A water-soluble triazole prodrug with broad-spectrum antifungal activity. Administered intravenously or orally with high oral bioavailability, isavuconazole is hydrolyzed to the active moiety BAL4815 by plasma esterases. BAL4815 inhibits fungal cytochrome P450 lanosterol 14-alpha-demethylase (CYP51), which catalyzes the conversion of lanosterol to ergosterol, an important component of the fungal cell membrane. CYP51 inhibition by this agent leads to a decrease in ergosterol pool, thus disturbing synthesis of the fungal cell membrane; increasing fungal cell membrane permeability; promoting the loss of essential intracellular elements; and resulting in fungal cell lysis and death.