A Study to Evaluate Microbiota Restoration Therapy for Recurrent Clostridium Difficile Infection


About this study

The purpose of this study is to evaluate microbiota suspension of intestinal microbes. Patients who have had at least one recurrence of Clostridium Difficile Infection (CDI) after a primary episode and have completed at least one round of standard-of-care oral antibiotic therapy or have had at least two episodes of severe CDI resulting in hospitalization may be eligible for the study. Subjects may receive a second RBX2660 enema if they are deemed treatment failures following the initial enema per the protocol-specified treatment failure definition.

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: 

  • ≥ 18 years old.
  • Medical record documentation of either:
    • a current diagnosis or history of recurrent CDI as determined by the treating physician;
    • or has had at least two episodes of severe CDI resulting in hospitalization.
  • Is currently taking or was just prescribed antibiotics to control CDI related diarrhea at the time of enrollment. Note: Subject’s CDI diarrhea must be controlled (< 3 unformed/loose stools/day; i.e., Bristol Stool Scale type 6-7, for the two consecutive days prior to the washout period) while taking antibiotics during screening.
  • Willing and able to have an enema(s).
  • Willing and able to complete the stool and blood testing required for the study.
  • Agrees to not take non-dietary probiotics from Screening through 8 weeks after receiving the last study enema (including OTC and prescription).
  • Agrees to not take any oral vancomycin, metronidazole, fidaxomicin, rifaximin, nitazoxanide, bezlotoxumab, or IVIG through the 8-week follow-up assessment unless newly prescribed by a treating investigator during the course of the study as a result of recurrent CDI diagnosis. Note: Use of IVIG for treatment of a nonCDI indication is allowed.
  • Agrees to practice a form of effective contraception during study participation; does not apply to persons with documented non-childbearing potential.
  • Has a negative urine pregnancy test at the time of enrollment and on the day of each enema prior to administration (females of childbearing potential only).
  • Willing and able to provide informed consent, and local privacy authorization as applicable.
  • Willing and able to complete the required Subject Diary.
  • Willing and able to meet all study requirements, including attending all assessment visits and telephone calls.

Exclusion Criteria:

  • A known history of refractory CDI.
  • Has continued CDI diarrhea despite being on a course of antibiotics prescribed for CDI treatment.
  • Requires systemic antibiotic therapy for a condition other than CDI.
  • Patient previously participated in a Rebiotix clinical study receiving RBX2660.
  • Fecal microbiota transplant (FMT) within the past 6 months.
  • FMT with an associated serious adverse event related to the FMT product or procedure.
  • Bezlotoxumab (CDI monoclonal antibodies) if received within the last year.
  • Disease symptoms (e.g., diarrhea) caused by a confirmed intestinal pathogen other than C. difficile.
  • Have a current colostomy.
  • Intraabdominal surgery within the last 60 days.
    • Note: laparoscopic procedures that do not involve the GI tract are permitted.
  • Planned surgery requiring perioperative antibiotics through the 8- week follow-up assessment.
  • Life expectancy of < 6 months.
  • CD4 count < 200/mm^3 during Screening.
  • An absolute neutrophil count of < 1000 cells/µL during Screening.
  • Known or suspected current (< 90 days) illicit drug use. Note: marijuana use is allowed.
  • Pregnant, breastfeeding, or intends to become pregnant during study participation.
  • Participating in a clinical study of another investigational product (drug, device or other) and has not completed the required follow-up period.
  • Subject is eligible for another RBX2660 study.
  • Subject, in the opinion of the investigator, for whatever reason, should be excluded from the study.

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

Jacksonville, Fla.

Mayo Clinic principal investigator

Maria Vazquez Roque, M.D., M.S.

Closed for enrollment

More information


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