CAR T cell therapy for multiple myeloma: where are we now and where are we headed?

Anti-BCMA CAR-T cell-based therapies and bispecific antibodies in the immunotherapy era: are we ready for this?

INTRODUCTION

Therapeutic strategies against multiple myeloma (MM) have evolved dramatically in recent decades, with unprecedent results in the treatment landscape, culminating in the recent incorporation of novel agents in the anti-myeloma armamentarium.

AREAS COVERED

BCMA represents one of the most promising targets in MM and currently available immune approaches, either approved or under active investigation, are clearly showing their greater potential over standard regimens. In this context, immunotherapies based on chimeric antigen receptor (CAR)-engineered T-cells and bispecific antibodies (BsAbs) have taken center stage, being the ones that are yielding the most promising results in clinical trials. This review focuses on the current landscape of BsAbs and CAR-T, summarizing the latest advances and possible future developments.

EXPERT OPINION

CAR-T and BsAbs anti-BCMA strategies represent breakthrough therapies against MM. However, their inclusion in clinical practice is almost feared, due to the associated limitations, some of which have been addressed here. Meanwhile, all the efforts should be focused on individualizing and choosing the most suitable candidates for each treatment and to understand how to combine, or sequence, these therapies to improve efficacy and minimize toxicity, especially for those patients with limited available treatment options.

CAR-T-Cell Therapy in Multiple Myeloma: B-Cell Maturation Antigen (BCMA) and Beyond

Significant progress has been achieved in the realm of therapeutic interventions for multiple myeloma (MM), leading to transformative shifts in its clinical management. While conventional modalities such as surgery, radiotherapy, and chemotherapy have improved the clinical outcomes, the overarching challenge of effecting a comprehensive cure for patients afflicted with relapsed and refractory MM (RRMM) endures. Notably, adoptive cellular therapy, especially chimeric antigen receptor T-cell (CAR-T) therapy, has exhibited efficacy in patients with refractory or resistant B-cell malignancies and is now also being tested in patients with MM. Within this context, the B-cell maturation antigen (BCMA) has emerged as a promising candidate for CAR-T-cell antigen targeting in MM. Alternative targets include SLAMF7, CD38, CD19, the signaling lymphocyte activation molecule CS1, NKG2D, and CD138. Numerous clinical studies have demonstrated the clinical efficacy of these CAR-T-cell therapies, although longitudinal follow-up reveals some degree of antigenic escape. The widespread implementation of CAR-T-cell therapy is encumbered by several barriers, including antigenic evasion, uneven intratumoral infiltration in solid cancers, cytokine release syndrome, neurotoxicity, logistical implementation, and financial burden. This article provides an overview of CAR-T-cell therapy in MM and the utilization of BCMA as the target antigen, as well as an overview of other potential target moieties.

Combination Treatment Targeting mTOR and MAPK Pathways Has Synergistic Activity in Multiple Myeloma

Multiple myeloma (MM) is an incurable, malignant B cell disorder characterized by frequent relapses and a poor prognosis. Thus, new therapeutic approaches are warranted. The phosphatidylinositol-3-kinase (PI3K) pathway plays a key role in many critical cellular processes, including cell proliferation and survival. Activated PI3K/AKT (protein kinases B)/mTOR (mammalian target of rapamycin) signaling has been identified in MM primary patient samples and cell lines. In this study, the efficacy of PI3K and mTOR inhibitors in various MM cell lines representing three different prognostic subtypes was tested. Whereas MM cell lines were rather resistant to PI3K inhibition, treatment with the mTOR inhibitor temsirolimus decreases the phosphorylation of key molecules in the PI3K pathway in MM cell lines, leading to G₀/G₁ cell cycle arrest and thus reduced proliferation. Strikingly, the efficacy of temsirolimus was amplified by combining the treatment with the Mitogen-activated protein kinase kinase (MEK) inhibitor trametinib. Our findings provide a scientific rationale for the simultaneous inhibition of mTOR and MEK as a novel strategy for the treatment of MM.

Recent findings on chimeric antigen receptor (CAR)-engineered immune cell therapy in solid tumors and hematological malignancies

Advancements in adoptive cell therapy over the last four decades have revealed various new therapeutic strategies, such as chimeric antigen receptors (CARs), which are dedicated immune cells that are engineered and administered to eliminate cancer cells. In this context, CAR T-cells have shown significant promise in the treatment of hematological malignancies. However, many obstacles limit the efficacy of CAR T-cell therapy in both solid tumors and hematological malignancies. Consequently, CAR-NK and CAR-M cell therapies have recently emerged as novel therapeutic options for addressing the challenges associated with CAR T-cell therapies. Currently, many CAR immune cell trials are underway in various human malignancies around the world to improve antitumor activity and reduce the toxicity of CAR immune cell therapy. This review will describe the comprehensive literature of recent findings on CAR immune cell therapy in a wide range of human malignancies, as well as the challenges that have emerged in recent years.

Promising therapeutic approaches for relapsed/refractory multiple myeloma

OBJECTIVE

Treatment strategies for relapsed/refractory MM are particularly complex. In particular, patients who are refractory to the three classes of therapies have limited therapeutic options and poor survival. Fortunately, promising treatments are emerging, but their incorporation into existing treatments still needs to be defined. We will describe the latest trends and emerging developments in the field of therapies for RRMM by analyzing the most recent clinical data and new technologies in drug development.

METHODS

Pubmed, Embase and Cochrane Library were searched to select eligible studies, the clinical data of new promising treatments were reviewed. The key results of the most recent clinical trial were summarized in Table.

