The DSMM V protocol is to compare a consolidation treatment for standard-risk patients not displaying del(13) at initial diagnosis following two cycles of high-dose melphalan 200 mg/m² each supported by autologous stem cell retransfusion with interferon versus PEG-interferon. Patients with del(13) are screened for availability of a fully HLA-matched related or unrelated donor. If patient's informed consent is obtained additionally, he is scheduled to undergo an allogeneic SCT following the first cycle of high-dose melphalan. All other subjects are to proceed to a second course of high-dose melphalan similar to the standard-risk group. Initial cytoreduction is foreseen with four cycles of anthracycline-dexamethasone combination followed by combination therapy with ifosfamide/epirubicine/etoposide for stem-cell collection.