Detecting monoclonal immunoglobulins in human serum using mass spectrometry.

We assessed the ability of a mass spectrometry-based technique, called monoclonal immunoglobulin rapid accurate mass measurement (miRAMM), to extend the analytical range of M-protein detection in serum samples obtained from myeloma patients in stringent complete response (sCR) post-autologous stem cell transplant (ASCT). To aid the M-protein detection post ASCT, the accurate molecular mass of the M-protein light chain at diagnosis was determined in all patients (N=30) and used to positively identify clones in the sCR serum. Day 100 post-ASCT, sCR samples had miRAMM identifiable M-proteins in 81% of patients. Patients who had achieved only a partial remission (PR) pre-ASCT and those with IgG isotypes serum samples had the highest rate of M-protein detection by miRAMM. miRAMM positivity at single time points (day 100, 6 months or 12 months) did not correlate with progression-free survival (PFS). In contrast, sCR patients who did not decrease their miRAMM M-protein intensities in serial measurements had shorter PFS than those whose miRAMM intensities decreased (median 17.9 months vs 51.6 months; P<0.0017). miRAMM M-protein is a more sensitive blood-based test than traditional M-protein tests and could cost effectively aid in serially monitoring complete remission for continue response or biochemical relapse.

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High sensitivity blood-based M-protein detection in sCR patients with multiple myeloma

Quantitative analysis of immunoglobulin subclasses and subclass specific glycosylation by LC-MS-MRM in liver disease.

Secondary immunodeficiencies occur as a consequence of various diseases, including hematological malignancies, and the use of pharmacological therapies, such as immunosuppressive, anti-inflammatory, and biological drugs. Infections are the main cause of morbidity and mortality in multiple myeloma (MM) and chronic lymphocytic leukemia (CLL) patients. Recent advances in treatment have prolonged the duration of remission and the time between relapse phases in MM and CLL patients. However, managing multiple relapses and the use of salvage therapies can lead to cumulative immunosuppression and a higher risk of infections. The pathogenesis of immune deficiency secondary to lymphoproliferative malignancy is multifactorial including disease- and treatment-related factors. Supportive treatment, including early vaccination, anti-infective prophylaxis, and replacement immunoglobulin, plays a key role in preventing infections in MM and CLL. This article provides an overview of the basic immunology necessary to understand the pathogenesis of secondary immunodeficiency and the infectious complications in MM and CLL. We also discuss the evidence supporting the role of prophylactic replacement immunoglobulin treatment in patients with antibody failure secondary to MM and CLL and the indications for its use. Copyright © 2016 John Wiley & Sons, Ltd.

Secondary immunodeficiency in lymphoproliferative malignancies.

BACKGROUND: Analytically sensitive techniques for measuring minimal residual disease (MRD) in multiple myeloma (MM) currently require invasive and costly bone marrow aspiration. These methods include immunohistochemistry (IHC), flow cytometry, quantitative PCR, and next-generation sequencing. An ideal MM MRD test would be a serum-based test sensitive enough to detect low concentrations of Ig secreted from multifocal lesions.

METHODS: Patient serum with abundant M-protein before treatment was separated on a 1-dimensional SDS-PAGE gel, and the Ig light-chain (LC) band was excised, trypsin digested, and analyzed on a Q Exactive mass spectrometer by LC-MS/MS. We used the peptide's abundance and sequence to identify tryptic peptides that mapped to complementary determining regions of Ig LCs. The clonotypic target tryptic peptides were used to monitor MRD in subsequent serum samples with prior affinity enrichment.

RESULTS: Sixty-two patients were tested, 20 with no detectable disease by IHC and 42 with no detectable disease by 6-color flow cytometry. A target peptide that could be monitored was identified in 57 patients (91%). Of these 57, detectable disease by LC-MS/MS was found in 52 (91%).

CONCLUSIONS: The ability to use LC-MS/MS to measure disease in patients who are negative by bone marrow–based methodologies indicates that a serum-based approach has more analytical sensitivity and may be useful for measuring deeper responses to MM treatment. The method requires no bone marrow aspiration.

