VNP40101M in Treating Young Patients With Recurrent, Progressive, or Refractory Primary Brain Tumors

DISEASE CHARACTERISTICS: Histologically confirmed* primary brain tumor, including benign brain tumors (e.g., low-grade glioma) Recurrent or progressive disease OR refractory to standard therapy NOTE: *Patients with intrinsic brain stem or diffuse optic pathway tumors do not require histological confirmation, but must have clinical and/or radiographic evidence of disease progression No bone marrow disease PATIENT CHARACTERISTICS: Age 21 and under Performance status Karnofsky 50-100% (for patients > 16 years of age) OR Lansky 50-100% (for patients ≤ 16 years of age) Life expectancy Not specified Hematopoietic Absolute neutrophil count ≥ 1,000/mm^3* Platelet count ≥ 100,000/mm^3* Hemoglobin ≥ 8 g/dL* NOTE: *Unsupported Hepatic Bilirubin ≤ 1.5 times upper limit of normal (ULN) ALT and AST ≤ 2.5 times ULN No overt hepatic disease Renal BUN < 25 mg/dL Creatinine ≤ 1.5 times ULN for age OR Glomerular filtration rate > 70 mL/min No overt renal disease Cardiovascular Shortening fraction ≥ 30% by echocardiogram OR Ejection fraction ≥ 50% by gated radionucleotide study No clinically significant cardiac arrhythmia by EKG No overt cardiac disease Pulmonary DLCO ≥ 60% of predicted Chest X-ray normal (defined as absence of pulmonary infiltrates, pneumonitis, pleural effusion, pulmonary hemorrhage, or fibrosis) AND a resting pulse oximetry reading of > 94% in room air (for patients who cannot perform the DLCO) No overt pulmonary disease Other Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception Neurologic deficits allowed provided there has been no deficit progression for ≥ 1 week before study entry No uncontrolled infection No known hypersensitivity to polyethylene glycol PRIOR CONCURRENT THERAPY: Biologic therapy At least 6 months since prior allogeneic bone marrow or stem cell transplantation At least 3 months since prior autologous bone marrow or stem cell transplantation More than 1 week since prior colony-stimulating factors (e.g., filgrastim [G-CSF], sargramostim [GM-CSF], or epoetin alfa) At least 3 weeks since prior myelosuppressive anticancer biologic therapy No concurrent routine colony-stimulating factors Chemotherapy At least 3 weeks since prior myelosuppressive anticancer chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered Endocrine therapy Concurrent corticosteroids allowed provided dose is stable or decreasing for ≥ 1 week before study entry Radiotherapy At least 3 months since prior craniospinal irradiation ≥ 18 Gy At least 2 weeks since prior focal irradiation to the primary tumor and/or symptomatic metastatic sites Surgery Not specified Other At least 7 days since prior nonmyelosuppressive anticancer therapy At least 7 days since prior investigational agents Concurrent enzyme-inducing anticonvulsant drugs allowed No other concurrent anticancer or experimental agents or therapies