RC-01, a novel LpxC inhibitor, displays highly potent inhibitory activity against the bacterial LpxC enzyme with an IC50 at subnanomolar levels.  The LpxC enzyme is a highly attractive target in gram-negative pathogens – it is required for bacterial growth and virulence and has no mammalian homologue. RC-01 has potent in vitro and in vivo activity against gram-negative bacteria, including MDR Enterobacteriaceae and P. aeruginosa, which remain an urgent unmet medical need.   In vitro, RC-01 has shown rapid in vitro and in vivo bactericidal activity.  Due to its unique mode of action, RC-01 does not exhibit cross-resistance with other antibiotic classes. RC-01 has demonstrated potent in vivo efficacy against clinical isolates of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli, carbapenemase-producing Enterobacteriaceae, and MDR P. aeruginosa in various infection models (in both neutropenic and immunocompetent animals).  RC-01 has a favorable distribution-metabolism-PK (DMPK) profile and was well tolerated in preclinical toxicology studies.  No toxicity related to previous LpxC inhibitors was observed with RC-01. Both in vitro and animal in vivo efficacy and safety data fully support its clinical development as a potential human therapeutic agent for the treatment of serious bacterial infections caused by gram-negative pathogens in the hospital setting.