Monoclonal Antibody Therapy in Treating Patients With Follicular or Mantle Cell Lymphoma

OBJECTIVES: * Assess the clinical efficacy of consolidation treatment with rituximab in terms of response rate in patients with follicular (closed to accrual 9/18/00) or mantle cell lymphoma. * Compare the event free survival of patients after induction with or without consolidation. * Compare the tolerability of these two treatment regimens by these patients. OUTLINE: This is a randomized, open label, multicenter study. Patients are stratified according to participating center, histology (follicular (closed to accrual 9/18/00) vs mantle cell), status of disease (de novo vs relapsed vs resistant), response after induction (stable disease vs partial or complete response), and treatment status (treated vs untreated). All patients receive induction therapy consisting of rituximab IV over 3-5 hours once a week during weeks 1-4. Patients are then randomized to one of two treatment arms. * Arm I: Patients are observed. * Arm II: Patients receive rituximab IV over 3-5 hours once a week during weeks 12, 20, 28, and 36. Patients are followed weekly for the first month; every 8 weeks for the next 8 months; then at 12, 18, and 24 months; and then annually for the next 3 years. PROJECTED ACCRUAL: A total of 240 patients (120 per arm) will be accrued for this study within 3-4 years.