Inclusion Criteria:

          -  Patients with a confirmed diagnosis of symptomatic multiple myeloma stage I to III
             according to the International Staging System ISS (see appendix A), i.e. at least one
             of the CRAB criteria should be present;

          -  Measurable disease as defined by the presence of M-protein in serum or urine (serum
             M-protein> 10 g/l or urine M-protein > 200 mg/24 hours), or abnormal free light chain
             ratio;

          -  Age 18-65 years inclusive;

          -  WHO performance status 0-3 (WHO=3 is allowed only when caused by MM and not by
             comorbid conditions);

          -  Negative pregnancy test at inclusion if applicable;

          -  Written informed consent.

        Inclusion for randomisation 1:

          -  WHO performance 0-2;

          -  Bilirubin and transaminases < 2.5 times the upper limit of normal values;

          -  A suitable stem cell graft containing at least 4 x 106 CD34+ cells/kg (or according to
             national guidelines).

        Inclusion for randomisation 2:

          -  Bilirubin and transaminases < 2.5 times the upper limit of normal values;

          -  ANC >= 0.5 x 109/l and platelets > 20 x 10^9/l;

          -  Patient is able to adhere to the requirements of the Lenalidomide Pregnancy Prevention
             Risk Management Plan.

        Exclusion Criteria:

          -  Known intolerance of Boron;

          -  Systemic AL amyloidosis;

          -  Primary Plasmacell Leukemia;

          -  Non-secretory MM;

          -  Previous chemotherapy or radiotherapy except local radiotherapy in case of local
             myeloma progression or corticosteroids maximum 5 days for symptom control;

          -  Severe cardiac dysfunction (NYHA classification II-IV);

          -  Significant hepatic dysfunction, unless related to myeloma;

          -  Patients with GFR <15 ml/min,

          -  Patients known to be HIV-positive;

          -  Patients with active, uncontrolled infections;

          -  Patients with neuropathy, CTC grade 2 or higher;

          -  Patients with a history of active malignancy during the past 5 years with the
             exception of basal carcinoma of the skin or stage 0 cervical carcinoma;

          -  Patients who are not willing or capable to use adequate contraception during the
             therapy (all men, all pre-menopausal women);

          -  Lactating women.

        Exclusion for randomisation 1:

          -  Severe pulmonary, neurologic, or psychiatric disease;

          -  CTCAE grade 3-4 polyneuropathy during Bortezomib treatment;

          -  Allogeneic Stem Cell Transplantation (Allo SCT) planned;

          -  Progressive disease.'

        Exclusion for randomisation 2:

          -  Progressive disease;

          -  Neuropathy, except CTCAE grade 1;

          -  CTCAE grade 3-4 polyneuropathy during Bortezomib treatment.