RESULTS

A total of 13 studies were included in the final analysis involving anti-BCMA CAR T-cell therapy, Combined CAR T-cell therapy, antibody-drug conjugates, bispecific Ab therapy and CELMoDs. The key efficacy and side effects of treatments were summarized.

CONCLUSIONS

There is great promise for a set of next-generation of rescue therapies, including CAR T-cell therapy, bispecific antibodies, antibody-drug conjugates, and novel PROteolysis Targeting Chimeras. Emerging new treatments for MM provide more choices for relapsed/refractory multiple myeloma (RRMM). The optimal therapy for each patient should be based on disease-related factors, such as previous therapies, duration of response to prior drugs, clinical and biochemical features of relapse, and the relationship of patient comorbidities with known AE profiles of the different therapies.

Effect of Autologous Stem Cell Transplantation Combined with Modified VTD Regimen on Elderly Patients with Multiple Myeloma and Its Influence on miRNA Cytokines

OBJECTIVE

To explore the effect of autologous stem cell transplantation combined with modified VTD regimen on elderly patients with multiple myeloma and its influence on miRNA cytokines.

METHODS

The data of 42 elderly patients with multiple myeloma who were treated in our hospital from May 2010 to June 2018 were retrospectively analyzed, and they were divided into the combined group (autologous stem cell transplantation combined with improved VTD scheme, n = 25) and the control group (improved VTD scheme, n = 17) according to different treatment schemes, and the clinical efficacy of the two groups was compared. The levels of CD3+, CD4+, CD4+/CD8+, and Treg were measured in the two groups. The expression levels of miRNA-15a, miRNA-16, and miRNA-21 in the bone marrow fluid of the two groups were measured before and after treatment. The levels of M protein and myeloma cells in the two groups were detected. Comparing the incidence of adverse reactions between the two groups, the Kaplan-Meier method was used for survival analysis.

RESULTS

The total effective rate of the combined group (84.00%) was higher than that of the control group (52.94%), and the difference was statistically significant (P < 0.05). After treatment, the levels of CD3+, CD4+, CD4+/CD8+, Treg, miRNA-15a, and miRNA-16 in the combined group were higher than those in the control group, and the levels of miRNA-21, M protein, and myeloma cells were lower than those in the control group, with statistical significance (P < 0.05). There was no significant difference in adverse reactions between the two groups (P > 0.05). The first, second, and third year survival rates of group A (96.00%, 88.00%, and 80.00%) were significantly higher than those of the control group (70.59%, 58.82%, and 47.06%), and the difference was statistically significant (P < 0.05).

CONCLUSION

Autologous stem cell transplantation combined with a modified VTD regimen can effectively improve the immune function and survival rate of elderly patients with multiple myeloma, which is safe and effective.

Inflammation and infection in plasma cell disorders: how pathogens shape the fate of patients

The role of infection and chronic inflammation in plasma cell disorders (PCD) has been well-described. Despite not being a diagnostic criterion, infection is a common complication of most PCD and represents a significant cause of morbidity and mortality in this population. As immune-based therapeutic agents are being increasingly used in multiple myeloma, it is important to recognize their impact on the epidemiology of infections and to identify preventive measures to improve outcomes. This review outlines the multiple factors attributed to the high infectious risk in PCD (e.g. the underlying disease status, patient age and comorbidities, and myeloma-directed treatment), with the aim of highlighting future prophylactic and preventive strategies that could be implemented in the clinic. Beyond this, infection and pathogens as an entity are believed to also influence disease biology from initiation to response to treatment and progression through a complex interplay involving pathogen exposure, chronic inflammation, and immune response. This review will outline both the direct and indirect role played by oncogenic pathogens in PCD, highlight the requirement for large-scale studies to decipher the precise implication of the microbiome and direct pathogens in the natural history of myeloma and its precursor disease states, and understand how, in turn, pathogens shape plasma cell biology.

An Overview of CAR T Cell Mediated B Cell Maturation Antigen Therapy

Multiple Myeloma (MM) is one of the incurable types of cancer in plasma cells. While immense progress has been made in the treatment of this malignancy, a large percentage of patients were unable to adapt to such therapy. Additionally, these therapies might be associated with significant diseases and are not always tolerated well in all patients. Since cancer in plasma cells has no cure, patients develop resistance to treatments, resulting in R/R MM (Refractory/Relapsed Multiple Myeloma). BCMA (B cell maturation antigen) is primarily produced on mature B cells. It's up-regulation and activation are associated with multiple myeloma in both murine and human models, indicating that this might be an effective therapeutic target for this type of malignancy. Additionally, BCMA's predictive value, association with effective clinical trials, and capacity to be utilized in previously difficult to observe patient populations, imply that it might be used as a biomarker for multiple myeloma. Numerous kinds of BCMA-targeting medicines have demonstrated antimyeloma efficacy in individuals with refractory/relapsed MM, including CAR T-cell (Chimeric antigen receptor T cell) treatments, ADCs (Antibody-drug conjugate s), bispecific antibody constructs. Among these medications, CART cell-mediated BCMA therapy has shown significant outcomes in multiple myeloma clinical trials. This review article outlines CAR T cell mediated BCMA medicines have the efficiency to change the therapeutic pattern for multiple myeloma significantly.

Targeted therapy of multiple myeloma

Multiple myeloma (MM) is a malignant proliferative disease of monoclonal plasma cells (PCs) and is characterized by uncontrolled proliferation of PCs and excessive production of specific types of immunoglobulins. Since PCs are terminally differentiated B cells, the World Health Organization (WHO) classifies MM as lymphoproliferative B-cell disease. The incidence of MM is 6-7 cases per 100,000 people in the world every year and the second most common cancer in the blood system. Due to the effects of drug resistance and malignant regeneration of MM cells in the microenvironment, all current treatment methods can prolong both overall and symptom-free survival rates of patients with MM but cannot cure MM. Both basic and clinical studies have proven that targeted therapy leads to a clear and significant prolongation of the survival of patients with MM, but when the disease recurs again, resistance to the previous treatment will occur. Therefore, the discovery of new targets and treatment methods plays a vital role in the treatment of MM. This article introduces and summarizes targeted MM therapy, potential new targets, and future precision medicine in MM.

