Isavuconazole for the prophylaxis and treatment of invasive fungal disease: A single-center experience

Background: Invasive fungal disease (IFD) is a serious complication among the immunocompromised population. Isavuconazole is a newer broad-spectrum antifungal agent with promising efficacy and safety. However, there remains limited data to favor its use over current first-line agents. Objectives: We aimed to evaluate isavuconazole use and describe rates of associated breakthrough invasive fungal disease (bIFD). Methods: A single-center, retrospective study was conducted to evaluate patients receiving isavuconazole for prophylaxis or treatment of IFD between July 1, 2017 and December 31, 2018. Patient-related and outcomes data were extracted from electronic medical records. Descriptive statistics were used to analyze our findings. Results: A total of 54 patients received 61 isavuconazole courses. Isavuconazole was most commonly prescribed for primary prophylaxis in the acute myeloid leukemia (AML) and allogeneic hematopoietic stem cell transplant (HSCT) population along with treatment for possible invasive fungal disease. The primary reasons for choosing isavuconazole included QTc shortening effects, decreased risk of acute kidney injury, broader spectrum of activity, and concern for breakthrough invasive fungal disease on a different prophylactic agent. We found a breakthrough rate of 8.5% for patients and 7.8% for courses. Conclusions: Isavuconazole appears to be a promising alternative for prophylaxis and treatment of invasive fungal disease. We observed similar bIFD rates and improved tolerability when compared to historical data for posaconazole and voriconazole.