Evaluation of iMS-IP assay for the detection and typing of monoclonal immunoglobulins.

Evaluation of ims-IP assay for the detection and typing of monoclonal immunoglobulins by mass spectrometry.

Impact of Next-Generation Flow (NGF) Minimal Residual Disease (MRD) Monitoring in Multiple Myeloma (MM): Results from the Pethema/GEM2012 Trial

Evaluation of the Cepheid GeneXpert BCR-ABL Assay

<div>AbstractPurpose:<p>We investigated both the clinical utilities and the prognostic impacts of the clonotypic peptide mass spectrometry (MS)-EasyM, a blood-based minimal residual disease (MRD) monitoring protocol in multiple myeloma.</p>Experimental Design:<p>A total of 447 sequential serum samples from 56 patients with multiple myeloma were analyzed using EasyM. Patient-specific M-protein peptides were sequenced from diagnostic samples; sequential samples were quantified by EasyM to monitor the M-protein. The performance of EasyM was compared with serum immunofixation electrophoresis (IFE), bone marrow multiparameter flow cytometry (MFC), and next-generation flow cytometry (NGF) detection. The optimal balance of EasyM sensitivity/specificity versus NGF (10<sup>−5</sup> sensitivity) was determined and the prognostic impact of MS-MRD status was investigated.</p>Results:<p>Of the 447 serum samples detected and measured by EasyM, 397, 126, and 92 had time-matching results for comparison with serum IFE, MFC-MRD, and NGF-MRD, respectively. Using a dotp >0.9 as the MS-MRD positive, sensitivity was 99.6% versus IFE and 100.0% versus MFC and NGF. Using an MS negative cutoff informed by ROC analysis (<1.86% of that at diagnosis), EasyM sensitivity remained high versus IFE (88.3%), MFC (85.1%), and NGF (93.2%), whereas specificity increased to 90.4%, 55.8%, and 93.2%, respectively. In the multivariate analysis, older diagnostic age was an independent predictor for progression-free survival [PFS; high risk (HR), 3.15; 1.26–7.86], the best MS-MRD status (MS-MRD negative) was independent predictor for both PFS (HR, 0.25; 0.12–0.52) and overall survival (HR, 0.16; 0.06–0.40).</p>Conclusions:<p>EasyM is a highly sensitive and minimal invasive method of MRD monitoring in multiple myeloma; MS-MRD had significant predictive ability for survival outcomes.</p></div>

<div>AbstractPurpose:<p>We investigated both the clinical utilities and the prognostic impacts of the clonotypic peptide mass spectrometry (MS)-EasyM, a blood-based minimal residual disease (MRD) monitoring protocol in multiple myeloma.</p>Experimental Design:<p>A total of 447 sequential serum samples from 56 patients with multiple myeloma were analyzed using EasyM. Patient-specific M-protein peptides were sequenced from diagnostic samples; sequential samples were quantified by EasyM to monitor the M-protein. The performance of EasyM was compared with serum immunofixation electrophoresis (IFE), bone marrow multiparameter flow cytometry (MFC), and next-generation flow cytometry (NGF) detection. The optimal balance of EasyM sensitivity/specificity versus NGF (10<sup>−5</sup> sensitivity) was determined and the prognostic impact of MS-MRD status was investigated.</p>Results:<p>Of the 447 serum samples detected and measured by EasyM, 397, 126, and 92 had time-matching results for comparison with serum IFE, MFC-MRD, and NGF-MRD, respectively. Using a dotp >0.9 as the MS-MRD positive, sensitivity was 99.6% versus IFE and 100.0% versus MFC and NGF. Using an MS negative cutoff informed by ROC analysis (<1.86% of that at diagnosis), EasyM sensitivity remained high versus IFE (88.3%), MFC (85.1%), and NGF (93.2%), whereas specificity increased to 90.4%, 55.8%, and 93.2%, respectively. In the multivariate analysis, older diagnostic age was an independent predictor for progression-free survival [PFS; high risk (HR), 3.15; 1.26–7.86], the best MS-MRD status (MS-MRD negative) was independent predictor for both PFS (HR, 0.25; 0.12–0.52) and overall survival (HR, 0.16; 0.06–0.40).</p>Conclusions:<p>EasyM is a highly sensitive and minimal invasive method of MRD monitoring in multiple myeloma; MS-MRD had significant predictive ability for survival outcomes.</p></div>

