Chimeric Antigen Receptor T Cells against CD19 for Multiple Myeloma

IL-18-secreting multiantigen targeting CAR T cells eliminate antigen-low myeloma in an immunocompetent mouse model

ABSTRACT

Multiple myeloma is a plasma cell malignancy that is currently incurable with conventional therapies. Following the success of CD19-targeted chimeric antigen receptor (CAR) T cells in leukemia and lymphoma, CAR T cells targeting B-cell maturation antigen (BCMA) more recently demonstrated impressive activity in relapsed and refractory myeloma patients. However, BCMA-directed therapy can fail due to weak expression of BCMA on myeloma cells, suggesting that novel approaches to better address this antigen-low disease may improve patient outcomes. We hypothesized that engineered secretion of the proinflammatory cytokine interleukin-18 (IL-18) and multiantigen targeting could improve CAR T-cell activity against BCMA-low myeloma. In a syngeneic murine model of myeloma, CAR T cells targeting the myeloma-associated antigens BCMA and B-cell activating factor receptor (BAFF-R) failed to eliminate myeloma when these antigens were weakly expressed, whereas IL-18-secreting CAR T cells targeting these antigens promoted myeloma clearance. IL-18-secreting CAR T cells developed an effector-like T-cell phenotype, promoted interferon-gamma production, reprogrammed the myeloma bone marrow microenvironment through type-I/II interferon signaling, and activated macrophages to mediate antimyeloma activity. Simultaneous targeting of weakly-expressed BCMA and BAFF-R with dual-CAR T cells enhanced T-cell:target-cell avidity, increased overall CAR signal strength, and stimulated antimyeloma activity. Dual-antigen targeting augmented CAR T-cell secretion of engineered IL-18 and facilitated elimination of larger myeloma burdens in vivo. Our results demonstrate that combination of engineered IL-18 secretion and multiantigen targeting can eliminate myeloma with weak antigen expression through distinct mechanisms.

Optimizing Ex Vivo CAR-T Cell-Mediated Cytotoxicity Assay through Multimodality Imaging

CAR-T cell-based therapies have demonstrated remarkable efficacy in treating malignant cancers, especially liquid tumors, and are increasingly being evaluated in clinical trials for solid tumors. With the FDA's initiative to advance alternative methods for drug discovery and development, full human ex vivo assays are increasingly essential for precision CAR-T development. However, prevailing ex vivo CAR-T cell-mediated cytotoxicity assays are limited by their use of radioactive materials, lack of real-time measurement, low throughput, and inability to automate, among others. To address these limitations, we optimized the assay using multimodality imaging methods, including bioluminescence, impedance tracking, phase contrast, and fluorescence, to track CAR-T cells co-cultured with CD19, CD20, and HER2 luciferase reporter cancer cells in real-time. Additionally, we varied the ratio of CAR-T cells to cancer cells to determine optimal cytotoxicity readouts. Our findings demonstrated that the CAR-T cell group effectively attacked cancer cells, and the optimized assay provided superior temporal and spatial precision measurements of ex vivo CAR-T killing of cancer cells, confirming the reliability, consistency, and high throughput of the optimized assay.

Emerging Targets and Therapeutics in Immuno-Oncology: Insights from Landscape Analysis

In the ever-evolving landscape of cancer research, immuno-oncology stands as a beacon of hope, offering novel avenues for treatment. This study capitalizes on the vast repository of immuno-oncology-related scientific documents within the CAS Content Collection, totaling over 350,000, encompassing journals and patents. Through a pioneering approach melding natural language processing with the CAS indexing system, we unveil over 300 emerging concepts, depicted in a comprehensive "Trend Landscape Map". These concepts, spanning therapeutic targets, biomarkers, and types of cancers among others, are hierarchically organized into eight major categories. Delving deeper, our analysis furnishes detailed quantitative metrics showcasing growth trends over the past three years. Our findings not only provide valuable insights for guiding future research endeavors but also underscore the merit of tapping the vast and unparalleled breadth of existing scientific information to derive profound insights.

Extended characterization of anti-CD19 CAR T cell products manufactured at the point of care using the CliniMACS Prodigy system: comparison of donor sources and process duration

BACKGROUND AIMS

The CliniMACS Prodigy closed system is widely used for the manufacturing of chimeric antigen receptor T cells (CAR-T cells). Our study presents an extensive immunophenotypic and functional characterization and comparison of the properties of anti-CD19 CAR-T cell products obtained during long (11 days) and short (7 days) manufacturing cycles using the CliniMACS Prodigy system, as well as cell products manufactured from different donor sources of T lymphocytes: from patients, from patients who underwent HSCT, and from haploidentical donors. We also present the possibility of assessing the efficiency of transduction by an indirect method.

METHODS

Seventy-six CD19 CAR-T cell products were manufactured using the CliniMACS Prodigy automated system. Immunophenotypic properties, markers of cell activation and exhaustion, antitumor, anti-CD19 specific activity in vitro of the manufactured cell products were evaluated. As an indirect method for assessing the efficiency of transduction, we used the method of functional assessment of cytokine secretion and expression of the CD107a marker after incubation of CAR-T cells with tumor targets.

RESULTS

The CliniMACS Prodigy platform can produce a product of CD19 CAR-T cells with sufficient cell expansion (4.6 × 109 cells-median for long process [LP] and 1.6 × 109-for short process [SP]), transduction efficiency (43.5%-median for LP and 41.0%-for SP), represented mainly by T central memory cell population, with low expression of exhaustion markers, and with high specific antitumor activity in vitro. We did not find significant differences in the properties of the products obtained during the 7- and 11-day manufacturing cycles, which is in favor of reducing the duration of production to 7 days, which may accelerate CAR-T therapy. We have shown that donor sources for CAR-T manufacturing do not significantly affect the composition and functional properties of the cell product.

CONCLUSIONS

This study demonstrates the possibility of using the CliniMACS Prodigy system with a shortened 7-day production cycle to produce sufficient amount of functional CAR-T cells. CAR transduction efficiency can be measured indirectly via functional assays.

miR-34a promotes the immunosuppressive function of multiple myeloma-associated macrophages by dampening the TLR-9 signaling

BACKGROUND

Promising outcomes have been observed in multiple myeloma (MM) with the use of immunotherapies, specifically chimeric antigen receptor T (CAR-T) cell therapy. However, a portion of MM patients do not respond to CAR-T therapy, and the reasons for this lack of response remain unclear. The objective of this study was to investigate the impact of miR-34a on the immunosuppressive polarization of macrophages obtained from MM patients.

METHODS

The levels of miR-34a and TLR9 (Toll-like receptor 9) were examined in macrophages obtained from both healthy individuals and patients with MM. ELISA was employed to investigate the cytokine profiles of the macrophage samples. Co-culture experiments were conducted to evaluate the immunomodulatory impact of MM-associated macrophages on CAR-T cells.

