Definitions of disease relapse
| Disease progression |
| Increase of 25% from lowest response value in any of the following |
| Serum M-component (absolute increase must be ≥0.5 g/dL) and/or |
| Urine M-component (absolute increase must be ≥200 mg/24 h) and/or |
| In patients without measurable serum or urine M protein levels: |
| Difference between involved and uninvolved free light chain values (absolute increase must be >10 mg/dL) |
| In patients without measurable serum, urine M protein, or free light chain values, bone marrow plasma cell percentage (absolute percentage must be ≥10%) |
| Definite development of new bone lesions or soft tissue plasmacytomas or definite increase in size of existing bone lesions or soft tissue plasmacytomas |
| Development of hypercalcemia (corrected serum calcium >11.5 mg/dL) that can be attributed solely to the plasma cell proliferative disorder |
| Significant paraprotein relapse |
| Doubling of the M-component in 2 consecutive measurements separated ≤2 months |
| Increase in the absolute level of serum M protein by ≥1 g/dL |
| Increase in urine M protein by ≥500 mg/24 h |
| Increase in involved free light chain level by ≥20 mg/dL (plus an abnormal FLC ratio) in 2 consecutive measurements separated by ≤2 months |
| Disease progression |
| Increase of 25% from lowest response value in any of the following |
| Serum M-component (absolute increase must be ≥0.5 g/dL) and/or |
| Urine M-component (absolute increase must be ≥200 mg/24 h) and/or |
| In patients without measurable serum or urine M protein levels: |
| Difference between involved and uninvolved free light chain values (absolute increase must be >10 mg/dL) |
| In patients without measurable serum, urine M protein, or free light chain values, bone marrow plasma cell percentage (absolute percentage must be ≥10%) |
| Definite development of new bone lesions or soft tissue plasmacytomas or definite increase in size of existing bone lesions or soft tissue plasmacytomas |
| Development of hypercalcemia (corrected serum calcium >11.5 mg/dL) that can be attributed solely to the plasma cell proliferative disorder |
| Significant paraprotein relapse |
| Doubling of the M-component in 2 consecutive measurements separated ≤2 months |
| Increase in the absolute level of serum M protein by ≥1 g/dL |
| Increase in urine M protein by ≥500 mg/24 h |
| Increase in involved free light chain level by ≥20 mg/dL (plus an abnormal FLC ratio) in 2 consecutive measurements separated by ≤2 months |
Adapted from Rajkumar et al.65