Temozolomide Plus Irinotecan in Treating Patients With Recurrent Malignant Glioma

DISEASE CHARACTERISTICS: Histologically confirmed supratentorial malignant primary glioma of one of the following subtypes: Glioblastoma multiforme Anaplastic astrocytoma Anaplastic oligodendroglioma Mixed malignant glioma Original histology of low-grade glioma allowed if subsequent histological confirmation of malignant glioma Measurable recurrent or residual primary disease by MRI Lesions with clearly defined margins Evidence of tumor recurrence or progression by MRI or CT scan Confirmation of true progressive disease by PET or thallium scan, magnetic resonance spectroscopy, or surgical documentation after prior interstitial brachytherapy or stereotactic radiosurgery No more than 3 relapses after prior chemotherapy/cytotoxic therapy (including polifeprosan 20 with carmustine implant) for phase I and no more than 2 relapses for phase II PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 60-100% Life expectancy: Not specified Hematopoietic: WBC at least 3,000/mm^3 Absolute neutrophil count at least 1,500/mm^3 Platelet count at least 100,000/mm^3 Hemoglobin at least 10 g/dL Hepatic: Bilirubin no greater than 1.5 mg/dL SGOT no greater than 2 times upper limit of normal Renal: Creatinine no greater than 1.5 mg/dL Cardiovascular: No uncontrolled hypertension, unstable angina, or symptomatic congestive heart failure No myocardial infarction within the past 6 months No serious uncontrolled cardiac arrhythmia Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No mental incapacitation HIV negative No AIDS-related disease No significant ongoing alcoholism or substance abuse No severe nonmalignant systemic disease No active infection No other severe disease that would preclude study PRIOR CONCURRENT THERAPY: Biologic therapy: At least 1 week since prior interferon or thalidomide and recovered No concurrent anticancer immunotherapy No concurrent sargramostim (GM-CSF) No concurrent prophylactic filgrastim (G-CSF) during first course of study therapy Chemotherapy: See Disease Characteristics Recovered from prior chemotherapy At least 2 weeks since prior vincristine At least 3 weeks since prior procarbazine At least 4 weeks since prior cytotoxic chemotherapy (6 weeks for nitrosourea) Prior radiosensitizers allowed No prior temozolomide or irinotecan No other concurrent anticancer chemotherapy Endocrine therapy: At least 1 week since prior tamoxifen and recovered No concurrent anticancer hormonal therapy Phase II: Non-increasing dose of corticosteroids allowed Radiotherapy: See Disease Characteristics At least 4 weeks since prior radiotherapy and recovered No concurrent anticancer radiotherapy Surgery: See Disease Characteristics At least 1-3 weeks since prior surgical resection and recovered Other: At least 1 week since prior noncytotoxic agents (e.g., isotretinoin) and recovered Concurrent enzyme-inducing anti-epileptic drugs with or without steroids allowed No concurrent valproic acid as a single agent No concurrent medication that would preclude study (e.g., nonsteroidal immunosuppressive agents) No other concurrent investigational drugs No concurrent participation in other clinical study