Elotuzumab: the first approved monoclonal antibody for multiple myeloma treatment

Advancements in adoptive CAR immune cell immunotherapy synergistically combined with multimodal approaches for tumor treatment

Adoptive immunotherapy, notably involving chimeric antigen receptor (CAR)-T cells, has obtained Food and Drug Administration (FDA) approval as a treatment for various hematological malignancies, demonstrating promising preclinical efficacy against cancers. However, the intricate and resource-intensive autologous cell processing, encompassing collection, expansion, engineering, isolation, and administration, hamper the efficacy of this therapeutic modality. Furthermore, conventional CAR T therapy is presently confined to addressing solid tumors due to impediments posed by physical barriers, the potential for cytokine release syndrome, and cellular exhaustion induced by the immunosuppressive and heterogeneous tumor microenvironment. Consequently, a strategic integration of adoptive immunotherapy with synergistic multimodal treatments, such as chemotherapy, radiotherapy, and vaccine therapy etc., emerges as a pivotal approach to surmount these inherent challenges. This collaborative strategy holds the key to addressing the limitations delineated above, thereby facilitating the realization of more precise personalized therapies characterized by heightened therapeutic efficacy. Such synergistic strategy not only serves to mitigate the constraints associated with adoptive immunotherapy but also fosters enhanced clinical applicability, thereby advancing the frontiers of therapeutic precision and effectiveness.

Cardiovascular adverse events associated with targeted therapies for multiple myeloma: a pharmacovigilance study

Introduction

Multiple myeloma (MM) is a leading cause of hematopoietic cancer-related mortality, accounting for 20% of deaths. MM-targeted therapies have demonstrated efficacy, and since 2015, the United States Food and Drug Administration (FDA) has approved five targeted drugs. However, their cardiovascular safety has not been comprehensively evaluated.

Objective

This study aimed to investigate the association between MM-targeted therapy and cardiovascular adverse events (AEs).

Methods

Disproportionality analysis was conducted on reports from the FDA AE Reporting System database from 2014 to the second quarter of 2023. Cardiovascular AEs were grouped into nine narrow categories using the Standardized Medical Dictionary for Regulatory Activities Queries (SMQs).

Results

A total of 3,228 cardiovascular AE cases involving MM-targeted therapy were extracted and analyzed. Significant disproportionality was identified for daratumumab, elotuzumab, and isatuximab. Among the nine narrow SMQ categories, the three most reported cardiovascular AEs were cardiomyopathy, cardiac arrhythmias, and embolic and thrombotic events. Noninfectious myocarditis/pericarditis, cardiac arrhythmias, and embolic and thrombotic events exhibited the strongest signal strengths. The cardiovascular AE risk was higher within the first month and gradually decreased thereafter; however, it increased rapidly again after 1 year. This trend was observed for all cardiovascular AEs. The Kaplan-Meier curve and the log-rank test revealed that isatuximab and elotuzumab exhibited a significantly lower probability of cardiovascular AEs than daratumumab (p < 0.001).

Conclusions

MM-targeted therapy is significantly associated with an increased risk of previously unknown cardiovascular AE profiles, with the range and onset differing among various drugs, thereby warranting specific monitoring and appropriate management.

A comprehensive review of the PTEN/PI3K/Akt axis in multiple myeloma: From molecular interactions to potential therapeutic targets

Phosphatase and tensin homolog (PTEN), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (Akt) signaling pathways contribute to the development of several cancers, including multiple myeloma (MM). PTEN is a tumor suppressor that influences the PI3K/Akt/mTOR pathway, which in turn impacts vital cellular processes like growth, survival, and treatment resistance. The current study aims to present the role of PTEN and PI3K/Akt/mTOR signaling in the development of MM and its response to treatment. In addition, the molecular interactions in MM that underpin the PI3K/Akt/mTOR pathway and address potential implications for the development of successful treatment plans are also discussed in detail. We investigate their relationship to both upstream and downstream regulators, highlighting new developments in combined therapies that target the PTEN/PI3K/Akt axis to overcome drug resistance, including the use of PI3K and mitogen-activated protein kinase (MAPK) inhibitors. We also emphasize that PTEN/PI3K/Akt pathway elements may be used in MM diagnosis, prognosis, and therapeutic targets.

Promising immunotherapeutic approaches for primary effusion lymphoma

Primary effusion lymphoma (PEL) is a large B-cell neoplasm usually presenting as a serious effusion in body cavities without detectable tumor masses. It is an AIDS-related non-Hodgkin's lymphoma (HL) with human herpes virus 8 (HHV8)/Kaposi sarcoma-associated herpes virus (KSHV) infection. A combination antiretroviral therapy (cART) prolongs the lifespan of AIDS and AIDS-related malignant lymphoma patients, but PEL continues to have a dismal prognosis. PEL showed disappointing outcomes with standard chemotherapy such as CHOP or CHOP-like regimens. A PEL status highlights the urgent need for new therapeutic approaches and treatment strategies and improve clinical outcomes. This review discusses the current knowledge and some recent clinical trials for PEL in the platform of immunotherapy as well as promising future immunotherapeutic approaches for PEL.

Bispecific Antibodies in the Treatment of Multiple Myeloma

The treatment of multiple myeloma (MM) is evolving rapidly. In recent years, T-cell-based novel immunotherapies emerged as new treatment strategies for patients with relapsed/refractory MM, including highly effective new options like chimeric antigen receptor (CAR)-modified T cells and bispecific antibodies (bsAbs). Currently, B-cell maturation antigen is the most commonly used target antigen for CAR T-cell and bsAb therapies in MM. Results from different clinical trials have demonstrated promising efficacy and acceptable safety profile of bsAb in RRMM.

