Imatinib Mesylate and Temozolomide in Treating Patients With Malignant Glioma

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