The safety cohort, as outlined in the preceding protocol version 1.1 (D)_16.01.2012 of the CTU10.041/BRd-study, was omitted. The safety data of the phase I/II study (RBP-01/08 / OSHO- #077) investigating the safety and tolerability of bendamustine 75mg/m2/d, p.o. on d1+2 and lenalidomide 25mg/d, p.o. on d1-21 have become available and were published at the 17th congress of the European Hematology Association in 2012, Abstract #0848) The data demonstrate the safety and tolerability of the target dose-level of bendamustine 75mg/m2/d, p.o. on d1+2 in combination with lenalidomide 25mg/d, p.o. on d1-21 in patients with pre-treated multiple myeloma. Thus, the safety cohort, was no longer necessary and the appropriate parts of the protocol were deleted (section 1, 3.2, 6, 14.1, 15). Label Change of Ribomustin® in Levact® Bendamustine-hydrochloride had received a marketing authorization in Germany and the following Member States of the EU: Austria, Belgium, Denmark, Finland, France, Ireland, Italy, Luxembourg, Norway, Poland, Spain and the United Kingdom (UK) for the treatment of patients with indolent non-Hodgkin's lymphoma (NHL), chronic lymphocytic leukaemia (CLL) and multiple myeloma. Concomitant with this authorization a) the former German trade name Ribomustin® changed into Levact® b) the safety information of the Summary of Product Characteristics (SmPC) changed The study protocol was changed appropriately in section 4.1 and 12.3. To allow patients with relapsed or refractory multiple myeloma without measurable M-protein in the serum or urine but with abnormal elevated serum free light chain concentrations to participate in this clinical trial, the inclusion criterion bullet point #4 in section 7.1 of the study protocol has been extended appropriately. Concomitantly, the efficacy assessments in section 9.2.3 and response criteria to assess the primary and secondary endpoints in section 14.2 and 14.3.1 and appendix 4 and 5 have been changed accordingly. In

Allowance to enrol patients with prior lenalidomide treatment: Modification of in-and exclusion criteria regarding the previous prohibition of prior treatment with lenalidomide prior to study entry Extension of the inclusion criterion bullet point # 12 in section 7.1 of the protocol regarding enrolment of patients with prior malignancies Possibility of patients to proceed trial treatment in the maintenance treatment phase if study treatment has to be prematurely terminated in the induction treatment phase due to toxicities. Modification of Efficacy and Survival Assessments of patients withdrawn from study treatment

Due to low patient recruitment at the beginning of the study, the study duration was extended for additionally 24 months. Extension of one inclusion criterion regarding the measurability of the disease Patients with non-measurable MM by electrophoresis could be enrolled, if serum IgA levels were > ULN by direct serum-IgA measurement. Only in that case, direct IgA measurement should be used for response assessment. Addition of further rules of drug modification in section 13.8 Bendamustine and Lenalidomide dose modifications for non-hematologic toxicity during a cycle Due to emerging rash following bendamustine administration during study treatment, binding rules for dose modifications for bendamustine related rash became necessary. Addition of further information regarding response assessment in section 14.3.1 and appendix 5 Due to the addition of a fourth possibility of disease measurement (direct IgA measurement in case of patients with non-measurable disease by electrophoresis but show serum IgA levels> ULN), response assessment had been concomitantly adopted.