In Group 1, participants were to receive a total of five oral doses of ceftibuten ledaborbactam etzadroxil (600 mg ceftibuten/600 mg ledaborbactam etzadroxil) every 12 hours. Following the fifth dose, each participant was to undergo one standardized bronchoscopy with bronchoalveolar lavage (BAL) at one of five designated timepoints (2, 4, 6, 8, and 12 hours), with five participants assigned to each timepoint.
In Group 2, participants were to receive a total of five doses of 600 mg oral ceftibuten alone every 12 hours. After the last dose, each participant was to undergo one standardized bronchoscopy with BAL at one of two designated timepoints (4 and 12 hours), with three participants assigned to each timepoint.
Blood samples to determine plasma concentrations of ceftibuten, ledaborbactam etzadroxil (Group 1 only), and urea were to be collected at the designated timepoints.