Serum (1→3)-β-d-glucan levels in persistently neutropenic rabbits of the experimental pulmonary aspergillosis model in groups of untreated controls and rabbits receiving oral doses of isavuconazole (BAL4815). An initial loading dose of 90 mg/kg of isavuconazole was administered orally, and thereafter the drug was administered daily at 20, 40, and 60. Values are (1→3)-β-d-glucan concentrations. P values are indicated as follows: *, P < 0.05, decrease of plasma (1→3)-β-d-glucan concentrations in ISA20-treated rabbits in comparison to that of UC; ¶, P < 0.01, decrease of plasma (1→3)-β-d-glucan concentrations in ISA40- and ISA60-treated rabbits in comparison to that of UC.