Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed malignant glioma

- Anaplastic astrocytoma (AA) OR

- Glioblastoma multiforme (GBM)

- Recurrent or progressive disease by contrast-enhanced CT scan or MRI after primary
surgery and radiotherapy

- At least 1 bidimensionally measurable lesion

- At least 1 cm by 1 cm on contrast-enhanced CT scan or MRI

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- ECOG 0-2

Life expectancy:

- At least 12 weeks

Hematopoietic:

- Absolute granulocyte count at least 1,500/mm3

- Platelet count at least 120,000/mm3

Hepatic:

- Bilirubin normal

- AST and ALT no greater than 2.5 times upper limit of normal

Renal:

- Creatinine normal OR

- Creatinine clearance at least 60 mL/min

Cardiovascular:

- No symptomatic congestive heart failure

- No unstable angina pectoris

- No cardiac arrhythmia

Pulmonary:

- DLCO at least 70% of predicted

- FVC at least 70% of predicted

Other:

- No other malignancy within the past 5 years except adequately treated nonmelanoma
skin cancer or curatively treated carcinoma in situ of the cervix

- No ongoing or active uncontrolled infection

- No other serious illness or medical condition that would preclude study

- No history of significant neurologic or psychiatric disorder that would preclude
study

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception during and for at least 3 months
after study

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- At least 6 weeks since prior immunotherapy

- No concurrent immunotherapy

Chemotherapy:

- At least 6 weeks since prior chemotherapy

- No more than 1 prior adjuvant chemotherapy regimen for AA

- No prior chemotherapy for recurrent disease

- No other concurrent chemotherapy

Endocrine therapy:

- Patients must be on a stable dose of steroids for at least 2 weeks prior to study

Radiotherapy:

- See Disease Characteristics

- At least 4 weeks since prior radiotherapy

- No prior radiotherapy for recurrent disease

- No concurrent radiotherapy

Surgery:

- See Disease Characteristics

- Prior surgery for recurrent disease (e.g., stereotactic biopsy or partial resection)
allowed

- At least 4 weeks since prior surgery (except for biopsy)

Other:

- At least 6 weeks since prior investigational agents

- No other concurrent investigational agents

- No other concurrent anticancer treatment