Treatment With Velcade (Bortezomib) Plus Dexamethasone (VD) or VD Plus Cyclophosphamide or VD Plus Lenalidomide in Patients With Multiple Myeloma Stabilized After 4 Cycles of VD

Inclusion Criteria:

* Patient has relapsed/progressed or is refractory for multiple myeloma following 1 previous line of therapy
* Measurable secretory multiple myeloma: measurable disease for secretory multiple myeloma is defined by at least one of the following measurements: serum monoclonal protein greater than or equal to 1 g/dl (\> 10 gm/l) \[10g/l\], urine M-protein of ≥200 mg/24 hours
* Patient has a Karnofsky performance status of ≥ 60
* Patient has a life expectancy estimated at screening of at least 6 months
* Patient fulfills defined pretreatment laboratory requirements at and within 14 days before baseline

Exclusion Criteria:

* Patient received more than 1 previous line of therapy for multiple myeloma
* Patient has known allergy or hypersensitivity to bortezomib, Dexamethasone and/or Cyclophosphamide and/or Lenalidomide or any of the constituent compounds such as boron, mannitol, or lactose
* Patient has oligosecretory or non-secretory multiple myeloma
* Patient received nitrosoureas or any other chemotherapy (including thalidomide), clarithromycin, interferon within 6 weeks before enrolment. Note: subjects can have received thalidomide or interferon as maintenance therapy, according to local standard of care
* Patient received corticosteroids (\> 10 mg/day prednisone or equivalent) within 3 weeks before enrolment. Note: subjects can have received steroids (dexamethasone or equivalent) as maintenance therapy according to local standard of care. In addition, subjects can have received a cumulative dose of up to 160 mg of dexamethasone or equivalent as emergency therapy within 3 weeks prior to study entry.