The Boulder, Colorado-based company, Crestone, recently announced results of a phase 2 clinical trial for their investigational antibiotic, CRS3123, which showed a clinical cure at day 12 in 97% of study participants. Among the 43 patients in the primary intent-to-treat (ITT) analysis population, clinical cure rates were comparable in all 3 treatment groups, including 28/29 (97%) in patients receiving 1 of 2 dosages of CRS3123 versus 13/14 (93%) in those receiving vancomycin. There were no clinical failures at the day 12 time point; the results in 2 patients were indeterminate.
“It is now abundantly clear that curbing C difficile while preserving healthy intestinal flora is what we want in a CDI therapeutic,” Mark Wilcox, MD, professor at Leeds Teaching Hospitals and University of Leeds and lead on CDI for UK Health Security Agency, said in a statement. “The outcome of this phase 2 study further reinforces that goal.” The university is performing the epidemiology analysis and toxin testing for this study.
The trial is a randomized, double-blind, comparator-controlled, multicenter study evaluating the safety and efficacy of 2 dosages of CRS3123 (200 mg and 400 mg) administered twice-daily compared with vancomycin 125 mg administered 4 times daily in 43 adults diagnosed with a primary episode or first recurrence of CDI. The duration of treatment for all study treatment arms was 10 days. Patients with clinically documented, toxin-positive CDI were enrolled at sites in the U.S. and Canada. The primary endpoint was defined as the rate of clinical cure at day 12 in the ITT population. Secondary and exploratory endpoints included rates of recurrence and global cure, time to resolution of diarrhea and the effect of CRS3123 on commensal bacteria in the gut.
What You Need to Know
Crestone's CRS3123 demonstrated a 97% clinical cure rate by day 12 in patients with C difficile infections (CDI), comparable to vancomycin, a commonly used antibiotic.
CRS3123 targets a specific bacterial enzyme (methionyl-tRNA synthetase) that is not present in human cells or other gut microbiota, making it effective in treating C difficile while preserving healthy gut bacteria.
Based on the positive results of the Phase 2 trial, the National Institute of Allergy and Infectious Diseases (NIAID) is providing $4.5 million in funding to support further microbiome studies and manufacturing process optimizations.
