- Patients with measurable disease, defined by any of the following: serum monoclonal protein >= 1.0 g by protein electrophoresis; > 200 mg of monoclonal protein in the urine on 24-hour electrophoresis; serum immunoglobulin free light chain >= 10 mg/dL AND abnormal serum immunoglobulin kappa to lambda free light chain ratio; or monoclonal bone marrow plasmacytosis >= 30% (evaluable disease)