Monitor (MM).
  • Participants of childbearing potential: use of adequate contraception for at least 4 weeks prior to enrollment and agreement to use such a method during trial participation and for an additional 4 weeks after the last dose of blinded study product. Note: Definitions of participants of childbearing potential and adequate contraception are provided in Section 13.1.
  • Agrees to refrain from ingestion of probiotics* or fermented foods** from 7 days prior to study product administration, while on blinded study product, and through Day 36 (Visit 7).
  • E.g., probiotic nutritional Lactobacillus or Bifidobacterium supplements, yogurt, kefir, any "live and active culture" nutritional product, etc.
  • E.g., kombucha, fermented pickled vegetables, etc.
  • Has good health by medical history, vital signs, physical examination, and concomitant medication review*. Participants should be stable based on their condition over the last 3 months prior to enrollment.
  • As defined by not requiring a change in therapy (including dose or frequency) or medical care for worsening disease for at least 3 months prior to enrollment. Vital signs must not meet Grade 1 or higher.
  • Not using medications daily that may affect gut motility, gastric acidity, or baseline gut function* within 3 months of enrollment and through Day 36 (Visit 7).
  • E.g., proton pump inhibitors, opioids, anti-diarrheal agents, anti-constipation agents, daily Over-the-counter [OTC] "heartburn" relief medications.
  • Not using glucagon-like peptide-1 (GLP-1) receptor agonists within 6 weeks of enrollment.
  • Any elective surgery (including dental) that required preoperative or postoperative antibiotics must have been completed at least 3 months prior to enrollment.
  • No history of Clostridioides difficile infection [CDI] (suspected or proven), no recent hospital admissions (within 3 years), and no receipt of systemic antibiotics known to increase risk of CDI* (within 6 months).
  • Systemic antibiotics that are known to increase the risk of CDI include lincosamides (e.g., clindamycin), monobactams (e.g., aztreonam), extended-spectrum penicillin combinations with beta-lactamase inhibitors (e.g., piperacillin-tazobactam), carbapenems (e.g., imipenem, meropenem, ertapenem), third generation or higher cephalosporins, and fluoroquinolones. Common oral antibiotics that would be allowable or are not known to significantly increase risk of CDI include amoxicillin, azithromycin, cephalexin, doxycycline, metronidazole, and trimethoprim/sulfamethoxazole.
  • No history of other enteric infections or diarrheal illness within 3 months of enrollment.

Who cannot join

  • Dwells in a long-term care or skilled nursing facility (living independently with limited nursing care is allowable).
  • Known to be pregnant or has a positive pregnancy test at screening or enrollment.
  • Currently breastfeeding a child.
  • Known to have a yeast allergy or significant hypersensitivity to any components of the study product; including S. boulardii (or any S. boulardii-based nutritional supplement), hydroxypropyl methylcellulose, and Microcrystalline cellulose [MCC].
  • Hydroxypropyl methylcellulose is the major component of the capsule shell and MCC is the placebo component.
  • Known to have significant hypersensitivity to a first-line antifungal therapy (i.e., fluconazole or amphotericin B) against Saccharomyces.
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  • Known to be immunocompromised or have known or suspected congenital or acquired immunodeficiency, as determined by the investigator.
  • Receipt of immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within 3 years of enrollment.
  • Receipt of chronic (>/=14 days) immunosuppressive corticosteroids at a dose of >/=20 mg prednisone daily or prednisone equivalent within 30 days of enrollment, including oral, parenteral, or high dose inhaled* corticosteroids.
  • High-dose inhaled corticosteroid is defined as >800 mcg/day of beclomethasone dipropionate chlorofluorocarbon compounds [CFC] or equivalent. Intra-articular, intranasal, and topical steroids are allowable.
  • Active malignancy or history of malignancy in the past 3 years (non-melanoma, excised, cured skin cancers are allowed).
  • History of or testing positive for human immunodeficiency virus (HIV), hepatitis B, or active hepatitis C at screening (positive hepatitis C antibody and detectable hepatitis C virus RNA).
  • Anticipated or current receipt of kidney dialysis treatment.
  • Concurrent, acutely life-threatening disease or condition, or any unstable medical history, as determined by the investigator.
  • Significant chronic gastrointestinal [GI] condition(s) or disease*.
  • Includes diagnosis of inflammatory bowel disease or active Rome IV irritable bowel syndrome, poorly controlled Celiac disease, active gastroparesis, toxic megacolon, colostomy, intestinal resection (except uncomplicated appendectomy), ileus, short gut syndrome, or recent (within 6 months of enrollment) diverticular bleeding requiring surgical intervention or transfusion.
  • Recent (within 6 months of enrollment) history of difficulty with swallowing food, liquids, or pills.
  • Prosthetic heart valve or indwelling foreign structure within vascular supply (e.g., no central line or indwelling catheter) or known to have moderate to severe valvular disease.
  • History of alcohol abuse or drug addiction within 5 years of enrollment or that might interfere with the ability to comply with trial procedures.
  • Diagnosis of schizophrenia, bipolar disease, or other significant psychiatric disease in the opinion of the investigator that may interfere with or pose a problem with compliance with the study or the welfare of the participant.
  • Presence of mild, acute, or self-limited condition, such as fever or cough or other symptoms of upper respiratory tract infection within 7 days prior to planned randomization.
  • Any chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with trial conduct or completion or participant safety.
  • Identified as a study site or contract research organization employee or family member who is involved in the protocol and may have direct access to trial-related data.
  • Participating in another clinical trial investigating a vaccine, drug, medical device, or medical procedure within 4 weeks of enrollment through the last visit of the study.

