Purpose: primary systemic amyloidosis is an immunoglobulin deposition disorder in which insoluble light chains cause organ dysfunction and death. The established conventional therapy is treatment with melphalan and prednisone. We investigated whether treatment with multiple alkylating agents improved the response rare or survival time, compared with melphalan and prednisone therapy. Patients and Methods: We treated 101 patients with biopsy-proven primary amyloidosis. The patients were randomly assigned to receive melphalan and prednisone (52 patients) or vincristine, carmustine, melphalan, cyclophosphamide, and prednisone (49 patients). patients were stratified according to the presence of cardiac involvement; time from diagnosis to randomization, serum beta(2)-microglobulin level, and whether peripheral neuropathy was the major manifestation of the disease. Results: The median duration of survival after randomization was 29 months, with no differences in survival time between the two groups. There were 29 patients who fulfilled the response criteria: 15 in the vincristine, carmustine, melphalan, cyclophosphamide, and prednisone arm and 14 in the melphalan and prednisone arm. Conclusion: Therapy with multiple alkylating agents did not result in a higher response rate or longer survival time, compared with standard melphalan and prednisone treatment in patients with primary systemic amyloidosis. J Clin Oncol 17:262-267. (C) 1999 by American Society of Clinical Oncology.