Clinical potential of SLAMF7 antibodies - focus on elotuzumab in multiple myeloma

GP, Gopalakrishnan AV. Role of Immune Cells and Receptors in Cancer Treatment: An Immunotherapeutic Approach

Cancer immunotherapy moderates the immune system’s ability to fight cancer. Due to its extreme complexity, scientists are working to put together all the puzzle pieces to get a clearer picture of the immune system. Shreds of available evidence show the connection between cancer and the immune system. Immune responses to tumors and lymphoid malignancies are influenced by B cells, γδT cells, NK cells, and dendritic cells (DCs). Cancer immunotherapy, which encompasses adoptive cancer therapy, monoclonal antibodies (mAbs), immune checkpoint therapy, and CART cells, has revolutionized contemporary cancer treatment. This article reviews recent developments in immune cell regulation and cancer immunotherapy. Various options are available to treat many diseases, particularly cancer, due to the progress in various immunotherapies, such as monoclonal antibodies, recombinant proteins, vaccinations (both preventative and curative), cellular immunotherapies, and cytokines.

Chimeric Antigen Receptor T-Cell Therapeutics for Multiple Myeloma: Moving Into the Spotlight

ABSTRACT

Chimeric antigen receptor (CAR) T-cell therapy has quickly emerged as a highly promising treatment for patients with relapsed and refractory multiple myeloma. There are numerous candidates under development, each with their unique characteristics and points of differentiation. The most recent US Food and Drug Administration approval of the first B-cell maturation antigen-targeted CAR-T cell therapy on March 26, 2021, has paved a path forward for the eventual evaluation of more of these investigational agents undergoing clinical trials. Herein, we highlight, from a clinical development perspective, the CAR-T cell therapies farthest along in development with updated data from the American Society of Hematology 2020 annual meeting. We also discuss potential paths of overcoming resistance to these therapies and the future direction for CAR-T cell therapeutics in multiple myeloma.

Bone Marrow Mesenchymal Stromal Cells Can Render Multiple Myeloma Cells Resistant to Cytotoxic Machinery of CAR T Cells through Inhibition of Apoptosis

PURPOSE

The microenvironment of multiple myeloma (MM) can critically impair therapy outcome, including immunotherapies. In this context, we have earlier demonstrated that bone marrow mesenchymal stromal cells (BMMSC) protect MM cells against the lytic machinery of MM-reactive cytotoxic T cells (CTL) and daratumumab-redirected natural killer (NK) cells through the upregulation of antiapoptotic proteins Survivin and Mcl-1 in MM cells. Here, we investigated the significance of this mode of immune escape on T cells engineered to express chimeric antigen receptors (CAR T cells).

EXPERIMENTAL DESIGN

We tested the cytolytic ability of a panel of 10 BCMA-, CD38-, and CD138-specific CAR T cells with different affinities against a model MM cell line and against patient-derived MM cells in the presence versus absence of BMMSCs.

RESULTS

Although BMMSCs hardly protected MM cells from lysis by high-affinity, strongly lytic BCMA- and CD38-CAR T cells, they significantly protected against lower affinity, moderately lytic BCMA-, CD38-, and CD138-specific CAR T cells in a cell-cell contact-dependent manner. Overall, there was a remarkable inverse correlation between the protective ability of BMMSCs and the lytic activity of all CAR T cells, which was dependent on CAR affinity and type of costimulation. Furthermore, BMMSC-mediated resistance against CAR T cells was effectively modulated by FL118, an inhibitor of antiapoptotic proteins Survivin, Mcl-1, and XIAP.

CONCLUSIONS

These results extend our findings on the negative impact of the microenvironment against immunotherapies and suggest that outcome of CAR T cell or conventional CTL therapies could benefit from inhibition of antiapoptotic proteins upregulated in MM cells through BMMSC interactions.