Novel CS1 CAR-T Cells and Bispecific CS1-BCMA CAR-T Cells Effectively Target Multiple Myeloma

Multiple myeloma (MM) is a hematological cancer caused by abnormal proliferation of plasma cells in the bone marrow, and novel types of treatment are needed for this deadly disease. In this study, we aimed to develop novel CS1 CAR-T cells and bispecific CS1-BCMA CAR-T cells to specifically target multiple myeloma. We generated a new CS1 (CD319, SLAM-7) antibody, clone (7A8D5), which specifically recognized the CS1 antigen, and we applied it for the generation of CS1-CAR. CS1-CAR-T cells caused specific killing of CHO-CS1 target cells with secretion of IFN-gamma and targeted multiple myeloma cells. In addition, bispecific CS1-BCMA-41BB-CD3 CAR-T cells effectively killed CHO-CS1 and CHO-BCMA target cells, killed CS1/BCMA-positive multiple myeloma cells, and secreted IFN-gamma. Moreover, CS1-CAR-T cells and bispecific CS1-BCMA CAR-T cells effectively blocked MM1S multiple myeloma tumor growth in vivo. These data for the first time demonstrate that novel CS1 and bispecific CS1-BCMA-CAR-T cells are effective in targeting MM cells and provide a basis for future clinical trials.

A combination of carfilzomib, dexamethasone, and daratumumab for treatment of adult patients with relapsed/refractory multiple myeloma in two dosing regimens: once-weekly and twice-weekly

INTRODUCTION

Despite the development of new therapeutic agents, relapsed/refractory multiple myeloma (RRMM) is associated with poor survival outcomes. Furthermore, many patients develop resistance to immunomodulatory drugs (IMiD), creating a need for IMiD-free regimens. Areas covered: This review focuses on the combination of carfilzomib, dexamethasone, and daratumumab (KdD or DKd) which has shown promising results in patients with RRMM who have tried multiple lines of therapy, and has been approved in the U.S., EU, and Japan. The KdD triplet has two recommended dosage regimens, carfilzomib once-weekly (KdD70 QW) and carfilzomib twice-weekly (KdD56 BIW), with comparable efficacy and safety profiles. Expert opinion: These options provide flexibility to patients and healthcare providers, especially in the era of COVID-19. Carfilzomib-based regimens remain a standard of care based on multiple randomized phase 3 studies. Additional studies are currently underway investigating carfilzomib-based regimens such as KdD combined with novel agents. Nevertheless, KdD is one of the most efficacious options for patients with RRMM.

Depletion of high-content CD14+ cells from apheresis products is critical for successful transduction and expansion of CAR T cells during large-scale cGMP manufacturing

With the US Food and Drug Administration (FDA) approval of four CD19- and one BCMA-targeted chimeric antigen receptor (CAR) therapy for B cell malignancies, CAR T cell therapy has finally reached the status of a medicinal product. The successful manufacturing of autologous CAR T cell products is a key requirement for this promising treatment modality. By analyzing the composition of 214 apheresis products from 210 subjects across eight disease indications, we found that high CD14+ cell content poses a challenge for manufacturing CAR T cells, especially in patients with non-Hodgkin's lymphoma and multiple myeloma caused by the non-specific phagocytosis of the magnetic beads used to activate CD3+ T cells. We demonstrated that monocyte depletion via rapid plastic surface adhesion significantly reduces the CD14+ monocyte content in the apheresis products and simultaneously boosts the CD3+ content. We established a 40% CD14+ threshold for the stratification of apheresis products across nine clinical trials and demonstrated the effectiveness of this procedure by comparing manufacturing runs in two phase 1 clinical trials. Our study suggests that CD14+ content should be monitored in apheresis products, and that the manufacturing of CAR T cells should incorporate a step that lessens the CD14+ cell content in apheresis products containing more than 40% to maximize the production success.

Targeting BCMA in Multiple Myeloma

PURPOSE OF REVIEW

Despite considerable advances in the treatment of multiple myeloma (MM) in the last decade, a significant number of patients still progress on current available therapies. Here, we review treatment modalities used to target BCMA in the treatment of MM, specifically antibody-drug conjugates (ADC), bispecific antibody constructs, and chimeric antibody receptor (CAR) modified T-cell therapies. We will provide an overview of therapies from these classes that have presented or published clinical data, as well as data on mechanisms of resistance to these novel agents.

RECENT FINDINGS

Clinical trials exploring different BCMA-targeting modalities to treat multiple myeloma are underway and demonstrate promising results. In relapsed/refractory multiple myeloma, anti-BCMA ADCs and bispecific antibody constructs are showing impressive efficacy with manageable side effect profiles. In parallel, adoptive cellular therapy has induced dramatic durable responses in multiply relapsed and refractory myeloma patients. Therapeutic approaches targeting BCMA hold significant potential in the management of multiple myeloma and will soon be incorporated in combination with current standard therapies to improve outcomes for patients with multiple myeloma. In addition, novel approaches are being evaluated to overcome resistance mechanisms to anti-BCMA therapies.

