DISEASE CHARACTERISTICS:

• Histologically confirmed primary grade 3 or 4 malignant glioma of 1 of the following types:

  • Glioblastoma multiforme
  • Gliosarcoma
  • Anaplastic astrocytoma
  • Anaplastic oligodendroglioma
• Patients with recurrent disease whose original diagnostic pathology confirmed malignant glioma will not need re-biopsy
• Measurable recurrent or residual primary disease on contrast-enhanced MRI or CT scan
• Failed ≥ 1 prior chemotherapy regimen (with or without radiotherapy)

PATIENT CHARACTERISTICS:

• Karnofsky performance status 60-100%
• Hematocrit > 29%
• Absolute neutrophil count > 1,500/mm^3
• Platelets > 125,000/mm^3
• Serum SGOT and bilirubin < 1.5 times upper limit of normal
• Creatinine < 1.5 mg/dL
• Urine protein:creatinine ratio ≤ 1.0
• Blood pressure ≤ 150/100 mmHg
• No unstable angina
• No New York Heart Association class II or greater congestive heart failure
• No myocardial infarction within the past 6 months
• No stroke within the past 6 months
• No clinically significant peripheral vascular disease
• No evidence of bleeding diathesis or coagulopathy
• No significant traumatic injury within the past 28 days

PRIOR CONCURRENT THERAPY:

• At least 4 weeks must have elapsed since prior chemotherapy or radiotherapy unless there is unequivocal evidence of tumor progression
• At least 6 weeks since prior surgical resection
• No previous major surgical procedures or open biopsies within 28 days prior to study entry
• No previous minor surgical procedures, fine needle aspirations, or core biopsies within 7 days prior to study entry
• No anticipated need for major surgical procedures during the course of the study
• No concurrent aspirin, non-steroidal anti-inflammatory drugs, or clopidogrel