Any closer to successful therapy of multiple myeloma? CAR-T cell is a good reason for optimism

Despite many recent advances on cancer novel therapies, researchers have yet a long way to cure cancer. They have to deal with tough challenges before they can reach success. Nonetheless, it seems that recently developed immunotherapy-based therapy approaches such as adoptive cell transfer (ACT) have emerged as a promising therapeutic strategy against various kinds of tumors even the cancers in the blood (liquid cancers). The hematological (liquid) cancers are hard to be targeted by usual cancer therapies, for they do not form localized solid tumors. Until recently, two types of ACTs have been developed and introduced; tumor-infiltrating lymphocytes (TILs) and chimeric antigen receptor (CAR)-T cells which the latter is the subject of our discussion. It is interesting about engineered CAR-T cells that they are genetically endowed with unique cancer-specific characteristics, so they can use the potency of the host immune system to fight against either solid or liquid cancers. Multiple myeloma (MM) or simply referred to as myeloma is a type of hematological malignancy that affects the plasma cells. The cancerous plasma cells produce immunoglobulins (antibodies) uncontrollably which consequently damage the tissues and organs and break the immune system function. Although the last few years have seen significant progressions in the treatment of MM, still a complete remission remains unconvincing. MM is a medically challenging and stubborn disease with a disappointingly low rate of survival rate. When comparing the three most occurring blood cancers (i.e., lymphoma, leukemia, and myeloma), myeloma has the lowest 5-year survival rate (around 40%). A low survival rate indicates a high mortality rate with difficulty in treatment. Therefore, novel CAR-T cell-based therapies or combination therapies along with CAT-T cells may bring new hope for multiple myeloma patients. CAR-T cell therapy has a high potential to improve the remission success rate in patients with MM. To date, many preclinical and clinical trial studies have been conducted to investigate the ability and capacity of CAR T cells in targeting the antigens on myeloma cells. Despite the problems and obstacles, CAR-T cell experiments in MM patients revealed a robust therapeutic potential. However, several factors might be considered during CAR-T cell therapy for better response and reduced side effects. Also, incorporating the CAT-T cell method into a combinational treatment schedule may be a promising approach. In this paper, with a greater emphasis on CAR-T cell application in the treatment of MM, we will discuss and introduce CAR-T cell's history and functions, their limitations, and the solutions to defeat the limitations and different types of modifications on CAR-T cells.

Perspectives for the Use of CAR-T Cells for the Treatment of Multiple Myeloma

During recent years considerable progress has been made in the treatment of multiple myeloma. However, despite the current improvements in the prognosis of this malignancy, it always ends with relapse, and therefore new therapy approaches for destroying resistant cancer cells are needed. Presently, there is great hope being placed in the use of immunotherapy against refractory/relapsed multiple myeloma which is unresponsive to any other currently known drugs. The most promising one is CAR-T cell therapy which has already shown tremendous success in treating other malignancies such as acute lymphoblastic leukaemia (ALL) and could potentially be administered to multiple myeloma patients. CAR-T cells equipped with receptors against BCMA (B-cell maturation antigen), which is a surface antigen that is highly expressed on malignant cells, are now of great interest in this field with significant results in clinical trials. Furthermore, CAR-T cells with other receptors and combinations of different strategies are being intensively studied. However, even with CAR-T cell therapy, the majority of patients eventually relapse, which is the greatest limitation of this therapy. Serious adverse events such as cytokine release syndrome or neurotoxicity should also be considered as possible side effects of CAR-T cell therapy. Here, we discuss the results of CAR-T cell therapy in the treatment of multiple myeloma, where we describe its main advantages and disadvantages. Additionally, we also describe the current results that have been obtained on using combinations of CAR-T cell therapies with other drugs for the treatment of multiple myeloma.

Current Status of Chimeric Antigen Receptor T-Cell Therapy in Multiple Myeloma

Multiple myeloma (MM) is an incurable malignancy of plasma cells. Recently multiple new therapeutic options have been introduced which was able to improve overall survival but ultimately patient become refractory specifically in patients with poor cytogenetics. Therefore, novel therapeutic options like immunotherapy are needed to improve outcomes. Chimeric antigen receptor (CAR) T-cell therapy is immunotherapy in which T cell are genetically engineered against a tumor-specific antigen and transfused back to the patient to mount major histocompatibility complex-independent cancer-specific immune response. The success of CAR T-cell therapy in lymphoid malignancies encouraged its development in MM. Most of the clinical studies target B-cell maturation antigen in relapsed refractory MM and relapse is the major issue. In this article, we will present the basics of CAR T-cell therapy, the most recent clinical and preclinical data, and we will discuss the future therapeutic realm of CAR T cells in MM.

