Inclusion Criteria:

- Patients must have a MRI consistent with a WHO grade IV primary malignant glioma
(glioblastoma multiforme or gliosarcoma), and be candidates for surgical resection
with Gliadel wafer placement. Patients have to be within 6 weeks of the last major
surgical procedure.

- Age ≥ 18 years

- Candidates for Gliadel

- If a prior procedure was done, an interval of at least 2 weeks and not > 8 weeks
between prior major surgical procedure and study enrollment

- No prior radiotherapy or chemotherapy for a brain tumor

- Karnofsky > 60%

- Hemoglobin ≥ 9.0 g/dl, ANC ≥ 1,500 cells/microliters, platelets ≥ 125,000
cells/microliters

- Serum creatinine ≤ 1.5 mg/dl, serum 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 CNS hemorrhage on baseline MRI or CT scan.

- Prior treatment with Avastin for any condition

- Prior, unrelated malignancy requiring active treatment with the exception cervical
carcinoma in situ and adequately treated basal cell or squamous cell carcinoma of the
skin

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 the first Avastin infusion 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 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