This Phase 2 trial tested a new drug called CRS3123 against the standard treatment vancomycin for C. diff infection. The study included 43 adults in the USA and Canada who had their first episode or first recurrence of the infection. Participants took CRS3123 twice daily or vancomycin four times daily for 12 to 15 days.
The main result was clinical cure, defined as survival and resolution of diarrhea. At the test-of-cure visit, 93% of patients taking the lower CRS3123 dose were cured. All patients taking the higher CRS3123 dose were cured. This matched the 93% cure rate seen in the vancomycin group.
The study also tracked how often the infection came back. Fewer patients in the CRS3123 groups had a recurrence compared to the vancomycin group through day 40. One additional recurrence occurred in the higher CRS3123 dose group by day 70. Side effects were mild to moderate and similar across all groups. The only serious event was pneumonia in a vancomycin patient, which was unrelated to the drug. Because this was a small early trial, these results need confirmation in larger studies.