Subjects must have one of the following systemic or invasive fungal infections at baseline: (1) systemic or invasive infection due to a fungal pathogen for which there is no currently licensed treatment; (2) systemic or invasive fungal infection, with evidence of failure and/or intolerance/toxicity to treatment with approved systemic antifungal agents. Definition of failure to treatment with approved systemic antifungal agents: a) for invasive aspergillosis and other invasive fungal infections: lack of clinical response after at least 7 days of systemic antifungal treatment at adequate doses; or b) for Candida esophagitis only: lack of clinical response after at least 14 days of fluconazole at a dose of greater than or equal to 200 mg/day. Definition of intolerance/toxicity to treatment with approved systemic antifungal agents: a) intolerance to the infusion-related toxicities of amphotericin B preparations despite appropriate supportive therapy; b) nephrotoxicity defined as a serum creatinine that had increased by greater than or equal to 1.5 mg/dl while receiving amphotericin B therapy or c) preexisting renal impairment defined as a serum creatinine that increased to greater than or equal to 2.0 mg/dl due to reasons other than amphotericin B.