Which response categories does this cover?

It classifies sCR (stringent complete response), CR, VGPR, PR, MR, SD, and PD using the IMWG 2016 uniform criteria for measurable disease. The highest category whose thresholds are met is reported.

What defines a complete response?

CR requires negative serum and urine immunofixation, disappearance of any soft-tissue plasmacytomas, and bone marrow plasma cells below 5%. Stringent CR adds a normal serum free light-chain ratio and absence of clonal plasma cells.

How is VGPR distinguished from PR?

VGPR requires at least a 90% reduction in serum M-protein with urine M-protein below 100 mg per 24 hours, or M-protein detectable only by immunofixation. PR requires only a 50% serum reduction with a 90% urine reduction or urine below 200 mg per 24 hours.

When is progressive disease flagged?

The tool flags PD when serum or urine M-protein rises by 25% or more from the lowest response value. PD is checked before all response categories because it overrides them.

Does this assess minimal residual disease?

No. MRD-negative status requires flow cytometry or next-generation sequencing on marrow and is not modelled here. This calculator handles serum and urine M-protein based response only.

Haematologic Response Criteria Calculator (CR/VGPR/PR)

The International Myeloma Working Group (IMWG) response criteria give haematologists a uniform language for how well a treatment is working in multiple myeloma. This calculator applies the 2016 criteria to your laboratory values and returns the matching response category.

How it works

The criteria are evaluated in a strict hierarchy. Progressive disease is checked first, then responses from most to least stringent:

PD   ≥25% rise in serum or urine M-protein from nadir
sCR  CR + normal free light-chain ratio + no clonal plasma cells
CR   serum + urine immunofixation negative AND marrow plasma cells <5%
VGPR ≥90% serum reduction AND urine M-protein <100 mg/24h
PR   ≥50% serum reduction AND (≥90% urine reduction OR urine <200 mg/24h)
MR   25–49% serum reduction (relapsed/refractory setting)
SD   none of the above met

The percentage reduction is computed as (baseline − post) / baseline × 100 for both serum and urine fractions.

Example and notes

A patient with baseline serum M-protein of 4.0 g/dL falling to 0.3 g/dL is a 93% reduction; with urine M-protein dropping to 40 mg/24h this reaches VGPR. If serum and urine immunofixation then turn negative and marrow plasma cells fall below 5%, the response becomes CR. Note that this tool covers measurable M-protein disease only; light-chain-only and oligosecretory myeloma use serum free light-chain criteria that are not modelled here.