Efficacy of Humanized Anti-BCMA CAR T Cell Therapy in Relapsed/Refractory Multiple Myeloma Patients With and Without Extramedullary Disease

In recent years, many new treatments for relapsed/refractory (R/R) multiple myeloma (MM) have improved patient prognosis, but the prognosis of patients with extramedullary MM is still particularly poor. Therefore, more efficacious therapies and novel strategies are urgently needed for these patients. The aim of this study was to observe and compare the efficacy and safety of humanized anti-B cell maturation antigen (anti-BCMA) chimeric antigen receptor (CAR) T cell therapy in R/R MM patients with and without extramedullary disease. Seven R/R MM patients with extramedullary disease and 13 without extramedullary disease received humanized anti-BCMA CAR T cell therapy. The overall response rate was not different between patients with and without extramedullary disease. There was no difference in the progression-free survival (PFS) or overall survival (OS) rates between the two groups at 180 days, but the PFS and OS rates in patients with extramedullary disease were lower at 360 days than those in patients without extramedullary disease. Although some patients with extramedullary disease experienced further disease progression, their M protein level did not increase. We did not see this change trend of M protein in patients without extramedullary disease. However, this was not observed in patients without extramedullary disease. Among patients who responded to CAR T cell therapy, the grades of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxic syndrome (ICANS) were much higher among patients with extramedullary disease. In summary, R/R MM patients with extramedullary disease could benefit from humanized anti-BCMA CAR T cell therapy in the short term, although the CRS and ICANS grades were much higher in patients with extramedullary disease. Therefore, anti-BCMA CAR T cell therapy allows for a remission time for R/R MM patients with extramedullary disease, which could be maintained by bridging hematopoietic stem cell transplantation, radiotherapy, and other therapies.

Clinical Trial Registration

http://www.chictr.org.cn/index.aspx, identifiers ChiCTR1800017051 and ChiCTR2000033925.

Chimeric Antigen Receptor-T Cells: A Pharmaceutical Scope

Cancer is among the leading causes of death worldwide. Therefore, improving cancer therapeutic strategies using novel alternatives is a top priority on the contemporary scientific agenda. An example of such strategies is immunotherapy, which is based on teaching the immune system to recognize, attack, and kill malignant cancer cells. Several types of immunotherapies are currently used to treat cancer, including adoptive cell therapy (ACT). Chimeric Antigen Receptors therapy (CAR therapy) is a kind of ATC where autologous T cells are genetically engineered to express CARs (CAR-T cells) to specifically kill the tumor cells. CAR-T cell therapy is an opportunity to treat patients that have not responded to other first-line cancer treatments. Nowadays, this type of therapy still has many challenges to overcome to be considered as a first-line clinical treatment. This emerging technology is still classified as an advanced therapy from the pharmaceutical point of view, hence, for it to be applied it must firstly meet certain requirements demanded by the authority. For this reason, the aim of this review is to present a global vision of different immunotherapies and focus on CAR-T cell technology analyzing its elements, its history, and its challenges. Furthermore, analyzing the opportunity areas for CAR-T technology to become an affordable treatment modality taking the basic, clinical, and practical aspects into consideration.

Resveratrol induces AMPK and mTOR signaling inhibition-mediated autophagy and apoptosis in multiple myeloma cells

Resveratrol, a natural compound extracted from the skins of grapes, berries, or other fruits, has been shown to have anti-tumor effects against multiple myeloma (MM) via promoting apoptosis and inhibiting cell viability. In addition to apoptosis, autophagy also plays a significant role in anti-tumor effects. However, whether autophagy is involved in anti-MM activity of resveratrol remains unclear. In this study, human MM cell lines U266, RPMI-8226, and NCI-H929 were treated with resveratrol. Cell Counting Kit-8 assay and colony formation assay were used to measure cell viability. Western blot analysis was used to detect apoptosis- and autophagy-associated proteins. 3-Methyladenine (3-MA) was applied to inhibit autophagy. Results showed that resveratrol inhibited cell viability and colony formation via promoting apoptosis and autophagy in MM cell lines U266, RPMI-8226, and NCI-H929. Resveratrol promoted apoptosis-related proteins, Caspase-3 activating poly-ADP-ribose polymerase and Caspase-3 cleavage, and decreased the protein level of Survivin in a dose-dependent manner. Additionally, resveratrol upregulated the levels of LC3 and Beclin1 in a dose-dependent way, indicating that autophagy might be implicated in anti-MM effect of resveratrol. Furthermore, 3-MA relieved the cytotoxicity of resveratrol by blocking the autophagic flux. Resveratrol increased the phosphorylation of adenosine monophosphate (AMP)-activated protein kinase and decreased the phosphorylation of mammalian target of rapamycin (mTOR) and its downstream substrates p70S6K and 4EBP1 in a dose-dependent manner, leading to autophagy. Therefore, our results suggest that resveratrol exerts anti-MM effects through apoptosis and autophagy, which can be used as a new therapeutic strategy for MM in clinic.

CAR T-cell therapy in multiple myeloma: more room for improvement

The emergence of various novel therapies over the last decade has changed the therapeutic landscape for multiple myeloma. While the clinical outcomes have improved significantly, the disease remains incurable, typically in patients with relapsed and refractory disease. Chimeric antigen receptor (CAR) T-cell therapies have achieved remarkable clinical success in B-cell malignancies. This scope of research has more recently been extended to the field of myeloma. While B-cell maturation antigen (BCMA) is currently the most well-studied CAR T antigen target in this disease, many other antigens are also undergoing intensive investigations. Some studies have shown encouraging results, whereas some others have demonstrated unfavorable results due to reasons such as toxicity and lack of clinical efficacy. Herein, we provide an overview of CAR T-cell therapies in myeloma, highlighted what has been achieved over the past decade, including the latest updates from ASH 2020 and discussed some of the challenges faced. Considering the current hits and misses of CAR T therapies, we provide a comprehensive analysis on the current manufacturing technologies, and deliberate on the future of CAR T-cell domain in MM.