Risk of atrial fibrillation in patients with multiple myeloma: what is known and directions for future study

BACKGROUND

Multiple myeloma (MM) is a prevalent hematological tumor, and recent clinical data have highlighted the significance of atrial fibrillation (AF) as a crucial complication affecting the prognosis of MM. This review aims to consolidate findings from published clinical studies, focusing on the epidemiological characteristics of AF in MM patients and the associated risks arising from MM treatments such as autologous hematopoietic stem cell transplantation, proteasome inhibitors, and immunomodulatory agents.

MAIN BODY

While existing data partially demonstrate a strong correlation between MM and AF, further clinical studies are necessary to comprehensively investigate their association. These studies should encompass various aspects, including the risk of AF resulting from MM treatment, the impact of AF-induced embolic events and heart failure on MM prognosis, as well as the influence of AF management methods like catheter ablation or left atrial appendage closure on MM prognosis.

CONCLUSIONS

The supplementation of future data will provide more precise guidance for managing MM patients. By incorporating information regarding AF risk associated with MM treatment and examining the effects of AF management strategies on MM prognosis, healthcare professionals can enhance their decision-making process when caring for individuals with MM.

Proteomic Alteration in the Progression of Multiple Myeloma: A Comprehensive Review

Multiple myeloma (MM) is an incurable hematologic malignancy. Most MM patients are diagnosed at a late stage because the early symptoms of the disease can be uncertain and nonspecific, often resembling other, more common conditions. Additionally, MM patients are commonly associated with rapid relapse and an inevitable refractory phase. MM is characterized by the abnormal proliferation of monoclonal plasma cells in the bone marrow. During the progression of MM, massive genomic alterations occur that target multiple signaling pathways and are accompanied by a multistep process involving differentiation, proliferation, and invasion. Moreover, the transformation of healthy plasma cell biology into genetically heterogeneous MM clones is driven by a variety of post-translational protein modifications (PTMs), which has complicated the discovery of effective treatments. PTMs have been identified as the most promising candidates for biomarker detection, and further research has been recommended to develop promising surrogate markers. Proteomics research has begun in MM, and a comprehensive literature review is available. However, proteomics applications in MM have yet to make significant progress. Exploration of proteomic alterations in MM is worthwhile to improve understanding of the pathophysiology of MM and to search for new treatment targets. Proteomics studies using mass spectrometry (MS) in conjunction with robust bioinformatics tools are an excellent way to learn more about protein changes and modifications during disease progression MM. This article addresses in depth the proteomic changes associated with MM disease transformation.

Biological research on the occurrence and development of multiple myeloma and its treatment

INTRODUCTION

To review the pathogenesis and treatment of multiple myeloma (MM). MM is a hematological malignancy with abnormal plasma cell proliferation in bone marrow. Due to the emergence of drug resistance, MM is still an incurable malignancy, which requires further exploration of pathogenesis and effective therapeutic targets.

METHODS

In this paper, the method of literature review is adopted to obtain the information about MM. Based on the literature, comprehensive and systematic review is made.

RESULTS

MM is a complex pathophysiological process with great heterogeneity, mainly reflected in genomic instability and bone marrow microenvironment. At present, the treatment of MM has made great progress, proteasome inhibitors and immunomodulatory drugs are widely used in clinic. Allogeneic stem cell transplantation may be the only promising cure for MM, and its high transplant-related mortality limits its clinical application.

CONCLUSIONS

The future of MM treatment lies in the development of more targeted therapies, novel immunotherapies, and a better understanding of the disease's molecular and genetic basis.

Safety and efficacy of Elotuzumab combination therapy for patients with multiple myeloma: A systematic review and meta-analysis

OBJECTIVE

We evaluate the efficacy and safety of Elotuzumab, an immunostimulatory monoclonal antibody, in combination with concomitant treatment regimens for multiple myeloma (MM) patients.

RESEARCH DESIGN AND METHODS

PubMed, Scopus, Web of Science, and EMBASE databases were searched systematically up to 2 August 2022.

RESULTS

Five randomized control trials with a total of 1,763 participants were included. Elotuzumab combination therapy improved PFS and OS by 14% (hazard ratio [HR] 0.86) and 20% (HR 0.80), respectively, relative to the non-Elotuzumab regimen. Adding Elotuzumab to Lenalidomide plus Dexamethasone regimen (HR 0.82) or Pomalidomide plus Dexamethasone regimen (HR 0.54) were considered to improve the PFS. Meanwhile, the risk of disease progression was only reduced for patients with relapsed/refractory MM (HR 0.70) but not for newly diagnosed/untreated MM (HR 0.93). Finally, the risk of serious adverse events (RR 1.12) and the risk of infection (RR 1.09) and cardiac disorders (RR 1.32) were higher for the experimental group compared to the control group.

CONCLUSIONS

Our findings showed that Elotuzumab combination therapy prolonged OS and PFS compared to non-Elotuzumab treatments in patients with MM. However, further investigations are required to establish the most effective combination of the Elotuzumab regimen.

Cardiovascular complications of modern multiple myeloma therapy: A pharmacovigilance study

AIMS

Multiple myeloma accounts for over 10-15% of haematological malignancies. Continued molecular advances have resulted in the development of new drugs for treatment of multiple myeloma. Four drugs were approved by the Food and Drug Administration (FDA) in 2015, but their safety is not well defined. The aim of this study is to delineate the cardiovascular adverse events of these drugs.

METHODS

We reviewed the adverse cardiac events of newly approved FDA drugs since 2015 using the US FDA Adverse Events Reporting System (FAERS) database. We calculated the reporting odds ratio (ROR) with 95% confidence interval (CIs) for the drugs that have the highest incidence of cardiovascular adverse events.

