Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed intracranial malignant glioma, including glioblastoma
multiforme, gliosarcoma, anaplastic astrocytoma, anaplastic oligodendroglioma,
anaplastic mixed oligoastrocytoma, or malignant astrocytoma not otherwise specified

- Unequivocal evidence of relapsed or refractory disease by MRI or CT scan and/or tumor
resection

- Steroid therapy prior to MRI or CT scan must have been at a stable dose for at
least 5 days

- Failed prior radiotherapy

- Must have confirmation of true progression rather than radiation necrosis
if previously treated with interstitial brachytherapy or stereotactic
radiosurgery

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- Karnofsky 60-100%

Life expectancy

- More than 2 months

Hematopoietic

- Absolute neutrophil count at least 1,500/mm3

- Platelet count at least 100,000/mm3

- Hemoglobin greater than 9 g/dL

- No history of bleeding disorder

Hepatic

- Bilirubin less than 1.5 mg/dL

- SGPT less than 2.5 times normal

- Alkaline phosphatase less than 2.5 times normal

Renal

- Creatinine less than 1.5 times upper limit of normal (ULN) OR

- BUN less than 1.5 times ULN

Cardiovascular

- No deep vein thrombosis within the past 3 weeks (must be clinically stable)

Pulmonary

- No pulmonary embolism within the past 3 weeks (must be clinically stable)

Other

- No peripheral neuropathy grade 2 or greater

- No active infection

- No other serious concurrent medical illness

- No concurrent illness that may obscure toxicity or dangerously alter drug metabolism

- No other malignancy within the past 3 years except nonmelanoma skin cancer or
carcinoma in situ of the cervix

- Must participate in the System for Thalidomide Education and Prescribing Safety
program

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use 2 forms of effective contraception for 1 month before,
during, and for 1 month after study

PRIOR CONCURRENT THERAPY:

Biologic therapy

- No prior oral thalidomide or celecoxib for more than 2 months duration

Chemotherapy

- No prior oral etoposide or cyclophosphamide for more than 2 months duration

- Prior standard-dose IV etoposide and cyclophosphamide allowed

Endocrine therapy

- See Disease Characteristics

- Concurrent steroids allowed

Radiotherapy

- See Disease Characteristics

- At least 4 weeks since prior radiotherapy

Surgery

- See Disease Characteristics

- Prior surgery for relapsed or refractory disease allowed

- Recovered from prior surgery

- No concurrent surgery

Other

- No other concurrent investigational agents or treatment

- No other concurrent anticancer therapy

- Concurrent antiseizure medications allowed