In vitro evaluation of E-4695, a new fluoro-naphthyridine

Compound E-4695, a C-7 azetidinyl fluoro-naphthyridine, was compared to six structurally related quinolones and was generally two- to four-fold more active than ciprofloxacin. E-4695 was particularly active against Staphylococcus aureus (MIC90 0.06 mg/l), Staphylococcus haemolyticus (MIC90 0.5 mg/l), Klebsiella spp. (MIC90 less than or equal to 0.015 mg/l), Serratia marcescens (MIC90 0.06 mg/l), Acinetobacter spp. (MIC90 less than or equal to 0.015 mg/l), Pseudomonas aeruginosa (MIC90 0.5 mg/l), Xanthomonas maltophilia (MIC90 0.5 mg/l), and Neisseria gonorrhoeae (MIC90 less than or equal to 0.001 mg/l). This new quinolone-like drug requires further investigations to confirm these promising in vitro findings.