RESULTS

Among the medications that have approved for multiple myeloma between 2015 and 2020, 4 novel drugs showed the highest incidence of cardiotoxicity. ROR (95% CI) for atrial fibrillation due to elotuzumab, ixazomib, daratumumab and panobinostat compared to other FAERS drugs was 5.8 (4.4-7.7), 1.9 (1.5-2.3), 4.8 (4.2-5.6) and 5.7 (4.1-8.1), respectively. The ROR (95% CI) for cardiac failure was 8.2 (6.4-10.5), 4.7 (4.1-5.4), 5.8 (4.9-6.7) and 5.6 (3.8-8.1) and ROR (95% CI) for coronary disease was 2.7 (1.9-3.9), 2.7 (2.3-3.2), 2.3 (1.9-2.8) and 4.6 (3.2-6.6) due to elotuzumab, ixazomib, daratumumab and panobinostat compared to all other drugs in FAERS.

CONCLUSION

Our results demonstrated that certain newly approved antimyeloma therapies are significantly associated with previously unknown cardiotoxicity. These results warrant further studies and highlight the importance of considering the cardiac history of patients with multiple myeloma when utilizing these novel agents.

Alternative splicing in multiple myeloma is associated with the non-homologous end joining pathway

Alternative splicing plays a pivotal role in tumorigenesis and proliferation. However, its pattern and pathogenic role has not been systematically analyzed in multiple myeloma or its subtypes. Alternative splicing profiles for 598 newly diagnosed myeloma patients with comprehensive genomic annotation identified primary translocations, 1q amplification, and DIS3 events to have more differentially spliced events than those without. Splicing levels were correlated with expression of splicing factors. Moreover, the non-homologous end joining pathway was an independent factor that was highly associated with splicing frequency as well as an increased number of structural variants. We therefore identify an axis of high-risk disease encompassing expression of the non-homologous end joining pathway, increase structural variants, and increased alternative splicing that are linked together. This indicates a joint pathogenic role for DNA damage response and alternative RNA processing in myeloma.

Normalization of the Immunological Microenvironment and Sustained Minimal Residual Disease Negativity: Do We Need Both for Long-Term Control of Multiple Myeloma?

Over the past two decades, the treatment landscape for multiple myeloma (MM) has progressed significantly, with the introduction of several new drug classes that have greatly improved patient outcomes. At present, it is well known how the bone marrow (BM) microenvironment (ME) exerts an immunosuppressive action leading to an exhaustion of the immune system cells and promoting the proliferation and sustenance of tumor plasma cells. Therefore, having drugs that can reconstitute a healthy BM ME can improve results in MM patients. Recent findings clearly demonstrated that achieving minimal residual disease (MRD) negativity and sustaining MRD negativity over time play a pivotal prognostic role. However, despite the achievement of MRD negativity, patients may still relapse. The understanding of immunologic changes in the BM ME during treatment, complemented by a deeper knowledge of plasma cell genomics and biology, will be critical to develop future therapies to sustain MRD negativity over time and possibly achieve an operational cure. In this review, we focus on the components of the BM ME and their role in MM, on the prognostic significance of MRD negativity and, finally, on the relative contribution of tumor plasma cell biology and BM ME to long-term disease control.

Elotuzumab, a potential therapeutic humanized anti-SLAMF7 monoclonal antibody, enhances natural killer cell-mediated killing of primary effusion lymphoma cells

Primary effusion lymphoma (PEL) is a rare aggressive B-cell non-Hodgkin's lymphoma with no optimal treatment. Signaling lymphocytic activation molecule-F7 (SLAMF7, CD319), a type I transmembrane glycoprotein highly expressed in multiple myeloma (MM), represents a promising target for mAb-based immunotherapy. SLAMF7 also expresses on several hematopoietic lineages including NK cells. Elotuzumab (Elo), a humanized antibody targeting SLAMF7, is approved by FDA for MM treatment. In this study, we analyzed the expression of SLAMF7 on seven PEL cell lines. All PEL cells and NK cells showed high expression of SLAMF7. NK cells were enriched from PBMCs of healthy donors by MACS and expanded by co-culturing with MHC-class I negative K562 cells in the presence of IL-2 and IL-15. Expanded NK cells showed direct killing, and Elo demonstrated potent ADCC against PEL in an Effector:Target (E:T) dependent manner. Surface expression of CD107a on NK cells also increased in the process of ADCC. We also examined SLAMF7 expression of NK subpopulations and found that the CD56+CD16+ NK subpopulation demonstrated the highest SLAMF7 expression. Full-length-Elo but not F(ab')2-Elo exerts direct engagement to the expressing SLAMF7 on NK cells, promotes CD107a expression, and further augments NK cytotoxicity toward PEL. Elo enhanced survival of PEL-bearing immunodeficient mice with adoptive transfer of human NK cells. Taken together, our results show that NK cells play roles in PEL killing, and Elo causes ADCC/SLAMF7 ligation to boost NK cytotoxicity against PEL, offering promising preclinical evidence of Elo as a therapeutic monoclonal antibody treatment for PEL.

