BACKGROUNDInvasive mold infections (IMI) directly impact life expectancy, especially with delayed therapy. Among IMI, aspergillosis (IA) is more common than mucormycosis (IM), resulting in IA-targeted empirical treatment with voriconazole for suspected invasive pulmonary aspergillosis (IPA), despite IM ineffectiveness. Recently, isavuconazole was approved in Canada for IA and IM. The primary objective was to assess the cost-effectiveness of isavuconazole compared to voriconazole for suspected IPA in Canada. A secondary objective was to assess the impact of varying time horizons to address the wide spectrum of life expectancies, according to patients underlying diseases.RESEARCH DESIGN AND METHODSA 5-year decision-tree was developed from the Canadian Ministry of Health (MoH) and societal perspectives. Efficacy parameters were extracted from SECURE/VITAL trials. Costs included treatment acquisition, hospitalization, adverse events and productivity loss. 3- and 10-year time horizon alternative scenarios and extensive sensitivity analyses were also conducted.RESULTSFrom a MoH perspective, isavuconazole compared to voriconazole resulted in an incremental cost-utility ratio (ICUR) of $C30,160/QALY. 3- and10-year ICURs were also cost-effective, relative to a willingness-to-pay threshold of $C50,000/QALY.CONCLUSIONSThis study demonstrates that, in comparison to voriconazole, isavuconazole is a cost-effective strategy for the treatment of patients with suspected IPA, regardless of their life expectancy.