How I prevent infections in patients receiving CD19-targeted chimeric antigen receptor T cells for B-cell malignancies

Adoptive immunotherapy using B-cell-targeted chimeric antigen receptor (CAR)-modified T cells to treat hematologic malignancies is transforming cancer care for patients with refractory or relapsed diseases. Recent and anticipated regulatory approval for products targeting acute lymphoblastic leukemia, lymphomas, and multiple myeloma have led to global implementation of these novel treatments. The rapidity of commercial utilization of CAR-T-cell therapy has created a largely unexplored gap in patient supportive-care approaches. Such approaches are critical in these complex patients given their high net state of immunosuppression prior to CAR-T-cell infusion coupled with unique acute and persistent insults to their immune function after CAR-T-cell infusion. In this "How I Treat" article, we focus on key questions that arise during 3 phases of management for patients receiving CD19-targeted CAR-T cells: pre CAR-T-cell infusion, immediate post CAR-T-cell infusion, and long-term follow-up. A longitudinal patient case is presented for each phase to highlight fundamental issues including infectious diseases screening, antimicrobial prophylaxis, immunoglobulin supplementation, risk factors for infection, and vaccination. We hope this discussion will provide a framework for institutions and health care providers to formulate their own approach to preventing infections in light of the paucity of data specific to this treatment modality.

Emerging immunotherapies in multiple myeloma

Despite considerable advances in treatment approaches in the past two decades, multiple myeloma remains an incurable disease. Treatments for myeloma continue to evolve with many emerging immunotherapies. The first immunotherapy used to treat hematologic cancers, including multiple myeloma, was an allogeneic stem cell transplant. In the mid-2000s, immunomodulatory drugs thalidomide, lenalidomide, and subsequently pomalidomide were proven to be effective in multiple myeloma and substantially improved survival. The next wave of immunotherapies for multiple myeloma included the monoclonal antibodies daratumumab and elotuzumab, which were approved by the Food and Drug Administration in 2015. Subsequently, a variety of immunotherapies have been developed for multiple myeloma, including chimeric antigen receptor T cells, bispecific antibodies, antibody drug conjugates, and checkpoint inhibitors. Many of these emerging treatments target the B cell maturation antigen, which is expressed on plasma cells, although several other novel receptors are also being studied. This review summarizes the evidence of these various immunotherapies, their mechanism of action, and data from clinical trials regarding the treatments' safety and efficacy.

Advances in engineering local drug delivery systems for cancer immunotherapy

Cancer immunotherapy aims to leverage the immune system to suppress the growth of tumors and to inhibit metastasis. The recent promising clinical outcomes associated with cancer immunotherapy have prompted research and development efforts towards enhancing the efficacy of immune checkpoint blockade, cancer vaccines, cytokine therapy, and adoptive T cell therapy. Advancements in biomaterials, nanomedicine, and micro-/nano-technology have facilitated the development of enhanced local delivery systems for cancer immunotherapy, which can enhance treatment efficacy while minimizing toxicity. Furthermore, locally administered cancer therapies that combine immunotherapy with chemotherapy, radiotherapy, or phototherapy have the potential to achieve synergistic antitumor effects. Herein, the latest studies on local delivery systems for cancer immunotherapy are surveyed, with an emphasis on the therapeutic benefits associated with the design of biomaterials and nanomedicines. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Lessons Learned from Checkpoint Blockade Targeting PD-1 in Multiple Myeloma

Immune checkpoints and agonists modulate ongoing, antigen-specific immune responses. Therapeutic blockade of CTLA-4, PD-1, and PD-L1 has proven to be an effective treatment approach for a subset of patients with a variety of cancers of epithelial, mesenchymal, or hematologic origin. In multiple myeloma, a B-cell lymphoid malignancy of terminally differentiated plasma cells, PD-1 pathway blockade is ineffective as a single agent. The initial promise in combination approaches utilizing anti-PD-1 with the immunomodulatory drugs, lenalidomide or pomalidomide, was not confirmed in randomized trials. Here, we explore available data for and against manipulation of the PD-1 pathway and other immune checkpoints in myeloma and highlight several promising concepts and challenges that face ongoing development of immunotherapeutics for this disease.

Daratumumab monotherapy for patients with intermediate-risk or high-risk smoldering multiple myeloma: a randomized, open-label, multicenter, phase 2 study (CENTAURUS)

Current guidelines for smoldering multiple myeloma (SMM) recommend active monitoring until the onset of multiple myeloma (MM) before initiating treatment or enrollment in a clinical trial. Earlier intervention may delay progression to MM. In CENTAURUS, 123 patients with intermediate-risk or high-risk SMM were randomly assigned to daratumumab 16 mg/kg intravenously on extended intense (intense), extended intermediate (intermediate), or short dosing schedules. At the prespecified primary analysis (15.8-month median follow-up), the complete response (CR) rates (co-primary endpoint) were 2.4%, 4.9%, and 0% for intense, intermediate, and short dosing, respectively; the co-primary endpoint of CR rate >15% was not met. Progressive disease (PD)/death rates (number of patients who progressed or died divided by total duration of progression-free survival [PFS] in patient-years; co-primary endpoint) for intense, intermediate, and short dosing were 0.055 (80% confidence interval [CI], 0.014-0.096), 0.102 (80% CI, 0.044-0.160), and 0.206 (80% CI, 0.118-0.295), respectively, translating to a median PFS ≥24 months in all arms (P < 0.0001, <0.0001, and =0.0213, respectively). With longer follow-up (median follow-up, 25.9 months), CR rates were 4.9%, 9.8%, and 0% for intense, intermediate, and short dosing, respectively. PD/death rates for intense, intermediate, and short dosing were 0.059 (80% CI, 0.025-0.092), 0.107 (80% CI, 0.058-0.155), and 0.150 (80% CI, 0.089-0.211), respectively, again translating to a median PFS ≥ 24 months in all arms (P < 0.0001 for all arms). Twenty-four-month PFS rates were 89.9% (90% CI, 78.5-95.4%), 82.0% (90% CI, 69.0-89.9%), and 75.3% (90% CI, 61.1-85.0%) for intense, intermediate, and short dosing, respectively. Pharmacokinetic analyses indicated that intense dosing maintained target-saturating trough concentrations in most patients throughout weekly, every-2-week, and every-4-week dosing periods. No new safety signals were observed. These data provide the basis for an ongoing phase 3 study of daratumumab in SMM.