Practical guidance for new multiple myeloma treatment regimens: A nursing perspective

As is the case for solid tumors, treatment paradigms have shifted from non-specific chemotherapeutic agents towards novel targeted drugs in the treatment of patients with multiple myeloma (MM). Currently, multiple targeted therapies are available to treat patients augmenting the arsenal of modalities which also includes chemotherapy, immunotherapy, radiation therapy, hematopoietic stem cell transplantation (HSCST) and chimeric antigen T-cell therapy (CAR-T). These novel, targeted agents have dramatically increased optimism for patients, who may now be treated over many years with successive regimens. As fortunate as we are to have these new therapies available for our patients, this advantage is juxtaposed with the challenges involved with delivering them safely. While each class of agents has demonstrated efficacy, in terms of response rates and survival, they also exert class effects which pose risks for toxicity. In addition, newer generation agents within the classes often have slightly different toxicity profiles than did their predecessors. These factors must be addressed, and their risks mitigated by the multidisciplinary team. This review presents a summary of the evolution of drug development for MM. For each targeted agent, the efficacy data from pivotal trials and highlights of the risks that were demonstrated in trials, as well as during post-marketing surveillance, are presented. Specific risks associated with agents within the classes, that are not shared with all new class members, are described. A table presenting these potential risks, with recommended nursing actions to mitigate toxicity, is provided as a quick reference that nurses may use during the planning, and provision, of patient care.

FDA-Approved Drugs for Hematological Malignancies-The Last Decade Review

Simple Summary

Hematological malignancies are diseases involving the abnormal production of blood cells. The aim of the study is to collect comprehensive information on new drugs used in the treatment of blood cancers which have introduced into therapy in the last decade. The approved drugs were analyzed for their structures and their biological activity mechanisms.

Abstract

Hematological malignancies, also referred to as blood cancers, are a group of diseases involving abnormal cell growth and persisting in the blood, lymph nodes, or bone marrow. The development of new targeted therapies including small molecule inhibitors, monoclonal antibodies, bispecific T cell engagers, antibody-drug conjugates, recombinant immunotoxins, and, finally, Chimeric Antigen Receptor T (CAR-T) cells has improved the clinical outcomes for blood cancers. In this review, we summarized 52 drugs that were divided into small molecule and macromolecule agents, approved by the Food and Drug Administration (FDA) in the period between 2011 and 2021 for the treatment of hematological malignancies. Forty of them have also been approved by the European Medicines Agency (EMA). We analyzed the FDA-approved drugs by investigating both their structures and mechanisms of action. It should be emphasized that the number of targeted drugs was significantly higher (46 drugs) than chemotherapy agents (6 drugs). We highlight recent advances in the design of drugs that are used to treat hematological malignancies, which make them more effective and less toxic.

Antibody Therapy: From Diphtheria to Cancer, COVID-19, and Beyond

The dawn of the 20th century saw the formative years of developments in immunology. In particular, immunochemistry, specifically pertaining to antibodies, was extensively studied. These studies laid the foundations for employing antibodies in a variety of ways. Not surprisingly, antibodies have been used for applications ranging from biomedical research to disease diagnostics and therapeutics to evaluation of immune responses during natural infection and those elicited by vaccines. Despite recent advancements in cellular immunology and the excitement of T cell therapy, use of antibodies represents a large proportion of immunotherapeutic approaches as well as clinical interventions. Polyclonal antibodies in the form of plasma or sera continue to be used to treat a number of diseases, including autoimmune disorders, cancers, and infectious diseases. Historically, antisera to toxins have been the longest serving biotherapeutics. In addition, intravenous immunoglobulins (IVIg) have been extensively used to treat not only immunodeficiency conditions but also autoimmune disorders. Beyond the simplistic suppositions of their action, the IVIg have also unraveled the immune regulatory and homeostatic ramifications of their use. The advent of monoclonal antibodies (MAbs), on the other hand, has provided a clear pathway for their development as drug molecules. MAbs have found a clear place in the treatment of cancers and extending lives and have been used in a variety of other conditions. In this review, we capture the important developments in the therapeutic applications of antibodies to alleviate disease, with a focus on some of the recent developments.

Downregulation of Chemokine CCL20 Involved in Myeloma Cells Resistant to Elotuzumab and Lenalidomide

Objective

Few studies have focused on investigating resistance mechanisms in myeloma immunotherapy. This study aimed to explore the relevant factor involved in the resistance of Elotuzumab and lenalidomide.

Methods

Cell models which are resistant to Elotuzumab and lenalidomide were constructed; different expression genes in U266/WT (UW) and resistant UR, UE, and URE cells were detected by using gene expression microarray. RT-qPCR validated CCL20 mRNA expression of four cell lines and patient samples; bioinformatics analysis of CCL20 expressions in NDMM and RRMM; ELISA detected the presence of CCL20 in the plasma of MM patients; constructed UR mouse xenograft model to explore whether or not CCL20 reverse lenalidomide treatment in vivo.

Results

Cell models which are resistant to Elotuzumab and lenalidomide (UR, UE, URE) were successfully constructed. CCL20 gene expression decreased in resistant myeloma cell lines and RRMM patients. Furthermore, RRMM patients were found to have lower levels of CCL20 protein in their plasma compared to NDMM. CCL20 increase the sensitivity of drug-resistant myeloma cells to immunomodulatory drugs both in vivo and in vitro.

Conclusion

The expression of CCL20 was decreased in lenalidomide and Elotuzumab resistant U266 cells and in RRMM patients. CCL20 could therefore possibly increase the sensitivity of lenalidomide and Elotuzumab.

An update on B-cell maturation antigen-targeted therapies in Multiple Myeloma

Introduction: B-cell maturation antigen (BCMA) targeted therapy (BCMA-TT) has emerged as a promising treatment for Multiple Myeloma (MM). the three most common treatment modalities for targeting BCMA are antibody-drug conjugates (ADCs), bispecific antibody constructs, including BiTE (bispecific T-cell engager) immuno-oncology therapies, and chimeric antigen receptor (CAR)-modified T-cell therapy.Areas covered: The review provides an overview of the main published studies on clinical and pre-clinical data from trials using BCMA-TT.Expert opinion: Despite progresses in survival outcomes and the availability of new drugs, MM remains an incurable disease. ADC is a promising antibody-based treatment and Belantamab mafodotin showed an anti-myeloma effect alone or in combination with other drugs. The major issue of ADC is the occurrence of events interfering with the efficacy and the off-target cytotoxicity. Bispecific antibody constructs are off-the-shelf therapies characterized by a potential rapid availability. The most critical limitation of bispecific antibody constructs is their short half-life necessitating prolonged intravenous infusion. CAR-T cells produced unprecedented results in heavily pretreated RRMM. The most common toxicities include neurologic toxicity and cytokine release syndrome, B-cell aplasia, cytopenias, and hypogammaglobulinemia. Further studies are needed to detect which are the eligible patients who could benefit from one treatment more than another.

