Replidyne Inc. last week unveiled REP3123, a MetRS inhibitor in preclinical development that the company thinks will be more effective for severe Clostridium difficile-associated diarrhea than vancomycin.

RDYN thinks REP3123 will have two other advantages over vancomycin: it may reduce CDAD relapses because it reduces the bacterium's sporulation and toxin production, and it should have less effect on beneficial gut flora because it has a narrow spectrum of activity against C. difficile, including the BI/NAP1 and VRE strains. BI/NAP1 has increased sporulation over other strains of C. difficile, while VRE is resistant to vancomycin.