Combination Chemotherapy With or Without Monoclonal Antibody Therapy in Treating Patients With Stage III or Stage IV Low-Grade Non-Hodgkin's Lymphoma

Randomized phase III trial to compare the effectiveness of two regimens of combination chemotherapy followed by rituximab or observation in treating patients who have stage III or stage IV low-grade non-Hodgkin's lymphoma. Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Combining more than one drug may kill more cancer cells. Monoclonal antibodies such as rituximab can locate cancer cells and either kill them or deliver cancer-killing substances to them without harming normal cells. It is not yet known which regimen of combination chemotherapy, with or without rituximab, is more effective for non-Hodgkin's lymphoma

PRIMARY OBJECTIVES: I. To compare the response rate, time to progression, time to treatment failure, and survival for patients with low grade lymphoma treated with the cyclophosphamide - fludarabine regimen with a control arm consisting of standard treatment with CVP. II. To determine the effect of maintenance with anti-CD20 (IDEC C2B8) on time to progression, time to treatment failure, and survival and its effects on lymphocyte number, subsets, and quantitative immunoglobulin levels over time. OUTLINE: This a two step, stratified, randomized study. Patients are stratified for arms I and II (step 1) by age (under 60 vs 60 and over), tumor burden (high vs low), histology (follicular vs other), and B symptoms (present vs absent). After arms I and II have been completed, patients are stratified in arms III and IV (step 2) by extent of residual disease (minimal vs gross), histology (follicular vs other), and initial tumor burden. ARM I (CLOSED AS OF 9/2000): Patients receive cyclophosphamide IV over 30-45 minutes on day 1 and fludarabine IV over 10-20 minutes on days 1-5. Treatment repeats every 28 days in the absence of disease progression for a minimum of 4 courses and a maximum of 6 courses. ARM II: Patients receive cyclophosphamide IV over 30-45 minutes and vincristine IV on day 1, and oral prednisone on days 1-5. Treatment repeats every 21 days in the absence of disease progression for a minimum of 6 courses and a maximum of 8 courses. After completion of therapy on arm I or II, patients are randomized into step 2 of this study comprising arms III and IV. ARM III: Patients receive maintenance therapy with rituximab (IDEC-C2B8 monoclonal antibody) IV weekly for 4 weeks. Courses repeat every 6 months for 2 years. Maintenance therapy begins 4 weeks after the last chemotherapy. ARM IV: Patients undergo no maintenance therapy and are observed. Patients are followed every 3 months for 2 years, every 6 months for the next 3 years, and then annually thereafter.