Clonotypic Light Chain Peptides Identified for Monitoring Minimal Residual Disease in Multiple Myeloma Without Bone Marrow Aspiration

Purpose
Quantitative mass spectrometry assays for immunoglobulins (Igs) are compared with existing clinical methods in samples from patients with plasma cell dyscrasias, e.g. multiple myeloma.

/pdf/quantification-of-peptides-from-immunoglobulin-constant-and-556ihijdws.pdf

Quantification of peptides from immunoglobulin constant and variable regions by LC‐MRM MS for assessment of multiple myeloma patients

Multiple myeloma is an incurable disease, although patient survival has increased with the availability of novel agents. Both multiple myeloma and its therapies often affect the renal, immune, skeletal, hematologic, and nervous systems. The resulting organ dysfunctions often impair the quality of life of affected patients, complicate and limit subsequent therapies, and may result in significant mortality. Research on the treatment of complications of multiple myeloma has been limited; hence, preventative and management strategies for patients with these complications are heterogeneous and often based on anecdotal experience. In this paper, we review the effects of myeloma and the novel therapies on organ systems and suggest management strategies.

https://downloads.hindawi.com/journals/ah/2010/343089.pdf

State-of-the-Art Management of Complications of Myeloma and Its Treatment.

Targeted immunotherapy has arisen over the past decade to the forefront of cancer care. Notably, targeted therapies such as antibody-drug conjugates (ADCs) are becoming more recognized for a novel approach in cancer treatment. The mechanism of action of ADCs incorporates a monoclonal antibody portion directed against the tumor cell antigen and attached to the tumoricidal portion via chemical linkage. The binding of the monoclonal antibody portion allows for tumor cell internalization of the ADC and precise release of the toxic payload within the cancer cell. Multiple myeloma (MM) is an incurable cancer for which belantamab mafodotin was the first-in-class ADC to achieve United States Food and Drug Administration (FDA) approval for treatment of this disease. Clinical trials are currently evaluating other ADCs in the treatment of MM. In this review, a look at the current ADCs being tested in MM clinical trials with a focus on those that are more promising and a potential next-in-line for FDA approval for treatment of MM is discussed.

/pdf/antibody-drug-conjugate-therapies-in-multiple-myeloma-whats-v6mgoml3.pdf

Antibody-drug conjugate therapies in multiple myeloma—what’s next on the horizon?

Selinexor is an orally bioavailable selective inhibitor of nuclear export compound that inhibits exportin-1 (XPO1), a novel therapeutic target that is overexpressed in multiple myeloma (MM) and is responsible for the transport of ∼220 nuclear proteins to the cytoplasm, including tumour suppressor proteins. Inhibition of this process has demonstrated substantial antimyeloma activity in preclinical studies, both alone and in combination with established MM therapeutics. Based on a clinical trial programme encompassing multiple combination regimens, selinexor-based therapy has been approved for the treatment of relapsed/refractory MM (RRMM), with selinexor-dexamethasone approved in the later-relapse setting for penta-refractory patients and selinexor-bortezomib-dexamethasone approved for patients who have received ≥1 prior therapy. Here, we provide a comprehensive review of the clinical data on selinexor-based regimens, including recent updates from the 2022 American Society of Hematology annual meeting, and summarise ongoing studies of this novel targeted agent in newly diagnosed MM and RRMM. 

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/jha2.709

Selinexor: Targeting a novel pathway in multiple myeloma

P-006: Real world experience of patients treated with idecabtagene vicleucel: a BCMA-directed chimeric antigen receptor T-cell therapy for multiple myeloma

Monique A. Hartley-Brown

Papers

Quantification of peptides from immunoglobulin constant and variable regions by LC‐MRM MS for assessment of multiple myeloma patients

State-of-the-Art Management of Complications of Myeloma and Its Treatment.

Antibody-drug conjugate therapies in multiple myeloma—what’s next on the horizon?

Selinexor: Targeting a novel pathway in multiple myeloma

P-006: Real world experience of patients treated with idecabtagene vicleucel: a BCMA-directed chimeric antigen receptor T-cell therapy for multiple myeloma