• Assessment of safety, toxicity and tolerability Estimation of the proportion of renal-compromised multiple Myeloma patients who have received at least 1 prior line of therapy who respond to bortezomib treatment [ Time Frame: efficacy and safety will be assessed each cycle and the last measurement will take place at 30-45 days after the last dose of Velcade. ] [ Designated as safety issue: Yes ]
  

• Best Response; Time to Progression; Duration of Response; Renal Function; Quality of Life; [ Time Frame: every three months for up to two years after the last dose of Velcade ] [ Designated as safety issue: No ]
  

Limited Kidney function is a condition that can result from high cancer burden on the body and can result in increased toxicity of anti-cancer treatment. The rationale for this open label study is to assess prospectively the safety and efficacy of bortezomib in renal-compromised patients with multiple myeloma. The study hypothesis is that the study drug will be safe and effective in treatment of previously-treated multiple myeloma patients with limited kidney function. The efficacy of bortezomib will be assessed by measuring serum M-protein and urine M-protein (monoclonal paraprotein) levels at the beginning of each treatment cycle before the injection of the study drug. Safety will be assessed by the monitoring of adverse events, physical examinations (including peripheral neurological examinations), vital sign measurements, hematology and serum biochemistry tests from the time the patient signs the informed consent form until the final /early termination visit. Patients will be treated with bortezomib for up to eight 21-day treatment cycles

Patients enrolled in the study will be treated with bortezomib for up to eight 21-day treatment cycles. The patients will receive intravenous injections of bortezomib on Days 1, 4, 8, and 11. The starting dose of bortezomib, which is also the standard dose in myeloma patients, will be 1.3 mg/m2.