Elevated programmed cell death-1 protein/ligand (PD-1/PD-L1) and variants are associated with susceptibility to multiple myeloma: a case-control study in the Chinese cohort

Multiple myeloma (MM) is a malignant disorder characterised by progressive immune dysregulation. The importance of programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) in MM has been documented in various populations, but studies have been limited to the Chinese cohort. In the present study, we examined the role of PD-1/PDL-1 in large cohorts of Chinese patients with MM and healthy controls to reveal a possible association with MM. Three hundred thirty-four MM patients and 202 healthy age-sex-matched subjects were enrolled in the present study. Serum levels of PD-1 and PD-L1 were quantified by ELISA. Percentages of T cells (CD4+ and CD8+ T cells) expressing PD-1 receptor were assessed by flow cytometry. Variants in PD-L1 (rs4143815) and PD-1 gene (rs2227981, rs2227982, rs7421861 and rs11568821) were genotyped by PCR-RFLP method. Patients with multiple myeloma had higher levels of PD-1 and PDL-1 than healthy controls, indicating an important role for programmed cell death protein-1 and its ligand in the pathogenesis of MM. T cells expressing PD-1 receptors were also significantly higher in MM patients than in controls. Mutants for PD-L1 (rs4143815) and PD-1 (rs2227982 and rs7421861) polymorphisms were significantly more common in MM than in HC. Interestingly, PD-L1 (rs4143815) and PD-1 (rs2227982 and rs7421861) variants were linked to higher sPD-L1 and sPD-1 levels, respectively. PD-1/PD-L1 levels are significantly higher in MM patients and could be a promising biomarker for the disease. Variants of PD-L1 and PD-1 are linked to serum-soluble proteins and are associated with the development of MM.

Microparticles and PD1 interplay added a prognostic impact in treatment outcomes of patients with multiple myeloma

Although multiple myeloma (MM) is still considered as an incurable disease by current standards, the development of several combination therapies, and immunotherapy approaches has raised the hope towards transforming MM into an indolent, chronic disease, and possibly achieving a cure. We tried to shed light on the expression of PD1 and different Microparticles (MPs) in MM and their interplay as a mechanism of resistance to standardized treatments, in addition, find their associations with prognostic factors of symptomatic MM. Thirty patients with newly diagnosed and chemotherapy naïve active MM, along with 19 healthy participants of comparable age and sex were recruited, after diagnosis of MM; blood samples were collected from both patients and controls for flow cytometric detection of CD4+, CD8+, CD4+PD1+, and CD8+PD1+T cells, total MPs, CD138+ MPs, and platelet MPs. MM patients had statistically significant higher levels of TMPs, CD138+ MPs compared to their controls, while PMPs exhibited no significant difference between both groups. Statistically significant higher percentages of CD8+, PD1CD8+, PD1CD4+T cells were detected in patients compared to controls, while the latter group had a significantly higher percentage of CD4+T cells than MM patients, patients who did not achieve complete response, had significantly higher percentages of PMPs, CD138+MPs, PD1+CD8+, PD1+CD4+, and CD8+T cells (cutoff values = 61, 10.6, 13.5, 11.3 and 20.1 respectively), (p-values = 0.002, 0.003, 0.017, 0.001 and 0.008 respectively). Microparticles and PD1 expressions were associated with proliferative potential and resistance to Bortezomib-based treatments, our results suggested that they played a crucial role in myeloma progression.

Investigational agents in immunotherapy: a new horizon for the treatment of multiple myeloma

The treatment of multiple myeloma (MM) has gone through several major advances over the last 5 years with the introduction of next generation proteasome inhibitors (PI; carfilzomib, ixazomib) and immunomodulatory derivatives (IMiD; pomalidomide), with these new agents having a substantial impact on patient outcome. However, despite these advances, MM remains a highly resistant disease given its propensity for clonal heterogeneity and its complex interaction with the surrounding bone marrow microenvironment. Almost all patients eventually relapse despite therapeutic responses to a PI, IMiD or both. With the regulatory approval of the monoclonal antibodies Daratumumab and Elotuzumab in 2015, impressive and durable responses are being observed, even in heavily pre-treated patients who have exhausted other therapeutic options, suggesting immunological approaches in this setting have real merit. This review will focus on newer monoclonal antibodies and chimeric-antigen receptor (CAR) T cell strategies currently under investigation and in various stages of clinical development.

How to Think About Risk in Myeloma

An integral part of myeloma therapy is risk stratification of newly diagnosed patients. This method involves a combination of staging and genetic risk assessment. Although survival has dramatically improved for patients with genetically defined, standard-risk myeloma, those with high-risk disease remain a therapeutic challenge. Current treatment approaches might include the use of combination therapy for induction and maintenance. Future approaches are expected to involve drugs that are "risk agnostic," such as monoclonal antibodies and immunotherapy.

Is immunotherapy here to stay in multiple myeloma?

