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Study on VE303 for Preventing Recurrent C. difficile Infection in Patients

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying a condition known as Clostridioides difficile infection, often referred to as CDI. This infection can cause severe diarrhea and other intestinal issues. The study is testing a new treatment called VE303, which is a capsule containing live bacteria that are believed to help restore balance in the gut. The trial will compare the effects of VE303 with a placebo, which looks like the VE303 capsule but does not contain any active bacteria.

The purpose of the study is to see if VE303 can prevent the recurrence of CDI. Participants in the study will be randomly assigned to receive either VE303 or the placebo. The study is designed to be double-blind, meaning neither the participants nor the researchers will know who is receiving the actual treatment or the placebo. The treatment will be taken orally, and the study will last for several weeks, with follow-up checks to monitor the participants' health and any recurrence of the infection.

Throughout the study, participants will be asked to attend regular visits, provide samples, and complete questionnaires to help researchers gather data on the effectiveness of VE303. The main goal is to determine if VE303 can reduce the rate of CDI recurrence by the end of the study period. Participants' health and any side effects will be closely monitored to ensure safety and gather comprehensive results.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Enrollment

    Eligibility is determined based on age and medical history related to Clostridioides difficile infection (CDI).

    Participants must have a laboratory-confirmed episode of CDI and meet specific criteria related to age and risk factors.

  2. Step 2

    Completion of Standard Care Antibiotic Therapy

    Participants complete a course of standard care (SoC) antibiotic therapy for CDI, lasting between 10 to 21 days.

    The choice of antibiotic is determined by the physician, and tapering of antibiotics is not allowed.

  3. Step 3

    Randomization and Start of Study Drug

    Participants are randomly assigned to receive either the study drug VE303 or a placebo.

    The first dose of the study drug is administered on the last planned day of SoC antibiotic therapy or no later than one day after completion.

  4. Step 4

    Study Drug Administration

    Participants take the study drug in the form of oral capsules.

    The capsules are visually identical, ensuring that neither the participant nor the study team knows whether VE303 or placebo is being administered.

  5. Step 5

    Monitoring and Follow-Up

    Participants are monitored for recurrence of CDI and any adverse events for up to 24 weeks.

    Regular assessments include providing blood and stool samples, completing questionnaires, and attending study visits.

  6. Step 6

    End of Study

    The primary endpoint is the proportion of participants with laboratory-confirmed CDI recurrence through Week 8.

    Secondary endpoints include the incidence of adverse events and the relationship between VE303 colonization and CDI recurrence.

Who can join the trial?

17 criteria

  • For Stage 1: Must be at least 12 years old (or 18 years in some countries) and have had a confirmed episode of **Clostridioides difficile infection (CDI)**, with at least one previous occurrence in the last 6 months.
  • For Stage 2: Must be at least 75 years old with a confirmed episode of CDI, or at least 12 years old (or 18 years in some countries) with a confirmed episode of CDI and at least two of the following risk factors:
    • Age 65 or older
    • Kidney problems, shown by a specific test result
    • Regular use of a type of medication called a **proton pump inhibitor (PPI)** in the past 2 months and expected to continue using it
    • Previous CDI episode between 6 and 12 months before joining the study
    • Weakened immune system due to a disease or its treatment
    • Had an organ or stem cell transplant
    • For both Stage 1 and Stage 2: The CDI episode must include:
      • At least 3 loose bowel movements in 24 hours for at least 2 days
      • Symptoms started within 4 weeks before starting antibiotic treatment for CDI
      • A stool sample tested positive for CDI before or shortly after starting antibiotics
      • Diarrhea not likely caused by something else
      • For both Stage 1 and Stage 2: Must complete a course of antibiotics for at least 10 days, up to 21 days, and show improvement with fewer than 3 loose bowel movements per day for at least 2 days.
      • For both Stage 1 and Stage 2: If able to have children, must have a negative pregnancy test and agree to use effective birth control, remain abstinent, or have a partner who cannot have children.
      • For both Stage 1 and Stage 2: Must be able to take the first dose of the study drug on the last day of antibiotic treatment or the day after.
      • For both Stage 1 and Stage 2: Must have recovered from any severe CDI complications and be stable.
      • For both Stage 1 and Stage 2: Must be able and willing to follow study procedures, such as taking capsules, attending visits, providing samples, and completing questionnaires.
      • For both Stage 1 and Stage 2: Must provide written consent to participate, understanding the risks and benefits. If under 18, a legal guardian must also provide consent.

Who cannot join the trial?

8 criteria

  • Individuals who do not have a **Clostridioides difficile infection**. This is a type of bacterial infection that affects the intestines.
  • Participants who are not within the specified age range for the study.
  • Individuals who are not able to follow the study procedures or instructions.
  • People who have other medical conditions that might interfere with the study or its results.
  • Participants who are taking medications that could affect the study outcomes.
  • Individuals who are pregnant or breastfeeding.
  • People who have participated in another clinical trial recently.
  • Individuals who have a history of substance abuse or other factors that might affect their ability to participate in the study.
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Investigated drugs

VE303 is a medication being studied for its ability to prevent the recurrence of Clostridioides difficile infection (CDI). This medication is part of a clinical trial aimed at reducing the chances of CDI coming back in patients who have already experienced an infection. The trial is designed to see if VE303 can effectively lower the recurrence rate of CDI compared to not receiving the active treatment.

What is already known about the treatment

VE303 – VE303 is an investigational medication administered orally, currently being studied in a Phase 3 clinical trial for its potential to prevent recurrent Clostridioides difficile infections. This medication is not yet approved for general medical use, but it is being actively researched in medical literature. The main therapeutic indication for VE303 is to reduce the recurrence of Clostridioides difficile infections, which are serious bacterial infections affecting the colon. VE303 works by modulating the gut microbiome to restore a healthy balance of bacteria, thereby preventing the overgrowth of harmful bacteria. It is classified pharmacologically as a microbiome therapeutic.

Investigated diseases

Clostridioides difficile infection – This infection is caused by the bacterium Clostridioides difficile, which primarily affects the colon. It often occurs after the use of antibiotics, which can disrupt the normal balance of bacteria in the gut. Symptoms typically include diarrhea, abdominal pain, and fever. The infection can lead to inflammation of the colon, known as colitis. In some cases, it may cause severe complications like dehydration or bowel perforation. The disease can recur, especially if the initial infection is not fully resolved.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2022-502972-22-00Protocol codeVE303-003Estimated enrolment420 patientsSponsorVedanta Biosciences Inc.

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