Microbiota Restoration Therapy for Recurrent Clostridium Difficile Infection (PUNCHCD3)

This is a prospective, multicenter, randomized, double-blinded, placebo-controlled Phase 3
study of a microbiota suspension of intestinal microbes. The primary assessments for this
study are (i) efficacy of RBX2660 as compared to a Placebo in preventing recurrent episodes
of CDI and (ii) safety via assessment of adverse events. Follow-up office visits occur at
weeks 1-, 4- and 8 after completing the blinded study treatment. Telephone assessments for
adverse events occur during weeks 2, 3 and 6 after the study enema and at months 3 and 6.
Patients who have had at least one recurrence 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 within the last year may be eligible for the
study. Study Subjects who are deemed failures following the blinded treatment per the
pre-specified treatment failure definition may elect to receive an unblinded RBX2660 enema.

Inclusion Criteria:

1. ≥ 18 years old.

2. Medical record documentation of recurrent CDI per the study definition, that includes
either: a) at least one recurrence after a primary episode and has completed at least
one round of standard-of-care oral antibiotic therapy or b) has had at least two
episodes of severe CDI resulting in hospitalization within the last year.

3. A positive stool test for the presence of toxigenic C. difficile within 30 days prior
to or on the date of enrollment.

4. 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) while
taking this course of antibiotics]

Exclusion Criteria:

1. Currently has continued CDI diarrhea despite being on antibiotics prescribed for CDI
treatment.

2. Previous fecal transplant

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

4. Diagnosis of irritable bowel syndrome (IBS) as determined by Rome III criteria.

5. Compromised immune system (e.g. immunosuppressed due to a medical condition or
medication; current or recent (< 90 days) treatment with chemotherapy)

6. An absolute neutrophil count of <1000 cells/µL during screening.

7. Pregnant, breastfeeding, or intends to become pregnant during study participation.