Discovery of MK-7655, a β-lactamase inhibitor for combination with Primaxin®

beta-Lactamase inhibitors with a bicyclic urea core and a variety of heterocyclic side chains were prepared and evaluated as potential partners for combination with imipenem to overcome class A and C beta-lactamase mediated antibiotic resistance. The piperidine analog 3 (MK-7655) inhibited both class A and C beta-lactamases in vitro. It effectively restored imipenem's activity against imipenem-resistant Pseudomonas and Klebsiella strains at clinically achievable concentrations. A combination of MK-7655 and Primaxin (R) is currently in phase II clinical trials for the treatment of Gram-negative bacterial infections. (C) 2014 Elsevier Ltd. All rights reserved.