A landmark Phase 2 randomized controlled trial demonstrates the safety, tolerability, and promising efficacy of CRS3123 as a novel treatment for Clostridioides difficile infection.
The Lancet Infectious Diseases • January 22, 2026
“Both doses of CRS3123 were deemed safe and well tolerated and showed efficacy similar to vancomycin, with lower rates of recurrence.”
Phase 2 Randomized Controlled Trial
NCT04781387 · Double-blind, Vancomycin-Controlled, Multicentre
Key Findings—Phase 2 RCT
CRS3123 achieved clinical cure rates comparable to vancomycin, with markedly lower C. diff recurrence at Day 40
97%
Clinical Cure
CRS3123 (combined groups, TOC)
93%
Clinical Cure
Vancomycin (comparator, TOC)
4%
Recurrence at Day 40
CRS3123 (combined groups)
23%
Recurrence at Day 40
Vancomycin (comparator)
Why This Matters
C. difficile infection affects nearly half a million Americans annually and carries a recurrence rate of up to 25% with standard-of-care antibiotics. CRS3123’s novel mechanism, inhibiting methionyl-tRNA synthetase, not only eliminates active infection but disrupts toxin production and spore formation, directly targeting the drivers of recurrence. These Phase 2 results support advancement of CRS3123 into Phase 3 development.