The purpose of this study is to test the effectiveness and safety of adding cyclophosphamide or lenalidomide to the VD combination in the treatment of patients with multiple myeloma that have achieved a stable response after 4 initial cycles of treatment with VD. Multiple myeloma is the second most common cancer of the blood. Bortezomib disrupts the life cycle of the cell, affecting numerous biologic pathways, including those related to growth and survival of cancer cells.