Isavuconazole and voriconazole for the treatment of chronic pulmonary aspergillosis: A retrospective comparison of rates of adverse events

BACKGROUND: Long-term oral triazole antifungal therapy is the cornerstone of management for patients with chronic pulmonary aspergillosis (CPA). Itraconazole is the first-line choice of treatment. Voriconazole, posaconazole or isavuconazole can be used as alternative treatments in case of resistance or intolerance. All of these can cause significant adverse drug reactions. OBJECTIVES: To evaluate how CPA patients tolerate voriconazole and isavuconazole after prior triazole therapy. METHODS: We performed a retrospective observational study at the UK National Aspergillosis Centre. Medical records for all consecutive CPA patients started on isavuconazole and voriconazole during an observation period of 12 and 6 months respectively were analysed. RESULTS: During this study period, 20 patients were started on isavuconazole and 21 patients on voriconazole. Adverse events were seen in 18 of 21 (86%) the patients in the voriconazole group and 12 of 20 (60%) in the isavuconazole group (P = 0.02). For those who developed adverse events to these agents, the rates of discontinuation of therapy were comparable (ie 10/18 [56%], voriconazole vs 8/12 [67%], isavuconazole; P = 0.54). Five (25%) patients in the isavuconazole group who were intolerant to other triazoles tolerated the standard dose of isavuconazole. CONCLUSIONS: Compared with isavuconazole, adverse events were significantly higher in CPA patients commenced on voriconazole. Isavuconazole may be an option for those patients who are intolerant to other triazoles.