<br>        Inclusion Criteria:<br><br>          1. Confirmed diagnosis of untreated multiple myeloma requiring systemic therapy<br>             (diagnostic criteria (IMWG updated criteria (2014)1) see appendix IA. For some<br>             patients systemic therapy may be required though these diagnostic criteria are not<br>             fulfilled. In this case the GMMG study office has to be consulted prior to inclusion.)<br><br>          2. Patient is eligible for high dose therapy and autologous stem cell transplantation.<br><br>          3. Measurable disease, defined as any quantifiable monoclonal protein value, defined by<br>             at least one of the following three measurements:2<br><br>               -  Serum M-protein = 10g/l (for IgA = 5g/l)<br><br>               -  Urine light-chain (M-protein) of = 200 mg/24 hours<br><br>               -  Serum FLC assay: involved FLC level = 10 mg/dl provided sFLC ratio is abnormal<br><br>          4. Age 18 - 70 years inclusive<br><br>          5. WHO performance status 0-2<br><br>          6. Negative pregnancy test at inclusion (females of childbearing potential)<br><br>          7. All patients must agree on the requirements regarding the lenalidomide pregnancy<br>             prevention plan described in section 6. For all men and females of childbearing<br>             potential: patients must be willing and capable to use adequate contraception during<br>             the complete therapy.<br><br>          8. All patients must<br><br>               -  agree to abstain from donating blood while taking lenalidomide and for 28 days<br>                  following discontinuation of lenalidomide therapy<br><br>               -  agree not to share study drug lenalidomide with another person and to return all<br>                  unused study drug to the investigator or pharmacist<br><br>          9. Ability of patient to understand character and individual consequences of the clinical<br>             trial<br><br>         10. Provide written informed consent (must be available before enrolment in the trial)<br><br>        Exclusion Criteria<br><br>          1. Patient has known hypersensitivity (or contraindication) to dexamethasone, sucrose<br>             histidine (as base and hydrochloride salt), boron, mannitol, and polysorbate 80 or any<br>             of the components of study therapy that are not amenable to premedication with<br>             steroids or H2 blockers that would prohibit further treatment with these agents.<br><br>          2. Systemic AL amyloidosis (except for AL amyloidosis of the skin or the bone marrow)<br><br>          3. Plasma cell leukemia<br><br>          4. Previous chemotherapy or radiotherapy during the past 5 years except local<br>             radiotherapy in case of local myeloma progression. (Note: patients may have received a<br>             cumulative dose of up to 160 mg of dexamethasone or equivalent as emergency therapy.)<br>             Previous therapy due to smouldering myeloma may be acceptable. In this case the GMMG<br>             study office has to be consulted prior to inclusion<br><br>          5. Severe cardiac dysfunction (NYHA classification III-IV), ejection fraction < 40%<br><br>          6. Significant hepatic dysfunction (ASAT and/or ALAT = 3 times normal level and/or serum<br>             bilirubin = 1.5 times normal level if not due to hereditary abnormalities as Gilbert's<br>             disease), unless related to myeloma.<br><br>          7. Patients with active or history of hepatitis B or C<br><br>          8. HIV positivity<br><br>          9. Patients with active, uncontrolled infections<br><br>         10. Patients with severe renal insufficiency (Creatinine Clearance < 30ml/min)<br><br>         11. Patients with peripheral neuropathy or neuropathic pain, CTC grade 2 or higher (as<br>             defined by the NCI Common Terminology Criteria for Adverse Events (NCI CTCAE) Version<br>             5.0)<br><br>         12. Patients with a history of active malignancy during the past 5 years with the<br>             exception of following malignancies after curative therapy: basal cell carcinoma of<br>             the skin, squamous cell skin carcinoma, stage 0 cervical carcinoma or any in situ<br>             malignancy<br><br>         13. Patients with acute diffuse infiltrative pulmonary and/or pericardial disease<br><br>         14. Autoimmune hemolytic anemia with positive Coombs test or immune thrombocytopenia<br><br>         15. Platelet count < 75 x 109/l<br><br>         16. Haemoglobin < 8.0 g/dl, unless related to myeloma<br><br>         17. Absolute neutrophil count (ANC) < 1.0 x 109/l (the use of colony stimulating factors<br>             within 14 days before the test is not allowed)<br><br>         18. Corrected serum calcium > 14 mg/dl (> 3.5 mmol/l)<br><br>         19. Unable or unwilling to undergo thromboprophylaxis<br><br>         20. Pregnancy and lactation<br><br>         21. Participation in other clinical trials. This does not include long-term follow-up<br>             periods without active drug treatment of previous studies during the last 6 months.<br><br>         22. Prisoners or subjects who are legally institutionalized, or those unwilling or unable<br>             to comply with scheduled visits, drug administration plan, laboratory tests, other<br>             study procedures, and study restrictions.<br><br>        No patients will be allowed to enrol in this trial more than once.<br><br>        -<br>