Inclusion Criteria:

- Patients must have histologically confirmed diagnosis of WHO grade IV primary
malignant glioma (glioblastoma multiforme or gliosarcoma). Patients have to be
within 6 weeks of the last major surgical procedure.

- Age > or = to 18 years.

- An interval of at least 2 weeks and not > 6 weeks between prior major surgical
procedure and study enrollment.

- No prior radiotherapy or chemotherapy for a brain tumor

- Karnofsky > or = to 60%.

- Hemoglobin ≥ 9.0 g/dl, absolute neutrophil count (ANC) ≥ 1,500 cells/microliter,
platelets ≥ 125,000 cells/microliter.

- Serum creatinine ≤ 1.5 mg/dl, serum glutamic oxaloacetic transaminase (SGOT) and
bilirubin ≤ 1.5 times upper limit of normal.

- Signed informed consent approved by the Institutional Review Board

- If sexually active, patients must agree to use appropriate contraceptive measures for
the duration of the study and for 6 months afterwards as stated in the informed
consent.

Exclusion Criteria:

- Pregnancy or breast feeding.

- Co-medication that may interfere with study results; e.g. immuno-suppressive agents
other than corticosteroids.

- Active infection requiring IV antibiotics.

- Prior treatment with radiotherapy or chemotherapy for a brain tumor, irrespective of
the grade of the tumor.

- Evidence of > grade 1 central nervous system (CNS) hemorrhage on baseline MRI on CT
scan.

Avastin-specific Exclusion Criteria:

- Inadequately controlled hypertension (defined as systolic blood pressure > 150 and/or
diastolic blood pressure > 100 mmHg)

- Prior history of hypertensive crisis or hypertensive encephalopathy

- New York Heart Association (NYHA) Grade II or greater congestive heart failure

- History of myocardial infarction or unstable angina within 6 months prior to study
enrollment

- History of stroke or transient ischemic attack within 6 months prior to study
enrollment

- Significant vascular disease (e.g., aortic aneurysm, requiring surgical repair or
recent peripheral arterial thrombosis) within 6 months prior to study enrollment

- History of hemoptysis (≥ ½ teaspoon of bright red blood per episode) within 1 month
prior to study enrollment

- Evidence of bleeding diathesis or coagulopathy (in the absence of therapeutic
anticoagulation)

- Major surgical procedure, open biopsy, or significant traumatic injury within 28 days
prior to study enrollment or anticipation of need for major surgical procedure during
the course of the study

- Core biopsy or other minor surgical procedure, excluding placement of a vascular
access device, within 7 days prior to study enrollment

- History of abdominal fistula, gastrointestinal perforation within 6 months prior to
study enrollment

- Serious, non-healing wound, active ulcer, or untreated bone fracture

- Proteinuria at screening as demonstrated by either urine protein:creatinine (UPC)
ratio ≥ 1.0 at screening OR urine dipstick for proteinuria ≥ 2+ (patients discovered
to have ≥2+ proteinuria on dipstick urinalysis at baseline should undergo a 24-hour
urine collection and must demonstrate ≤ 1g of protein in 24 hours to be eligible).

- Known hypersensitivity to any component of Avastin

- Pregnant (positive pregnancy test) or lactation. Use of effective means of
contraception (men and women) in subjects of child-bearing potential