A Trial of CP101 for the Prevention of Recurrent CDI (PRISM4)

Inclusion Criteria: * Ability to provide written informed consent * Men or women over 18 years of age or older * Current diagnosis of a recurrence of non-severe, non-complicated CDI * Subject has a clinical response to standard-of-care CDI antibiotics for the most recent CDI episode * History of recurrent CDI defined as: * ≥ 3 episodes of CDI, with 2 episodes occurring within the previous 6 months (inclusive of the current episode); OR * Patients with a history of 2 episodes of CDI occurring within the previous 6 months (inclusive of the current episode) may be eligible if 65 years of age or older. * For the Qualifying CDI episode, the following criteria must be satisfied: * History of diarrhea (\> 3 unformed stools per day) for 2 or more consecutive days that is clinically consistent with CDI. AND * Documented positive stool test by local laboratory for toxigenic C. difficile (toxin enzyme immunoassay \[EIA\] or polymerase chain reaction \[PCR\]-based testing) for the current CDI episode and within 45 days prior to Randomization. AND * Received a course of SOC CDI antibiotics for the most recent CDI episode (for 10 to 21 days, with exact duration, antibiotic type, and dose at the discretion of the Investigator). AND * Demonstrated an adequate clinical response, defined as ≤ 3 unformed stools in 24 hours for 2 or more consecutive days during SOC CDI antibiotics prior to Randomization. Exclusion Criteria: * Known stool sample testing positive for enteric pathogen(s) (e.g., Salmonella, Shigella, diarrhoeagenic E. coli, Campylobacter, Giardia) within 28 days prior to Screening * Pregnant, breast-feeding, or planning to become pregnant during the trial * Historical or current diagnosis of inflammatory bowel disease * Recent diagnosis (\<6 months prior to screening) of diarrhea-predominant irritable bowel syndrome (post-infection or non-related to an enteric infection) * Initiation of any systemic cancer treatment (e.g., chemotherapy, radiotherapy, biologic, immunotherapy, others) for active malignancy * Major intra-abdominal surgery (e.g., bowel resection) * Known primary or secondary immunodeficiency