SUMMARY  

• Daratumumab is a human IgG monoclonal antibody which is very similar in size to endogenous monoclonal immunoglobulin (M-protein). As a result, if daratumumab is present in a patient's serum, a daratumumab band may be detected on immunofixation electrophoresis (IFE) gels and misinterpreted as endogenous M-protein.¹
• International Myeloma Working Group (IMWG) criteria to assess treatment response includes assessment of M-protein by IFE.² Misinterpretation of serum protein electrophoresis (SPE) or IFE assays can result in an incorrect determination of complete response and impact an accurate assessment of patient prognosis.³
• Mitigation of daratumumab interference with IFE has been demonstrated using gel-shift assays with a daratumumab-specific anti-idiotype antibody.¹

PRODUCT LABELING

Please refer to the following sections of the Full Prescribing Information which are relevant to your inquiry: WARNINGS AND PRECAUTIONS, DRUG INTERACTIONS.

Interference with Determination of Complete Response

Daratumumab is a human IgG kappa monoclonal antibody that can be detected on both the SPE and IFE assays used for the clinical monitoring of endogenous M-protein (see Drug Interactions [7.1]). This interference can impact the determination of complete response and of disease progression in some DARZALEX and DARZALEX FASPRO-treated patients with IgG kappa myeloma protein.^4,5

Interference with Serum Protein Electrophoresis and Immunofixation Tests

Daratumumab may be detected on SPE and IFE assays used for monitoring disease M-protein. This can lead to false positive SPE and IFE assay results for patients with IgG kappa myeloma protein impacting initial assessment of complete responses by IMWG criteria. In DARZALEX and DARZALEX FASPRO-treated patients with persistent very good partial response, where daratumumab interference is suspected, consider using a Food and Drug administration (FDA)-approved daratumumab-specific IFE assay to distinguish daratumumab from any remaining endogenous M-protein in the patient’s serum, to facilitate determination of a complete response.^4,5

BACKGROUND/GUIDELINES

HYDRASHIFT 2/4 DARATUMUMAB immunofixation ASSAY

In January 2018, Sebia received 510(k) clearance from the United States FDA for its HYDRASHIFT 2/4 daratumumab assay, intended to be used with Sebia’s Hydragel immunofixation test, for the qualitative detection of M-proteins in human serum by IFE.⁶ The Sebia HYDRASHIFT 2/4 daratumumab in vitro (IVD) can be used to assess response in daratumumab-treated patients with IgG-kappa multiple myeloma.⁷

additional INFORMATION

For more information about the HYDRASHIFT 2/4 daratumumab assay, including how to order the test, sample requirements, turn-around-time, CPT codes, assay methodology, description of the clinical significance and other FAQs, please contact Sebia customer service at 1-770-446-3707.

Literature Search

A literature search of MEDLINE^®, Embase^®, BIOSIS Previews^®, and Derwent Drug File databases (and/or other resources, including internal/external databases) was conducted on 19 June 2024.