RESULTS

There was an observed suppressed activation of macrophages and CD4+ T lymphocytes in the blood samples of MM patients. Overexpression of miR-34a in MM-associated macrophages dampened the TLR9 expression and impaired the inflammatory polarization. In both the co-culture system and an animal model, MM-associated macrophages suppressed the activity and tumoricidal effect of CAR-T cells in a miR-34a-dependent manner.

CONCLUSION

The findings imply that targeting the macrophage miR-34a/TLR9 axis could potentially alleviate the immunosuppression associated with CAR-T therapy in MM patients.

Current and Future Trends of Colorectal Cancer Treatment: Exploring Advances in Immunotherapy

Cancer of the colon and rectum (CRC) has been identified among the three most prevalent types of cancer and cancer-related deaths for both sexes. Even though significant progress in surgical and chemotherapeutic techniques has markedly improved disease-free and overall survival rates in contrast to those three decades ago, recent years have seen a stagnation in these improvements. This underscores the need for new therapies aiming to augment patient outcomes. A number of emerging strategies, such as immune checkpoint inhibitors (ICIs) and adoptive cell therapy (ACT), have exhibited promising outcomes not only in preclinical but also in clinical settings. Additionally, a thorough appreciation of the underlying biology has expanded the scope of research into potential therapeutic interventions. For instance, the pivotal role of altered telomere length in early CRC carcinogenesis, leading to chromosomal instability and telomere dysfunction, presents a promising avenue for future treatments. Thus, this review explores the advancements in CRC immunotherapy and telomere-targeted therapies, examining potential synergies and how these novel treatment modalities intersect to potentially enhance each other's efficacy, paving the way for promising future therapeutic advancements.

A new vision of the efficacy of both CAR-NK and CAR-T cells in treating cancers and autoimmune diseases

Chimeric Antigen Receptor (CAR) based therapies are becoming increasingly important in treating patients. CAR-T cells have been shown to be highly effective in the treatment of hematological malignancies. However, harmful therapeutic barriers have been identified, such as the potential for graft-versus-host disease (GVHD), neurotoxicity, and cytokine release syndrome (CRS). As a result, CAR NK-cell therapy is expected to be a new therapeutic option. NK cells act as cytotoxic lymphocytes, supporting the innate immune response against autoimmune diseases and cancer cells by precisely detecting and eliminating malignant cells. Genetic modification of these cells provides a dual approach to the treatment of AD and cancer. It can be used through both CAR-independent and CAR-dependent mechanisms. The use of CAR-based cell therapies has been successful in treating cancer patients, leading to further investigation of this innovative treatment for alternative diseases, including AD. The complementary roles of CAR T and CAR NK cells have stimulated exploration in this area. Our study examines the latest research on the therapeutic effectiveness of these cells in treating both cancer and ADs.

Chimeric Antigen Receptor (CAR) T-Cell Therapy in Hematologic Malignancies: Clinical Implications and Limitations

Chimeric antigen receptor (CAR) T-cell therapy has become a powerful treatment option in B-cell and plasma cell malignancies, and many patients have benefited from its use. To date, six CAR T-cell products have been approved by the FDA and EMA, and many more are being developed and investigated in clinical trials. The whole field of adoptive cell transfer has experienced an unbelievable development process, and we are now at the edge of a new era of immune therapies that will have its impact beyond hematologic malignancies. Areas of interest are, e.g., solid oncology, autoimmune diseases, infectious diseases, and others. Although much has been achieved so far, there is still a huge effort needed to overcome significant challenges and difficulties. We are witnessing a rapid expansion of knowledge, induced by new biomedical technologies and CAR designs. The era of CAR T-cell therapy has just begun, and new products will widen the therapeutic landscape in the future. This review provides a comprehensive overview of the clinical applications of CAR T-cells, focusing on the approved products and emphasizing their benefits but also indicating limitations and challenges.

Improving cell reinfusion to enhance the efficacy of chimeric antigen receptor T-cell therapy and alleviate complications

Adoptive cell therapy (ACT) is a rapidly expanding area within the realm of transfusion medicine, focusing on the delivery of lymphocytes to trigger responses against tumors, viruses, or inflammation. This area has quickly evolved from its initial promise in immuno-oncology during preclinical trials to commercial approval of chimeric antigen receptor (CAR) T-cell therapies for leukemia and lymphoma (Jun and et al., 2018) [1]. CAR T-cell therapy has demonstrated success in treating hematological malignancies, particularly relapsed/refractory B-cell acute lymphoblastic leukemia and non-Hodgkin's lymphoma (Qi and et al., 2022) [2]. However, its success in treating solid tumors faces challenges due to the short-lived presence of CAR-T cells in the body and diminished T cell functionality (Majzner and Mackall, 2019) [3]. CAR T-cell therapy functions by activating immune effector cells, yet significant side effects and short response durations remain considerable obstacles to its advancement. A prior study demonstrated that the therapeutic regimen can induce systemic inflammatory reactions, such as cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), tumor lysis syndrome (TLS), off-target effects, and other severe complications. This study aims to explore current research frontiers in this area.

Update on the current and future use of CAR-T to treat multiple myeloma

Chimeric antigen receptor T-cell (CAR-T) therapy has become an important intervention in the management of relapsed and relapsed/refractory multiple myeloma (MM). Currently, B-cell maturation antigen (BCMA) is the most targeted surface protein due to its ubiquitous expression on plasma cells, with increasing expression of this essential transmembrane protein on malignant plasma cells as patients develop more advanced disease. This review will explore the earliest CAR-T trials in myeloma, discuss important issues involved in CAR-T manufacturing and processing, as well as review current clinical trials that led to the approval of the two commercially available CAR-T products, Idecabtagene vicleucel and ciltacabtagene autoleucel. The most recent data from trials investigating the use of CAR-T as an earlier line of therapy will be presented. Finally, the problem of relapses after CAR-T will be presented, including several theories as to why CAR-T therapies fail and possible clinical caveats. The next generation of MM-specific CAR-T will likely include new targets such as G-protein-coupled receptor class C, Group 5, member D (GPRC5D) and signaling lymphocyte activation molecular Family 7 (SLAMF7). The role of CAR-T in the treatment of MM will undoubtedly increase exponentially in the next decade.

The preclinical discovery and clinical development of ciltacabtagene autoleucel (Cilta-cel) for the treatment of multiple myeloma

INTRODUCTION

Despite remarkable therapeutic advances over the last two decades, which have resulted in dramatic improvements in patient survival, multiple myeloma (MM) is still considered an incurable disease. Therefore, there is a high need for new treatment strategies. Genetically engineered/redirected chimeric antigen receptor (CAR) T cells may represent the most compelling modality of immunotherapy for cancer treatment in general, and MM in particular. Indeed, unprecedented response rates have led to the recent approvals of the first two BCMA-targeted CAR T cell products idecabtagene-vicleucel ('Ide-cel') and ciltacabtagene-autoleucel ('Cilta-Cel') for the treatment of heavily pretreated MM patients. In addition, both are emerging as a new standard-of-care also in earlier lines of therapy.

AREAS COVERED

This article briefly reviews the history of the preclinical development of CAR T cells, with a particular focus on Cilta-cel. Moreover, it summarizes the newest clinical data on Cilta-cel and discusses strategies to further improve its activity and reduce its toxicity.

