Monoclonal Antibody Therapy in Relapsed Non-Hodgkin's After Chemotherapy and Autologous Stem Cell Transplantation

OBJECTIVES: * Determine the maximum tolerated dose of yttrium Y 90-labeled ibritumomab tiuxetan when administered with rituximab in patients with B-cell non-Hodgkin's lymphoma who have relapsed after high-dose chemotherapy and autologous hematopoietic stem cell transplantation. * Determine the safety and efficacy of this regimen in these patients. OUTLINE: This is a dose-escalation study of yttrium Y 90-labeled ibritumomab tiuxetan (IDEC-Y2B8). * Phase I: Patients receive rituximab IV over 4-6 hours followed by indium In 111-labeled ibritumomab tiuxetan (IDEC-In2B8) IV over 10 minutes on day 0. Patients receive rituximab IV again on day 7 followed by IDEC-Y2B8 IV over 10 minutes. Cohorts of 3-6 patients receive escalating doses of IDEC-Y2B8 until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose at which 3 of 6 patients experience dose-limiting toxicity. * Phase II: Once the MTD is determined, 58 additional patients are treated at that dose level as in phase I. Patients are followed at 6 weeks, every 3 months for 1 year, every 6 months for 2 years, and then annually thereafter. PROJECTED ACCRUAL: Approximately 78 patients (20 for phase I and 58 for phase II) will be accrued for this study within 2 years.