The PHASE 3 REVISIT study has demonstrated that aztreonam–avibactam is a promising treatment for complicated intra-abdominal infections and hospital-acquired or ventilator-associated pneumonia (HAP–VAP) caused by Gram-negative bacteria. As antimicrobial resistance continues to threaten current treatment options, this new combination therapy could provide a valuable alternative, particularly for infections involving carbapenem-resistant pathogens.
In the multinational, open-label study, 422 hospitalised adults were randomly assigned to receive either aztreonam–avibactam (with metronidazole for intra-abdominal infections) or meropenem, with or without colistin. Of these, 271 had at least one Gram-negative pathogen identified at baseline, with Enterobacterales being the most common. Among isolates tested, 24% were carbapenemase-positive, highlighting the urgent need for effective non-carbapenem options.
Clinical cure rates at the test-of-cure visit were comparable between the treatment groups, with 68.4% of patients in the aztreonam–avibactam arm achieving clinical cure, compared to 65.7% in the meropenem group. In patients with complicated intra-abdominal infections, cure rates were 76.4% and 74.0%, respectively, while in HAP–VAP cases, they were 45.9% and 41.7%. Importantly, 28-day all-cause mortality was lower with aztreonam–avibactam (4%) compared to meropenem (7%). The difference was most pronounced in HAP–VAP patients, where mortality was 11% with aztreonam–avibactam versus 19% with meropenem.
Aztreonam–avibactam was well tolerated, with no treatment-related serious adverse events reported. Its safety profile was consistent with aztreonam monotherapy, reinforcing its potential as a viable alternative for resistant Gram-negative infections. With antimicrobial resistance on the rise, these findings support the use of aztreonam–avibactam as a potential new treatment option in complicated infections.
Ada Enesco, EMJ
Reference
Carmeli Y et al; COMBACTE-CARE consortium REVISIT study group. Aztreonam-avibactam versus meropenem for the treatment of serious infections caused by Gram-negative bacteria (REVISIT): a descriptive, multinational, open-label, phase 3, randomised trial. Lancet Infect Dis. 2025;25(2):218-30.
