Iodine I 131 Monoclonal Antibody BC8, Cyclophosphamide, and Total Body Irradiation for Advanced Acute Lymphocytic Leukemia

OBJECTIVES: I. Assess the efficacy and toxicity of iodine I 131 monoclonal antibody BC8, cyclophosphamide, and total body irradiation in patients with advanced acute lymphocytic leukemia who are receiving HLA matched related or unrelated bone marrow transplantation. II. Determine the maximum tolerated dose (MTD) of iodine I 131 monoclonal antibody BC8 in these patients. III. Estimate the MTD of radiation delivered by iodine I 131 monoclonal antibody BC8 to the marrow. IV. Study the influence of marrow cellularity, level of antigen expression by leukemic cells, and degree of antigen saturation by antibody on the biodistribution of iodine I 131 monoclonal antibody BC8 in these patients. OUTLINE: This is a dose-escalation study. All patients receive a test dose of iodine I 131 monoclonal antibody BC8 (MOAB BC8) IV over several hours 6-14 days prior to the therapeutic dose. Patients receive the therapeutic dose of iodine I 131 MOAB BC8 IV over several hours on day -11, total body irradiation over 30-40 minutes twice a day on days -6 to -4, and cyclophosphamide IV over 1 hour on days -3 and -2. Patients undergo allogenic bone marrow transplantation on day 0. Patients receive intrathecal methotrexate twice prior to transplantation and then every other week for 4 weeks beginning on day 32 posttransplant. Cohorts of 4 patients receive escalating doses of iodine I 131 monoclonal antibody until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 4 patients experience dose-limiting toxicity. Patients are followed for the first 100 days, at 6, 9 and 12 months, every 6 months for 1 year, and then annually thereafter. PROJECTED ACCRUAL: A total of 40 patients will be accrued for this study within 4 years.