Use of isavuconazole in critically ill patients in intensive care units: A prospective, observational, multicentre, cohort study

Objectives In this multicentre, prospective study, we aimed to describe the use of isavuconazole in critically ill adult patients in ICU, in terms of patient characteristics, infection characteristics and outcomes. Methods Prospective, observational study of ICU patients treated with isavuconazole from January 2023 to 30 April 2025 in 17 centres (ISA-SITA study within the MULTI-SITA project). Results A total of 177 ICU patients treated with isavuconazole were included in the study. Most patients showed at least one European Organisation for Research and Treatment of Cancer/Mycoses Study Group Education and Research Consortium (EORTC/MSGERC) or FUNgal Diseases in adult patients in Intensive Care Unit (FUNDICU) host factor (141/177, 79.7%). Overall, 82/177 patients (46.3%) had either proven or probable invasive mould disease (6 and 76, respectively, mostly invasive pulmonary aspergillosis). In patients with proven or probable disease, 30-day mortality was 44.0%, and 90-day mortality was 62.2%. In multivariable analyses, SOFA score (HR 1.14 per one point increase, 95% CI 1.03-1.26, P = 0.010) and concomitant bacterial pneumonia (HR 2.32, 95% CI 1.17-4.59, P = 0.016) were associated with 30-day mortality, whereas prior hospitalization (HR 2.26, 95% CI 1.19-4.27, P = 0.013) and SOFA score (HR 1.17 per one point increase, 95% CI 1.07-1.28, P < 0.001) were associated with 90-day mortality. Conclusions Diverse patterns of isavuconazole use were observed in a large cohort of critically ill adult patients, and the drug was well tolerated. Mortality was lower than many previous estimates in critically ill patients and could serve as a basis for future standardized comparisons.