Real-world experience with Isavuconazole therapy in a large tertiary hospital in Cambridge, UK

Abstract

Background: Isavuconazole (ISV) is a second-generation triazole antifungal used for invasive fungal infections (IFIs). Here, we describe our experiences of ISV. Methods: This single-centre retrospective study included all patients who commenced a course of ISV over a 3-year period (1/7/16-30/6/19). ISV was used for the treatment of IFIs when no alternative was suitable. Demographics, clinical details and antimicrobial history were obtained from our integrated electronic health record and laboratory system (EPIC). Results: Twenty-four patients, aged between 17–78 years (median 54), received ISV in the study period. Sixteen (67%) were haematology patients. Using EORTC criteria, six had possible invasive aspergillosis (IA), 1 had a possible yeast infection, 13 had probable IA, 3 had proven IA and one had a proven yeast infection. Four were neutropenic (neutrophil count <0.5x109/L) and 7 had renal impairment. Half of the patients (12/24; 50%) had received a transplant prior to commencing (nine allografts, one kidney, one lung, one multi-visceral) and a further two underwent an allograft whilst receiving ISV. ISV pre-dose levels ranged from 1.29–7.7mg/L (median 2.73mg/L; IQR 2.1 – 3.13mg/L). ISV was given for 1–733 days (median 42 days). In patients who were still alive during therapy, the treatment duration ranged from 3–342 days (median 97 days). Ten were dead within 42-84 days of commencing therapy; 6 had died by the end of therapy. Conclusion: Our findings suggest that ISV is used infrequently, predominantly in haematology. More data is needed to determine optimal treatment course and the role of therapeutic drug monitoring.