Autologous or Donor Stem Cell Transplantation in Treating Patients With Recurrent Non-Hodgkin's Lymphoma (BMT CTN 0202)

BACKGROUND: Although patients with follicular non-Hodgkin's lymphoma (NHL) typically experience a relatively indolent course, the disease is rarely curable with conventional chemotherapy. Patients with follicular NHL are usually treated only when symptoms require palliation or if bulky disease exists since no survival advantage has been shown as compared to administering conventional treatment at initial diagnosis. While most patients achieve a remission with initial chemotherapy, a continuous pattern of relapse occurs, resulting in progressively shorter remission durations. Additionally, the increased response rates conferred by anthracycline-containing regimens have not translated into improved survival and thus the median survival time of 6 to 10 years has not been significantly impacted over the last decade. DESIGN NARRATIVE: The overall study design is a comparison of two treatment arms determined by biologic assignment, based on the availability of an HLA-matched sibling, in patients diagnosed with relapsed follicular non-Hodgkin's lymphoma. Patients without an HLA-matched sibling will receive an autologous HSCT. Patients with an HLA-matched sibling will receive a non-myeloablative allogeneic HSCT. The overall study design is that of biologic assignment, based on the availability of an HLA-matched sibling, to one of two strategies to improve the outcome for follicular lymphoma patients with chemosensitive disease. All patients will undergo cytoreduction with cyclophosphamide 4 gm/m\^2 and rituximab 375 mg/m\^2 x 2 doses. Rituximab will be given in two doses, approximately 1 week apart, with the cyclophosphamide administered the day after the first dose of rituximab. Patients assigned to the autologous arm will have their hematopoietic stem cells mobilized from this cytoreductive regimen. Patients with an HLA-matched sibling will undergo a non-myeloablative allogeneic HSCT. Pre-transplant conditioning will consist of fludarabine 30 mg/m\^2/day and cyclophosphamide 750 mg/m\^2/day x 3 days with rituximab 375 mg/m\^2/day on Days -13 and -6 pre-HSCT and on Days +1 and +8 post-HSCT. The immunosuppressive regimen will consist of tacrolimus and methotrexate (MTX) to control graft-versus-host and host-versus-graft reactions. Patients without an HLA-matched sibling who have collected an adequate autologous hematopoietic cell graft, defined as at least 2.0 \* 10\^6 CD34+ cells/kg, will receive a preparative regimen of total body irradiation (TBI) 1200 cGy or Carmustine (BCNU) 15 mg/kg. In addition, VP-16 60 mg/kg and cyclophosphamide 100 mg/kg will be given for both autologous preparative regimens. Post-autologous HSCT therapy with rituximab 375 mg/m\^2 weekly x 4 doses will commence between Days 42-75 post-HSCT.