Monoclonal Antibodies: Leading Actors in the Relapsed/Refractory Multiple Myeloma Treatment

Multiple myeloma is a complex hematologic malignancy, and despite a survival improvement related to the growing number of available therapeutic options since 2000s, it remains an incurable disease with most patients experiencing relapse. However, therapeutic options for this disease are constantly evolving and immunotherapy is becoming the mainstay of the therapeutic armamentarium of Multiple Myeloma (MM), starting with monoclonal antibodies (MoAbs) as elotuzumab, daratumumab and isatuximab. Elotuzumab, the first in class targeting SLAMF7, in combination with lenalidomide and dexamethasone and daratumumab, directed against CD38, in combination with Rd and with bortezomib and dexamethasone (Vd), have been approved for the treatment of relapsed/refractory MM (RRMM) after they demonstrated excellent efficacy. More recently, another anti-CD38 MoAb named isatuximab was approved by FDA in combination with pomalidomide-dexamethasone (Pd) in the same setting. Many phase II and III trials with regimens containing these MoAbs are ongoing, and when available, preliminary data are very encouraging. In this review we will describe the results of major clinical studies that have been conducted with elotuzumab, daratumumab and isatuximab in RRMM, focusing on phase III trials. Moreover, we will summarized the emerging MoAbs-based combinations in the RRMM landscape.

Bispecific Antibodies: A New Era of Treatment for Multiple Myeloma

Despite the introduction of novel agents such as proteasome inhibitors, immunomodulatory drugs, and autologous stem cell transplant, multiple myeloma (MM) largely remains an incurable disease. In recent years, monoclonal antibody-based treatment strategies have been developed to target specific surface antigens on MM cells. Treatment with bispecific antibodies (bsAbs) is an immunotherapeutic strategy that leads to an enhanced interaction between MM cells and immune effector cells, e.g., T-cells and natural killer cells. With the immune synapse built by bsAbs, the elimination of MM cells can be facilitated. To date, bsAbs have demonstrated encouraging results in preclinical studies, and clinical trials evaluating bsAbs in patients with MM are ongoing. Early clinical data show the promising efficacy of bsAbs in relapsed/refractory MM. Together with chimeric antigen receptor-modified (CAR)-T-cells, bsAbs represent a new dimension of precision medicine. In this review, we provide an overview of rationale, current clinical development, resistance mechanisms, and future directions of bsAbs in MM.

The Society for Immunotherapy of Cancer consensus statement on immunotherapy for the treatment of multiple myeloma

Outcomes in multiple myeloma (MM) have improved dramatically in the last two decades with the advent of novel therapies including immunomodulatory agents (IMiDs), proteasome inhibitors and monoclonal antibodies. In recent years, immunotherapy for the treatment of MM has advanced rapidly, with the approval of new targeted agents and monoclonal antibodies directed against myeloma cell-surface antigens, as well as maturing data from late stage trials of chimeric antigen receptor CAR T cells. Therapies that engage the immune system to treat myeloma offer significant clinical benefits with durable responses and manageable toxicity profiles, however, the appropriate use of these immunotherapy agents can present unique challenges for practicing physicians. Therefore, the Society for Immunotherapy of Cancer convened an expert panel, which met to consider the current role of approved and emerging immunotherapy agents in MM and provide guidance to the oncology community by developing consensus recommendations. As immunotherapy evolves as a therapeutic option for the treatment of MM, these guidelines will be updated.

Checkpoint Inhibitors and Engineered Cells: New Weapons for Natural Killer Cell Arsenal Against Hematological Malignancies

Natural killer (NK) cells represent one of the first lines of defense against malignant cells. NK cell activation and recognition are regulated by a balance between activating and inhibitory receptors, whose specific ligands can be upregulated on tumor cells surface and tumor microenvironment (TME). Hematological malignancies set up an extensive network of suppressive factors with the purpose to induce NK cell dysfunction and impaired immune-surveillance ability. Over the years, several strategies have been developed to enhance NK cells-mediated anti-tumor killing, while other approaches have arisen to restore the NK cell recognition impaired by tumor cells and other cellular components of the TME. In this review, we summarize and discuss the strategies applied in hematological malignancies to block the immune check-points and trigger NK cells anti-tumor effects through engineered chimeric antigen receptors.

Infectious Complications of Biological and Small Molecule Targeted Immunomodulatory Therapies

The past 2 decades have seen a revolution in our approach to therapeutic immunosuppression. We have moved from relying on broadly active traditional medications, such as prednisolone or methotrexate, toward more specific agents that often target a single receptor, cytokine, or cell type, using monoclonal antibodies, fusion proteins, or targeted small molecules. This change has transformed the treatment of many conditions, including rheumatoid arthritis, cancers, asthma, and inflammatory bowel disease, but along with the benefits have come risks. Contrary to the hope that these more specific agents would have minimal and predictable infectious sequelae, infectious complications have emerged as a major stumbling block for many of these agents. Furthermore, the growing number and complexity of available biologic agents makes it difficult for clinicians to maintain current knowledge, and most review articles focus on a particular target disease or class of agent. In this article, we review the current state of knowledge about infectious complications of biologic and small molecule immunomodulatory agents, aiming to create a single resource relevant to a broad range of clinicians and researchers. For each of 19 classes of agent, we discuss the mechanism of action, the risk and types of infectious complications, and recommendations for prevention of infection.

