Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed malignant glioma, including the following:

- Glioblastoma multiforme

- Gliosarcoma

- Anaplastic astrocytoma or anaplastic glioma

- Malignant glioma not otherwise specified

- Evidence of tumor recurrence or progression by MRI or CT scan with contrast

- CT scan or MRI must be performed ≤ 96 hours post-operatively (≤ 2 weeks prior to
study registration) or 4-6 weeks post-operatively to assess residual disease in
patients who have undergone recent resection of recurrent or progressive tumor

- Steroid dosage must have been stable for ≥ 5 days

- Failed ≥ 1 prior systemic treatment with chemotherapy or biologic agents (excluding
polifeprosan 20 with carmustine implant [Gliadel wafers])

- Failed prior external-beam radiotherapy

- If received prior interstitial brachytherapy or stereotactic radiosurgery, true
progressive disease (rather than radiation necrosis) must be confirmed by positron
emission tomography, single-photon emission computer tomography with thallium,
magnetic resonance (MR) spectroscopy, MR perfusion, or surgical documentation

PATIENT CHARACTERISTICS:

- Karnofsky performance status 70-100%

- Life expectancy > 8 weeks

- WBC > 3,000/mm³

- Absolute neutrophil count > 1,500/mm³

- Platelet count > 100,000/mm³

- Hemoglobin > 10 g/dL (transfusion allowed)

- SGOT and SGPT < 1.5 times upper limit of normal (ULN)

- Bilirubin < 1.5 times ULN

- Creatinine < 1.5 mg/dL

- Blood pressure ≤ 150/100 mm Hg

- No unstable angina

- No New York Heart Association class II-IV congestive heart failure

- No stroke or myocardial infarction within the past 6 months

- No clinically significant peripheral vascular disease

- No evidence of bleeding diathesis or coagulopathy

- Urine protein:creatinine ratio < 1.0

- No significant medical illness that would preclude study participation or cannot be
adequately controlled with appropriate therapy

- No other serious medical illness or infection

- No disease that would obscure toxicity or dangerously alter drug metabolism

- No significant traumatic injury within the past 28 days

- No abdominal fistula, gastrointestinal perforation, or intra-abdominal abscess within
the past 6 months

- No serious, nonhealing wound, ulcer, or bone fracture

- No history of any other cancer (except nonmelanoma skin cancer or carcinoma in situ
of the cervix) unless cancer is in complete remission and patient is off all therapy
for that cancer for ≥ 3 years

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- More than 4 weeks since prior surgery for recurrent or progressive disease and
recovered

- More than 28 days since prior major surgical procedure or open biopsy

- At least 4 weeks since prior cytotoxic therapy (6 weeks for nitrosoureas)

- At least 2 weeks since prior vincristine

- At least 3 weeks since prior procarbazine hydrochloride

- At least 1 week since prior noncytotoxic agents (e.g., interferon, tamoxifen,
thalidomide, or isotretinoin)

- Radiosensitizer does not count

- At least 4 weeks since prior experimental biologic agents (e.g., epidermal growth
factor receptor [EGFR] inhibitors)

- More than 7 days since prior minor surgery, such as fine-needle aspirations or core
biopsies

- No concurrent combination anti-retroviral therapy for HIV-positive patients

- No concurrent enzyme-inducing anticonvulsants (EIACs)

- Patients on EIACs must switch to nonenzyme-inducing convulsants ≥ 2 weeks prior
to study enrollment