SM-295291

SM-295291 is an investigational **parenteral 2-aryl carbapenem antibiotic** developed by Astellas for community-acquired bacterial infections. Preclinical data describe it as a broad-spectrum, bactericidal **beta-lactam** with potent activity against pathogens including methicillin-susceptible *Staphylococcus aureus*, *Streptococcus pneumoniae* including penicillin-resistant strains, *Streptococcus pyogenes*, *Enterococcus faecalis*, *Klebsiella pneumoniae*, *Moraxella catarrhalis*, *Haemophilus influenzae* including beta-lactamase-negative ampicillin-resistant strains, and *Neisseria gonorrhoeae* including ciprofloxacin-resistant isolates. Like other carbapenems, its therapeutic effect is understood to result from inhibition of bacterial cell-wall synthesis through binding to penicillin-binding proteins, leading to bactericidal activity. It showed no meaningful activity against *Pseudomonas aeruginosa* in the cited preclinical work, was reported to be stable to human dehydropeptidase I, and had intravenous pharmacokinetics in monkeys similar to meropenem. An orally bioavailable medoxomil ester prodrug of SM-295291 has been described separately as SM-368589. Publicly available evidence supports preclinical development, but there is no clear evidence of marketed status.