CAR-T cells secreting BiTEs circumvent antigen escape without detectable toxicity

Targeting capabilities of engineered extracellular vesicles for the treatment of neurological diseases

Recent advances in research on extracellular vesicles have significantly enhanced their potential as therapeutic agents for neurological diseases. Owing to their therapeutic properties and ability to cross the blood-brain barrier, extracellular vesicles are recognized as promising drug delivery vehicles for various neurological conditions, including ischemic stroke, traumatic brain injury, neurodegenerative diseases, glioma, and psychosis. However, the clinical application of natural extracellular vesicles is hindered by their limited targeting ability and short clearance from the body. To address these limitations, multiple engineering strategies have been developed to enhance the targeting capabilities of extracellular vesicles, thereby enabling the delivery of therapeutic contents to specific tissues or cells. Therefore, this review aims to highlight the latest advancements in natural and targeting-engineered extracellular vesicles, exploring their applications in treating traumatic brain injury, ischemic stroke, Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, glioma, and psychosis. Additionally, we summarized recent clinical trials involving extracellular vesicles and discussed the challenges and future prospects of using targeting-engineered extracellular vesicles for drug delivery in treating neurological diseases. This review offers new insights for developing highly targeted therapies in this field.

Unravelling the modified T cell receptor through Gen-Next CAR T cell therapy in Glioblastoma: Current status and future challenges

PURPOSE

Despite current technological advancements in the treatment of glioma, immediate alleviation of symptoms can be catered by therapeutic modalities, including surgery, chemotherapy, and combinatorial radiotherapy that exploit aberrations of glioma. Additionally, a small number of target antigens, their heterogeneity, and immune evasion are the potential reasons for developing targeted therapies. This oncologic milestone has catalyzed interest in developing immunotherapies against Glioblastoma to improve overall survival and cure patients with high-grade glioma. The next-gen CAR-T Cell therapy is one of the effective immunotherapeutic strategies in which autologous T cells have been modified to express receptors against GBM and it modulates cytotoxicity.

METHODS

In this review article, we examine preclinical and clinical outcomes, and limitations as well as present cutting-edge techniques to improve the function of CAR-T cell therapy and explore the possibility of combination therapy.

FINDINGS

To date, several CAR T-cell therapies are being evaluated in clinical trials for GBM and other brain malignancies and multiple preclinical studies have demonstrated encouraging outcomes.

IMPLICATIONS

CAR-T cell therapy represents a promising therapeutic paradigm in the treatment of solid tumors but a few limitations include, the blood-brain barrier (BBB), antigen escape, tumor microenvironment (TME), tumor heterogeneity, and its plasticity that suppresses immune responses weakens the ability of this therapy. Additional investigation is required that can accurately identify the targets and reflect the similar architecture of glioblastoma, thus optimizing the efficiency of CAR-T cell therapy; allowing for the selection of patients most likely to benefit from immuno-based treatments.

ZP4: A novel target for CAR-T cell therapy in triple negative breast cancer

Triple-negative breast cancer (TNBC) remains one of the most challenging subtypes of breast cancer to treat due to a lack of effective targeted therapies. Chimeric antigen receptor (CAR)-T cells hold promise, but their efficacy in solid tumors is often limited by on-target/off-tumor toxicities. Through comprehensive bioinformatic analysis of public RNA and proteomic data, we identified zona pellucida glycoprotein 4 (ZP4) as a novel target for TNBC. ZP4 RNA and protein were detected in a subset of TNBC patient samples and patient-derived xenograft (PDX) models, with expression otherwise restricted to oocytes. We generated 89 ZP4-specific novel monoclonal antibodies and used the single-chain variable fragment (scFv) antigen binding domains from the top three candidates to engineer CAR constructs. ZP4 CAR-T cells demonstrated efficacy against ZP4-expressing TNBC cells and PDX models. Additionally, we found that variations in the scFv antigen binding domain significantly influence CAR-T cell function.