Overview of anti-BCMA CAR-T immunotherapy for multiple myeloma and relapsed/refractory multiple myeloma

Multiple myeloma (MM) is a haematological malignancy caused by malignant proliferation of plasma cells in bone marrow. In recent years, MM patients are commonly treated with chemotherapy, autologous stem cell transplantation, protease inhibitors, immunomodulatory drugs and monoclonal antibodies, however most patients eventually relapse. Therefore, more effective therapies are highly needed. Anti-BCMA CAR-T therapy, a novel and efficacious method for treating MM and relapsed/refractory multiple myeloma (RRMM), has been designed and applied in clinics. The CAR-T can specifically recognize the targeted molecule B cell maturation antigen (BCMA) and kill MM cells expressing BCMA and several clinical trials have revealed high response rates in the therapy. Herein, we summarize the developments, the current design and clinical trials, the side effects of anti-BCMA CAR-T therapy and comparison of it with other CAR-T therapies.

Cardiovascular Effects of CAR T Cell Therapy: A Retrospective Study

BACKGROUND

Anti-CD19 chimeric antigen receptor (CAR) T cell (CART19) therapy holds great promise in the treatment of hematological malignancies. A high occurrence of cardiac dysfunction has been noted in children treated with CART19 therapy.

OBJECTIVES

We aimed to define the occurrence of major cardiovascular events (MACE) in adult patients treated with CART19 cells and assess the relationships between clinical factors, echocardiographic parameters, laboratory values, and cardiovascular outcomes.

METHODS

Baseline clinical, laboratory and echocardiographic parameters were collected in 145 adult patients undergoing CART19 cell therapy. MACE included cardiovascular death, symptomatic heart failure, acute coronary syndrome, ischemic stroke and de novo cardiac arrhythmia. Baseline parameters associated with MACE were identified using Cox proportional cause-specific hazards regression analysis.

RESULTS

Thirty-one patients had MACE (41 events) at a median time of 11 days (Q1-Q3:6-151 days) after CART19 cell infusion. The median follow-up period was 456 days (Q1-Q3: 128-1214 days). Sixty-one patients died. Cytokine release syndrome (CRS) occurred 176 times in 104 patients; the median time to CRS was 6 days (Q1-Q3: 1-8 days). The Kaplan-Meier estimates for MACE and CRS at 30 days were 17% and 53% respectively. The KM estimates for survival at 1 year was 71%. Multivariable Cox proportional cause-specific hazards regression analysis determined that baseline creatinine and Grade 3 or 4 CRS were independently associated with MACE.

CONCLUSION

Patients treated with CART19 are at an increased risk of MACE and may benefit from cardiovascular surveillance. Further large prospective studies are needed to confirm the incidence and risk factors predictive of MACE.

Cellular Immunotherapy for Multiple Myeloma

Cellular immunotherapy for myeloma has the unique potential both to potently kill the malignant clone and to evoke a memory response to protect from relapse. Understanding the complex interactions between the malignant clone and the microenvironment that promote immune escape is critical to evoke effective antimyeloma immunity. Tremendous progress has been made in the area of cancer vaccines and adoptive T-cell therapy in recent years. Careful study of the mechanisms of response and of immune escape will be critical to developing novel combination therapies and ultimately to improve outcomes for patients with myeloma.

CAR T and CAR NK cells in multiple myeloma: Expanding the targets

Multiple myeloma (MM) is a haematologic malignancy with significant improvements in the overall survival over the last decade. However, patients still relapse and die due to a lack of treatment options. Ultimately, novel therapies with the potential for long term remissions are needed for patients with advanced MM. Research efforts for such immune therapies were not successful until recently when the first immunotherapies for MM were approved in 2015 and many more are under development. In this review, we focus on adoptive cell therapies including CAR T-cell and CAR NK-cell therapies for patients with MM. We will provide an update on clinical and translational advances with a focus on results from ongoing clinical trials with BCMA targeted cellular therapies and the development of other novel targets, changes in the manufacturing process, trials focusing on earlier lines of therapy and combinations with other therapies as well as off the shelf products.

