DISEASE CHARACTERISTICS:

• Histologically confirmed grade 4 astrocytoma at primary diagnosis or recurrence

  • Gliosarcoma allowed
• Evidence of tumor progression by MRI or CT scan after radiotherapy or first-line chemotherapy
• Measurable or evaluable disease by MRI or CT scan

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-2

Life expectancy:

• Not specified

Hematopoietic:

• Absolute neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3
• Hemoglobin at least 9 g/dL

Hepatic:

• Bilirubin no greater than 1.5 mg/dL
• SGOT no greater than 3 times upper limit of normal

Renal:

• Creatinine no greater than 2.0 mg/dL

Cardiovascular:

• No myocardial infarction within the past 6 months
• No congestive heart failure requiring ongoing maintenance therapy for life-threatening ventricular arrhythmias

Other:

• Cholesterol no greater than 350 mg/dL
• Triglycerides no greater than 400 mg/dL
• Willing to provide correlative laboratory samples
• No uncontrolled infection
• No known hypersensitivity to any components of CCI-779, diphenhydramine hydrochloride, or other similar antihistamines
• No other medical reason that would preclude diphenhydramine premedication
• No other active malignancy
• No other severe disease that would preclude study participation
• Not immunocompromised unless due to corticosteroids
• HIV negative
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• See Disease Characteristics
• Prior adjuvant chemotherapy allowed
• More than 4 weeks since prior chemotherapy (6 weeks for nitrosoureas)
• No more than 1 prior chemotherapy regimen for recurrent/progressive disease
• No prior polifeprosan 20 with carmustine implant (Gliadel)

Endocrine therapy:

• Must be on fixed dose of corticosteroids (or no corticosteroids) at least 1 week prior to baseline scan

Radiotherapy:

• See Disease Characteristics
• At least 12 weeks since prior radiotherapy
• No prior stereotactic radiosurgery or interstitial brachytherapy unless there is a separate lesion on MRI that is outside of the previously treated field

Surgery:

• No prior resection since last chemotherapy or radiotherapy unless there is unequivocal tumor growth on neuro-imaging study since surgery or there is a separate lesion not present in the surgical bed

Other:

• More than 4 weeks since prior investigational agents