Immune escape and impaired immune surveillance have been identified as emerging hallmarks of cancer.1 Multiple myeloma represents a genuine example of disrupted immune surveillance characterized by: impaired antibody production, deregulation of the T and natural killer cell compartment, disruption of antigen presentation machinery, upregulation of inhibitory surface ligands, and recruitment of immunosuppressive cells. Although the potential value of immunotherapeutic interventions had a clear antecedent in the graft-versus-myeloma effect induced by allogeneic stem cell transplant and donor lymphocyte infusions, it is only recently that this field has faced a real revolution. In this review we discuss the current results obtained with immune approaches in patients with multiple myeloma that have placed this disease under the scope of immuno-oncology, bringing new therapeutic opportunities for the treatment of multiple myeloma patients.

Targeting the PD-1/PD-L1 axis in multiple myeloma: a dream or a reality?

The programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway is a negative regulator of immune activation that is upregulated in multiple myeloma and is a critical component of the immunosuppressive tumor microenvironment. Expression is increased in advanced disease and in the presence of bone marrow stromal cells. PD-1/PD-L1 blockade is associated with tumor regression in several malignancies, but single-agent activity is limited in myeloma patients. Combination therapy involving strategies to expand myeloma-specific T cells and T-cell activation via PD-1/PD-L1 blockade are currently being explored.

MMSA-1 expression pattern in multiple myeloma and its clinical significance

Multiple myeloma-associated antigen-1 (MMSA-1) is a novel multiple myeloma (MM)-associated antigen which has been recently identified. Herein, we have tried to examine its clinical significance by studying the relationship between its expression and selected clinicopathological features. We extracted mononuclear cells from the bone marrow of MM patients and healthy donors and compared the MMSA-1 expression by RT-PCR and Western blot analysis. In addition, we also analyzed MMSA-1 expression in patients that were grouped based on selected clinical parameters. Moreover, the impact of MMSA-1 on patients' survival was also explored. MMSA-1 mRNA and protein were significantly upregulated in MM patients in comparison with healthy donors. Moreover, among the newly diagnosed and relapsed/refractory patients, the MMSA-1 expression was higher in relapsed/refractory patients. In addition, MMSA-1 mRNA expression not only showed significantly higher correlation with clinical parameters such as age, Durie and Salmon stage, bone lesion condition, albumin, creatinine and lactate dehydrogenase but also has a close relationship with myeloma bone disease-related cytokines, genetic abnormalities and treatment response. Multivariate COX analysis predicted MMSA-1 and LDH levels to be independently associated with a poor progression-free survival and overall survival in myeloma patients. Our findings provide initial proof of concept that MMSA-1 is a potent gene that is specifically expressed in MM patients and could be a feasible biomarker and independent prognostic factor.

The antigenic landscape of multiple myeloma: mass spectrometry (re)defines targets for T-cell-based immunotherapy

Direct analysis of HLA-presented antigens by mass spectrometry provides a comprehensive view on the antigenic landscape of different tissues/malignancies and enables the identification of novel, pathophysiologically relevant T-cell epitopes. Here, we present a systematic and comparative study of the HLA class I and II presented, nonmutant antigenome of multiple myeloma (MM). Quantification of HLA surface expression revealed elevated HLA molecule counts on malignant plasma cells compared with normal B cells, excluding relevant HLA downregulation in MM. Analyzing the presentation of established myeloma-associated T-cell antigens on the HLA ligandome level, we found a substantial proportion of antigens to be only infrequently presented on primary myelomas or to display suboptimal degrees of myeloma specificity. However, unsupervised analysis of our extensive HLA ligand data set delineated a panel of 58 highly specific myeloma-associated antigens (including multiple myeloma SET domain containing protein) which are characterized by frequent and exclusive presentation on myeloma samples. Functional characterization of these target antigens revealed peptide-specific, preexisting CD8(+) T-cell responses exclusively in myeloma patients, which is indicative of pathophysiological relevance. Furthermore, in vitro priming experiments revealed that peptide-specific T-cell responses can be induced in response-naive myeloma patients. Together, our results serve to guide antigen selection for T-cell-based immunotherapy of MM.

The comprehensive clinical management of multiple myeloma and related-plasma cell disorders

Whilst we think of multiple myeloma and related plasma cell disorders as incurable to date, never before has there been such hope and enthusiasm about advances in the research and treatment of these various diseases. Translational research is very much at the forefront of progress for further refining targeted therapies and continuing to improve clinical efficacy. Whilst some of these advances in the last decade have been truly dramatic in their scope and timing, it is also worth noting that relatively incremental changes have favorably impacted on patient outcome, and this comprehensive clinical management review captures these accordingly. We hope therefore that this concise overview will give readers, be they specialist hemato-oncologists, or other providers and researchers in the field, an enlightening insight into the exciting future of therapeutic opportunities, as well as a practical 'hands on' approach.