Paving the Way toward Successful Multiple Myeloma Treatment: Chimeric Antigen Receptor T-Cell Therapy

Despite the significant progress of modern anticancer therapies, multiple myeloma (MM) is still incurable for the majority of patients. Following almost three decades of development, chimeric antigen receptor (CAR) T-cell therapy now has the opportunity to revolutionize the treatment landscape and meet the unmet clinical need. However, there are still several major hurdles to overcome. Here we discuss the recent advances of CAR T-cell therapy for MM with an emphasis on future directions and possible risks. Currently, CAR T-cell therapy for MM is at the first stage of clinical studies, and most studies have focused on CAR T cells targeting B cell maturation antigen (BCMA), but other antigens such as cluster of differentiation 138 (CD138, syndecan-1) are also being evaluated. Although this therapy is associated with side effects, such as cytokine release syndrome and neurotoxicity, and relapses have been observed, the benefit–risk balance and huge potential drive the ongoing clinical progress. To fulfill the promise of recent clinical trial success and maximize the potential of CAR T, future efforts should focus on the reduction of side effects, novel targeted antigens, combinatorial uses of different types of CAR T, and development of CAR T cells targeting more than one antigen.

Current advances in chimeric antigen receptor T-cell therapy for refractory/relapsed multiple myeloma

Multiple myeloma (MM), considered an incurable hematological malignancy, is characterized by its clonal evolution of malignant plasma cells. Although the application of autologous stem cell transplantation (ASCT) and the introduction of novel agents such as immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) have doubled the median overall survival to eight years, relapsed and refractory diseases are still frequent events in the course of MM. To achieve a durable and deep remission, immunotherapy modalities have been developed for relapsed/refractory multiple myeloma (RRMM). Among these approaches, chimeric antigen receptor (CAR) T-cell therapy is the most promising star, based on the results of previous success in B-cell neoplasms. In this immunotherapy, autologous T cells are engineered to express an artificial receptor which targets a tumor-associated antigen and initiates the T-cell killing procedure. Tisagenlecleucel and Axicabtagene, targeting the CD19 antigen, are the two pacesetters of CAR T-cell products. They were approved by the US Food and Drug Administration (FDA) in 2017 for the treatment of acute lymphocytic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL). Their development enabled unparalleled efficacy in combating hematopoietic neoplasms. In this review article, we summarize six promising candidate antigens in MM that can be targeted by CARs and discuss some noteworthy studies of the safety profile of current CAR T-cell therapy.

Chimeric antigen receptor T cell therapies for multiple myeloma

Multiple myeloma (MM) is the second most common hematologic malignancy and remains incurable despite the advent of numerous new drugs such as proteasome inhibitors (PIs), immunomodulatory agents (IMiDs), and monoclonal antibodies. There is an unmet need to develop novel therapies for refractory/relapsed MM. In the past few years, chimeric antigen receptor (CAR)-modified T cell therapy for MM has shown promising efficacy in preclinical and clinical studies. Furthermore, the toxicities of CAR-T cell therapy are manageable. This article summarizes recent developments of CAR-T therapy in MM, focusing on promising targets, new technologies, and new research areas. Additionally, a comprehensive overview of antigen selection is presented along with preliminary results and future directions of CAR-T therapy development.

Exploiting NK Cell Surveillance Pathways for Cancer Therapy

Natural killer (NK) cells can evoke potent anti-tumour activity. This function is largely mediated through a battery of specialised cell-surface receptors which probe the tissue microenvironment for changes in surface and secretory phenotypes that may alert to the presence of infection or malignancy. These receptors have the potential to arouse the robust cytotoxic and cytokine-secreting functions of NK cells and so must be tightly regulated to prevent autoimmunity. However, such functions also hold great promise for clinical intervention. In this review, we highlight some of the latest breakthroughs in fundamental NK cell receptor biology that have illuminated our understanding of the molecular strategies NK cells employ to perceive malignant cells from normal healthy cells. Moreover, we highlight how these sophisticated tumour recognition strategies are being harnessed for cancer immunotherapies in the clinic.