Preclinical Characterization of an Antibody-Drug Conjugate Targeting CS-1 and the Identification of Uncharacterized Populations of CS-1-Positive Cells

Multiple myeloma is a hematologic cancer that disrupts normal bone marrow function and has multiple lines of therapeutic options, but is incurable as patients ultimately relapse. We developed a novel antibody-drug conjugate (ADC) targeting CS-1, a protein that is highly expressed on multiple myeloma tumor cells. The anti-CS-1 mAb specifically bound to cells expressing CS-1 and, when conjugated to a cytotoxic pyrrolobenzodiazepine payload, reduced the viability of multiple myeloma cell lines in vitro In mouse models of multiple myeloma, a single administration of the CS-1 ADC caused durable regressions in disseminated models and complete regression in a subcutaneous model. In an exploratory study in cynomolgus monkeys, the CS-1 ADC demonstrated a half-life of 3 to 6 days; however, no highest nonseverely toxic dose was achieved, as bone marrow toxicity was dose limiting. Bone marrow from dosed monkeys showed reductions in progenitor cells as compared with normal marrow. In vitro cell killing assays demonstrated that the CS-1 ADC substantially reduced the number of progenitor cells in healthy bone marrow, leading us to identify previously unreported CS-1 expression on a small population of progenitor cells in the myeloid-erythroid lineage. This finding suggests that bone marrow toxicity is the result of both on-target and off-target killing by the ADC.

Systematically optimized BCMA/CS1 bispecific CAR-T cells robustly control heterogeneous multiple myeloma

Chimeric antigen receptor (CAR)-T cell therapy has shown remarkable clinical efficacy against B-cell malignancies, yet marked vulnerability to antigen escape and tumor relapse exists. Here we report the rational design and optimization of bispecific CAR-T cells with robust activity against heterogeneous multiple myeloma (MM) that is resistant to conventional CAR-T cell therapy targeting B-cell maturation antigen (BCMA). We demonstrate that BCMA/CS1 bispecific CAR-T cells exhibit superior CAR expression and function compared to T cells that co-express individual BCMA and CS1 CARs. Combination therapy with anti-PD-1 antibody further accelerates the rate of initial tumor clearance in vivo, while CAR-T cell treatment alone achieves durable tumor-free survival even upon tumor re-challenge. Taken together, the BCMA/CS1 bispecific CAR presents a promising treatment approach to prevent antigen escape in CAR-T cell therapy against MM, and the vertically integrated optimization process can be used to develop robust cell-based therapy against novel disease targets.

Carfilzomib and dexamethasone versus eight cycles of bortezomib and dexamethasone in patients with relapsed or refractory multiple myeloma: an indirect comparison using data from the phase 3 ENDEAVOR and CASTOR trials

In ENDEAVOR, carfilzomib and dexamethasone (Kd56) demonstrated significant improvement in progression-free survival (PFS) compared with bortezomib and dexamethasone (Vd). Both agents were administered until disease progression; the EU label for Vd, however, stipulates a maximum of eight treatment cycles. Here, matching-adjusted treatment comparison was used to compare efficacy of Kd56 with Vd, if Vd was administered for 8 cycles (Vd-8). Data from ENDEAVOR and CASTOR trials (which compared daratumumab, bortezomib, and dexamethasone with Vd-8) were used. Hazard ratios of PFS were estimated for Vd vs. Vd-8 and Kd vs. Vd-8. For cycles 1-8, risk reduction in PFS for Kd56 vs. Vd-8 was equal to that estimated in ENDEAVOR (HR: 0.53; 95% CI 0.44-0.65). Beyond eight cycles, risk reduction in PFS for Kd56 and Vd-8 was estimated to be 60% (HR: 0.40; 95% CI 0.26-0.63). The analysis suggested that PFS benefit of Kd56 over Vd increases when Vd is given for eight cycles only.

Biological Therapy of Hematologic Malignancies: Toward a Chemotherapy- free Era

Less than 70 years ago, the vast majority of hematologic malignancies were untreatable diseases with fatal prognoses. The development of modern chemotherapy agents, which had begun after the Second World War, was markedly accelerated by the discovery of the structure of DNA and its role in cancer biology and tumor cell division. The path travelled from the first temporary remissions observed in children with acute lymphoblastic leukemia treated with single-agent antimetabolites until the first cures achieved by multi-agent chemotherapy regimens was incredibly short. Despite great successes, however, conventional genotoxic cytostatics suffered from an inherently narrow therapeutic index and extensive toxicity, which in many instances limited their clinical utilization. In the last decade of the 20th century, increasing knowledge on the biology of certain malignancies resulted in the conception and development of first molecularly targeted agents designed to inhibit specific druggable molecules involved in the survival of cancer cells. Advances in technology and genetic engineering enabled the production of structurally complex anticancer macromolecules called biologicals, including therapeutic monoclonal antibodies, antibody-drug conjugates and antibody fragments. The development of drug delivery systems (DDSs), in which conventional drugs were attached to various types of carriers including nanoparticles, liposomes or biodegradable polymers, represented an alternative approach to the development of new anticancer agents. Despite the fact that the antitumor activity of drugs attached to DDSs was not fundamentally different, the improved pharmacokinetic profiles, decreased toxic side effects and significantly increased therapeutic indexes resulted in their enhanced antitumor efficacy compared to conventional (unbound) drugs. Approval of the first immune checkpoint inhibitor for the treatment of cancer in 2011 initiated the era of cancer immunotherapy. Checkpoint inhibitors, bispecific T-cell engagers, adoptive T-cell approaches and cancer vaccines have joined the platform so far, represented mainly by recombinant cytokines, therapeutic monoclonal antibodies and immunomodulatory agents. In specific clinical indications, conventional drugs have already been supplanted by multi-agent, chemotherapy-free regimens comprising diverse immunotherapy and/or targeted agents. The very distinct mechanisms of the anticancer activity of new immunotherapy approaches not only call for novel response criteria, but might also change fundamental treatment paradigms of certain types of hematologic malignancies in the near future.

