Table 6.

Additional response criteria for specific disease stages³⁰

Category	Criteria
Definition of relapsed myeloma and relapsed and refractory myeloma	Relapsed myeloma: at least one prior regimen, and not meeting criteria for relapsed and refractory myeloma
	Relapsed and refractory myeloma: relapse of disease while on salvage therapy, or progression within 60 days of most recent therapy
Minor response (MR) in patients with relapsed refractory myeloma	≥25% but <49% reduction of serum M protein and reduction in 24 h urine M protein by 50–89%, which still exceeds 200 mg per 24 h
	In addition to the above criteria, if present at baseline, 25–49% reduction in the size of soft tissue plasmacytomas is also required
	No increase in size or number of lytic bone lesions (development of compression fracture does not exclude response)
Progression to active myeloma in patients with smoldering myeloma	Evidence of progression based on the IMWG criteria for progressive disease in myeloma (Table 5) and
	Any one or more of the following felt related to the underlying clonal plasma cell proliferative disorder
	Development of new soft tissue plasmacytomas or bone lesions
	Hypercalcemia (>11 mg/100 ml)
	Decrease in hemoglobin of ≥2 g/100 ml
	Serum creatinine level ≥2 mg/100 ml

Abbreviation: IMWG, International Myeloma Working Group. Adapted with permission from Anderson et al.³⁰