Table 1.

IMWG Criteria for treatment initiation in Multiple Myeloma [3]

(A) Classic CRAB criteria
Evidence of end-organ damage that can be attributed to the underlying plasma cell proliferative disorder, specifically	Hypercalcemia: serum calcium > 0.25 mmol/L (>1 mg/dL) higher than the upper limit of normal or >2.75 mmol/L (>11 mg/dL)
	Renal insufficiency: creatinine clearance <40 mL per minute or serum creatinine > 177 µmol/L (>2 mg/dL)
	Anemia: hemoglobin value of >20 g/L below the lowest limit of normal, or a hemoglobin value < 100 g/L
	Bone lesions: one or more osteolytic lesion on skeletal radiography, CT, or PET/CT. If bone marrow has <10% clonal plasma cells, more than one bone lesion is required to distinguish from solitary plasmacytoma with minimal marrow involvement
(B) “SLIM-CRAB” criteria defining “early myeloma” (in the absence of A criteria)
Any one or more of the following biomarkers of malignancy	60% or greater clonal plasma cells on bone marrow examination
	Serum involved/uninvolved free light chain ratio of 100 or greater, provided the absolute level of the involved light chain is at least 100 mg/L (a patient’s “involved” free light chain—either kappa or lambda—is the one that is above the normal reference range; the “uninvolved” free light chain is the one that is typically in, or below, the normal range)
	More than one focal lesion on MRI that is at least 5 mm or greater in size