EXPERT OPINION

Modern next-generation immunotherapy is continuously transforming the MM treatment landscape. Despite several caveats of CAR T cell therapy, including its toxicity, costs, and limited access, prolonged disease-free survival and potential cure of MM are finally within reach.

Chimeric Antigen Receptor T Cells in the Treatment of Multiple Myeloma

Chimeric antigen receptor T cells (CARTs) represent another powerful way to leverage the immune system to fight malignancy. Indeed, in multiple myeloma, the high response rate and duration of response to B cell maturation antigen-targeted therapies in later lines of disease has led to 2 Food and Drug Administration (FDA) drug approvals and opened the door to the development of this drug class. This review aims to provide an update on the 2 FDA-approved products, summarize the data for the most promising next-generation multiple myeloma CARTs, and outline current challenges in the field and potential solutions.

A State-of-the-Art Review on the Recent Advances of Mesenchymal Stem Cell Therapeutic Application in Systematic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease with an unknown etiology that has widespread clinical and immunological manifestations. Despite the increase in knowledge about the pathogenesis process and the increase in treatment options, however, the treatments fail in half of the cases. Therefore, there is still a need for research on new therapies. Mesenchymal stem cells (MSCs) are powerful regulators of the immune system and can reduce the symptoms of systemic lupus erythematosus. This study aimed to review the mechanisms of immune system modulation by MSCs and the role of these cells in the treatment of SLE. MSCs suppress T lymphocytes through various mechanisms, including the production of transforming growth factor-beta (TGF-B), prostaglandin E2 (PGE2), nitric oxide (NO), and indolamine 2 and 3-oxygenase (IDO). In addition, MSCs inhibit the production of their autoantibodies by inhibiting the differentiation of lymphocytes. The production of autoantibodies against nuclear antigens is an important feature of SLE. On the other hand, MSCs inhibit antigen delivery by antigen-presenting cells (APCs) to T lymphocytes. Studies in animal models have shown the effectiveness of these cells in treating SLE. However, few studies have been performed on the effectiveness of this treatment in humans. It can be expected that new treatment strategies for SLE will be introduced in the future, given the promising results of MSCs application.

BCMA CAR-T cells in multiple myeloma-ready for take-off?

Although the approval of new drugs has improved the clinical outcome of multiple myeloma (MM), it was widely regarded as incurable over the past decades. However, recent advancements in groundbreaking immunotherapies, such as chimeric antigen receptor T cells (CAR-T), have yielded remarkable results in heavily pretreated relapse/refractory patients, instilling hope for a potential cure. CAR-T are genetically modified cells armed with a novel receptor to specifically recognize and kill tumor cells. Among the potential targets for MM, the B-cell maturation antigen (BCMA) stands out since it is highly and almost exclusively expressed on plasma cells. Here, we review the currently approved BCMA-directed CAR-T products and ongoing clinical trials in MM. Furthermore, we explore innovative approaches to enhance BCMA-directed CAR-T and overcome potential reasons for treatment failure. Additionally, we explore the side effects associated with these novel therapies and shed light on accessibility of CAR-T therapy around the world.

Bispecific BCMA/CD24 CAR-T cells control multiple myeloma growth

Anti-multiple myeloma B cell maturation antigen (BCMA)-specific chimeric antigen receptor (CAR) T-cell therapies represent a promising treatment strategy with high response rates in myeloma. However, durable cures following anti-BCMA CAR-T cell treatment of myeloma are rare. One potential reason is that a small subset of minimal residual myeloma cells seeds relapse. Residual myeloma cells following BCMA-CAR-T-mediated treatment show less-differentiated features and express stem-like genes, including CD24. CD24-positive myeloma cells represent a large fraction of residual myeloma cells after BCMA-CAR-T therapy. In this work, we develop CD24-CAR-T cells and test their ability to eliminate myeloma cells. We find that CD24-CAR-T cells block the CD24-Siglec-10 pathway, thereby enhancing macrophage phagocytic clearance of myeloma cells. Additionally, CD24-CAR-T cells polarize macrophages to a M1-like phenotype. A dual-targeted BCMA-CD24-CAR-T exhibits improved efficacy compared to monospecific BCMA-CAR-T-cell therapy. This work presents an immunotherapeutic approach that targets myeloma cells and promotes tumor cell clearance by macrophages.

CAR-T Therapy in Relapsed Refractory Multiple Myeloma

Multiple myeloma is a plasma cell neoplasm. The emergence of proteasome inhibitors, immunomodulatory drugs, and anti-CD38 monoclonal antibodies has improved the prognosis of multiple myeloma patients. However, some patients are still insensitive to conventional therapy or frequently relapse after remission. Chemotherapy based on proteasome inhibitors or immunomodulatory drugs is ineffective in controlling the progression of relapsed refractory multiple myeloma. No consensus has been reached on treating relapsed refractory multiple myeloma to date. Recently chimeric antigen receptor T cells therapy has shown promising results that could achieve rapid remissions of patients and improve their prognoses. Additionally, most patients in chimeric antigen receptor T cell clinical trials were triple-refractory multiple myeloma patients, indicating that chimeric antigen receptor T cell immunotherapy could overcome drug resistance to new drugs. Since single immunotherapies are prone to acquired resistance, combination immunotherapies based on emerging immunotherapies may solve this issue. Achieving complete remission and minimal residual disease negative status as soon as possible is beneficial to patients. This paper reviewed the main chimeric antigen receptor T cell products in relapsed refractory multiple myeloma, and it explained the drug resistance mechanism and improvement methods of chimeric antigen receptor T cells therapy. This review summarized the best beneficiaries of chimeric antigen receptor T cell therapy and the salvage treatment of disease recurrence after chimeric antigen receptor T cell therapy, providing some ideas for the clinical application of chimeric antigen receptor T cells.

Characterization of novel CD19-specific VHHs isolated from a camelid immune library by phage display

BACKGROUND

Monoclonal antibody (mAb)-based immunotherapies have achieved promising outcomes in the treatment of immunological and oncological indications. CD19 is considered one of the most qualified antigens in the treatment of B-cell neoplasms. VHHs (nanobodies) are known for their physicochemical advantages over conventional mAbs rendering them suitable therapeutics and diagnostic tools. Herein, we aimed to isolate CD19-specific VHHs from a novel immune library using phage display.

METHODS

An immune VHH gene library was constructed. Using phage display and after five biopanning rounds, two monoclonal CD19-specific VHHs were isolated. The selected VHHs were expressed, purified, and characterized in terms of their affinity, specificity, sensitivity, and ability to target CD19-positive cell lines. Moreover, in silico analyses were employed for further characterization.