Induction Therapy for Newly Diagnosed Multiple Myeloma

The frontline therapy for newly diagnosed multiple myeloma (MM) has continued to evolve over the last 10 years. There has been a growing emphasis on achieving the best depth of response in the context of minimal residual disease negativity, given its prognostic correlation with superior overall survival. Another important area of emphasis has been to improve prognostication and staging by including information on disease biology. There also a growing appreciation of global differences in drug access and patterns of care. The current review explores each of these areas and how best to incorporate the emerging induction regimens in to schema of MM therapy.

The future of myeloma precision medicine: integrating the compendium of known drug resistance mechanisms with emerging tumor profiling technologies

Multiple myeloma (MM) is a hematologic malignancy that is considered mostly incurable in large part due to the inability of standard of care therapies to overcome refractory disease and inevitable drug-resistant relapse. The post-genomic era has been a productive period of discovery where modern sequencing methods have been applied to large MM patient cohorts to modernize our current perception of myeloma pathobiology and establish an appreciation for the vast heterogeneity that exists between and within MM patients. Numerous pre-clinical studies conducted in the last two decades have unveiled a compendium of mechanisms by which malignant plasma cells can escape standard therapies, many of which have potentially quantifiable biomarkers. Exhaustive pre-clinical efforts have evaluated countless putative anti-MM therapeutic agents and many of these have begun to enter clinical trial evaluation. While the palette of available anti-MM therapies is continuing to expand it is also clear that malignant plasma cells still have mechanistic avenues by which they can evade even the most promising new therapies. It is therefore becoming increasingly clear that there is an outstanding need to develop and employ precision medicine strategies in MM management that harness emerging tumor profiling technologies to identify biomarkers that predict efficacy or resistance within an individual's sub-clonally heterogeneous tumor. In this review we present an updated overview of broad classes of therapeutic resistance mechanisms and describe selected examples of putative biomarkers. We also outline several emerging tumor profiling technologies that have the potential to accurately quantify biomarkers for therapeutic sensitivity and resistance at genomic, transcriptomic and proteomic levels. Finally, we comment on the future of implementation for precision medicine strategies in MM and the clear need for a paradigm shift in clinical trial design and disease management.

Long-Lived Plasma Cells in Mice and Men

Even though more than 30 years have passed since the eradication of smallpox, high titers of smallpox-specific antibodies are still detected in the blood of subjects vaccinated in childhood. In fact, smallpox-specific antibody levels are maintained in serum for more than 70 years. The generation of life-long immunity against infectious diseases such as smallpox and measles has been thoroughly documented. Although the mechanisms behind high persisting antibody titers in the absence of the causative agent are still unclear, long lived plasma cells (LLPCs) play an important role. Most of the current knowledge on LLPCs is based on experiments performed in mouse models, although the amount of data derived from human studies is increasing. As the results from mouse models are often directly extrapolated to humans, it is important to keep in mind that there are differences. These are not only the obvious such as the life span but there are also anatomical differences, for instance the adiposity of the bone marrow (BM) where LLPCs reside. Whether these differences have an effect on the function of the immune system, and in particular on LLPCs, are still unknown. In this review, we will briefly discuss current knowledge of LLPCs, comparing mice and humans.

SLAMF receptors on normal and malignant B cells

The Signaling Lymphocyte Activation Molecule family (SLAMF) is a collection of nine surface receptors expressed mainly on hematopoietic cells, and was found to modulate the behavior of immune cells. SLAMF receptors are expressed on B cells in health and disease. Each SLAM receptor has a unique differential expression pattern during the development and activation of B cells. Furthermore, recent findings have revealed a principal role for this family of receptors in B cell malignancies, emphasizing their importance in the control of malignant cell survival, cell to cell communication within the tumor microenvironment, retention in the supporting niches and regulation of T cell anti-tumor response. This review summarizes the latest studies regarding SLAMF expression and behavior in B cells and in B cell pathologies, and discusses the therapeutic potential of these receptors.

Monoclonal antibodies in cancer immunotherapy

Nowadays, in cancer treatments, immunotherapy which can be classified as a cancer type specific therapy is more popular than non-specific therapy methods such as surgery, radiotherapy and chemotherapy. The main aim of immunotherapy is to enable patients' immune system to target cancer cells and destroy them. The mainly used treatment methods in cancer immunotherapy are cancer vaccines, adoptive cell therapy, cytokines and monoclonal antibodies. In this review, we discuss the immunotherapy approaches, especially monoclonal antibodies which are mostly used in cancer immunotherapy in clinical applications.