B-cell maturation antigen (BCMA) in multiple myeloma: rationale for targeting and current therapeutic approaches

Despite considerable advances in the treatment of multiple myeloma (MM) in the last decade, a substantial proportion of patients do not respond to current therapies or have a short duration of response. Furthermore, these treatments can have notable morbidity and are not uniformly tolerated in all patients. As there is no cure for MM, patients eventually become resistant to therapies, leading to development of relapsed/refractory MM. Therefore, an unmet need exists for MM treatments with novel mechanisms of action that can provide durable responses, evade resistance to prior therapies, and/or are better tolerated. B-cell maturation antigen (BCMA) is preferentially expressed by mature B lymphocytes, and its overexpression and activation are associated with MM in preclinical models and humans, supporting its potential utility as a therapeutic target for MM. Moreover, the use of BCMA as a biomarker for MM is supported by its prognostic value, correlation with clinical status, and its ability to be used in traditionally difficult-to-monitor patient populations. Here, we review three common treatment modalities used to target BCMA in the treatment of MM: bispecific antibody constructs, antibody–drug conjugates, and chimeric antigen receptor (CAR)-modified T-cell therapy. We provide an overview of preliminary clinical data from trials using these therapies, including the BiTE® (bispecific T-cell engager) immuno-oncology therapy AMG 420, the antibody–drug conjugate GSK2857916, and several CAR T-cell therapeutic agents including bb2121, NIH CAR-BCMA, and LCAR-B38M. Notable antimyeloma activity and high minimal residual disease negativity rates have been observed with several of these treatments. These clinical data outline the potential for BCMA-targeted therapies to improve the treatment landscape for MM. Importantly, clinical results to date suggest that these therapies may hold promise for deep and durable responses and support further investigation in earlier lines of treatment, including newly diagnosed MM.

Bone Marrow Stromal Cells-Induced Drug Resistance in Multiple Myeloma

Multiple myeloma is a B-cell lineage cancer in which neoplastic plasma cells expand in the bone marrow and pathophysiological interactions with components of microenvironment influence many biological aspects of the malignant phenotype, including apoptosis, survival, proliferation, and invasion. Despite the therapeutic progress achieved in the last two decades with the introduction of a more effective and safe new class of drugs (i.e., immunomodulators, proteasome inhibitors, monoclonal antibodies), there is improvement in patient survival, and multiple myeloma (MM) remains a non-curable disease. The bone marrow microenvironment is a complex structure composed of cells, extracellular matrix (ECM) proteins, and cytokines, in which tumor plasma cells home and expand. The role of the bone marrow (BM) microenvironment is fundamental during MM disease progression because modification induced by tumor plasma cells is crucial for composing a "permissive" environment that supports MM plasma cells proliferation, migration, survival, and drug resistance. The "activated phenotype" of the microenvironment of multiple myeloma is functional to plasma cell proliferation and spreading and to plasma cell drug resistance. Plasma cell drug resistance induced by bone marrow stromal cells is mediated by stress-managing pathways, autophagy, transcriptional rewiring, and non-coding RNAs dysregulation. These processes represent novel targets for the ever-increasing anti-MM therapeutic armamentarium.

Tandem Autologous-Autologous versus Autologous-Allogeneic Hematopoietic Stem Cell Transplant for Patients with Multiple Myeloma: Long-Term Follow-Up Results from the Blood and Marrow Transplant Clinical Trials Network 0102 Trial

Allogeneic hematopoietic cell transplant (HCT) may improve long-term multiple myeloma (MM) control through the graft-versus-myeloma effect. The Blood and Marrow Transplant Clinical Trials Network 0102 trial was a biologic assignment trial comparing tandem autologous transplant (auto-auto) versus autologous followed by reduced-intensity allogeneic (auto-allo) transplant in patients with newly diagnosed MM with standard-risk (n = 625) or high-risk (n = 85; β₂-microglobulin at diagnosis ≥ 4 mg/dL or deletion of chromosome 13 by conventional karyotyping) disease. Although the initial 3-year analysis showed no difference in progression-free survival (PFS) between arms in either risk group, we hypothesized that long-term follow-up may better capture the impact of the graft-versus-myeloma effect. Median follow-up of survivors was over 10 years. Among standard-risk patients there was no difference in PFS (hazard ratio [HR], 1.11; 95% confidence interval [CI], .93 to 1.35; P = .25) or OS (HR, 1.03; 95% CI, .82 to 1.28; P = .82). The 6-year PFS was 25% in the auto-auto arm versus 22% in the auto-allo arm (P = .32), and 6-year overall survival (OS) was 60% and 59%, respectively (P = .85). In the high-risk group, although there was no statistically significant difference in PFS (HR, .66; 95% CI, .41 to 1.07; P = .07) and OS (HR, 1.01; 95% CI, .60 to 1.71; P = .96), a reduction in 6-year risk of relapse of 77% versus 47% (P = .005) was reflected in better PFS of 13% versus 31% (P = .05) but similar OS, at 47% versus 51% (P = .69). Allogeneic HCT can lead to long-term disease control in patients with high-risk MM and needs to be explored in the context of modern therapy.

Immune cells within the tumor microenvironment: Biological functions and roles in cancer immunotherapy

The immune cells within the tumor microenvironment (TME) play important roles in tumorigenesis. It has been known that these tumor associated immune cells may possess tumor-antagonizing or tumor-promoting functions. Although the tumor-antagonizing immune cells within TME tend to target and kill the cancer cells in the early stage of tumorigenesis, the cancer cells seems to eventually escape from immune surveillance and even inhibit the cytotoxic function of tumor-antagonizing immune cells through a variety of mechanisms. The immune evasion capability, as a new hallmark of cancer, accidently provides opportunities for new strategies of cancer therapy, namely harnessing the immune cells to battle the cancer cells. Recently, the administrations of immune checkpoint modulators (represented by anti-CTLA4 and anti-PD antibodies) and adoptive immune cells (represented by CAR-T) have exhibited unexpected antitumor effect in multiple types of cancer, bringing a new era for cancer therapy. Here, we review the biological functions of immune cells within TME and their roles in cancer immunotherapy, and discuss the perspectives of the basic studies for improving the effectiveness of the clinical use.

