Coinciding with the continually increasing population of immunocompromised patients worldwide, the incidence of
invasive fungal infections has grown over the past 4 decades. Unfortunately,
infections caused by both yeasts such as Candida and molds such as Aspergillus or Mucorales remain associated with unacceptably high morbidity and mortality. In addition, the available antifungals with proven efficacy in the treatment of these
infections remain severely limited. Although previously available second-generation
triazole antifungals have significantly expanded the spectrum of the
triazole antifungal class, these agents are laden with shortcomings in their safety profiles as well as formulation and pharmacokinetic challenges.
Isavuconazole, administered as the
prodrug isavuconazonium, is the latest second-generation
triazole antifungal to receive U.S. Food and Drug Administration approval. Approved for the treatment of both invasive
aspergillosis and invasive
mucormycosis, and currently under investigation for the treatment of
candidemia and
invasive candidiasis,
isavuconazole may have therapeutic advantages over its predecessors. With clinically relevant antifungal potency against a broad range of yeasts, dimorphic fungi, and molds,
isavuconazole has a spectrum of activity reminiscent of the polyene
amphotericin B. Moreover, clinical experience thus far has revealed
isavuconazole to be associated with fewer toxicities than
voriconazole, even when administered without therapeutic
drug monitoring. These characteristics, in an agent available in both a highly bioavailable oral and a β-
cyclodextrin-free intravenous formulation, will likely make
isavuconazole a welcome addition to the
triazole class of antifungals.