989. Isavuconazonium Sulfate Treatment of Blastomycosis: A Case Series

Abstract

Abstract Background Blastomyces fungi, endemic to the Ohio and Mississippi River Valleys, cause pneumonia and disseminated disease in both immunocompetent and immunocompromised patients. Prolonged antifungal therapy is commonly complicated by hepatic toxicity, QT prolongation, and drug interactions. Isavuconazonium sulfate is dosed once daily, does not prolong the QT interval, and has fewer drug interactions, but there is a paucity of data for its use in blastomycosis. Methods This case series of blastomycosis treated with isavuconazonium sulfate at the University of Wisconsin Hospital and Clinics from 2015 to December 2019 focuses on long term outcomes. Inclusion criteria were adults, that received at least one day of isavuconazole. Exclusion criteria was no blastomycosis diagnosis. Results Of 14 cases, median age was 53 years, 6/14 were female, 11/14 White, 2/14 Black, 1/14 Hmong, 6/14 had a solid organ transplant (4 renal, 1 heart, 1 bilateral lung), 1/14 on a TNF-alpha inhibitor (infliximab). Most cases, 9/14 had moderate severity illness requiring inpatient care, 2/14 required ICU level care, and 3/14 were outpatient. Most cases, 11/14, were initially treated with Liposomal Amphotericin B (LAMB) for a median duration of 14 days, 9/14 cases received itraconazole, 8/14 voriconazole, 1/14 posaconazole. Isavuconazonium sulfate was started after adverse drug effects with other azoles in 10/14 cases, prolonged QT interval in 3/14, drug interactions in 2/14, subtherapeutic azole levels in 2/14. Isavuconazonium sulfate was well tolerated and used for median duration of 255 (average 68% total treatment course). 3/14 cases had adverse reactions to isavuconazonium sulfate: nausea, rash, elevated liver enzymes. There was only one death during therapy from a fatal hemorrhagic stroke, and 2/14 cases were still on therapy at end of data collection. 11/14 were cured after treatment course. Conclusion This is the largest case series treating Blastomycosis with isavuconazonium sulfate, and it adds to the evidence that isavuconazonium sulfate can be safely used to treat pulmonary and disseminated blastomycosis. Prospective data is needed to compare isavuconazonium sulfate to other antifungals for the treatment of Blastomycosis. Disclosures All Authors: No reported disclosures