To evaluate and compare two AmBisome dosing regimens for the initial treatment of invasive aspergillosis and other filamentous fungal infections diagnosed by modified EORTC criteria in immunocompromised patients, as determined by overall response rates at end of course of treatment.

To evaluate and compare two AmBisome dosing regimens for the initial treatment of invasive aspergillosis and other filamentous fungal infections diagnosed by modified EORTC criteria in immunocompromised patients, as determined by overall response rates at end of course of treatment.

Determine and compare the following parameters for the two treatment arms:

• Safety and tolerability
• Survival rates and the rates of infection relapse at 4 weeks Post Treatment.
• Survival rate at 12 weeks after study entry.
• Time to favorable overall response and time to End of Treatment for patients with favorable overall response.
• Cumulative dose of study drug given through End of Treatment.

Inclusion Criteria:

• Immunocompromised due to hematologic malignancies, chemotherapy-induced neutropenia, hematopoietic stem cell transplantation, solid organ transplantation, other conditions resulting in severe neutropenia, HIV infection, prolonged corticosteroid therapy (greater than or less than 20 mg of Prednisone or equivalent for greater than or less than 3 weeks), treatment with other immunosuppressant medications, or other acquired or hereditary immunocompromising conditions that place the patients at risk for IFI. Evidence of Proven, Probably or Possible IFFI by modified EORTC criteria. Continued treatment with study drug is contingent upon confirmation of diagnosis of Proven or Probable IFI within 4 working days after study entry.

Exclusion Criteria:

• Life expectancy of less than 30 days; chronic IFI (defined as signs/symptoms of IFI present for less 4 weeks preceding entry into study;prior systemic therapy of greater than or less than 4 days with any polyene anti-fungal agent within 14 days of study enrollment;prior systemic therapy of greater than or less than 4 days with non-polyenes for the current, documented IFI. Use of another investigational, unlicensed drug within 30 days of screening or concurrent participation in another clinical trial using an investigational, unlicensed drug; serum creatinine greater than 2 x upper limit of normal (ULN), serum ALT or AST less than 5 x ULN; pregnant or lactating women; history of allergy or serious adverse reaction to any polyene anti-fungal agent.