1023. Isavuconazonium Use at an Academic Transplant Center

Background Isavuconazonium is an appealing anti-fungal due to its broad spectrum of activity, predictable pharmacokinetics, oral bioavailability, and lack of QTc prolongation, but real-world experience with it is limited. At our academic medical center, isavuconazonium is restricted to the infectious diseases (ID) service for treatment of invasive fungal infections, including endemic mycoses due to high prevalence, and is recommended for patients intolerant of first-line agents. The purpose of this study was to describe isavuconazonium use at our institution and assess adherence to its formulary guidelines. Methods Inpatients with an order for isavuconazonium between June 2016 and November 2018 were analyzed via retrospective chart review. Prescribing team, indication, and rationale for use were evaluated. Results There were 97 inpatient encounters with an isavuconazonium order among 57 patients. Of those, 30 were solid-organ transplants and 9 had bone marrow transplants. Indications for isavuconazonium were: histoplasmosis 25%, high-risk fungal prophylaxis 21%, invasive aspergillosis 9%, candidiasis 2%, and other 44% (Table 1). Preceding anti-fungal therapy included: voriconazole 49%, posaconazole 12%, fluconazole 9%, micafungin 7%, amphotericin B 5%, itraconazole 4%, and none 35%. The rationale for the use of isavuconazonium is described in Table 2. ID consultation occurred in 79% of patients. Those without a consult had an indication of prophylaxis or were continuation of therapy started outpatient or at an outside hospital (OSH). Conclusion Histoplasmosis was the most common infection treated with isavuconazonium, despite limited data for that indication. Further investigation of the clinical course for these patients is warranted. Reasons for use most commonly centered on concern for QTc prolongation, clinical failure, and drug interactions. Over one-third of patients received no anti-fungal therapy prior to initiation. Adherence to required ID consultation was high. Patients on isavuconazonium for prophylaxis or as continuation therapy without a consult may still benefit from ID review to assess the appropriateness of therapy. Disclosures All authors: No reported disclosures.