In this study patients with relapsed/progressive or refractory multiple myeloma will start treatment with bortezomiib and Dexamethasone. Response will be evaluated after four cycles. Patients with complete, very good partial response or partial response will continue treatment as initiated. Patients with stable disease will either continue treatment with the bortezomib/Dexamethasone combination for another four cycles or will receive Cyclophosphamide or Lenalidomide as an additional third agent for another four cycles.