RESULTS

A VHH library was developed, and because the outputs of the 4th biopanning round exhibited the most favorable characteristics, a panel of random VHHs was selected from them. Ultimately, two of the most favorable VHHs were selected and DNA sequenced (designated as GR37 and GR41). Precise experiments indicated that GR37 and GR41 exhibited considerable specificity, sensitivity, and affinity (1.15 × 107 M-1 and 2.08 × 107 M-1, respectively) to CD19. Flow cytometric analyses revealed that GR37 and GR41 could bind CD19 on the surface of cell lines expressing the antigen. Moreover, in silico experiments predicted that both VHHs target epitopes that are distinct from that targeted by the CD19-specific single-chain variable fragment (scFv) FMC63.

CONCLUSION

The selected VHHs can be used as potential targeting tools for the development of CD19-based immunotherapeutics.

Chimeric Antigen Receptor T Cells in Multiple Myeloma

Multiple myeloma is the second most common hematological malignancy with an approximate incidence of up to 8.5 cases per 100,000 persons per year. Over the last decade, therapy for multiple myeloma has undergone a revolutionary change. Chimeric antigen receptor (CAR) T-cell therapy has played a major role in this evolution. In this review, we discuss the existing state of CAR T-cell therapy in myeloma while evaluating several newer therapies and targets expected in the near future.

CAR T-Cell Therapy for Multiple Myeloma: A Clinical Practice-Oriented Review

The emergence of chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of hematologic malignancies, including multiple myeloma (MM). Two BCMA-directed CAR T-cell products - idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel) - have received US Food and Drug Administration (FDA) approval for patients with relapsed/refractory MM who underwent four or more prior lines of therapy (including an immunomodulatory agent, a proteasome inhibitor, and an anti-CD38 monoclonal antibody). Despite producing unprecedented response rates in an otherwise difficult to treat patient population, CAR T-cell therapies are commonly associated with immune-related adverse events (e.g., cytokine release syndrome and neurotoxicity), cytopenias, and infections. Moreover, many patients continue to exhibit relapse post-treatment, with resistance mechanisms yet to be fully understood. Ongoing basic, translational, and clinical research efforts are poised to generate deeper insights into the optimal utilization of these therapies, improve their efficacy, minimize associated toxicity, and identify new target antigens in patients with MM.

Long-term analysis of cellular immunity in patients with RRMM treated with CAR-T cell therapy

Chimeric antigen receptor T (CAR-T) cell therapy exhibits remarkable efficacy against refractory or relapsed multiple myeloma (RRMM); however, the immune deficiency following CAR-Ts infusion has not been well studied. In this study, 126 patients who achieved remission post-CAR-Ts infusion were evaluated for cellular immunity. Following lymphodepletion (LD) chemotherapy, the absolute lymphocyte count (ALC) and absolute counts of lymphocyte subsets were significantly lower than baseline at D0. Grade ≥ 3 lymphopenia occurred in 99% of patients within the first 30 days, with most being resolved by 180 days. The median CD4+ T-cell count was consistently below baseline and the lower limit of normal (LLN) levels at follow-up. Conversely, the median CD8+ T-cell count returned to the baseline and LLN levels by D30. The median B-cell count remained lower than baseline level at D60 and returned to baseline and LLN levels at D180. In the first 30 days, 27 (21.4%) patients had 29 infections, with the majority being mild to moderate in severity (21/29; 72.4%). After day 30, 44 (34.9%) patients had 56 infections, including 20 severe infections. One patient died from bacteremia at 3.8 months post-CAR-Ts infusion. In conclusion, most patients with RRMM experienced cellular immune deficiency caused by LD chemotherapy and CAR-Ts infusion. The ALC and most lymphocyte subsets gradually recovered after day 30 of CAR-Ts infusion, except for CD4+ T cells. Some patients experience prolonged CD4+ T-cell immunosuppression without severe infection.

A T cell receptor β chain-directed antibody fusion molecule activates and expands subsets of T cells to promote antitumor activity

Despite the success of programmed cell death-1 (PD-1) and PD-1 ligand (PD-L1) inhibitors in treating solid tumors, only a proportion of patients respond. Here, we describe a first-in-class bifunctional therapeutic molecule, STAR0602, that comprises an antibody targeting germline Vβ6 and Vβ10 T cell receptors (TCRs) fused to human interleukin-2 (IL-2) and simultaneously engages a nonclonal mode of TCR activation with costimulation to promote activation and expansion of αβ T cell subsets expressing distinct variable β (Vβ) TCR chains. In solution, STAR0602 binds IL-2 receptors in cis with Vβ6/Vβ10 TCRs on the same T cell, promoting expansion of human Vβ6 and Vβ10 CD4+ and CD8+ T cells that acquire an atypical central memory phenotype. Monotherapy with a mouse surrogate molecule induced durable tumor regression across six murine solid tumor models, including several refractory to anti-PD-1. Analysis of murine tumor-infiltrating lymphocyte (TIL) transcriptomes revealed that expanded Vβ T cells acquired a distinct effector memory phenotype with suppression of genes associated with T cell exhaustion and TCR signaling repression. Sequencing of TIL TCRs also revealed an increased T cell repertoire diversity within targeted Vβ T cell subsets, suggesting clonal revival of tumor T cell responses. These immunological and antitumor effects in mice were recapitulated in studies of STAR0602 in nonhuman primates and human ex vivo models, wherein STAR0602 boosted human antigen-specific T cell responses and killing of tumor organoids. Thus, STAR0602 represents a distinct class of T cell-activating molecules with the potential to deliver enhanced antitumor activity in checkpoint inhibitor-refractory settings.

Chimeric antigen receptor T cell-based targeting of CD317 as a novel immunotherapeutic strategy against glioblastoma

BACKGROUND

Chimeric antigen receptor (CAR) T cell therapy has proven to be successful against hematological malignancies. However, exploiting CAR T cells to treat solid tumors is more challenging for various reasons including the lack of suitable target antigens. Here, we identify the transmembrane protein CD317 as a novel target antigen for CAR T cell therapy against glioblastoma, one of the most aggressive solid tumors.

METHODS

CD317-targeting CAR T cells were generated by lentivirally transducing human T cells from healthy donors. The anti-glioma activity of CD317-CAR T cells toward various glioma cells was assessed in vitro in cell lysis assays. Subsequently, we determined the efficacy of CD317-CAR T cells to control tumor growth in vivo in clinically relevant mouse glioma models.

RESULTS

We generated CD317-specific CAR T cells and demonstrate strong anti-tumor activity against several glioma cell lines as well as primary patient-derived cells with varying CD317 expression levels in vitro. A CRISPR/Cas9-mediated knockout of CD317 protected glioma cells from CAR T cell lysis, demonstrating the target specificity of the approach. Silencing of CD317 expression in T cells by RNA interference reduced fratricide of engineered T cells and further improved their effector function. Using orthotopic glioma mouse models, we demonstrate the antigen-specific anti-tumor activity of CD317-CAR T cells, which resulted in prolonged survival and cure of a fraction of CAR T cell-treated animals.

CONCLUSIONS

These data reveal a promising role of CD317-CAR T cell therapy against glioblastoma, which warrants further evaluation to translate this immunotherapeutic strategy into clinical neuro-oncology.

