PRIOR CONCURRENT THERAPY: Biologic therapy: No prior immunotherapy for brain tumor No prior biologic therapy for brain tumor, including: Immunotoxins Immunoconjugates Antisense Peptide receptor antagonists Interferons Interleukins Tumor infiltrating lymphocytes Lymphokine activated killer cells Gene therapy No concurrent growth factors (e.g., filgrastim or epoetin alfa) Chemotherapy: No prior chemotherapy for brain tumor Endocrine therapy: Must be on stable corticosteroid regimen for at least 1 week (at least 5 days) No other prior hormonal therapy for brain tumor Radiotherapy: No prior radiotherapy for brain tumor Surgery: Recovered from prior surgery Other: No concurrent investigational agents No concurrent gold compounds (auronofin, gold sodium thiomalate) No concurrent herbal dietary supplements