Microbiota Restoration Therapy for Recurrent Clostridium Difficile Infection

This is the first prospective, multi-center, double-blinded, randomized controlled study of a
microbiota suspension derived from intestinal microbes. The primary assessments for this
study are (i) efficacy of RBX2660 compared to placebo at 8 weeks and (ii) safety via
assessment of adverse events. Study visits are at 1-, 4- and 8-weeks after treatment with
additional follow-up at 3, 6 12 and 24 months post treatment. Patients who have had at least
two recurrences of C. difficile infection (CDI) after a primary episode and have completed at
least two rounds 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. Patients
whose CDI returns in less than 8 weeks after the last assigned study treatment may be
eligible to receive up to 2 treatments with RBX2660 in the open-label portion of the study.

Inclusion Criteria:

- ≥ 18 years

- Medical record documentation of recurrent CDI either: a) at least two recurrences
after a primary episode and has completed at least two rounds of standard-of-care oral
antibiotic therapy or b) has had at least two episodes of severe CDI resulting in
hospitalization.

- Documented history that the subject's recurrent CDI is controlled while on antibiotics
even if the subject is not currently on antibiotics.

- A positive stool test for the presence of C. difficile within 60 days prior to
enrollment.

Exclusion Criteria:

- A known history of continued C. difficile diarrhea while taking on a course of
antibiotics prescribed for CDI treatment.

- Requires antibiotic therapy for a condition other than recurrent CDI.

- Previous fecal transplant prior to study enrollment.

- History of inflammatory bowel disease (IBD), e.g., ulcerative colitis, Crohn's
disease, or microscopic colitis.

- History of irritable bowel syndrome (IBS).

- History of chronic diarrhea.

- History of celiac disease.

- Colostomy.

- Planned surgery requiring perioperative antibiotics within 6 months of study
enrollment.

- Life expectancy of < 12 months.

- Compromised immune system.