Posaconazole Versus Micafungin for Prophylaxis Against Invasive Fungal Infections During Neutropenia in Patients Undergoing Chemotherapy for Acute Myelogenous Leukemia, Acute Lymphocytic Leukemia or Myelodysplastic Syndrome

The purpose of this study is to compare the effects, good and/or bad, of posaconazole and micafungin in preventing fungal infections after chemotherapy for acute leukemia or myelodysplastic syndrome. When people take chemotherapy, they are more likely to get infections. Posaconazole has been approved for the prevention of fungal infections in patients who receive induction chemotherapy for acute leukemia and myelodysplastic syndrome. Posaconazole is available only as an oral suspension and has to be given with food. After chemotherapy, many patients are not able to tolerate food or oral medication because of severe mucositis. Patients unable to tolerate food and oral medications cannot take posaconazole. Micafungin is an antifungal medication that is given only intravenously. Micafungin is approved for the treatment of certain fungal infections and for preventing fungal infections in patients who receive bone marrow transplant. The investigators know that micafungin is safe. Micafungin has not been tested for the prevention of fungal infections in patients receiving chemotherapy for acute leukemia and myelodysplastic syndrome. Because micafungin is given by vein, it can be given even in patients who cannot take food or medications by mouth after chemotherapy. In this study the investigators want to compare micafungin to posaconazole when given for the prevention of fungal infections in leukemia and myelodysplastic syndrome patients.