Imatinib Mesylate in Treating Patients With Recurrent Malignant Glioma or Meningioma

DISEASE CHARACTERISTICS: Histologically confirmed recurrent or unresectable malignant glioma Glioblastoma multiforme (phase I only) Anaplastic astrocytoma Anaplastic oligodendroglioma Anaplastic mixed oligoastrocytoma Malignant astrocytoma not otherwise specified Gliosarcoma Low-grade histology with subsequent diagnosis of malignant glioma allowed (phase I only) OR Histologically confirmed recurrent or unresectable benign or malignant meningioma (phase I only) No prior intracranial hemorrhage Failed prior radiotherapy Progressive or recurrent disease by MRI or CT scan and/or resection PET or thallium scan, MR spectroscopy, or surgical documentation required in patients who have received prior interstitial brachytherapy or stereotactic radiosurgery Stable dose of steroids for 5-7 days prior to MRI or CT scan PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 60-100% Life expectancy: More than 8 weeks Hematopoietic: Absolute neutrophil count at least 1,500/mm^3 Platelet count at least 100,000/mm^3 Hemoglobin at least 10 g/dL (transfusion allowed) Hepatic: Bilirubin less than 2 times upper limit of normal (ULN) SGOT less than 2 times ULN No significant hepatic disease Renal: Creatinine less than 1.5 mg/dL Creatinine clearance at least 60 mL/min No significant renal disease Cardiovascular: No significant cardiac disease No deep venous or arterial thrombosis within the past 6 weeks Pulmonary: No pulmonary embolism within the past 6 weeks Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective barrier contraception during and for up to 6 months after study participation No other serious concurrent medical illness No serious active infection No concurrent disease that would obscure toxicity or alter drug metabolism No other malignancy within the past 3 years except nonmelanoma skin cancer or carcinoma in situ of the cervix PRIOR CONCURRENT THERAPY: Biologic therapy: At least 1 week since prior interferon or thalidomide and recovered No concurrent immunotherapy No concurrent prophylactic filgrastim (G-CSF) Chemotherapy: Recovered from prior chemotherapy At least 4 weeks since prior cytotoxic therapy At least 2 weeks since prior vincristine At least 6 weeks since prior nitrosoureas At least 4 weeks since prior temozolomide At least 3 weeks since prior procarbazine Prior polifeprosan 20 with carmustine implant (Gliadel wafer) allowed Prior radiosensitizers allowed No other concurrent chemotherapy Phase I only: Prior chemotherapy required for anaplastic astrocytoma, anaplastic oligodendroglioma, and anaplastic mixed oligoastrocytoma Prior treatment for up to 3 relapses allowed Phase II only: Prior chemotherapy not required Prior treatment for up to 2 relapses allowed Endocrine therapy: See Disease Characteristics At least 1 week since prior tamoxifen and recovered No concurrent anticancer hormonal therapy Radiotherapy: See Disease Characteristics At least 4 weeks since prior radiotherapy No concurrent radiotherapy Surgery: See Disease Characteristics Recovered from prior surgical resection of recurrent or progressive disease Other: At least 1 week since prior non-cytotoxic agents and recovered At least 1 week since prior tretinoin and recovered At least 2 weeks since prior drugs that affect hepatic metabolism No other concurrent investigational agents No concurrent warfarin