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
  • Alliance for Multispecialty Research, LLC - Knoxville

    Knoxville, Tennessee, 37920

Other trials in United States

About this study

Official title: A Phase 1 Trial to Evaluate an Orally Ingested Probiotic Yeast Genetically Modified to Express a Tetra-specific Anti-toxin for Clostridioides Difficile

This is a Phase 1, first-in-human, double-blind, placebo-controlled, adaptive-design, single-site study, involving dose exploration cohorts.

During dose escalation, up to 4 cohorts, each consisting of up to 14 healthy adult (18-75 years, inclusive) study participants, will be randomly allocated to receive either FZ002 (n=12) or placebo (n=2). Dose escalation is designed to begin with the first cohort (Cohort 1) evaluating the lowest proposed dose of study product (1 capsules taken daily for 28 consecutive days). The first 3 participants will serve as sentinels and randomized in 2:1 ratio (FZ200: placebo). After review of the sentinel participants' data by the PSRT, the remaining participants (n=11) in the cohort will be randomly allocated in a 10:1 ratio (FZ002: placebo).

The primary objective is to evaluate safety and clinical tolerability of oral doses of FZ002 or placebo when taken for up to 28 days.

Read the detailed description

This is a Phase 1, first-in-human, double-blind, placebo-controlled, adaptive-design, single-site study, involving dose exploration cohorts.

During dose escalation, up to 4 cohorts, each consisting of up to 14 healthy adult (18-75 years, inclusive) study participants, will be randomly allocated to receive either FZ002 (n=12) or placebo (n=2). Dose escalation is designed to begin with the first cohort (Cohort 1) evaluating the lowest proposed dose of study product (1 capsules taken daily for 28 consecutive days). The first 3 participants will serve as sentinels and randomized in 2:1 ratio (FZ200: placebo). After review of the sentinel participants' data by the PSRT, the remaining participants (n=11) in the cohort will be randomly allocated in a 10:1 ratio (FZ002: placebo). PSRT review will be conducted after all sentinel participants in each cohort have completed 7 days of dosing. The PSRT review will also occur after all participants within a dose cohort have completed 28 days of dosing, prior to dosing the sentinel group at the next higher dose. Dose escalation to the next dose cohort may proceed only if no predefined halting rules have been met and no safety concerns have been identified. The safety data will include solicited adverse events, unsolicited adverse events, clinical assessments, and laboratory safety evaluations.

The primary objective is to evaluate safety and clinical tolerability of oral doses of FZ002 or placebo when taken for up to 28 days. The secondary objective is to evaluate laboratory adverse events with FZ002 or placebo when taken for up to 28 days.