Targeted single-cell proteomic analysis identifies new liquid biopsy biomarkers associated with multiple myeloma

Multiple myeloma (MM) is accompanied by alterations to the normal plasma cell (PC) proteome, leading to changes to the tumor microenvironment and disease progression. There is a great need for understanding the consequences that lead to MM progression and for the discovery of new biomarkers that can aid clinical diagnostics and serve as targets for therapeutics. This study demonstrates the applicability of utilizing the single-cell high-definition liquid biopsy assay (HDSCA) and imaging mass cytometry to characterize the proteomic profile of myeloma. In our study, we analyzed ~87,000 cells from seven patient samples (bone marrow and peripheral blood) across the myeloma disease spectrum and utilized our multiplexed panel to characterize the expression of clinical markers for PC classification, additional potential therapeutic targets, and the tumor microenvironment cells. Our analysis showed BCMA, ICAM3 (CD50), CD221, and CS1 (SLAMF7) as the most abundantly expressed markers on PCs across all myeloma stages, with BCMA, ICAM3, and CD221 having significantly higher expression levels on disease versus precursor PCs. Additionally, we identify significantly elevated levels of expression for CD74, MUM1, CD229, CD44, IGLL5, Cyclin D1, UBA52, and CD317 on PCs from overt disease conditions compared to those from precursor states.

Tumor-secreted IFI35 promotes proliferation and cytotoxic activity of CD8+ T cells through PI3K/AKT/mTOR signaling pathway in colorectal cancer

BACKGROUND

A large proportion of the patients with cancer do not respond to immunotherapies. Recent studies suggested an important role for tumor-infiltrating cytotoxic T lymphocytes (CTL) in enhancing response to immunotherapy. Here, we aim to identify gene that induce proliferative and cytotoxic states of CD8⁺ T cells, and to investigate its effect on CAR-T cells against colorectal cancer.

METHODS

Correlation between the expression of IFI35 with the activation and cytotoxicity of CD8⁺ T cells was assessed with TCGA and proteomic databases. Then we constructed murine colon cancer cells over-expressing IFI35 and tested their effect on anti-tumor immunity in both immunodeficient and immunocompetent mouse models. Flow cytometry and immunohistochemistry were performed to assess the immune microenvironment. Western blot analysis was used to identify the potential down-stream signaling pathway regulated by IFI35. We further investigated the efficacy of the rhIFI35 protein in combination with immunotherapeutic treatment.

RESULTS

The transcriptional and proteomic analysis of the activation and cytotoxicity of CD8⁺ T cells in human cancer samples demonstrated that IFI35 expression is correlated with increased CD8⁺ T cell infiltration and predicted a better outcome in colorectal cancer. The number and cytotoxicity of CD8⁺ T cells were significantly increased in IFI35-overexpressing tumors. Mechanistically, we identified that the IFNγ-STAT1-IRF7 axis stimulated IFI35 expression, and that IFI35-mediated regulation of CD8⁺ T cell proliferation and cytotoxicity was dependent on PI3K/AKT/mTOR signaling pathway in vitro. Furthermore, IFI35 protein enhanced the efficacy of CAR-T cells against colorectal cancer cells.

CONCLUSION

Our findings identify IFI35 as a new biomarker that can enhance the proliferation and function of CD8⁺ T cells, as well as increase the efficacy of CAR-T cells against colorectal cancer cells.

Embracing Myeloma Chimeric Antigen Receptor-T: From Scientific Design to Clinical Impact

Despite recent advancement of treatment strategies in multiple myeloma (MM), patients with relapsed/refractory MM disease, particularly after triple-class refractoriness, continue to have poor prognosis. Chimeric antigen receptor (CAR-T) cells were developed and applied to improve outcomes in this setting, and two products, idecabtagene vicleucel and ciltacabtagene autoleucel, both targeting B-cell maturation antigen, have been approved by the Food and Drug Administration in the United States and European Medicines Agency in Europe. Both have shown unprecedented clinical outcomes with high response rate and prolonged progression-free survival and overall survival in this patient population with grim prognosis. Currently, further investigations are ongoing for CAR-T targeting different tumor antigens such as G protein-coupled receptor, class C, group 5, member D or with different combinations of intracellular signaling domains, as well as fourth-generation CAR-T with antigen-unrestricted inducible cytokines. Although CAR-T therapies hold hopes and enthusiasm from the myeloma community, several hurdles remain before these treatments become available for all patients in need. These barriers include CAR-T-cell manufacturing availability, access to administering centers, financial cost, caregivers' availability, and socioeconomic and racial disparities. Expanding clinical trial eligibility criteria and real-world data collection and analysis is crucial to understand the efficacy and safety of CAR-T in the patient cohort who tends to be excluded from current trials.

Anti-BCMA/CD19 CAR T Cells with Early Immunomodulatory Maintenance for Multiple Myeloma Responding to Initial or Later-Line Therapy

We conducted a phase I clinical trial of anti-BCMA chimeric antigen receptor T cells (CART-BCMA) with or without anti-CD19 CAR T cells (huCART19) in multiple myeloma (MM) patients responding to third- or later-line therapy (phase A, N = 10) or high-risk patients responding to first-line therapy (phase B, N = 20), followed by early lenalidomide or pomalidomide maintenance. We observed no high-grade cytokine release syndrome (CRS) and only one instance of low-grade neurologic toxicity. Among 15 subjects with measurable disease, 10 exhibited partial response (PR) or better; among 26 subjects responding to prior therapy, 9 improved their response category and 4 converted to minimal residual disease (MRD)-negative complete response/stringent complete response. Early maintenance therapy was safe, feasible, and coincided in some patients with CAR T-cell reexpansion and late-onset, durable clinical response. Outcomes with CART-BCMA + huCART19 were similar to CART-BCMA alone. Collectively, our results demonstrate favorable safety, pharmacokinetics, and antimyeloma activity of dual-target CAR T-cell therapy in early lines of MM treatment.

SIGNIFICANCE

CAR T cells in early lines of MM therapy could be safer and more effective than in the advanced setting, where prior studies have focused. We evaluated the safety, pharmacokinetics, and efficacy of CAR T cells in patients with low disease burden, responding to current therapy, combined with standard maintenance therapy. This article is highlighted in the In This Issue feature, p. 101.

Chimeric antigen receptor T-cell therapy in multiple myeloma: A comprehensive review of current data and implications for clinical practice

Multiple myeloma (MM) is a hematologic malignancy defined by the clonal proliferation of transformed plasma cells. Despite tremendous advances in the treatment paradigm of MM, a cure remains elusive for most patients. Although long-term disease control can be achieved in a very large number of patients, the acquisition of tumor resistance leads to disease relapse, especially in patients with triple-class refractory MM (defined as resistance to immunomodulatory agents, proteosome inhibitors, and monoclonal antibodies). There is an unmet need for effective treatment options in these patients. Chimeric antigen receptor (CAR) T-cell therapy is a novel approach that has demonstrated promising efficacy in the treatment of relapsed, refractory MM (RRMM). These genetically modified cellular therapies have demonstrated deep and durable remissions in other B-cell malignancies, and current efforts aim to achieve similar results in patients with RRMM. Early studies have demonstrated remarkable response rates with CAR T-cell therapy in RRMM; however, durable responses with CAR T-cell therapies in myeloma have yet to be realized. In this comprehensive review, the authors describe the development of CAR T-cell therapies in myeloma, the outcomes of notable clinical trials, the toxicities and limitations of CAR T-cell therapies, and the strategies to overcome therapeutic challenges of CAR T cells in the hope of achieving a cure for multiple myeloma.

