MYRE is a phase III multicentric controlled national clinical trial conducted in patients with multiple myeloma and renal failure related to myeloma cast nephropathy (MCN). Its aims are to assess (1) the efficacy of bortezomib plus dexamethasone (BD), compared with cyclophosphamide, plus bortezomib and dexamethasone (C-BD) in patients with inaugural MCN not requiring hemodialysis; and (2) in patients with inaugural severe renal failure secondary to biopsy-proven MCN and requiring hemodialysis that of an intensive hemodialysis regimen using either a dialyser with very high permeability to proteins (TheraliteTM) or a conventional high-flux dialyser, while receiving chemotherapy with BD.