In this study will be randomised before induction treatment either to receive two courses of melphalan 200 mg/m2 (MEL200) or two courses of melphalan 100 mg/m2 (MEL100). Informed consent will be obtained upon enrolment. Inclusion criteria included: diagnosis of untreated Durie e Salmon stage IIA-IIIB measurable multiple myeloma; age < 65 years. Exclusion criteria included: prior treatment for myeloma; abnormal cardiac function, defined as systolic ejection fraction <50%; abnormal pulmonary spirometry test; serum bilirubins > 2.5 times normal and ALAT and/or ASAT > 2 times normal; seropositivity for HIV, HCV or HBV, active non-hematologic malignancies.