Myeloidcells in the immunosuppressive microenvironment in glioblastoma: The characteristics and therapeutic strategies

Glioblastoma (GBM) is the most common and lethal malignant tumor of the central nervous system in adults. Conventional therapies, including surgery, radiotherapy, and chemotherapy, have limited success in ameliorating patient survival. The immunosuppressive tumor microenvironment, which is infiltrated by a variety of myeloid cells, has been considered a crucial obstacle to current treatment. Recently, immunotherapy, which has achieved great success in hematological malignancies and some solid cancers, has garnered extensive attention for the treatment of GBM. In this review, we will present evidence on the features and functions of different populations of myeloid cells, and on current clinical advances in immunotherapies for glioblastoma.

Innovative Anti-CD38 and Anti-BCMA Targeted Therapies in Multiple Myeloma: Mechanisms of Action and Resistance

CD38 and B-cell maturation antigens (BCMAs) are prevalently expressed on neoplastic plasma cells in multiple myeloma (MM), making them ideal therapeutic targets. Anti-CD38 monoclonal antibodies, such as approved daratumumab and isatuximab, are currently the milestone in MM treatment because they induce plasma cell apoptosis and kill through several mechanisms, including antibody-dependent cellular cytotoxicity or phagocytosis. BCMA is considered an excellent target in MM, and three different therapeutic strategies are either already available in clinical practice or under investigation: antibody-drug conjugates, such as belantamab-mafodotin; bispecific T cell engagers; and chimeric antigen receptor-modified T cell therapies. Despite the impressive clinical efficacy of these new strategies in the treatment of newly diagnosed or multi-refractory MM patients, several mechanisms of resistance have already been described, including antigen downregulation, the impairment of antibody-dependent cell cytotoxicity and phagocytosis, T- and natural killer cell senescence, and exhaustion. In this review, we summarize the current knowledge on the mechanisms of action and resistance of anti-CD38 and anti-BCMA agents and their clinical efficacy and safety.

Chimeric antigen receptor T (CAR-T) cells: Novel cell therapy for hematological malignancies

Over the last decade, the emergence of several novel therapeutic approaches has changed the therapeutic perspective of human malignancies. Adoptive immunotherapy through chimeric antigen receptor T cell (CAR-T), which includes the engineering of T cells to recognize tumor-specific membrane antigens and, as a result, death of cancer cells, has created various clinical benefits for the treatment of several human malignancies. In particular, CAR-T-cell-based immunotherapy is known as a critical approach for the treatment of patients with hematological malignancies such as acute lymphoblastic leukemia (ALL), multiple myeloma (MM), chronic lymphocytic leukemia (CLL), acute myeloid leukemia (AML), Hodgkin lymphoma (HL), and non-Hodgkin's lymphoma (NHL). However, CAR-T-cell therapy of hematological malignancies is associated with various side effects. There are still extensive challenges in association with further progress of this therapeutic approach, from manufacturing and engineering issues to limitations of applications and serious toxicities. Therefore, further studies are required to enhance efficacy and minimize adverse events. In the current review, we summarize the development of CAR-T-cell-based immunotherapy and current clinical antitumor applications to treat hematological malignancies. Furthermore, we will mention the current advantages, disadvantages, challenges, and therapeutic limitations of CAR-T-cell therapy.

Chimeric antigen receptor T-cell therapy for multiple myeloma

Multiple myeloma (MM) is a malignant plasma cell disorder that remains incurable for most patients, as persistent clonal evolution drives new mutations which confer MM high-risk signatures and resistance to standard care. The past two decades have significantly refashioned the therapeutic options for MM, especially adoptive T cell therapy contributing to impressive response rate and clinical efficacy. Despite great promises achieved from chimeric antigen receptor T-cell (CAR-T) therapy, the poor durability and severe toxicity (cytokine release syndrome and neurotoxicity) are still huge challenges. Therefore, relapsed/refractory multiple myeloma (RRMM), characterized by the nature of clinicopathologic and molecular heterogeneity, is frequently associated with poor prognosis. B Cell Maturation Antigen (BCMA) is the most successful target for CAR-T therapy, and other potential targets either for single-target or dual-target CAR-T are actively being studied in numerous clinical trials. Moreover, mechanisms driving resistance or relapse after CAR-T therapy remain uncharacterized, which might refer to T-cell clearance, antigen escape, and immunosuppressive tumor microenvironment. Engineering CAR T-cell to improve both efficacy and safety continues to be a promising area for investigation. In this review, we aim to describe novel tumor-associated neoantigens for MM, summarize the data from current MM CAR-T clinical trials, introduce the mechanism of disease resistance/relapse after CAR-T infusion, highlight innovations capable of enhanced efficacy and reduced toxicity, and provide potential directions to optimize manufacturing processes.

Nano-Biohybrid DNA Engager That Reprograms the T-Cell Receptor

Although engineered T cells with transgenic chimeric antigen receptors (CARs) have made a breakthrough in cancer therapeutics, this approach still faces many challenges in the specificity, efficacy, and self-safety of genetic engineering. Here, we developed a nano-biohybrid DNA engager-reprogrammed T-cell receptor (EN-TCR) system to improve the specificity and efficacy, mitigate the excessive activation, and shield against risks from transgenesis, thus achieving a diversiform and precise control of the T-cell response. Utilizing modular assembly, the EN-TCR system can graft different specificities on T cells via antibody assembly. Besides, the designability of DNA hybridization enables precise target recognition by the library of multiantigen cell recognition circuits and allows gradual tuning of the T-cell activation level by the signaling switch and independent control over different types of T cells. Furthermore, we demonstrated the effectiveness of the system in tumor models. Together, this study provides a nongenetic T-cell engineering strategy to overcome major hindrances in T-cell therapy and may be extended to a general and convenient cell engineering strategy.

Innovation in BCMA CAR-T therapy: Building beyond the Model T

Autologous chimeric antigen receptor T-cell (CAR-T) therapies targeting B-cell maturation antigen (BCMA) have revolutionized the field of multiple myeloma in the same way that the Ford Model T revolutionized the original CAR world a century ago. However, we are only beginning to understand how to improve the efficacy and usability of these cellular therapies. In this review, we explore three automotive analogies for innovation with BCMA CAR-T therapies: stronger engines, better mileage, and hassle-free delivery. Firstly, we can build stronger engines in terms of BCMA targeting: improved antigen binding, tools to modulate antigen density, and armoring to better reach the antigen itself. Secondly, we can improve "mileage" in terms of response durability through ex vivo CAR design and in vivo immune manipulation. Thirdly, we can implement hassle-free delivery through rapid manufacturing protocols and off-the-shelf products. Just as the Model T set a benchmark for car manufacturing over 100 years ago, idecabtagene vicleucel and ciltacabtagene autoleucel have now set the starting point for BCMA CAR-T therapy with their approvals. As with any emerging technology, whether automotive or cellular, the best in innovation and optimization is yet to come.

Natural Killer Cells: A Promising Kit in the Adoptive Cell Therapy Toolbox

As an important component of the innate immune system, natural killer (NK) cells have gained increasing attention in adoptive cell therapy for their safety and efficacious tumor-killing effect. Unlike T cells which rely on the interaction between TCRs and specific peptide-MHC complexes, NK cells are more prone to be served as "off-the-shelf" cell therapy products due to their rapid recognition and killing of tumor cells without MHC restriction. In recent years, constantly emerging sources of therapeutic NK cells have provided flexible options for cancer immunotherapy. Advanced genetic engineering techniques, especially chimeric antigen receptor (CAR) modification, have yielded exciting effectiveness in enhancing NK cell specificity and cytotoxicity, improving in vivo persistence, and overcoming immunosuppressive factors derived from tumors. In this review, we highlight current advances in NK-based adoptive cell therapy, including alternative sources of NK cells for adoptive infusion, various CAR modifications that confer different targeting specificity to NK cells, multiple genetic engineering strategies to enhance NK cell function, as well as the latest clinical research on adoptive NK cell therapy.

Single cell characterization of myeloma and its precursor conditions reveals transcriptional signatures of early tumorigenesis

Multiple myeloma is a plasma cell malignancy almost always preceded by precursor conditions, but low tumor burden of these early stages has hindered the study of their molecular programs through bulk sequencing technologies. Here, we generate and analyze single cell RNA-sequencing of plasma cells from 26 patients at varying disease stages and 9 healthy donors. In silico dissection and comparison of normal and transformed plasma cells from the same bone marrow biopsy enables discovery of patient-specific transcriptional changes. Using Non-Negative Matrix Factorization, we discover 15 gene expression signatures which represent transcriptional modules relevant to myeloma biology, and identify a signature that is uniformly lost in abnormal cells across disease stages. Finally, we demonstrate that tumors contain heterogeneous subpopulations expressing distinct transcriptional patterns. Our findings characterize transcriptomic alterations present at the earliest stages of myeloma, providing insight into the molecular underpinnings of disease initiation.

Immunotherapy for the treatment of multiple myeloma

Despite advances in treatment for multiple myeloma, the majority of patients ultimately develop relapsed disease marked by immune evasion and resistance to standard therapy. Immunotherapy has emerged as a powerful tool for tumor-directed cytotoxicity with the unique potential to induce immune memory to reduce the risk of relapse. Understanding the specific mechanisms of immune dysregulation and dysfunction in advanced myeloma is critical to the development of further therapies that produce a durable response. Adoptive cellular therapy, most strikingly CAR T cell therapy, has demonstrated dramatic responses in the setting of refractory disease. Understanding the factors that contribute to immune evasion and the mechanisms of response and resistance to therapy will be critical to developing the next generation of adoptive cellular therapies, informing novel combination therapy, and determining the optimal time to incorporate immune therapy in the treatment of myeloma.

Delivering genes with human immunodeficiency virus-derived vehicles: still state-of-the-art after 25 years

Viruses are naturally endowed with the capacity to transfer genetic material between cells. Following early skepticism, engineered viruses have been used to transfer genetic information into thousands of patients, and genetic therapies are currently attracting large investments. Despite challenges and severe adverse effects along the way, optimized technologies and improved manufacturing processes are driving gene therapy toward clinical translation. Fueled by the outbreak of AIDS in the 1980s and the accompanying focus on human immunodeficiency virus (HIV), lentiviral vectors derived from HIV have grown to become one of the most successful and widely used vector technologies. In 2022, this vector technology has been around for more than 25 years. Here, we celebrate the anniversary by portraying the vector system and its intriguing properties. We dive into the technology itself and recapitulate the use of lentiviral vectors for ex vivo gene transfer to hematopoietic stem cells and for production of CAR T-cells. Furthermore, we describe the adaptation of lentiviral vectors for in vivo gene delivery and cover the important contribution of lentiviral vectors to basic molecular research including their role as carriers of CRISPR genome editing technologies. Last, we dwell on the emerging capacity of lentiviral particles to package and transfer foreign proteins.

Engineering T-cells with chimeric antigen receptors to combat hematological cancers: an update on clinical trials

Chimeric antigen receptor (CAR) redirected T-cells has shown efficacy in the treatment of B-cell leukemia/lymphoma, however, high numbers of relapses occur due to loss of targeted antigen or intrinsic failure of the CAR T-cells. In this situation modifications of the basic strategy are envisaged to reduce the risk of relapse, some of them are in early clinical exploration. These include simultaneous targeting of multiple antigens or combination of CAR T-cell therapy with other treatment modalities such as checkpoint inhibitors. The review evaluates and discusses these modified advanced therapies and pre-clinical approaches with respect to their potential to control leukemia and lymphoma in the long-term.

Chimeric antigen receptor T-cell therapy for relapsed and refractory thyroid cancer

The prognosis of most thyroid cancer patients is excellent, but for those with advanced or metastatic thyroid cancer, effective treatments are still lacking. Chimeric antigen receptor (CAR) T-cell therapy has gained remarkable achievements in hematologic malignancy but shown limited efficacy in solid tumors. In this report, we showed a relapsed and refractory thyroid cancer patient treated with TSHR + CD19 CAR-T, a combination of two 2nd generation CAR-T molecules targeting both TSHR and CD19. This patient finally achieved partial remission at 3 months and was tolerate well to the regimen. Our study suggested that the CAR-T therapy could be a feasible way in treating relapsed and refractory thyroid cancer.

Cytokines as an important player in the context of CAR-T cell therapy for cancer: Their role in tumor immunomodulation, manufacture, and clinical implications

CAR-T cell therapies have been recognized as one of the most advanced and efficient strategies to treat patients with hematologic malignancies. However, similar results have not been observed for the treatment of solid tumors. One of the explanations is the fact that tumors have extremely hostile microenvironments for the infiltration and effector activity of T-cells, mainly due to the presence of highly suppressive cytokines, hypoxia, and reactive oxygen species. Taking advantage of cytokines functionally, new fourth-generation CAR constructs have been developed to target tumor cells and additionally release cytokines that can contribute to the cytotoxicity of T-cells. The manufacturing process, including the use of cytokines in the expansion and differentiation of T cells, is also discussed. Finally, the clinical aspects and the influence of cytokines on the clinical condition of patients, such as cytokine release syndrome, who receive treatment with CAR-T cells are addressed. Therefore, this review aims to highlight how important cytokines are as one of the major players of cell therapy.

