Monoclonal Antibody Therapy, Combination Chemotherapy, and Peripheral Stem Cell Transplant in Non-Hodgkin's Lymphoma

Inclusion Criteria: Diagnosis of non-Hodgkin's lymphoma (NHL) of one of the following types: Diffuse large B-cell Composite (at least 50% of tumor showing diffuse histology) Diffuse mixed cell Immunoblastic Relapsed or refractory disease sensitive to initial or subsequent conventional therapy (at least a partial response) Eligible for high-dose carmustine, etoposide, cytarabine, and melphalan protocol and autologous bone marrow transplantation or peripheral blood stem cell transplantation Evidence of CD20 antigen expression in tumor tissue Bidimensionally measurable disease Adequate peripheral blood stem cells At least 15,000,000 CD34+ cells/kg or At least 25,000 granulocyte macrophage colony-forming units/kg Age: 19 to 70 Performance status: Karnofsky 70-100% Life expectancy: at least 4 months post-transplantation Bilirubin less than 2.0 mg/dL Creatinine less than 2.0 mg/dL Cardiac ejection fraction at least 40% for any of the following criteria: Age 60 and over Significant cardiac history (myocardial infarction or congestive heart failure) Received greater than 350 mg/m^2 of prior doxorubicin DLCO at least 50% of predicted HIV negative Fertile patients must use effective contraception during and for at least 6 months after study participation At least 4 weeks since prior biologic therapy and recovered Human antimouse antibody negative At least 4 weeks since prior cytotoxic chemotherapy and recovered At least 4 weeks since prior radiotherapy and recovered At least 4 weeks since prior immunosuppressants and recovered Exclusion Criteria: No progressive disease in a field that has been previously irradiated with more than 3,500 cGy within the past year No known brain or leptomeningeal metastases No active obstructive hydronephrosis No New York Heart Association class III or IV heart disease No evidence of severe organ dysfunction No other major medical illnesses No active infection requiring IV antibiotics No other malignancy within the past 5 years except adequately treated skin cancer or carcinoma in situ of the cervix Not pregnant/negative pregnancy test No prior peripheral blood stem cell transplantation following high-dose chemotherapy or chemoradiotherapy No other concurrent biologic therapy for NHL No concurrent steroids except maintenance-dose steroids for noncancerous disease No concurrent external beam radiotherapy for NHL No other concurrent participation on protocol involving non-FDA-approved drugs or biologics