No patients who have received intravenous amphotericin B or formulations of amphotericin B within 72 hours of entering the study or who require treatment with systemic antifungal agents other than FK463. Patients may continue to receive fluconazole prophylactically (no more than 400mg/day or 12mg/kg/day) while on study. All other systemic antifungals agents must be discontinued prior to the first dose of FK463.