Clinical activity of ceftazidime/avibactam against MDR Enterobacteriaceae and Pseudomonas aeruginosa: pooled data from the ceftazidime/avibactam Phase III clinical trial programme

Objectives: This analysis evaluated the clinical activity of ceftazidime/avibactam against MDR Enterobacteriaceae and Pseudomonas aeruginosa isolates pooled from the adult Phase III clinical trials in patients with complicated intra-abdominal infection (cIAI), complicated urinary tract infection (cUTI) or nosocomial pneumonia (NP) including ventilator-associated pneumonia (VAP). Methods: Baseline isolates from five Phase III randomized controlled trials of ceftazidime/avibactam versus predominantly carbapenem comparators in patients with cIAI (RECLAIM 1 and 2; NCT01499290 and RECLAIM 3; NCT01726023), cUTI (RECAPTURE 1 and 2; NCT01595438 and NCT01599806), NP including VAP (REPROVE; NCT01808092) and cIAI or cUTI caused by ceftazidime-non-susceptible Gram-negative pathogens (REPRISE; NCT01644643) were tested for MDR status and susceptibility to ceftazidime/avibactam and carbapenembased comparators using CLSI broth microdilution methodology. Microbiological and clinical responses for patients with > 1 MDR Enterobacteriaceae or P. aeruginosa isolate were assessed at the test-of-cure (TOC) visit. Results: In the pooled microbiologicallymodified ITT population, 1051 patients with MDR Enterobacteriaceae and 95 patients with MDR P. aeruginosa isolates were identified. Favourable microbiological response rates at TOC for all MDR Enterobacteriaceae and MDR P. aeruginosawere 78.4% and 57.1%, respectively, for ceftazidime/avibactam and 71.6% and 53.8%, respectively, for comparators. The proportions of patients with >= 1 MDR isolate who were clinically cured at TOCwere similar in the ceftazidime/avibactam (85.4%) and comparator (87.9%) arms. Conclusions: Ceftazidime/avibactamdemonstrated similar clinical efficacy to predominantly carbapenem comparators against MDR Enterobacteriaceae and P. aeruginosa, and may be a suitable alternative to carbapenembased therapies for cIAI, cUTI and NP/VAP caused by MDR Gram-negative pathogens.