Inclusion Criteria:

- Patients must be ≥ 3 years of age and ≤ 30 years of age at the time of study entry.

- Diagnosis:

- High-grade glioma;Patients must have had histologically verified anaplastic
astrocytoma, glioblastoma multiforme or gliosarcoma.Patients with primary spinal
cord tumors are eligible.

- Diffuse intrinsic pontine glioma (DIPG) are eligible.

- Performance Level: Karnofsky ≥ 50% for patients > 10 years of age and Lansky ≥ 50
for patients ≤ 10 years of age. Patients who are unable to walk because of
paralysis, but who are up in a wheelchair, will be considered ambulatory for the
purpose of assessing the performance score.

- Prior Therapy: no prior anticancer therapy.

- Concomitant Medications: The use of steroids is permissible.

- Organ Function Requirements All patients must have adequate organ function as defined
below.

- Adequate Bone Marrow Function

- Adequate Renal Function

- Adequate Liver Function

- Adequate Blood Clotting Defined As: INR, Fibrinogen, and PTT < Grade 2

- Central nervous system function. Patients with seizures may be enrolled if the
seizures are well-controlled with non-enzyme inducing anticonvulsants.

- Informed Consent. Patients and/or parents/legal guardians must have signed an
informed consent.

Exclusion Criteria:

- Patients with metastatic disease (i.e. M+ disease, or disease anywhere other than
primary site).

- Patients with evidence of a new intracranial hemorrhage that is larger than a
punctate size on baseline MRI scan.

- Allergies: Patients with a history of allergic reaction to Chinese hamster ovary cell
products, or other recombinant human antibodies.

- Pregnant or breast feeding women will not be entered on this study.

- Patients of childbearing or child-fathering potential must be willing to use a
medically acceptable form of birth control, which includes abstinence, while being
treated on this study.

- Infection: Patients who require IV antibiotics at time of enrollment, or who are
currently receiving treatment for Clostridium difficile infection are excluded.

- Thrombosis: Patients must not have been previously diagnosed with a deep venous or
arterial thrombosis (including pulmonary embolism), and must not have a known
thrombophilic condition.

- Serious or Non-Healing Wounds

- Surgical Procedures: Patients who have had major surgery should not receive the first
dose of bevacizumab until 28 days after major surgery.

- Patients with uncontrolled systemic hypertension.

- Proteinuria with a urine protein (albumin)/creatinine ratio of ≥1.0.