OBJECTIVES: Aztreonam in combination with avibactam (ATM-AVI) is approved in Europe in adult patients for the treatment of complicated intra-abdominal infection (cIAI), hospital-acquired pneumonia (HAP) including ventilator-associated pneumonia (VAP), complicated urinary tract infection (cUTI) including pyelonephritis and for infections due to aerobic gram-negative organisms with limited treatment options (LTO). This study quantified the value of ATM-AVI in treating HAP/VAP and cIAI caused by suspected MBL-Enterobacterales, to the Greek healthcare system, considering transmission and diversity value from the broader value framework for antimicrobials; STEDI (spectrum, transmission, enablement, diversity, insurance).

METHODS: A population-based mathematical model was developed to quantify the value of adding ATM-AVI into the treatment strategy for suspected MBL-Enterobacterales HAP/VAP and cIAI. ATM-AVI was assessed as a first-line treatment, to a simplified two-line treatment strategy (colistin + meropenem and colistin + aminoglycoside), on treatment outcomes and resistance development to determine transmission and diversity value. Inputs for efficacy, resistance, adverse events, and costs were sourced from the phase 3 trial program REVISIT, literature and expert opinion. A ten-year infection transmission horizon was used; quality-adjusted life years (QALYs) were estimated over a lifetime and valued using a willingness-to-pay threshold of €35,000 to calculate net monetary benefit (NMB). Costs and benefits were discounted at a rate of 3.5%.

RESULTS: In the base-case, over 10 years, approximately 3,700 patients were treated. The intervention strategy including ATM/AVI was dominant over the current strategy. ATM-AVI resulted in 1,474 fewer deaths, associated with 14,782 additional QALYs, and reduced overall LOS by 3,462 days. Lower cost of death offset increased treatment and hospitalization costs. The NMB of introducing ATM-AVI is €549 million.

CONCLUSIONS: The addition of ATM/AVI to the treatment strategy of suspected MBL-Enterobacterales HAP/VAP and cIAI in Greece is dominant and urgently needed. Modelling approaches incorporating the remaining STEDI elements will better demonstrate the true value of antimicrobials.