Patients will receive either IV micafungin 100 mg or placebo equivalent daily. Intravenous (IV)Voriconazole will be administered at a loading dose of 6 mg/kg every 12 hours for the first 24 hours followed by a maintenance dose of 4 mg/kg every 12 hours. Patients may be switched to oral voriconazole 200 mg BID provided aspergillosis response is achieved and gastrointestinal functions are intact.