Current developments in immunotherapy in the treatment of multiple myeloma

Multiple myeloma (MM) is the second most common hematologic malignancy and represents approximately 10% of all hematological neoplasms. Standard therapy consists of induction therapy followed by high-dose chemotherapy and autologous stem cell transplantation (ASCT) or, if ASCT cannot be performed, standard doublet, triplet, or quadruplet, novel agent-containing induction treatment until progression. Although MM is still regarded as mostly incurable by current standards, the development of several novel compounds, combination therapies, and immunotherapy approaches has raised great hopes about transforming MM into an indolent, chronic disease and possibly achieving a cure for individual patients. Several new inhibitory and immunological agents have been approved or are under intensive investigation and may lead to new therapeutic options for patients with relapsed/refractory MM, for patients ineligible for ASCT, and for patients after ASCT. Especially in the field of immunotherapy, including monoclonal antibodies, checkpoint inhibition, and chimeric antigen receptor T cells, current advances are rapid and highly promising. This review aims to summarize the newest and most promising immunotherapeutic agents for MM, their clinical efficacy, their adverse event (AE) profiles, and the ways in which these AEs can best be overcome or avoided. Cancer 2018;124:2075-85. © 2018 American Cancer Society.

Monoclonal Antibody Therapies for Hematological Malignancies: Not Just Lineage-Specific Targets

Today, monoclonal antibodies (mAbs) are a widespread and necessary tool for biomedical science. In the hematological cancer field, since rituximab became the first mAb approved by the Food and Drug Administration for the treatment of B-cell malignancies, a number of effective mAbs targeting lineage-specific antigens (LSAs) have been successfully developed. Non-LSAs (NLSAs) are molecules that are not restricted to specific leukocyte subsets or tissues but play relevant pathogenic roles in blood cancers including the development, proliferation, survival, and refractoriness to therapy of tumor cells. In consequence, efforts to target NLSAs have resulted in a plethora of mAbs-marketed or in development-to achieve different goals like neutralizing oncogenic pathways, blocking tumor-related chemotactic pathways, mobilizing malignant cells from tumor microenvironment to peripheral blood, modulating immune-checkpoints, or delivering cytotoxic drugs into tumor cells. Here, we extensively review several novel mAbs directed against NLSAs undergoing clinical evaluation for treating hematological malignancies. The review focuses on the structure of these antibodies, proposed mechanisms of action, efficacy and safety profile in clinical studies, and their potential applications in the treatment of hematological malignancies.

Chimeric antigen receptor T-cell therapies for multiple myeloma

Multiple myeloma (MM) is a nearly always incurable malignancy of plasma cells, so new approaches to treatment are needed. T-cell therapies are a promising approach for treating MM, with a mechanism of action different than those of standard MM treatments. Chimeric antigen receptors (CARs) are fusion proteins incorporating antigen-recognition domains and T-cell signaling domains. T cells genetically engineered to express CARs can specifically recognize antigens. Success of CAR-T cells (CAR-Ts) against leukemia and lymphoma has encouraged development of CAR-T therapies for MM. Target antigens for CARs must be expressed on malignant cells, but expression on normal cells must be absent or limited. B-cell maturation antigen is expressed by normal and malignant plasma cells. CAR-Ts targeting B-cell maturation antigen have demonstrated significant antimyeloma activity in early clinical trials. Toxicities in these trials, including cytokine release syndrome, have been similar to toxicities observed in CAR-T trials for leukemia. Targeting postulated CD19+ myeloma stem cells with anti-CD19 CAR-Ts is a novel approach to MM therapy. MM antigens including CD138, CD38, signaling lymphocyte-activating molecule 7, and κ light chain are under investigation as CAR targets. MM is genetically and phenotypically heterogeneous, so targeting of >1 antigen might often be required for effective treatment of MM with CAR-Ts. Integration of CAR-Ts with other myeloma therapies is an important area of future research. CAR-T therapies for MM are at an early stage of development but have great promise to improve MM treatment.