Inclusion Criteria:

• Subjects >=18 years of age
• High risk of poor enteral medication absorption, based on the effects of cytotoxic chemotherapy, as evidenced by, but not limited to, mucositis, nausea, vomiting, and diarrhea, at baseline.
• High risk of IFI based on anticipated or documented prolonged neutropenia (ANC <500/mm^3 [0.5 x 10^9/L]).
• Clinical laboratory safety tests within normal limits or clinically acceptable to the investigator or sponsor.
• Free of any clinically significant disease (other than the primary hematologic disease) that would interfere with the study evaluations.
• Subjects must be willing to give written informed consent and able to adhere to dosing, study visit schedule, and mandatory procedures.

Exclusion Criteria:

• Female subjects who are pregnant, intend to become pregnant, or are nursing.
• Excluded prior treatments. Subjects receiving systemic antifungal therapy (oral, intravenous, or inhaled) for the treatment of proven or probable IFI within 30 days of Enrollment (ie, voriconazole, fluconazole [FLU], or itraconazole [ITZ]).
• Subjects receiving posaconazole for prophylaxis against IFI 10 days prior to enrollment. (Subjects who are receiving either voriconazole or micafungin for prophylaxis against IFI should discontinue those therapies upon enrollment.)
• Subjects with moderate or severe liver dysfunction at Baseline, defined as aspartate aminotransferase (AST) or alanine aminotransferase (ALT) levels greater than two times the upper limit of normal (ULN), or a total bilirubin level greater than two times the ULN.
• Subjects who have taken prohibited medications more recently than the indicated washout period prior to Enrollment.
• Subjects who must take prohibited medications during the study.
• Subjects who are in a situation or have any condition that, in the opinion of the investigator, may interfere with optimal participation in the study.
• Subjects who have used any investigational drugs or biologic agents other than their chemotherapy regimens within 30 days of study entry.
• Subjects who are part of the staff personnel directly involved with this study.
• Subjects who are a family member of the investigational study staff.
• Prior enrollment in this study.
• Subjects with a history of hypersensitivity or idiosyncratic reactions to azole agents.
• Subjects with Eastern Cooperative Oncology Group (ECOG) performance status >2 prior to induction chemotherapy for their underlying disease.
• Subjects with proven or probable invasive or systemic fungal infection at Baseline.
• Subjects with a history of acute lymphoblastic leukemia or chronic myelogenous leukemia without blast crisis.