A Phase 2, Randomized, Double-Blind, Comparator-Controlled, Multicenter Study to Evaluate the Safety and Efficacy of CRS3123 Compared with Oral Vancomycin in Adults with Clostridioides difficile Infection


This is a research study to test if research medication CRS3123, is a safe and effective treatment of an infection due to a bacteria called Clostridioides difficile.
Diarrhea, the most common symptom of a C. difficile Infection, is caused by toxins produced by overgrowth of C.difficile in the bowel.
The study will test two different doses of CRS3123 compared to vancomycin, a standard antibiotic treatment.
The study has a screening period to determine if subject meet the required criteria to enroll in the study. During the study treatment period, each subject will receive 4 capsules of study medication each day for 10 days. After treatment there will be a follow-up period from day 11 through day 70 to check for recurrence of the infection.
Your participation in this study will last approximately 70 days and will include approximately up to 8 study visits to the study center.


Currently recruiting participants: Yes

Eligible gender: Male, Female

Eligible ages: 18 to 80

Inclusion criteria:

1. Adults, ≥ 18 years of age
2. Capable of giving signed informed consent
2. More than or equal to 3 diarrheal stools/day
3. Participants with a primary episode or second occurrence of Clostridium difficile infection
4. Female participants of childbearing potential must not be pregnant, plan to become pregnant during the study, or be breastfeeding.

Exclusion criteria:

1. More than 2 episodes of Clostridium difficile Infection
2. Antibiotic treatment for Clostridium difficile for more than 24 hours
3. Pregnant or breastfeeding women
4. Subjects no capable of signing the Informed Consent Form
5. History of epilepsy or known seizure disorder
6. Receipt of any research medication during the last month
7. Severe hepatic impairment
8. No willing to stop consumining capsules, powder or liquids that have bacteria or yeast (non-dietary probiotics) as primary ingredient throughout the duration of the study.
9. Participants currently taking digoxin
10. No willing to stop consumption of grapefruit and its juices as well as
foods containing curcumin (ie., turmeric)


This study is not currently accepting expressions of interest via the website. Please see contact information below.

Additional information

Contact information

Foothills Medical Centre - Microbial Health Clinic, South Tower

Principal investigator:

Thomas John Louie

Clinical trial: