Expression of chimeric receptor composed of immunoglobulin-derived V regions and T-cell receptor-derived C regions

Development of Beta-Amyloid-Specific CAR-Tregs for the Treatment of Alzheimer's Disease

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disease that remains uncured. Its pathogenesis is characterized by the formation of β-amyloid (Aβ) plaques. The use of antigen-specific regulatory T cells (Tregs) through adoptive transfer has shown promise for the treatment of many inflammatory diseases, although the effectiveness of polyspecific Tregs is limited. Obtaining a sufficient number of antigen-specific Tregs from patients remains challenging.

AIMS AND METHODS

To address this problem, we used an antibody-like single-chain variable fragment from a phage library and subsequently generated a chimeric antigen receptor (CAR) targeting β-amyloid.

RESULTS

The β-amyloid-specific CARs obtained were stimulated by both recombinant and membrane-bound Aβ isolated from the murine brain. The generated CAR-Tregs showed a normal Treg phenotype, were antigen-specific activatable, and had suppressive capacity.

CONCLUSION

This study highlights the potential of CAR technology to generate antigen-specific Tregs and presents novel approaches for developing functional CARs.

In Synergy: Optimizing CAR T Development and Personalizing Patient Care Using Single-Cell Technologies

Chimeric antigen receptor (CAR) T therapies hold immense promise to revolutionize cancer treatment. Nevertheless, key challenges, primarily in solid tumor settings, continue to hinder the application of this technology. Understanding CAR T-cell mechanism of action, in vivo activity, and clinical implications is essential for harnessing its full therapeutic potential. Single-cell genomics and cell engineering tools are becoming increasingly effective for the comprehensive research of complex biological systems. The convergence of these two technologies can accelerate CAR T-cell development. Here, we examine the potential of applying single-cell multiomics for the development of next-generation CAR T-cell therapies.

SIGNIFICANCE

Although CAR T-cell therapies have demonstrated remarkable clinical results in treating cancer, their effectiveness in most patients and tumor types remains limited. Single-cell technologies, which are transforming our understanding of molecular biology, provide new opportunities to overcome the challenges of CAR T-cell therapies. Given the potential of CAR T-cell therapy to tip the balance in the fight against cancer, it is important to understand how single-cell multiomic approaches can be leveraged to develop the next generations of more effective and less toxic CAR T-cell products and to provide powerful decision-making tools for clinicians to optimize treatment and improve patient outcomes.

Chimeric Antigen Receptor (CAR) T-Cell Therapy for Patients with Lung Cancer: Current Perspectives

Immunotherapy using chimeric antigen receptor (CAR)-engineered T-cells has achieved unprecedented efficacy in selected hematological cancers. However, solid tumors such as lung cancer impose several additional challenges to the attainment of clinical success using this emerging therapeutic modality. Lung cancer is the biggest cause of cancer-related mortality worldwide, accounting for approximately 1.8 million deaths worldwide each year. Obstacles to the development of CAR T-cell immunotherapy for lung cancer include the selection of safe tumor-selective targets, accounting for the large number of candidates that have been evaluated thus far. Tumor heterogeneity is also a key hurdle, meaning that single target-based approaches are susceptible to therapeutic failure through the emergence of antigen null cancers. There is also a need to enable CAR T-cells to traffic efficiently to sites of disease, to infiltrate tumor deposits and to operate within the hostile tumor microenvironment formed by solid tumors, resisting the onset of exhaustion. Multiple immune, metabolic, physical and chemical barriers operate at the core of malignant lesions, with potential for further heterogeneity and evolution in the face of selective therapeutic pressures. Although the extraordinarily adaptable nature of lung cancers has recently been unmasked, immunotherapy using immune checkpoint blockade can achieve long-term disease control in a small number of patients, establishing clinical proof of concept that immunotherapies can control advanced lung carcinomas. This review summarizes pre-clinical CAR T-cell research that is specifically focused on lung cancer in addition to published and ongoing clinical trial activity. A number of advanced engineering strategies are also described which are designed to bridge the gap to the attainment of meaningful efficacy using genetically engineered T-cells.

Comprehensive clinical evaluation of CAR-T cell immunotherapy for solid tumors: a path moving forward or a dead end?

INTRODUCTION

Chimeric Antigen Receptor (CAR)-T cell therapy is a form of adoptive cell therapy that has demonstrated tremendous results in the treatment of hematopoietic malignancies, leading to the US Food and Drug Administration (FDA) approval of four CD19-targeted CAR-T cell products. With the unprecedented success of CAR-T cell therapy in hematological malignancies, hundreds of preclinical studies and clinical trials are currently undergoing to explore the translation of this treatment to solid tumors. However, the clinical experience in non-hematologic malignancies has been less encouraging, with only a few patients achieving complete responses. Tumor-associated antigen heterogeneity, inefficient CAR-T cell trafficking and the immunosuppressive tumor microenvironment are considered as the most pivotal roadblocks in solid tumor CAR-T cell therapy.

MATERIALS AND METHODS

We reviewed the relevant literature/clinical trials for CAR-T cell immunotherapy for solid tumors from Pubmed and ClinicalTrials.gov.

CONCLUSION

Herein, we provide an update on solid tumor CAR-T cell clinical trials, focusing on the studies with published results. We further discuss some of the key hurdles that CAR-T cell therapy is encountering for solid tumor treatment as well as the strategies that are exploited to overcome these obstacles.

From bench to bedside: the history and progress of CAR T cell therapy

Chimeric antigen receptor (CAR) T cell therapy represents a major breakthrough in cancer care since the approval of tisagenlecleucel by the Food and Drug Administration in 2017 for the treatment of pediatric and young adult patients with relapsed or refractory acute lymphocytic leukemia. As of April 2023, six CAR T cell therapies have been approved, demonstrating unprecedented efficacy in patients with B-cell malignancies and multiple myeloma. However, adverse events such as cytokine release syndrome and immune effector cell-associated neurotoxicity pose significant challenges to CAR T cell therapy. The severity of these adverse events correlates with the pretreatment tumor burden, where a higher tumor burden results in more severe consequences. This observation is supported by the application of CD19-targeted CAR T cell therapy in autoimmune diseases including systemic lupus erythematosus and antisynthetase syndrome. These results indicate that initiating CAR T cell therapy early at low tumor burden or using debulking strategy prior to CAR T cell infusion may reduce the severity of adverse events. In addition, CAR T cell therapy is expensive and has limited effectiveness against solid tumors. In this article, we review the critical steps that led to this groundbreaking therapy and explore ongoing efforts to overcome these challenges. With the promise of more effective and safer CAR T cell therapies in development, we are optimistic that a broader range of cancer patients will benefit from this revolutionary therapy in the foreseeable future.

CX3CR1 deficiency-induced TIL tumor restriction as a novel addition for CAR-T design in solid malignancies

Advances in the understanding of the tumor microenvironment have led to development of immunotherapeutic strategies, such as chimeric antigen receptor T cells (CAR-Ts). However, despite success in blood malignancies, CAR-T therapies in solid tumors have been hampered by their restricted infiltration. Here, we used our understanding of early cytotoxic lymphocyte infiltration of human lymphocytes in solid tumors in vivo to investigate the receptors in normal, adjacent, and tumor tissues of primary non-small-cell lung cancer specimens. We found that CX3CL1-CX3CR1 reduction restricts cytotoxic cells from the solid-tumor bed, contributing to tumor escape. Based on this, we designed a CAR-T construct using the well-established natural killer group 2, member D (NKG2D) CAR-T expression together with overexpression of CX3CR1 to promote their infiltration. These CAR-Ts infiltrate tumors at higher rates than control-activated T cells or IL-15-overexpressing NKG2D CAR-Ts. This construct also had similar functionality in a liver-cancer model, demonstrating potential efficacy in other solid malignancies.

CAR-T Cells in the Treatment of Ovarian Cancer: A Promising Cell Therapy

Ovarian cancer (OC) is among the most common gynecologic malignancies with a poor prognosis and a high mortality rate. Most patients are diagnosed at an advanced stage (stage III or IV), with 5-year survival rates ranging from 25% to 47% worldwide. Surgical resection and first-line chemotherapy are the main treatment modalities for OC. However, patients usually relapse within a few years of initial treatment due to resistance to chemotherapy. Cell-based therapies, particularly adoptive T-cell therapy and chimeric antigen receptor T (CAR-T) cell therapy, represent an alternative immunotherapy approach with great potential for hematologic malignancies. However, the use of CAR-T-cell therapy for the treatment of OC is still associated with several difficulties. In this review, we comprehensively discuss recent innovations in CAR-T-cell engineering to improve clinical efficacy, as well as strategies to overcome the limitations of CAR-T-cell therapy in OC.

Adoptive cellular immunotherapy for solid neoplasms beyond CAR-T

In recent decades, immune checkpoint blockade and chimeric antigen receptor T cell (CAR-T) therapy are two milestone achievements in clinical immunotherapy. However, both show limited efficacies in most solid neoplasms, which necessitates the exploration of new immunotherapeutic modalities. The failure of CAR-T and immune checkpoint blockade in several solid neoplasms is attributed to multiple factors, including low antigenicity of tumor cells, low infiltration of effector T cells, and diverse mechanisms of immunosuppression in the tumor microenvironment. New adoptive cell therapies have been attempted for solid neoplasms, including TCR-T, CAR-natural killer cells (CAR-NK), and CAR-macrophages (CAR-M). Compared to CAR-T, these new adoptive cell therapies have certain advantages in treating solid neoplasms. In this review, we summarized the 40-year evolution of adoptive cell therapies, then focused on the advances of TCR-T, CAR-NK, and CAR-M in solid neoplasms and discussed their potential clinical applications.

CAR-T-Derived Extracellular Vesicles: A Promising Development of CAR-T Anti-Tumor Therapy

Extracellular vesicles (EVs) are a heterogenous population of plasma membrane-surrounded particles that are released in the extracellular milieu by almost all types of living cells. EVs are key players in intercellular crosstalk, both locally and systemically, given that they deliver their cargoes (consisting of proteins, lipids, mRNAs, miRNAs, and DNA fragments) to target cells, crossing biological barriers. Those mechanisms further trigger a wide range of biological responses. Interestingly, EV phenotypes and cargoes and, therefore, their functions, stem from their specific parental cells. For these reasons, EVs have been proposed as promising candidates for EV-based, cell-free therapies. One of the new frontiers of cell-based immunotherapy for the fight against refractory neoplastic diseases is represented by genetically engineered chimeric antigen receptor T (CAR-T) lymphocytes, which in recent years have demonstrated their effectiveness by reaching commercialization and clinical application for some neoplastic diseases. CAR-T-derived EVs represent a recent promising development of CAR-T immunotherapy approaches. This crosscutting innovative strategy is designed to exploit the advantages of genetically engineered cell-based immunotherapy together with those of cell-free EVs, which in principle might be safer and more efficient in crossing biological and tumor-associated barriers. In this review, we underlined the potential of CAR-T-derived EVs as therapeutic agents in tumors.

Systematic Review on CAR-T Cell Clinical Trials Up to 2022: Academic Center Input

The development of Chimeric Antigen Receptor T cells therapy initiated by the United States and China is still currently led by these two countries with a high number of clinical trials, with Europe lagging in launching its first trials. In this systematic review, we wanted to establish an overview of the production of CAR-T cells in clinical trials around the world, and to understand the causes of this delay in Europe. We particularly focused on the academic centers that are at the heart of research and development of this therapy. We counted 1087 CAR-T cells clinical trials on ClinicalTrials.gov (Research registry ID: reviewregistry1542) on the date of 25 January 2023. We performed a global analysis, before analyzing the 58 European trials, 34 of which sponsored by academic centers. Collaboration between an academic and an industrial player seems to be necessary for the successful development and application for marketing authorization of a CAR-T cell, and this collaboration is still cruelly lacking in European trials, unlike in the leading countries. Europe, still far behind the two leading countries, is trying to establish measures to lighten the regulations surrounding ATMPs and to encourage, through the addition of fundings, clinical trials involving these treatments.

Chimeric Antigen Receptor T-Cell Therapy for Solid Tumors: The Past and the Future

Chimeric antigen receptor (CAR) T-cell therapy is the new standard treatment for various indications in patients with advanced hematologic malignancies. Despite the several preclinical and early phase clinical trials, the overall clinical experience has been disappointing when applying this innovative therapy in solid tumors. The failure of CAR T-cell therapy and its limited antitumor activity in solid tumors have been attributed to several mechanisms, including tumor antigen heterogeneity, the hostile tumor microenvironment and poor trafficking of CAR T cells into tumor sites, and the unacceptable toxicities in some settings, among others. However, remarkable improvements have been made in understanding many of these failure mechanisms for which several emerging novel approaches are being applied to overcome these challenges. In this review, after a brief historic background for immunotherapy in solid tumors, we highlight the recent developments achieved in CAR T-cell designs, summarize completed clinical trials, and discuss current challenges facing CAR T-cell therapy and the suggested strategies to overcome these barriers.

CAR-T Cell Therapy and the Gut Microbiota

Chimeric antigen receptor (CAR) - T cell cancer therapy has yielded promising results in treating hematologic malignancies in clinical studies, and a growing number of CAR-T regimens are approved for clinical usage. While the therapy is considered of great potential in expanding the cancer immunotherapy arsenal, more than half of patients receiving CAR-T infusions do not respond, while others develop significant adverse effects, collectively indicating a need for optimization of CAR-T treatment to the individual. The microbiota is increasingly suggested as a major modulator of immunotherapy responsiveness. Studying causal microbiota roles possibly contributing to CAR-T therapy efficacy, adverse effects reduction, and prediction of patient responsiveness constitutes an exciting area of active research. Herein, we discuss the latest developments implicating human microbiota involvement in CAR-T therapy, while highlighting challenges and promises in harnessing the microbiota as a predictor and modifier of CAR-T treatment towards optimized efficacy and minimization of treatment-related adverse effects.

A Review of CAR-T Therapy in Pediatric and Young Adult B-Lineage Acute Leukemia: Clinical Perspectives in Singapore

Approximately 10-15% of pediatric B-cell acute lymphoblastic leukemia (B-ALL) are high risk at diagnosis or relapsed/ refractory. Prior to the availability of chimeric antigen receptor T-cell (CAR-T) in Singapore and the region, the treatment options for these paediatric and young adults are conventional salvage chemotherapy or chemo-immunotherapy regimens as a bridge to allogeneic total body irradiation-based hematopoietic stem cell transplantation (allo-HSCT). This results in significant acute and long-term toxicities, with suboptimal survival outcomes. Finding a curative salvage therapy with fewer long-term toxicities would translate to improved quality-adjusted life years in these children and young adults. In this review, we focus on the burden of relapsed/refractory pediatric B-ALL, the limitations of current strategies, the emerging paradigms for the role of CAR-T in r/r B-ALL, our local perspectives on the health economics and future direction of CAR-T therapies in pediatric patients.

[CAR-T cells development in solid tumors]

CAR-T cells have produced very promising results in the field of onco-hematology and have been rapidly approved for marketing in France for several years now. In solid tumors, current results are more disappointing. Indeed, many hurdles come in the way. Tumor vascularization, the strongly immunosuppressive microenvironment, the loss of the target antigen as well as T cell exhaustion are part of the explanation of those results. Hence many researchers are working to develop strategies to counteract these resistance mechanisms. Arming CAR-T cells with BiTEs, with immune checkpoint inhibitors or with interleukins seem to be effective ways to improve antitumor efficacy. Other strategies including vaccines association or local delivery of the CAR-T cells look very promising. Many Phase I studies are investigating these new strategies and are expected to improve the previous results obtained to date in this area.

Successful Generation of CD19 Chimeric Antigen Receptor T Cells from Patients with Advanced Systemic Lupus Erythematosus

Although it has been shown that the production of functional chimeric antigen receptor T cells is feasible in patients with B-cell malignancies, it is currently unclear whether sufficient amounts of functional autologous CAR T cells can be generated from patients with autoimmune diseases. Intrinsic T-cell abnormalities and T-cell-targeted immune suppression in patients with autoimmunity may hamper the retrieval of sufficient T cells and their transduction and expansion into CAR T cells. Patients with active systemic lupus erythematosus (SLE) underwent leukapheresis after tapering glucocorticoids and stopping T-cell-suppressive drugs. This material was used as source for manufacturing anti-CD19 CAR T-cell products (CAR) in clinical scale. Cells were transduced with a lentiviral anti-CD19 CAR vector and expanded under good manufacturing practice (GMP) conditions using a closed, semi-automatic system. Functionality of these CAR T cells derived from autoimmune patient cells was tested in vitro. Six SLE patients were analyzed. Leukapheresis could be successfully performed in all patients yielding sufficient T-cell numbers for clinical scale CAR T-cell production. In addition, CAR T cells showed high expansion rates and viability, leading to CAR T cells in sufficient doses and quality for clinical use. CAR T cells from all patients showed specific cytotoxicity against CD19+ cell lines in vitro. GMP grade generation of CD19 CAR T-cell products suitable for clinical use is feasible in patients with autoimmune disease.

Towards Novel Gene and Cell Therapy Approaches for Cervical Cancer

Cervical cancer is one of the most common malignancies in women, and the majority of cases are caused by infection with high-risk human papilloma virus (HPV) subtypes. Despite effective preventative measures, such as vaccinations against HPV, over 300,000 women die world-wide from cervical cancer each year. Once cervical cancer is diagnosed, treatment may consist of radial hysterectomy, or chemotherapy and radiotherapy, or a combination of therapies dependent upon the disease stage. Unfortunately, overall prognosis for patients with metastatic or recurrent disease remains poor. In these cases, immunotherapies may be useful based on promising preclinical work, some of which has been successfully translated to the clinic. For example, approaches using monoclonal antibodies directed against surface proteins important for control of immune checkpoints (i.e., immune checkpoint inhibitors) were shown to improve outcome in many cancer settings, including cervical cancer. Additionally, initial clinical studies showed that application of cytotoxic immune cells modified to express chimeric antigen receptors (CAR) or T cell receptors (TCR) for better recognition and elimination of tumor cells may be useful to control cervical cancer. This review explores these important topics, including strengths and limitations of standard and developing approaches, and how some novel treatment strategies may be optimally used to offer the best possible treatment for cervical cancer patients.

Cancer immunotherapy with CAR T cells: well-trodden paths and journey along lesser-known routes

BACKGROUND

Chimeric antigen receptor (CAR) T cell therapy is a clinically approved cancer immunotherapy approach using genetically engineered T cells. The success of CAR T cells has been met with challenges regarding efficacy and safety. Although a broad spectrum of CAR T cell variants and applications is emerging, this review focuses on CAR T cells for the treatment of cancer. In the first part, the general principles of adoptive cell transfer, the architecture of the CAR molecule, and the effects of design on function are presented. The second part describes five conceptual challenges that hinder the success of CAR T cells; immunosuppressive tumour microenvironment, T cell intrinsic properties, tumour targeting, manufacturing cellular product, and immune-related adverse events. Throughout the review, selected current approaches to address these issues are presented.

CONCLUSIONS

Cancer immunotherapy with CAR T cells represents a paradigm shift in the treatment of certain blood cancers that do not respond to other available treatment options. Well-trodden paths taken by pioneers led to the first clinical approval, and now the journey continues down lesser-known paths to treat a variety of cancers and other serious diseases with CAR T cells.

Current updates on generations, approvals, and clinical trials of CAR T-cell therapy

Chimeric antigen receptor (CAR) T-cell therapy is a novel, customized immunotherapy that is considered a 'living' and self-replicating drug to treat cancer, sometimes resulting in a complete cure. CAR T-cells are manufactured through genetic engineering of T-cells by equipping them with CARs to detect and target antigen-expressing cancer cells. CAR is designed to have an ectodomain extracellularly, a transmembrane domain spanning the cell membrane, and an endodomain intracellularly. Since its first discovery, the CAR structure has evolved greatly, from the first generation to the fifth generation, to offer new therapeutic alternatives for cancer patients. This treatment has achieved long-term and curative therapeutic efficacy in multiple blood malignancies that nowadays profoundly change the treatment landscape of lymphoma, leukemia, and multiple myeloma. But CART-cell therapy is associated with several hurdles, such as limited therapeutic efficacy, little effect on solid tumors, adverse effects, expensive cost, and feasibility issues, hindering its broader implications.

Learning from TCR Signaling and Immunological Synapse Assembly to Build New Chimeric Antigen Receptors (CARs)

Chimeric antigen receptor (CAR) T cell immunotherapy is a revolutionary pillar in cancer treatment. Clinical experience has shown remarkable successes in the treatment of certain hematological malignancies but only limited efficacy against B cell chronic lymphocytic leukemia (CLL) and other cancer types, especially solid tumors. A wide range of engineering strategies have been employed to overcome the limitations of CAR T cell therapy. However, it has become increasingly clear that CARs have unique, unexpected features; hence, a deep understanding of how CARs signal and trigger the formation of a non-conventional immunological synapse (IS), the signaling platform required for T cell activation and execution of effector functions, would lead a shift from empirical testing to the rational design of new CAR constructs. Here, we review current knowledge of CARs, focusing on their structure, signaling and role in CAR T cell IS assembly. We, moreover, discuss the molecular features accounting for poor responses in CLL patients treated with anti-CD19 CAR T cells and propose CLL as a paradigm for diseases connected to IS dysfunctions that could significantly benefit from the development of novel CARs to generate a productive anti-tumor response.

Cellular Immunotherapy for Medulloblastoma

Medulloblastoma (MB) is the most common malignant brain tumor in children, making up ~20% of all primary pediatric brain tumors. Current therapies consist of maximal surgical resection and aggressive radio- and chemotherapy. A third of the treated patients cannot be cured and survivors are often left with devastating long-term side effects. Novel efficient and targeted treatment is desperately needed for this patient population. Cellular immunotherapy aims to enhance and utilize immune cells to target tumors, and has been proven successful in various cancers. However, for MB, the knowledge and possibilities of cellular immunotherapy are limited. In this review, we provide a comprehensive overview of the current status of cellular immunotherapy for MB, from fundamental in vitro research to in vivo models and (ongoing) clinical trials. In addition, we compare our findings to cellular immunotherapy in glioma, an MB-like intracranial tumor. Finally, future possibilities for MB are discussed to improve efficacy and safety.

Evaluating the Therapeutic Potential of Idecabtagene Vicleucel in the Treatment of Multiple Myeloma: Evidence to Date

Over the past two decades, significant progress has been made in the diagnosis, risk assessment and treatment of patients with multiple myeloma, translating into remarkable improvements in survival outcomes. Yet, cure remains elusive, and almost all patients eventually experience relapse, particularly those with high-risk and refractory disease. Immune-based approaches have emerged as highly effective therapeutic options that have heralded a new era in the treatment of multiple myeloma. Idecabtagene vicleucel (ide-cel) is one such therapy that employs the use of genetically modified autologous T-cells to redirect immune activation in a tumor-directed fashion. It has yielded impressive responses even in patients with poor-risk disease and is the first chimeric antigen receptor (CAR) T-cell therapy to be approved for treatment in relapsed or refractory multiple myeloma. In this review, we examine the design and pharmacokinetics of ide-cel, audit evidence that led to its incorporation into the current treatment paradigm and provide insight into its clinical utilization with a focus on real-life intricacies.

A TCR-like CAR Promotes Sensitive Antigen Recognition and Controlled T-cell Expansion Upon mRNA Vaccination

Chimeric antigen receptor (CAR) T cells are efficacious in patients with B-cell malignancies, while their activity is limited in patients with solid tumors. We developed a novel heterodimeric TCR-like CAR (TCAR) designed to achieve optimal chain pairing and integration into the T-cell CD3 signaling complex. The TCAR mediated high antigen sensitivity and potent antigen-specific T-cell effector functions in short-term in vitro assays. Both persistence and functionality of TCAR T cells were augmented by provision of costimulatory signals, which improved proliferation in vitro and in vivo. Combination with a nanoparticulate RNA vaccine, developed for in vivo expansion of CAR T cells, promoted tightly controlled expansion, survival, and antitumor efficacy of TCAR T cells in vivo.

Significance

A novel TCAR is tightly controlled by RNA vaccine-mediated costimulation and may provide an alternative to second-generation CARs for the treatment of solid tumors.

Advances and challenges of CAR T therapy and suitability of animal models (Review)

Chimeric antigen receptors (CARs) recently gained momentum in cancer treatment due to their ability to promote T-cell mediated responses to a specific tumor-associated antigen. CARs are part of the adoptive cell transfer (ACT) strategies that utilize patients' T lymphocytes, genetically engineered to kill cancer cells. However, despite the therapy's success against blood-related malignancies, treating solid tumors has not reached its fullest potential yet. The reasons include the complex suppressive tumor microenvironment, mutations on cancer cells' target receptors, lethal side-effects, restricted trafficking into the tumor, suboptimal persistence in vivo and the lack of animal models that faithfully resemble human tumor's immunological responses. Currently, rodent models are used to investigate the safety and efficacy of CAR therapies. However, these models are limited in representing the human disease faithfully, fail to predict the adverse treatment events and overestimate the efficacy of the therapy. On the other hand, spontaneously developed tumors in dogs are more suited in CAR research and their efficacy has been demonstrated in a number of diseases, including lymphoma, osteosarcoma and mammary tumors. The present review discusses the design and evolution of CARs, challenges of CAR in solid tumors, human and canine clinical trials and advantages of the canine model.

Alternative CAR Therapies: Recent Approaches in Engineering Chimeric Antigen Receptor Immune Cells to Combat Cancer

For nearly three decades, chimeric antigen receptors (CARs) have captivated the interest of researchers seeking to find novel immunotherapies to treat cancer. CARs were first designed to work with T cells, and the first CAR T cell therapy was approved to treat B cell lymphoma in 2017. Recent advancements in CAR technology have led to the development of modified CARs, including multi-specific CARs and logic gated CARs. Other immune cell types, including natural killer (NK) cells and macrophages, have also been engineered to express CARs to treat cancer. Additionally, CAR technology has been adapted in novel approaches to treating autoimmune disease and other conditions and diseases. In this article, we review these recent advancements in alternative CAR therapies and design, as well as their mechanisms of action, challenges in application, and potential future directions.

Next Generation Natural Killer Cells for Cancer Immunotherapy

In recent years, immunotherapy for cancer has become mainstream with several products now authorized for therapeutic use in the clinic and are becoming the standard of care for some malignancies. Chimeric antigen receptor (CAR)-T cell therapies have demonstrated substantial efficacy for the treatment of hematological malignancies; however, they are complex and currently expensive to manufacture, and they can generate life-threatening adverse events such as cytokine release syndrome (CRS). The limitations of current CAR-T cells therapies have spurred an interest in alternative immunotherapy approaches with safer risk profiles and with less restrictive manufacturing constraints. Natural killer (NK) cells are a population of immune effector cells with potent anti-viral and anti-tumor activity; they have the capacity to swiftly recognize and kill cancer cells without the need of prior stimulation. Although NK cells are naturally equipped with cytotoxic potential, a growing body of evidence shows the added benefit of engineering them to better target tumor cells, persist longer in the host, and be fitter to resist the hostile tumor microenvironment (TME). NK-cell-based immunotherapies allow for the development of allogeneic off-the-shelf products, which have the potential to be less expensive and readily available for patients in need. In this review, we will focus on the advances in the development of engineering of NK cells for cancer immunotherapy. We will discuss the sourcing of NK cells, the technologies available to engineer NK cells, current clinical trials utilizing engineered NK cells, advances on the engineering of receptors adapted for NK cells, and stealth approaches to avoid recipient immune responses. We will conclude with comments regarding the next generation of NK cell products, i.e., armored NK cells with enhanced functionality, fitness, tumor-infiltration potential, and with the ability to overcome tumor heterogeneity and immune evasion.

Off-the-Shelf Chimeric Antigen Receptor Immune Cells from Human Pluripotent Stem Cells

Autologous chimeric antigen receptor (CAR) T cells have expanded the scope and therapeutic potential of anti-cancer therapy. Nevertheless, autologous CAR-T therapy has been challenging due to labor some manufacturing processes for every patient, and the cost due to the complexity of the process. Moreover, T cell dysfunction results from the immunosuppressive tumor microenvironment in certain patients. Considering technical challenges in autologous donors, the development of safe and efficient allogeneic CAR-T therapy will address these issues. Since the advent of the generation of immune cells from pluripotent stem cells (PSCs), numerous studies focus on the off-the-shelf generation of CAR-immune cells derived from the universal donor PSCs, which simplifies the manufacturing process and standardizes CAR-T products. In this review, we will discuss advances in the generation of immune cells from PSCs, together with the potential and perspectives of CAR-T, CAR-macrophages, and CAR-natural killer (NK) cells in cancer treatment. The combination of PSC-derived immune cells and CAR engineering will pave the way for developing next-generation cancer immunotherapy.

CAR T Cell Therapy in Primary Brain Tumors: Current Investigations and the Future

Chimeric antigen receptor T cells (CAR T cells) are engineered cells expressing a chimeric antigen receptor (CAR) against a specific tumor antigen (TA) that allows for the identification and elimination of cancer cells. The remarkable clinical effect seen with CAR T cell therapies against hematological malignancies have attracted interest in developing such therapies for solid tumors, including brain tumors. Glioblastoma (GBM) is the most common primary brain tumor in adults and is associated with poor prognosis due to its highly aggressive nature. Pediatric brain cancers are similarly aggressive and thus are a major cause of pediatric cancer-related death. CAR T cell therapy represents a promising avenue for therapy against these malignancies. Several specific TAs, such as EGFR/EGFRvIII, IL13Rα2, B7-H3, and HER2, have been targeted in preclinical studies and clinical trials. Unfortunately, CAR T cells against brain tumors have showed limited efficacy due to TA heterogeneity, difficulty trafficking from blood to tumor sites, and the immunosuppressive tumor microenvironment. Here, we review current CAR T cell approaches in treating cancers, with particular focus on brain cancers. We also describe a novel technique of focused ultrasound controlling the activation of engineered CAR T cells to achieve the safer cell therapies. Finally, we summarize the development of combinational strategies to improve the efficacy and overcome historical limitations of CAR T cell therapy.

CD123 and More: How to Target the Cell Surface of Blastic Plasmacytoid Dendritic Cell Neoplasm

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive leukemia derived from plasmacytoid dendritic cells (pDCs). It is associated with a remarkably poor prognosis and unmet need for better therapies. Recently, the first-in-class CD123-targeting therapy, tagraxofusp, was approved for treatment of BPDCN. Other CD123-targeting strategies are in development, including bispecific antibodies and combination approaches with tagraxofusp and other novel agents. In other blood cancers, adoptive T-cell therapy using chimeric antigen receptor (CAR)-modified T cells represents a promising new avenue in immunotherapy, showing durable remissions in some relapsed hematologic malignancies. Here, we report on novel and innovative therapies in development to target surface molecules in BPDCN currently in clinical trials or in preclinical stages. We also discuss new cell surface targets that may have implications for future BPDCN treatment.

Uniting Disciplines to Develop Therapeutics: Targeted mRNA Lipid Nanoparticles Reprogram the Immune System In Vivo to Treat Heart Disease

The burgeoning field of immunomedicine is primed to expand beyond oncology (Aghajanian et al., 2022). Over the past several decades, many cell-based therapies have been proposed, developed, and deployed in the clinic. The recent explosion of targeted cell therapies has primarily been aimed at oncological malignancies. In parallel, cardiology researchers have been investigating the various cell types that contribute to heart diseases, especially those responsible for tissue fibrosis and myocardial dysfunction. Our laboratory proposed in 2019 to unite these two disciplines: could a targeted cell therapy be used to ameliorate cardiac fibrosis (Aghajanian et al., 2019). Although preliminary results were encouraging, the genetic engineering approach used to manufacture immune cells would result in persistent cytolytic T cell if directly translated to humans. This would pose a safety concern since activated fibroblasts are essential cells in the setting of acute injury. Therefore, we developed a novel technology to deliver modified RNA to T cells in vivo, resulting in a transient antiactivated fibroblast therapeutic (Rurik et al., 2022). Although active for only a few days, these cells were sufficient to significantly improve cardiac function in a murine model of cardiac fibrosis. These results pave the way for low-cost and scalable, and dose-able and immune therapy for fibrotic disorders.

Strategies for Manipulating T Cells in Cancer Immunotherapy

T cells are attractive targets for the development of immunotherapy to treat cancer due to their biological features, capacity of cytotoxicity, and antigen-specific binding of receptors. Novel strategies that can modulate T cell functions or receptor reactivity provide effective therapies, including checkpoint inhibitor, bispecific antibody, and adoptive transfer of T cells transduced with tumor antigen-specific receptors. T cell-based therapies have presented successful pre-clinical/clinical outcomes despite their common immune-related adverse effects. Ongoing studies will allow us to advance current T cell therapies and develop innovative personalized T cell therapies. This review summarizes immunotherapeutic approaches with a focus on T cells. Anti-cancer T cell therapies are also discussed regarding their biological perspectives, efficacy, toxicity, challenges, and opportunities.

Engineering CAR T cells for enhanced efficacy and safety

Despite its success in treating hematologic malignancies, chimeric antigen receptor (CAR) T cell therapy faces two major challenges which hinder its broader applications: the limited effectiveness against solid tumors and the nonspecific toxicities. To address these concerns, researchers have used synthetic biology approaches to develop optimization strategies. In this review, we discuss recent improvements on the CAR and other non-CAR molecules aimed to enhance CAR T cell efficacy and safety. We also highlight the development of different types of inducible CAR T cells that can be controlled by environmental cues and/or external stimuli. These advancements are bringing CAR T therapy one step closer to safer and wider applications, especially for solid tumors.

Therapeutic potential of CAR T cell in malignancies: A scoping review

Although tremendous advancements in cancer therapy over the last several years, cancer still is a complex illness to cure. Traditional cancer treatments, including chemotherapy, radiotherapy, and surgery, have a poor therapeutic effect, emphasizing the significance of employing innovative treatments like activated cell therapy. Chimeric antigen receptor T cell is one of the most prevalent types of activated cell therapy have been developed to direct T lymphocytes toward cancers (CAR-T cells). CAR-T cells therapy has illustrated poor impact versus solid tumors despite the remarkable success in patients suffering from hematological malignancies. CAR-T cells must overcome various hurdles to obtain full responses to solid tumors, including growth, stability, trafficking, and destiny inside tumors. As a result, novel treatment methods will entail overcoming the challenges that CAR-T cells face in solid tumors. The use of CAR-T cells in combination with other therapeutic approaches such as chemotherapy, radiotherapy, immuno-checkpoint inhibitors, and oncolytic viruses can promote the effectiveness of CAR-T cell therapy for the treatment of solid tumors. However, more research is needed to determine the safety and effectiveness of these therapies. CAR-T cell treatment success rates vary by type of disease, but are predicted to reach up to 90% in patients with leukemia. However, since this kind of immunotherapy is still in its infancy, there is much to learn about its efficacy. This review provided an in-depth examination of CAR-T cell therapy and its success and failure as a cancer treatment approach. We also discuss combination therapies with CAR-T Cell.

HLA-independent T cell receptors for targeting tumors with low antigen density

Chimeric antigen receptors (CARs) are receptors for antigen that direct potent immune responses. Tumor escape associated with low target antigen expression is emerging as one potential limitation of their efficacy. Here we edit the TRAC locus in human peripheral blood T cells to engage cell-surface targets through their T cell receptor-CD3 complex reconfigured to utilize the same immunoglobulin heavy and light chains as a matched CAR. We demonstrate that these HLA-independent T cell receptors (HIT receptors) consistently afford high antigen sensitivity and mediate tumor recognition beyond what CD28-based CARs, the most sensitive design to date, can provide. We demonstrate that the functional persistence of HIT T cells can be augmented by constitutive coexpression of CD80 and 4-1BBL. Finally, we validate the increased antigen sensitivity afforded by HIT receptors in xenograft mouse models of B cell leukemia and acute myeloid leukemia, targeting CD19 and CD70, respectively. Overall, HIT receptors are well suited for targeting cell surface antigens of low abundance.

Chimeric antigen receptor engineered T cells and their application in the immunotherapy of solid tumours

In this article, we reviewed the current literature studies and our understanding of the parameters that affect the chimeric antigen receptor T cells (CAR-T's) activation, effector function, in vivo persistence, and antitumour effects. These factors include T cell subsets and their differentiation stages, the components of chimeric antigen receptors (CAR) design, the expression promoters and delivery vectors, and the CAR-T production process. The CAR signalling and CAR-T activation were also studied in comparison to TCR. The last section of the review gave special consideration of CAR design for solid tumours, focusing on strategies to improve CAR-T tumour infiltration and survival in the hostile tumour microenvironment. With several hundred clinical trials undergoing worldwide, the pace of CAR-T immunotherapy moves from bench to bedside is unprecedented. We hope that the article will provide readers a clear and comprehensive view of this rapidly evolving field and will help scientists and physician to design effective CAR-Ts immunotherapy for solid tumours.

Identification of Claudin 6-specific HLA class I- and HLA class II-restricted T cell receptors for cellular immunotherapy in ovarian cancer

Adoptive cell therapy (ACT) is one of promising immunotherapies for cancer patients by providing a large amount of cancer antigen-specific effector T cells that can be manufactured rapidly by ex vivo gene engineering. To provide antigen-specificity to patients’ autologous T cells in a short-term culture, T-cell receptors (TCRs) or chimeric antigen receptors (CARs) are transduced to bulk T cells. Because of intra- and inter-tumoral heterogeneity in tumor antigen expression, a repertoire of TCR or CAR genes targeting a wide range of tumor antigens are required for a broad and effective treatment by ACT. Here, we characterized immunogenicity of claudin 6 (CLDN6) in ovarian cancer patients and identified specific TCR genes from CD8⁺ and CD4⁺ T cells. CLDN6 protein was frequently expressed on EpCAM⁺ ovarian cancer cells but not CD45⁺ lymphocytes in tumor ascites of ovarian cancer patients. Spontaneous CLDN6-specific CD4⁺ and CD8⁺ T-cell response was detected in peripheral blood mononuclear cells (PBMCs) from 1 out of 17 ovarian cancer patients. HLA-A*02:01 (A2) and DR*04:04 (DR4)-restricted TCR genes were isolated from CLDN6-specific CD8⁺ and CD4⁺ T cells, respectively. T cells that were engineered with A2-restricted TCR gene recognized and killed A2⁺CLDN6⁺ cancer cells. DR4-restricted TCR-transduced T cells directly recognized DR4⁺CLDN6⁺-overexpressed cancer cells. Our results demonstrate that these CLDN6-specific TCR genes are useful as therapeutic genes for ACT to patients with ovarian and other solid tumors expressing CLDN6.

A roadmap for driving CAR T cells toward the oncogenic immunopeptidome

A critical barrier to CAR T cell therapy is the paucity of target antigens that are broadly and stably expressed exclusively in tumors. In their comprehensive multi-omics and pre-clinical study, Yarmarkovich et al. provide proof of principle for the development and efficacy of peptide centric (PC)-CARs targeting the oncogenic immunopeptidome of neuroblastoma.

CAR-Ts: new perspectives in cancer therapy

Chimeric antigen receptor (CAR)-T-cell therapy is a promising anticancer treatment that exploits the host's immune system to fight cancer. CAR-T cell therapy relies on immune cells being modified to express an artificial receptor targeting cancer-specific markers, and infused into the patients where they will recognize and eliminate the tumour. Although CAR-T cell therapy has produced encouraging outcomes in patients with haematologic malignancies, solid tumours remain challenging to treat, mainly due to the lack of cancer-specific molecular targets and the hostile, often immunosuppressive, tumour microenvironment. CAR-T cell therapy also depends on the quality of the injected product, which is closely connected to CAR design. Here, we explain the technology of CAR-Ts, focusing on the composition of CARs, their application, and limitations in cancer therapy, as well as on the current strategies to overcome the challenges encountered. We also address potential future targets to overcome the flaws of CAR-T cell technology in the treatment of cancer, emphasizing glycan antigens, the aberrant forms of which attain high tumour-specific expression, as promising targets for CAR-T cell therapy.

Cancer-Homing CAR-T Cells and Endogenous Immune Population Dynamics

Chimeric antigen receptor (CAR) therapy is based on patient blood-derived T cells and natural killer cells, which are engineered in vitro to recognize a target antigen in cancer cells. Most CAR-T recognize target antigens through immunoglobulin antigen-binding regions. Hence, CAR-T cells do not require the major histocompatibility complex presentation of a target peptide. CAR-T therapy has been tremendously successful in the treatment of leukemias. On the other hand, the clinical efficacy of CAR-T cells is rarely detected against solid tumors. CAR-T-cell therapy of cancer faces many hurdles, starting from the administration of engineered cells, wherein CAR-T cells must encounter the correct chemotactic signals to traffic to the tumor in sufficient numbers. Additional obstacles arise from the hostile environment that cancers provide to CAR-T cells. Intense efforts have gone into tackling these pitfalls. However, we argue that some CAR-engineering strategies may risk missing the bigger picture, i.e., that a successful CAR-T-cell therapy must efficiently intertwine with the complex and heterogeneous responses that the body has already mounted against the tumor. Recent findings lend support to this model.

Natural Receptor- and Ligand-Based Chimeric Antigen Receptors: Strategies Using Natural Ligands and Receptors for Targeted Cell Killing

Chimeric antigen receptor (CAR) T-cell therapy has been widely successful in the treatment of B-cell malignancies, including B-cell lymphoma, mantle cell lymphoma, and multiple myeloma; and three generations of CAR designs have led to effective FDA approved therapeutics. Traditionally, CAR antigen specificity is derived from a monoclonal antibody where the variable heavy (V_H) and variable light (V_L) chains are connected by a peptide linker to form a single-chain variable fragment (scFv). While this provides a level of antigen specificity parallel to that of an antibody and has shown great success in the clinic, this design is not universally successful. For instance, issues of stability, immunogenicity, and antigen escape hinder the translational application of some CARs. As an alternative, natural receptor- or ligand-based designs may prove advantageous in some circumstances compared to scFv-based designs. Herein, the advantages and disadvantages of scFv-based and natural receptor- or ligand-based CAR designs are discussed. In addition, several translational aspects of natural receptor- and ligand-based CAR approaches that are being investigated in preclinical and clinical studies will be examined.

Synergistic T cell signaling by 41BB and CD28 is optimally achieved by membrane proximal positioning within parallel chimeric antigen receptors

Second generation (2G) chimeric antigen receptors (CARs) contain a CD28 or 41BB co-stimulatory endodomain and elicit remarkable efficacy in hematological malignancies. Third generation (3G) CARs extend this linear blueprint by fusing both co-stimulatory units in series. However, clinical impact has been muted despite compelling evidence that co-signaling by CD28 and 41BB can powerfully amplify natural immune responses. We postulate that effective dual co-stimulation requires juxta-membrane positioning of endodomain components within separate synthetic receptors. Consequently, we designed parallel (p)CARs in which a 2G (CD28+CD3ζ) CAR is co-expressed with a 41BB-containing chimeric co-stimulatory receptor. We demonstrate that the pCAR platform optimally harnesses synergistic and tumor-dependent co-stimulation to resist T cell exhaustion and senescence, sustaining proliferation, cytokine release, cytokine signaling, and metabolic fitness upon repeated stimulation. When engineered using targeting moieties of diverse composition, affinity, and specificity, pCAR T cells consistently elicit superior anti-tumor activity compared with T cells that express traditional linear CARs.

[CAR-T cells gene therapy medicines: Regulatory status and pharmaceutical circuits in Europe and France]

CAR-T cells belong to a new class of biological medicines, referred to as Advanced Therapy Medicinal Products (ATMPs). Despite the cellular component, according to the regulatory definition, CAR-T cells are gene therapy medicines, a sub-category of ATMPs, since their therapeutic effect is the result of their genetic modification. The specificity and the complexity of these innovative drugs have required a complete reorganization of the hospital and pharmaceutical circuits, from the cell collection to the drug administration to the patient. Indeed, increased interaction and collaboration between different healthcare professionals is essential in order to guarantee the quality and safety of these innovative medicines.

Prospects for Development of Induced Pluripotent Stem Cell-Derived CAR-Targeted Immunotherapies

Technologies required to generate induced pluripotent stem cells (iPSC) were first described 15 years ago, providing a strong impetus to the field of regenerative medicine. In parallel, immunotherapy has finally emerged as a clinically meaningful modality of cancer therapy. In particular, impressive efficacy has been achieved in patients with selected haematological malignancies using ex vivo expanded autologous T cells engineered to express chimeric antigen receptors (CARs). While solid tumours account for over 90% of human cancer, they currently are largely refractory to this therapeutic approach. Nonetheless, given the considerable innovation taking place worldwide in the CAR field, it is likely that effective solutions for common solid tumours will emerge in the near future. Such a development will create significant new challenges in the scalable delivery of these complex, costly and individualised therapies. CAR-engineered immune cell products that originate from iPSCs offer the potential to generate unlimited numbers of homogeneous, standardised cell products in which multiple defined gene modification events have been introduced to ensure safety, potency and reproducibility. Here, we review some of the emerging strategies in use to engineer CAR-expressing iPSC-derived drug products.

Idecabtagene vicleucel (ide-cel) CAR T-cell therapy for relapsed and refractory multiple myeloma

Idecabtagene vicleucel (ide-cel), a novel chimeric antigen receptor (CAR) T-cell therapy targeting B-cell maturation antigen (BCMA), has recently gained approval by the US FDA for relapsed and refractory multiple myeloma (RRMM) after multicenter trials have demonstrated unprecedented results in this difficult-to-treat subgroup of patients. As the first CAR T-cell product approved for myeloma, ide-cel is poised to become a practice-changing treatment option. This first-in-class therapeutic offers hope for more durable remissions, as well as better quality of life, following a single infusion in a group of patients that previously had little hope. This paper reviews the ide-cel product in terms of design, pharmacology, efficacy and toxicity as described in studies reported to date.

T Cell Engaging Immunotherapies, Highlighting Chimeric Antigen Receptor (CAR) T Cell Therapy

In the past decade, chimeric antigen receptor (CAR) T cell technology has revolutionized cancer immunotherapy. This strategy uses synthetic CARs to redirect the patient's own immune cells to recognize specific antigens expressed on the surface of tumor cells. The unprecedented success of anti-CD19 CAR T cell therapy against B cell malignancies has resulted in its approval by the US Food and Drug Administration (FDA) in 2017. However, major scientific challenges still remain to be addressed for the broad use of CAR T cell therapy. These include severe toxicities, limited efficacy against solid tumors, and immune suppression in the hostile tumor microenvironment. Furthermore, CAR T cell therapy is a personalized medicine of which the production is time- and resource-intensive, which makes it very expensive. All these factors drive new innovations to engineer more powerful CAR T cells with improved antitumor activity, which are reviewed in this manuscript.

Disruption of adenosine 2A receptor improves the anti-tumor function of anti-mesothelin CAR T cells both in vitro and in vivo

Chimeric antigen receptor (CAR) T cells have been successfully used for the treatment of hematological malignancies including acute and chronic lymphoblastic leukemia. However, results of CAR T cell projects in solid tumors have been less impressive to date, partly because of immunosuppressive tumor microenvironment (TME). It is widely known that high adenosine production is an important factor causing tumor-induced immunosuppression in TME, and adenosine mediates the suppression of anti-tumor T cell responses via binding and signaling through adenosine 2a receptor (A2aR). Previous studies have shown that adenosine generated by cancer cells significantly inhibits T cell anti-tumor activity through binding and then activating adenosine 2A receptors (A2aRs) of T cells. Based on the previous work, in our study, we evaluated whether A2aR disruption by shRNA could enhance the anti-tumor function of anti-mesothelin (MSLN) CAR T cells both in vitro and in vivo. For this goal above, we used MSLN-positive human ovarian serous carcinoma cells (SKOV3) and human colon cancer cells (HCT116) as target cancer cells while MSLN-negative human ovarian cancer cells (ES2) as non-target cancer cells. We observed that targeting cell-intrinsic A2aR through shRNA overexpression caused significant A2aR disruption in CAR T cells and profoundly increased CAR T cell efficacy in both CAR T cell cytokine production and cytotoxicity towards MSLN-positive cancer cells in vitro. More importantly, in SKOV3 xenograft mouse models, anti-MSLN CAR-T cells significantly reduced the tumor burden compared with non-transduced T cells, and the anti-tumor activity of A2aR-disrupted anti-MSLN CAR-T cells was stronger than that of wild-type anti-MSLN CAR-T cells. Altogether, our study showed enhanced anti-tumor efficacy caused by shRNA-mediated A2aR disruption in anti-MSLN CAR T cells both in vitro and in vivo, which proved that shRNA-mediated modification of gene expression might be an excellent strategy for improving CAR T cell function in immunosuppressive tumor microenvironment (TME) and could potentially improve the outcome of treatment in clinical trials.

Using chimeric antigen receptor T-cell therapy to fight glioblastoma multiforme: past, present and future developments

Introduction

Glioblastoma multiforme (GBM) constitutes one of the deadliest tumors to afflict humans, although it is still considered an orphan disease. Despite testing multiple new and innovative therapies in ongoing clinical trials, the median survival for this type of malignancy is less than two years after initial diagnosis, regardless of therapy. One class of promising new therapies are chimeric antigen receptor T cells or CAR-T which have been shown to be very effective at treating refractory liquid tumors such as B-cell malignancies. However, CAR-T effectivity against solid tumors such as GBM has been limited thus far.

Methods

A Pubmed, Google Scholar, Directory of Open Access Journals, and Web of Science literature search using the terms chimeric antigen receptor or CAR-T, GBM, solid tumor immunotherapy, immunotherapy, and CAR-T combination was performed for publication dates between January 1987 and November 2021.

Results

In the current review, we present a comprehensive list of CAR-T cells developed to treat GBM, we describe new possible T-cell engineering strategies against GBM while presenting a short introductory history to the reader regarding the origin(s) of this cutting-edge therapy. We have also compiled a unique list of anti-GBM CAR-Ts with their specific protein sequences and their functions as well as an inventory of clinical trials involving CAR-T and GBM.

Conclusions

The aim of this review is to introduce the reader to the field of T-cell engineering using CAR-Ts to treat GBM and describe the obstacles that may need to be addressed in order to significantly delay the relentless growth of GBM.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11060-021-03902-8.

Cell Therapy: Types, Regulation, and Clinical Benefits

Cell therapy practices date back to the 19th century and continue to expand on investigational and investment grounds. Cell therapy includes stem cell- and non-stem cell-based, unicellular and multicellular therapies, with different immunophenotypic profiles, isolation techniques, mechanisms of action, and regulatory levels. Following the steps of their predecessor cell therapies that have become established or commercialized, investigational and premarket approval-exempt cell therapies continue to provide patients with promising therapeutic benefits in different disease areas. In this review article, we delineate the vast types of cell therapy, including stem cell-based and non-stem cell-based cell therapies, and create the first-in-literature compilation of the different "multicellular" therapies used in clinical settings. Besides providing the nuts and bolts of FDA policies regulating their use, we discuss the benefits of cell therapies reported in 3 therapeutic areas-regenerative medicine, immune diseases, and cancer. Finally, we contemplate the recent attention shift toward combined therapy approaches, highlighting the factors that render multicellular therapies a more attractive option than their unicellular counterparts.

Cellular Therapy Updates in B-Cell Lymphoma: The State of the CAR-T

Simple Summary

B-cell lymphomas are the most commonly occurring blood cancer and the second leading cause of cancer-related death among blood cancers. Chemotherapy and stem cell transplantation have long served as the standard therapies for relapsed or refractory aggressive B-cell lymphomas with very poor survival, historically. Recently, the development of multiple chimeric antigen receptor T-cell (CAR-T) products has translated into dramatically improved outcomes and survival for patients with relapsed or refractory B-cell lymphoma. Meanwhile, basic, translational and clinical development within the field has progressed rapidly. The aim of this review is to summarize the current state of the art of CAR-T therapies for B-cell lymphomas within this rapidly evolving field, focusing on current United States Food and Drug Administration (US FDA)-approved products and a selection of promising areas of future clinical development.

Abstract

Non-Hodgkin Lymphoma accounts for >460,000 cases and >240,000 deaths globally and >77,000 cases and >20,000 deaths in the U.S. annually, with ~85% of cases being B-cell malignancies. Until recently, patients with relapsed/refractory B-cell lymphoma following standard chemotherapy in combination with anti-CD20 monoclonal antibodies and autologous stem cell transplantation experienced a median overall survival (OS) of <6 months. However, with the approval of four different CD-19 CAR-T therapies between 2017 and 2021, approximately 60–80% of patients receiving CAR-T therapy now achieve an objective response with >3 years median OS. Here, we review the current state of the art of CD19 CAR-T therapies for B-cell lymphomas, focusing on current updates in US FDA-approved products, along with their associated efficacy and toxicities. Lastly, we highlight a selection of promising clinical developments in the field, including various novel strategies to increase CAR-T therapy efficacy while mitigating toxicity.

Challenges and Prospects for Designer T and NK Cells in Glioblastoma Immunotherapy

Glioblastoma (GBM) is the most prevalent, aggressive primary brain tumour with a dismal prognosis. Treatment at diagnosis has limited efficacy and there is no standardised treatment at recurrence. New, personalised treatment options are under investigation, although challenges persist for heterogenous tumours such as GBM. Gene editing technologies are a game changer, enabling design of novel molecular-immunological treatments to be used in combination with chemoradiation, to achieve long lasting survival benefits for patients. Here, we review the literature on how cutting-edge molecular gene editing technologies can be applied to known and emerging tumour-associated antigens to enhance chimeric antigen receptor T and NK cell therapies for GBM. A tight balance of limiting neurotoxicity, avoiding tumour antigen loss and therapy resistance, while simultaneously promoting long-term persistence of the adoptively transferred cells must be maintained to significantly improve patient survival. We discuss the opportunities and challenges posed by the brain contexture to the administration of the treatments and achieving sustained clinical responses.

Chimeric antigen receptor (CAR) immunotherapy: basic principles, current advances, and future prospects in neuro-oncology

With recent advances, chimeric antigen receptor (CAR) immunotherapy has become a promising modality for patients with refractory cancer diseases. The successful results of CAR T cell therapy in relapsed and refractory B-cell malignancies shifted the paradigm of cancer immunotherapy by awakening the scientific, clinical, and commercial interest in translating this technology for the treatment of solid cancers. This review elaborates on fundamental principles of CAR T cell therapy (development of CAR construct, challenges of CAR T cell therapy) and its application on solid tumors as well as CAR T cell therapy potential in the field of neuro-oncology. Glioblastoma (GBM) is identified as one of the most challenging solid tumors with a permissive immunological milieu and dismal prognosis. Standard multimodal treatment using maximal safe resection, radiochemotherapy, and maintenance chemotherapy extends the overall survival beyond a year. Recurrence is, however, inevitable. GBM holds several unique features including its vast intratumoral heterogeneity, immunosuppressive environment, and a partially permissive anatomic blood–brain barrier, which offers a unique opportunity to investigate new treatment approaches. Tremendous efforts have been made in recent years to investigate novel CAR targets and target combinations with standard modalities for solid tumors and GBM to improve treatment efficacy. In this review, we outline the history of CAR immunotherapy development, relevant CAR target antigens validated with CAR T cells as well as preclinical approaches in combination with adjunct approaches via checkpoint inhibition, bispecific antibodies, and second-line systemic therapies that enhance anticancer efficacy of the CAR-based cancer immunotherapy.