Inclusion Criteria:

- Adult patients, >/= 18 years of age

- Interval of at least 12 weeks from completion of adjuvant radiotherapy for gliomas to
study entry

- Karnofsky Performance Status of >/= 70 at screening

- Confirmed measurable disease per RANO

- Adequate hematologic and organ function

Patients enrolled in Stage 1:

- Histologically documented recurrent or progressive high-grade gliomas (WHO Grade
III-IV)

- Prior treatment with at least one regimen for gliomas (radiotherapy with or without
chemotherapy for Grade III gliomas and radiotherapy with chemotherapy for Grade IV
gliomas) and/or not considered to be a candidate for regimens known to provide
clinical benefit

Patients enrolled in Stage 2:

- Histologically documented recurrent or progressive glioblastoma (WHO Grade IV
gliomas)

- Prior treatment with one or two regimens for glioblastoma (with the initial regimen
consisting of radiotherapy with chemotherapy)

Exclusion Criteria:

- Treatment with anti-tumor therapy (approved or experimental) within 4 weeks prior to
initiation of study drug

- Requirement for anticoagulants such as warfarin or any other warfarin-derivative
anticoagulants; low-molecular-weight heparin is permitted

- Any contraindication to MRI examination

- Evidence of Grade >/= 1 intracranial hemorrhage

- Active congestive heart failure or ventricular arrhythmia requiring medication

- Clinically significant history of liver disease, including viral or other hepatitis,
current alcohol abuse or cirrhosis

- Unresolved toxicity from prior therapy with the exception of lymphopenia (for
patients with prior temozolomide) and alopecia

- Pregnant or lactating women