CAR T-Cell Therapy for Patients with Multiple Myeloma: Current Evidence and Challenges

The therapeutic landscape of multiple myeloma (MM) has benefited from an emergence of novel therapies over the last decade. By inducing T-cell kill of target cancer cells, chimeric antigen receptor (CAR) T-cell therapies have improved outcomes of patients with hematologic malignancies. B-cell maturation antigen (BCMA) is the current target antigen of choice for most CAR T-cell products under investigation for MM. However, their shortcomings deal with logistical and clinical challenges, including limited availability, manufacturing times, and toxicities. This article provides an overview of recently developed and investigational CAR T-cell therapies for MM, highlighting current evidence and challenges.

CAR T-Cell-Based gene therapy for cancers: new perspectives, challenges, and clinical developments

Chimeric antigen receptor (CAR)-T cell therapy is a progressive new pillar in immune cell therapy for cancer. It has yielded remarkable clinical responses in patients with B-cell leukemia or lymphoma. Unfortunately, many challenges remain to be addressed to overcome its ineffectiveness in the treatment of other hematological and solidtumor malignancies. The major hurdles of CAR T-cell therapy are the associated severe life-threatening toxicities such as cytokine release syndrome and limited anti-tumor efficacy. In this review, we briefly discuss cancer immunotherapy and the genetic engineering of T cells and, In detail, the current innovations in CAR T-cell strategies to improve efficacy in treating solid tumors and hematologic malignancies. Furthermore, we also discuss the current challenges in CAR T-cell therapy and new CAR T-cell-derived nanovesicle therapy. Finally, strategies to overcome the current clinical challenges associated with CAR T-cell therapy are included as well.

Statistical considerations for analyses of time-to-event endpoints in oncology clinical trials: Illustrations with CAR-T immunotherapy studies

Chimeric antigen receptor T-cell (CAR-T) therapy is an exciting development in the field of cancer immunology and has received a lot of interest in recent years. Many time-to-event (TTE) endpoints related to relapse, disease progression, and remission are analyzed in CAR-T studies to assess treatment efficacy. Definitions of these TTE endpoints are not always consistent, even for the same outcomes (e.g., progression-free survival), which often stems from analysis choices regarding which events to consider as part of the composite endpoint, censoring or competing risk in the analysis. Subsequent therapies such as hematopoietic stem cell transplantation are common but are not treated the same in different studies. Standard survival analysis methods are commonly applied to TTE analyses but often without full consideration of the assumptions inherent in the chosen analysis. We highlight two important issues of TTE analysis that arise in CAR-T studies, as well as in other settings in oncology: the handling of competing risks and assessing the association between a time-varying (post-infusion) exposure and the TTE outcome. We review existing analytical methods, including the cumulative incidence function and regression models for analysis of competing risks, and landmark and time-varying covariate analysis for analysis of post-infusion exposures. We clarify the scientific questions that the different analytical approaches address and illustrate how the application of an inappropriate method could lead to different results using data from multiple published CAR-T studies. Codes for implementing these methods in standard statistical software are provided.

Colorectal cancer immunotherapy-Recent progress and future directions

Compared with conventional chemotherapy and targeted therapy, immunotherapy has changed the treatment prospects of various solid tumors and has recently become the main treatment method for metastatic or recurrent solid tumors, including malignant melanoma, non-small-cell lung cancer, and renal cell carcinoma. The application of immune checkpoint inhibitor (ICI)-based immunotherapy in patients with colorectal cancer (CRC) has yielded satisfactory results in terms of safety and efficacy, and several immunotherapeutic agents, including pembrolizumab, nivolumab, and ipilimumab, have been approved for the treatment of advanced CRC. The advent of other immunotherapies, such as chimeric antigen receptor-modified T (CAR-T) cells or cancer vaccines, have also contributed to the development of immunotherapy for CRC. Here, we summarize the findings of recent clinical trials on the efficacy of immunotherapy in CRC and briefly describe the mechanisms associated with tumor-intrinsic resistance to ICIs. We then discuss potential biomarkers for predicting the efficacy of immunotherapy.

Chimeric Antigen Receptor T-Cells: An Overview of Concepts, Applications, Limitations, and Proposed Solutions

Adaptive immunity, orchestrated by B-cells and T-cells, plays a crucial role in protecting the body from pathogenic invaders and can be used as tools to enhance the body's defense mechanisms against cancer by genetically engineering these immune cells. Several strategies have been identified for cancer treatment and evaluated for their efficacy against other diseases such as autoimmune and infectious diseases. One of the most advanced technologies is chimeric antigen receptor (CAR) T-cell therapy, a pioneering therapy in the oncology field. Successful clinical trials have resulted in the approval of six CAR-T cell products by the Food and Drug Administration for the treatment of hematological malignancies. However, there have been various obstacles that limit the use of CAR T-cell therapy as the first line of defense mechanism against cancer. Various innovative CAR-T cell therapeutic designs have been evaluated in preclinical and clinical trial settings and have demonstrated much potential for development. Such trials testing the suitability of CARs against solid tumors and HIV are showing promising results. In addition, new solutions have been proposed to overcome the limitations of this therapy. This review provides an overview of the current knowledge regarding this novel technology, including CAR T-cell structure, different applications, limitations, and proposed solutions.

Overcome tumor relapse in CAR T cell therapy

Chimeric antigen receptor (CAR) T cell therapy is a novel therapeutic approach that uses gene editing techniques and lentiviral transduction to engineer T cells so that they can effectively kill tumors. However, CAR T cell therapy still has some drawbacks: many patients who received CAR T cell therapy and achieve remission, still had tumor relapse and treatment resistance, which may be due to tumor immune escape and CAR T cell dysfunction. To overcome tumor relapse, more researches are being done to optimize CAR T cell therapy to make it more precise and personalized, including screening for more specific tumor antigens, developing novel CAR T cells, and combinatorial treatment approaches. In this review, we will discuss the mechanisms as well as the progress of research on overcoming plans.

Anti-CD19 and anti-BCMA CAR T cell therapy followed by lenalidomide maintenance after autologous stem-cell transplantation for high-risk newly diagnosed multiple myeloma

Few prospective studies have examined posttransplant chimeric antigen receptor (CAR) T cell infusion as candidates for front-line consolidation therapy for high-risk multiple myeloma (MM) patients. This single-arm exploratory clinical trial is the first to evaluate the safety and efficacy of sequential anti-CD19 and anti-BCMA CAR-T cell infusion, followed by lenalidomide maintenance after autologous stem cell transplantation (ASCT), in 10 high-risk newly diagnosed multiple myeloma (NDMM) patients. The treatment was generally well tolerated, with hematologic toxicities being the most common grade 3 or higher adverse events. All patients had cytokine release syndrome (CRS), which was grade 1 in 5 patients (50%) and grade 2 in 5 patients (50%). No neurotoxicity was observed after CAR-T cell infusion. The overall response rate was 100%, with the best response being 90% for a stringent complete response (sCR), and 10% for a complete response (CR). At a median follow-up of 42 (36-49) months, seven (70%) of 10 patients showed sustained minimal residual disease (MRD) negativity for more than 2 years. The median progression-free survival (PFS) and overall survival (OS) were not reached. Although the sample size was small and there was a lack of control in this single-arm study, the clinical benefits observed warrant ongoing randomized controlled trials.