Nacubactam (FPI-1459) was developed as an antibacterial drug. Nacubactam successfully has completed phase I clinical trials for the treatment of serious gram-negative bacterial infections. The drug is currently being developed for the treatment of complicated urinary tract infection, hospital-acquired bacterial pneumonia, ventilator-associated bacterial pneumonia, and complicated intra-abdominal infections. FPI-1459 works through several mechanisms of action, inhibiting a number of beta-lactamase enzymes as well as certain bacterial cell wall enzymes. In January 2019, FPI-1459 received Fast Track and Qualified Infectious Disease Product designations from the U.S. Food and Drug Administration (FDA).