Building upon the success of CART19: chimeric antigen receptor T cells for hematologic malignancies

Chimeric antigen receptor T cell (CART) therapy has dramatically changed the therapeutic prospects for B cell malignancies. Over the last decade CD19-redirected CART have demonstrated the ability to induce deep, long-lasting remissions and possibly cure patients with relapsing B cell neoplasms. Such impressive results with CART19 fostered efforts to expand this technology to other incurable malignancies that naturally do not express CD19, such as acute myeloid leukemia (AML), Hodgkin lymphoma (HL) and multiple myeloma (MM). However, to reach this goal, several hurdles have to be overcome, in particular: (i) the apparent lack of suitable targets as effective as CD19; (ii) the immunosuppressive tumor microenvironment; (iii) intra-tumoral heterogeneity and antigen-negative relapses. Therefore, new strategies that allow safer and more potent CART platforms are under development and may provide grounds for new exciting breakthroughs in the field.

New Strategies Using Antibody Combinations to Increase Cancer Treatment Effectiveness

Antibodies have proven their high value in antitumor therapy over the last two decades. They are currently being used as the first-choice to treat some of the most frequent metastatic cancers, like HER2⁺ breast cancers or colorectal cancers, currently treated with trastuzumab (Herceptin) and bevacizumab (Avastin), respectively. The impressive therapeutic success of antibodies inhibiting immune checkpoints has extended the use of therapeutic antibodies to previously unanticipated tumor types. These anti-immune checkpoint antibodies allowed the cure of patients devoid of other therapeutic options, through the recovery of the patient’s own immune response against the tumor. In this review, we describe how the antibody-based therapies will evolve, including the use of antibodies in combinations, their main characteristics, advantages, and how they could contribute to significantly increase the chances of success in cancer therapy. Indeed, novel combinations will consist of mixtures of antibodies against either different epitopes of the same molecule or different targets on the same tumor cell; bispecific or multispecific antibodies able of simultaneously binding tumor cells, immune cells or extracellular molecules; immunomodulatory antibodies; antibody-based molecules, including fusion proteins between a ligand or a receptor domain and the IgG Fab or Fc fragments; autologous or heterologous cells; and different formats of vaccines. Through complementary mechanisms of action, these combinations could contribute to elude the current limitations of a single antibody which recognizes only one particular epitope. These combinations may allow the simultaneous attack of the cancer cells by using the help of the own immune cells and exerting wider therapeutic effects, based on a more specific, fast, and robust response, trying to mimic the action of the immune system.

Restoring Natural Killer Cell Immunity against Multiple Myeloma in the Era of New Drugs

Transformed plasma cells in multiple myeloma (MM) are susceptible to natural killer (NK) cell-mediated killing via engagement of tumor ligands for NK activating receptors or “missing-self” recognition. Similar to other cancers, MM targets may elude NK cell immunosurveillance by reprogramming tumor microenvironment and editing cell surface antigen repertoire. Along disease continuum, these effects collectively result in a progressive decline of NK cell immunity, a phenomenon increasingly recognized as a critical determinant of MM progression. In recent years, unprecedented efforts in drug development and experimental research have brought about emergence of novel therapeutic interventions with the potential to override MM-induced NK cell immunosuppression. These NK-cell enhancing treatment strategies may be identified in two major groups: (1) immunomodulatory biologics and small molecules, namely, immune checkpoint inhibitors, therapeutic antibodies, lenalidomide, and indoleamine 2,3-dioxygenase inhibitors and (2) NK cell therapy, namely, adoptive transfer of unmanipulated and chimeric antigen receptor-engineered NK cells. Here, we summarize the mechanisms responsible for NK cell functional suppression in the context of cancer and, specifically, myeloma. Subsequently, contemporary strategies potentially able to reverse NK dysfunction in MM are discussed.

A review discussing elotuzumab and its use in the second-line plus treatment of multiple myeloma

Monoclonal antibodies (mAb) represent a new frontier to treat newly diagnosed and relapsed-refractory multiple myeloma (MM). Elotuzumab, an mAb targeted SLAM7 in the plasma cells and natural killer cells surface, is the first mAb approved for the treatment of relapsed-refractory MM in combination with lenalidomide and dexamethasone. This approval was the final result of several preclinical and Phase I-II clinical studies leading to ELOQUENT-2 Phase III trial that demonstrated that elotuzumab adds a significant and durable value to standard therapy, paved the way of this new treatment strategy for MM. In this review we will describe elotuzumab mechanisms of action, clinical pharmacology and clinical studies that have led to these developments.

Recombinant Antibodies to Arm Cytotoxic Lymphocytes in Cancer Immunotherapy

Immunotherapy has the potential to support and expand the body's own armamentarium of immune effector functions, which have been circumvented during malignant transformation and establishment of cancer and is presently considered to be the most promising treatment option for cancer patients. Recombinant antibody technologies have led to a multitude of novel antibody formats, which are in clinical development and hold great promise for future therapies. Among these formats, bispecific antibodies are extremely versatile due to their high efficacy to recruit and activate anti-tumoral immune effector cells, their excellent safety profile, and the opportunity for use in combination with cellular therapies. This review article summarizes the latest developments in cancer immunotherapy using immuno-engagers for recruiting T cells and NK cells to the tumor site. In addition to antibody formats, malignant cell targets, and immune cell targets, opportunities for combination therapies, including check point inhibitors, cytokines and adoptive transfer of immune cells, will be summarized and discussed.

Cancer immunotherapy: Breakthrough or "deja vu, all over again"?

From the application of Coley's toxin in the early 1900s to the present clinical trials using immune checkpoint regulatory inhibitors, the history of cancer immunotherapy has consisted of extremely high levels of enthusiasm after anecdotal case reports of enormous success, followed by decreasing levels of enthusiasm as the results of controlled clinical trials are available. In this review, this pattern will be documented for the various immunotherapeutic approaches over the years. The sole exception being vaccination against cancer causing viruses, which have already prevented thousands of cancers. We can only hope that the present high level of enthusiasm for the use of immune stimulation by removal of blocks to cancer immunity will be more productive than the incremental improvements using previous immunotherapies.