PRIOR CONCURRENT THERAPY: Biologic therapy: No prior mouse monoclonal antibody or antibody fragment, or chimeric or humanized antibody At least 4 weeks since prior immunotherapy Chemotherapy: No prior carmustine, fluorouracil, vincristine, and streptozocin At least 4 weeks since prior chemotherapy Endocrine therapy: Not specified Radiotherapy: At least 4 weeks since prior radiotherapy Surgery: Not specified