Cardiotoxicity of Immune Therapy

The advent of immunotherapy, particularly immune checkpoint inhibitors and chimeric antigen receptor T-cell therapy, has ushered in a promising new era of treatment of patients with a variety of malignancies who historically had a poor prognosis. However, these therapies are associated with potentially life-threatening cardiovascular adverse effects. As immunotherapy evolves to include a wider variety of malignancies, risk stratification, prompt recognition, and treatment of cardiotoxicity will become increasingly important and hence cardiologists will need to play a fundamental role in the comprehensive care of these patients. This article reviews cardiotoxicity associated with contemporary immunotherapy and discusses potential management strategies.

CAR-T - and a side order of IgG, to go? - Immunoglobulin replacement in patients receiving CAR-T cell therapy

The development and regulatory approval of chimeric antigen receptor T cell (CAR-T) therapies targeting the B-lineage surface antigen CD19 represents a major milestone in cancer immunotherapy. This treatment also results in depletion of normal CD19+ B cells and is associated with hypogammaglobulinemia. These on-target, off-tumor toxicities may result in an increased risk for infection, particularly for encapsulated bacteria. Data regarding the efficacy and cost-effectiveness of prophylactic IgG replacement in CD19-targeted CAR-T cell therapy recipients is lacking, and current expert recommendations are extrapolated from the data for individuals with primary immune deficiencies. This article reviews CAR-T cell therapies targeting B-lineage lymphocytes, associated side effects, and considerations for the approach to management of hypogamaglobulinemia in this patient population. Studies are needed to establish evidence-based approaches to prophylactic immunoglobulin administration in this context, and strategies may differ by patient and CAR-T cell product characteristics.

Case-based roundtable on treatment approach for young, fit, newly diagnosed multiple myeloma patients

With the advent new proteasome inhibitors (carfilzomib, ixazomib), new immune-modulatory drugs (pomalidomide), and new monoclonal antibodies (elotuzimab, daratumumab) as approved treatments for myeloma, the therapeutic landscape for this disease has changed. In this chapter, using a case-based approach, I will provide a personal guide of how I approach myeloma therapy in a transplant eligible patient in 2018.

Therapy for relapsed multiple myeloma

Despite significant progress in our understanding and the development of novel therapies, most patients with multiple myeloma will experience relapse of their disease. Therapy of relapsed myeloma has improved due to the availability of novel agents that are highly active against the disease. However, the selection of therapy can be challenging due to the emergence of toxicities, comorbidities and frailty. In the following we discuss our approach to the treatment of the patient with relapsed myeloma.

Flow Cytometric Monitoring for Residual Disease in B Lymphoblastic Leukemia Post T Cell Engaging Targeted Therapies

The use of targeted therapy is growing in the setting of hematopoietic neoplasms. Flow cytometry is a cornerstone of residual disease monitoring post therapy in this group of malignancies. Often, there is overlap between antigens targeted by immunotherapies and gating reagents utilized for population identification by flow cytometry. Such overlap can render a previously excellent gating reagent inadequate for disease detection. Recently, several anti-CD19 T cell-engaging immunotherapeutic agents and an anti-CD22 immunotoxin have been FDA approved for use in B lymphoblastic leukemia (B-LL), with an anti-CD22 T cell-engaging agent in development. In the setting of such targeted therapies, CD19 and CD22 expression may be altered, compromising the use of these reagents for identification of abnormal blasts. We describe herein a strategy for flow cytometric monitoring for residual disease in patients with B-LL post T cell-engaging anti-CD19 and anti-CD22 therapies. © 2018 by John Wiley & Sons, Inc.

CAR-T Cells Based on Novel BCMA Monoclonal Antibody Block Multiple Myeloma Cell Growth

The cell-surface protein B cell maturation antigen (BCMA, CD269) has emerged as a promising target for CAR-T cell therapy for multiple myeloma. In order to create a novel BCMA CAR, we generated a new BCMA monoclonal antibody, clone 4C8A. This antibody exhibited strong and selective binding to human BCMA. BCMA CAR-T cells containing the 4C8A scFv were readily detected with recombinant BCMA protein by flow cytometry. The cells were cytolytic for RPMI8226, H929, and MM1S multiple myeloma cells and secreted high levels of IFN-γ in vitro. BCMA-dependent cytotoxicity and IFN-γ secretion were also observed in response to CHO (Chinese Hamster Ovary)-BCMA cells but not to parental CHO cells. In a mouse subcutaneous tumor model, BCMA CAR-T cells significantly blocked RPMI8226 tumor formation. When BCMA CAR-T cells were given to mice with established RPMI8226 tumors, the tumors experienced significant shrinkage due to CAR-T cell activity and tumor cell apoptosis. The same effect was observed with 3 humanized BCMA-CAR-T cells in vivo. These data indicate that novel CAR-T cells utilizing the BCMA 4C8A scFv are effective against multiple myeloma and warrant future clinical development.

CART cells are prone to Fas- and DR5-mediated cell death

Adoptive transfer of T cells transduced with Chimeric Antigen Receptors (CAR) are now FDA-approved for the treatment of B-cell malignancies. Yet, the functionality of the endogenous TCR in CART cells has not been fully assessed. Here, we demonstrate that CART cells progressively upregulate Fas, FasL, DR5 and TRAIL, which result in their programmed cell death, independently of antigen-mediated TCR or CAR activation. CART cell apoptosis occurs even when the CAR contains a single (co-)activatory domain such as CD3ζ, CD28 or 4-1BB. Importantly, the dominant role of the Fas and DR5 pathways in CART cell apoptosis is demonstrated by the significant rescue of CART cells upon in vivo blockade by combined Fas-Fc and DR5-Fc recombinant proteins. These observations are of crucial importance for the long-term persistence of CART cells and for the development of new applications including the combined TCR and CAR activation against solid tumors.