A Study of VE303 for Prevention of Recurrent Clostridium Difficile Infection


About this study

The purpose of this study is to evaluate the safety and effectiveness of VE303 for participants with primary C. difficile infection (pCDI) at high risk for recurrence or subjects with recurrent C. difficile infections (rCDI).

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria: 

  • Able and willing to provide written informed consent.
  • Subjects with a qualifying CDI episode who have a prior history of CDI diarrhea or first occurrence of CDI diarrhea with a higher risk for recurrence (≥ 65 years of age).
  • CDI symptoms must have started within 30 days (inclusive) prior to the day of randomization.
  • The diarrhea is considered unlikely to have another etiology. 
  • Complete an Investigator's choice SOC antibiotic regimen of a minimum of 10 days and up to 21 days of total duration.
  • Have a positive C. difficile stool.
  • Recovered from any complications of severe or fulminant CDI and clinically stable by the time of randomization.

Exclusion Criteria:

  • History of diarrhea (defined as 3 or more loose stools per day lasting for at least 4 weeks) that is not related to C. difficile infection within the 3 months prior to randomization. 
  • Known or suspected toxic megacolon and/or known small bowel ileus at the time of randomization. 
  • Contraindication to oral/enteral therapy (e.g., severe reflux, severe nausea/vomiting, or ileus). 
  • Prior administration of genetically modified investigational live bacterial/fungal/bacteriophage/viral isolates for CDI-associated diarrhea.
  • History of administration of fecally-derived investigational live biotherapeutic products, or fecally-derived live bacterial isolates for CDI-associated diarrhea including fecal microbiota transplantation (FMT) within the last 6 months. 
  • Use of drugs that alter gut motility.
  • History of acute leukemia or hematopoietic stem cell transplantation or myelosuppressive chemotherapy within 2 months prior to randomization. 
  • Subjects with compromised immune system.
  • Major gastrointestinal surgery (e.g., significant bowel resection or diversion) within 3 months prior to randomization or any history of total colectomy or bariatric surgery that disrupts the gastrointestinal lumen. 
  • History of confirmed celiac disease, inflammatory bowel disease, short gut, gastrointestinal tract fistulas, or ischemia.

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status

Scottsdale/Phoenix, Ariz.

Mayo Clinic principal investigator

Robert Orenstein, D.O.

Closed for enrollment

More information


Publications are currently not available

Study Results Summary

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Supplemental Study Information

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Additional contact information

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