Purpose:We investigated both the clinical utilities and the prognostic impacts of the clonotypic peptide mass spectrometry (MS)-EasyM, a blood-based minimal residual disease (MRD) monitoring protocol in multiple myeloma.Experimental Design:A total of 447 sequential serum samples from 56 patients with multiple myeloma were analyzed using EasyM. Patient-specific M-protein peptides were sequenced from diagnostic samples; sequential samples were quantified by EasyM to monitor the M-protein. The performance of EasyM was compared with serum immunofixation electrophoresis (IFE), bone marrow multiparameter flow cytometry (MFC), and next-generation flow cytometry (NGF) detection. The optimal balance of EasyM sensitivity/specificity versus NGF (10−5 sensitivity) was determined and the prognostic impact of MS-MRD status was investigated.Results:Of the 447 serum samples detected and measured by EasyM, 397, 126, and 92 had time-matching results for comparison with serum IFE, MFC-MRD, and NGF-MRD, respectively. Using a dotp >0.9 as the MS-MRD positive, sensitivity was 99.6% versus IFE and 100.0% versus MFC and NGF. Using an MS negative cutoff informed by ROC analysis (<1.86% of that at diagnosis), EasyM sensitivity remained high versus IFE (88.3%), MFC (85.1%), and NGF (93.2%), whereas specificity increased to 90.4%, 55.8%, and 93.2%, respectively. In the multivariate analysis, older diagnostic age was an independent predictor for progression-free survival [PFS; high risk (HR), 3.15; 1.26–7.86], the best MS-MRD status (MS-MRD negative) was independent predictor for both PFS (HR, 0.25; 0.12–0.52) and overall survival (HR, 0.16; 0.06–0.40).Conclusions:EasyM is a highly sensitive and minimal invasive method of MRD monitoring in multiple myeloma; MS-MRD had significant predictive ability for survival outcomes.

Impact of Normalized Free Light Chain Ratio for Assessment of Monoclonal Protein in Patients with Light Chain Only and Oligosecretory Myeloma

A Pre-Existing Plasma Cell Disorder Occurs in Most Patients with Multiple Myeloma.

NGS-Based Immunoglobulin Gene Sequencing for Diagnosis and MRD Monitoring of Multiple Myeloma

Understanding multiple myeloma

Background: Treatment options for multiple myeloma (MM) patients have expanded and improved outcomes. Autologous stem cell transplantation, immunomodulatory drugs (IMiDs), monoclonal antibodies, and CAR-T cell therapy have direct and indirect immune modulating effects that favor patient responses. However, the majority of patients still relapse due to minimal residual disease (MRD). Current flow cytometry methods that monitor MRD and bone marrow immune cell populations require large cell numbers to achieve assay sensitivity. New approaches are needed to better capture high-resolution data given the limited recovery of bone marrow specimens. Here, we describe the simultaneous monitoring of immune cell subsets in the bone marrow and MRD using a single antibody panel and the Cytek Aurora full-spectrum flow cytometry platform. In a Phase 1/2 study to evaluate an off-the-shelf, allogeneic human placental-derived NK cell product in newly diagnosed MM, this method enables correlative analysis of MRD state with immune profiling. Methods: Bone marrow aspirate (BMA) from 5 patients with newly diagnosed MM following induction therapy were collected for MRD assessment in parallel using next-generation sequencing (NGS) and MRD evaluation by flow cytometry. BMA was lysed of red blood cells and 2x107 cells were stained using TCRγδ, CD16, CD8, CD33, CD117, CD11c, CD3, CD19, CD1c, CD45, CD38, CD14, HLA-DR, CD138, CD141, CD34, CD25, CRTH2, CD56, CD303, CD4, and CD127. Cells were acquired on a Cytek Aurora 4 laser system followed by data analysis using FlowJo software. MRD threshold of 10-5 was used for positivity for both modalities of testing. Results: The 22-parameter panel resolved the majority of immune cell subpopulations present in the bone marrow and peripheral blood including granulocytes, B cells, plasma cells, monocytes, MDSCs, plasmacytoid and classical dendritic cells, NK cells, and T cells (CD4, CD8, NKT, γδT, Treg). Total plasma cells were identified based upon CD38+CD138+ co-staining. Myeloma cells could be identified based on aberrant expression of CD45, CD19, CD56, and CD117. Of the five patients evaluated, one patient was MRD negative by NGS and flow cytometry with no detectable cells. One patient was MRD negative by NGS (0.7x10-5) but positive by flow cytometry (1.53x10-5). The three remaining patients were positive by NGS (6.32x10-4, 7.51x10-4, and 4.78x10-4) and flow cytometry (2.46x10-4, 5.37x10-4, and 9.74x10-4). Conclusion: Utilizing full-spectrum flow cytometry provides streamlined monitoring of MRD while capturing BMA-associated immune cell populations. Compared to validated measures of MRD testing by NGS, our flow cytometry approach provides comparable results while profiling myeloid and lymphoid cell subpopulations, which enables correlative analyses of underlying pathophysiological activities. Citation Format: William van der Touw, Bhavani Stout, James McCauley, Tanel Mahlakõiv, Robert Hariri, Xiaokui Zhang. Simultaneous monitoring of immune cell subsets and minimal residual disease in bone marrow aspirate using full-spectrum flow cytometry [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 513.

Targeted Mass Spectrometry-Based Serum M-Protein Monitoring for Early Relapse Detection

Prognostic Implications of Serum Monoclonal Protein Positivity By Mass-Fix in Bone Marrow Minimal Residual Disease Negative (MRD-) Patients with Multiple Myeloma

Comparison Of Hevylite™ Assay and Plasma Cell Immunophenotyping For Response Evaluation and Residual Disease Characterisation In IgA Myeloma

Minimal Residual Disease in Myeloma: Are We There Yet?