Being tested
FZ002, Placebo for FZ002
Keywords
Clostridioides difficile, Clostridium difficile, Phase 1, Probiotic Yeast, Tetra-specific Anti-toxin
Medical subject headings
Clostridium Infections

What participants receive

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

  • FZ002Biological

    A recombinant live biotherapeutic product (rLBP) for oral administration, bioengineered from the parental S. boulardii (Sb) strain to constitutively produce ABAB, an anti-toxin against TcdA and TcdB of CDiff, intended to reduce the risk of CDI recurrence.

  • Placebo for FZ002Other

    The placebo is a capsule filled with commercially sourced pharmaceutical-grade microcrystalline cellulose (MCC), an inert substance. No anticipated risk related to the study product.

Study groups in NCT07649096
Study groupRoleWhat they receive
Cohort 1 Arm FZ002ExperimentalHealthy adults administered 1 capsule of FZ002 orally once daily for 28 days. N=12
Receives: Biological: FZ002
Cohort 1 Arm PlaceboPlacebo comparatorHealthy adults administered 1 capsule of placebo orally once daily for 28 days. N=2
Receives: Other: Placebo for FZ002
Cohort 2 Arm FZ002ExperimentalHealthy adults administered 1 capsule of FZ002 orally Q12H for 28 days. N=12
Receives: Biological: FZ002
Cohort 2 Arm PlaceboPlacebo comparatorHealthy adults administered 1 capsule of placebo orally Q12H for 28 days. N=2
Receives: Other: Placebo for FZ002
Cohort 3 Arm FZ002ExperimentalHealthy adults administered 2 capsules of FZ002 orally Q12H for 28 days. N=12
Receives: Biological: FZ002
Cohort 3 Arm PlaceboPlacebo comparatorHealthy adults administered 2 capsules of placebo orally Q12H for 28 days. N=2
Receives: Other: Placebo for FZ002
Cohort 4 Arm FZ002ExperimentalHealthy adults administered with 4 capsules of FZ002 orally Q12H for 28 days. N=12
Receives: Biological: FZ002
Cohort 4 Arm PlaceboPlacebo comparatorHealthy adults administered with 4 capsules of placebo orally Q12H for 28 days. N=2
Receives: Other: Placebo for FZ002

What is being measured

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

  1. Occurrence of serious adverse events (SAEs)

    Measured: Through Day 208

  2. Occurrence of solicited adverse events (AEs)

    Solicited AEs will include headache, fever, nausea, abdominal pain, diarrhea, malaise, constipation, fatigue, and vomiting. Oral temperatures will be measured daily.

    Measured: Through Day 35

  3. Occurrence of unsolicited AEs

    Measured: Through Day 57

  4. The occurrence of any positive yeast blood culture for Saccharomyces

    Measured: Days 8 and 29

Secondary outcomes (1)
  1. The occurrence of safety laboratory adverse events

    laboratory parameters include White blood cell [WBC], Absolute neutrophil count [ANC], Hemoglobin [Hg], Platelets [PLT], creatinine, Alanine aminotransferase [ALT], Aspartate aminotransferase [AST], and total bilirubin

    Measured: Days 8 and 29

Timeline

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

  1. First posted16 Jun 2026
  2. Study start29 Oct 2026 (estimated)
  3. Primary completion22 Aug 2028 (estimated)
  4. Study completion22 Sep 2028 (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 1
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Sequential
Masking
Triple blind
Who is masked
Participant, Care provider, Investigator
Enrolment
56 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07649096
Sponsor's protocol ID
24-0034
Other IDs
75N93022D00018
Status last verified
Sep 2026
First submitted
11 Jun 2026
Last updated
26 Oct 2026
Results posted
No
FDA-regulated drug
Yes
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing FZ002 in people with Clostridium Difficile Infection, run by National Institute of Allergy and Infectious Diseases (NIAID) 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 20 inclusion and 24 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 26 Oct 2026. 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 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

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 William B Smith (18663059100, william.smith@amr-clinical.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Occurrence of serious adverse events (SAEs) (time frame: Through Day 208). The study lists 4 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 26 Oct 2026.

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