High-dose chemotherapy with melphalan and autologous stem cell transplantation (ASCT) remains an integral component of the myeloma treatment algorithm for patients considered eligible for the procedure, nowadays performed in myeloma patients up to the age of 75 years. Despite remarkable progress using novel agents both for induction before ASCT as well for maintenance after ASCT, definite cure in myeloma patients remains exceptional due to residual disease escaping intensive treatment. Martino et al. recently reported data on the feasibility and efficacy of the combination of bendamustine and melphalan (BenMel) as a conditioning regimen to second ASCT in patients with myeloma. In addition, extensive experience is available on the use of bendamustine (200mg/m2/day given on days -7 and -6) together with melphalan (140mg/m2/day day -1) and two additional drugs, cytarabine and etoposide (each on days -5 to -2) in the BeEAM conditioning regimen which is increasingly used as the standard conditioning regimen in lymphoma patients, also in the investigators' clinic, with an acceptable tolerability and safety profile. In summary, these data suggest that combinations of melphalan and bendamustine are usually well tolerated and that the maximum tolerated dose of bendamustine is not reached with the doses of 200mg/m2/day given on two days added to melphalan,etoposide and cytarabine (BeEAM regimen). The investigators therefore suggest in this study to directly compare bendamustine 200 mg/m2/day (on days -4 and -3) plus melphalan 100mg/m2/day (on days -2 and -1) with melphalan 100mg/m2/day (days -2 and -1) in a randomized trial.