- Subjects must have measurable disease on study entry. Measurable disease may include quantifiable or detectable levels of serum or urine paraprotein. For patients with minimally secretory disease or non-secretory myeloma on study entry, serum free lambda or kappa light chain levels or the serum free light chain ratio may be measured and used for disease monitoring if abnormal. Likewise, for patients with IgA MM in which serum protein electrophoresis is deemed unreliable due to co-migration of normal serum proteins with the paraprotein, elevated total serum IgA levels may be considered measurable disease.