Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed malignant glioma

- Any of the following subtypes:

- Glioblastoma multiforme

- Gliosarcoma

- Anaplastic astrocytoma

- Anaplastic oligodendroglioma

- Anaplastic oligoastrocytoma

- Previous histologic diagnosis of a lower grade of glioma allowed if there is
histologic evidence of progression to a diagnosis of malignant glioma

- Multifocal disease allowed

- Must have undergone prior conventional external-beam radiation therapy

- Stable disease, disease recurrence, or relapsed disease

- Must not have received any systemic therapy for this recurrence or relapse

- No prior progressive disease

- No central/systemic fluid collections (pericardial effusion, pulmonary effusion,
ascites) ≥ grade 2

- No evidence of intratumor hemorrhage on pretreatment diagnostic imaging, except for
stable post-operative grade 1 hemorrhage

PATIENT CHARACTERISTICS:

- Karnofsky performance status 70-100%

- Absolute neutrophil count > 1,500/mm³

- Hemoglobin > 9 g/dL

- Platelet count > 100,000/mm³

- AST and ALT < 2.5 times upper limit of normal (ULN)

- Bilirubin < 1.5 times ULN

- Creatinine < 1.5 times ULN

- No chronic renal disease

- No active uncontrolled infection

- No uncontrolled diabetes

- No excessive risk of bleeding, as defined by occurrence of any of the following:

- Stroke within the past 6 months

- History of CNS or intraocular bleed

- Septic endocarditis

- No history of labile hypertension

- No congestive heart failure

- No poorly controlled hypertension

- No myocardial infarction within the past 6 months

- No history of poor compliance with antihypertensive regimen

- No other severe and/or uncontrolled medical disease that would preclude study
participation

- No peripheral edema ≥ grade 2

- No gastrointestinal bleeding

- No gross hematuria

- No other active systemic bleeding

- Patients must not have experienced toxicity ≥ grade 3 with prior treatment with
either temozolomide or imatinib mesylate

- No other primary malignancy within the past 5 years except basal cell skin cancer or
carcinoma in situ of the cervix or other cancer not currently clinically significant
nor requiring active interventions

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- Recovered from all prior therapy

- Prior surgical resection(s) allowed

- At least 2 weeks since prior surgery

- At least 2 weeks since prior chemotherapy (6 weeks for nitrosoureas)

- At least 2 weeks since prior external-beam radiotherapy

- At least 2 weeks since prior investigational drugs

- More than 1 week since prior biologic, immunotherapeutic, or cytostatic agents

- No concurrent warfarin