Orphan drugs for the treatment of aspergillosis: Focus on isavuconazole

Invasive aspergillosis (IA) is a particularly devastating manifestation of Aspergillus infection affecting profoundly immunocompromised patients. Voriconazole has been approved as first-line therapy for IA since 2003; however, nonlinear pharmacokinetics, adverse effects, and drug-drug interactions at time hinder its use. Isavuconazole is a new broad-spectrum triazole with potent activity against Aspergillus species. In animal models and clinical trials in humans, isavuconazole has shown comparable efficacy to that of voriconazole in the treatment of IA. Advantages of isavuconazole include a more favorable pharmacokinetic profile and fewer adverse events. This review summarizes the pharmacologic characteristics, in vitro activity, and clinical data supporting the use of isavuconazole as an emerging alternative therapy for IA.