CS-834 (Sankyo)

CS-834, a carbapenem antibiotic from Sankyo, is in phase II clinical trials for respiratory and urinary tract infections. It is the orally active prodrug of R-95867, to which it is rapidly converted, and is therefore of particular interest as there are, as yet, no oral carbapenems commercially available. CS-834 demonstrated a better overall profile against Gram-positive and Gram-negative species, such as Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae, compared with several cephalosporins, including cefdinir and cefditoren pivoxil when administered orally in mice. Only Pseudomonas and Enterococcus species showed low susceptibility to the compound.