Beyond the blood: expanding CAR T cell therapy to solid tumors

Chimeric antigen receptor (CAR) T cell therapy stands as a transformative advancement in immunotherapy, triumphing against hematological malignancies and, increasingly, autoimmune disorders. After a decade of relatively modest results for solid tumors, recent clinical trials and patient reports have also started to yield promising outcomes in glioblastoma and other challenging solid tumor entities. This Perspective seeks to explore the reasons behind these latest achievements and discusses how they can be sustained and expanded through different strategies involving CAR engineering and synthetic biology. Furthermore, we critically analyze how these breakthroughs can be leveraged to maintain momentum and broaden the therapeutic impact of CAR T cells across a variety of solid tumor landscapes.

The development and potent antitumor efficacy of CD44/CD133 dual-targeting IL7Rα-armored CAR-T cells against glioblastoma

Tumor heterogeneity and an immunosuppressive microenvironment pose significant challenges for immunotherapy against solid tumors, particularly glioblastoma multiforme (GBM). Recent studies have highlighted the crucial role of glioma stem cells (GSCs) in tumor recurrence and therapeutic resistance. In this context, we developed a tandem chimeric antigen receptor (CAR)-T cell targeting CD44 and CD133 (PROM1), containing a truncated IL-7 receptor alpha intracellular domain (Δ7R) between the CD28 costimulatory receptor and the CD3ζ signaling chain (Tanζ-T28-Δ7R). Our target identification and validation were carried out using GSCs, samples from GBM patients, and the corresponding sequencing data. The antitumor efficacy of CAR-T cells was evaluated in patient-derived GSCs, intracranial xenograft models, patient-derived xenograft models, and glioblastoma organoids (GBOs). Single-cell RNA sequencing and mass cytometry were used to determine the immune phenotypes of CAR-T cells. We showed that locoregionally administered Tanζ-T28-Δ7R CAR-T cells induced long-term tumor regression with the desired safety outcomes. Patient-derived autologous Tanζ-T28-Δ7R CAR-T cells showed robust antitumor activity against GBOs. Our pre-clinical data has demonstrated the translational potential of Tanζ-T28-Δ7R CAR-T cell against GBM.

Targeting cardiac fibrosis with Chimeric Antigen Receptor-Engineered Cells

Cardiac fibrosis poses a significant challenge in cardiovascular diseases due to its intricate pathogenesis, and there is currently no standardized and effective treatment approach. The fibrotic process entails the involvement of various cell types and molecular mechanisms, such as fibroblast activation and proliferation, increased collagen synthesis, and extracellular matrix rearrangement. Traditional therapies often fall short in efficacy or carry substantial side effects. However, recent studies have shown that Chimeric Antigen Receptor T (CAR-T) cells can selectively target and eliminate activated cardiac fibroblasts (CFs) in mice, leading to reduced cardiac fibrosis and improved myocardial tissue compliance. This breakthrough presents a new and promising avenue for treating cardiac fibrosis. Currently, CAR-T cell-based therapy for cardiac fibrosis is undergoing animal experimentation, indicating ample scope for enhancement. Future investigations could explore the application of CAR cell therapy in cardiac fibrosis treatment, including the potential of CAR-natural killer (CAR-NK) cells and CAR macrophages (CAR-M), offering novel insights and strategies for combating cardiac fibrosis.

Antibody-Nanoparticle Conjugates in Therapy: Combining the Best of Two Worlds

Monoclonal antibodies (mAbs) and antibody fragments have revolutionized medicine as highly specific binding agents and inhibitors. At the same time, several types of nanomaterials, including liposomes, lipid nanoparticles (NPs), polymersomes, metal and metal oxide NPs, and protein nanostructures, are increasingly utilized and explored for therapeutic potential due to their versatility, chemical and physical properties, and tunability. However, nanomaterials alone often lack specificity, leading to relatively low efficacy and/or high toxicity. To address this problem, a rapidly emerging area is antibody-nanomaterial conjugates (ANCs), which combine the precise targeting specificity of antibodies with the effector functionality of the nanomaterial. In this review, we give a brief introduction to mAbs and major conjugation techniques, describe major classes of nanomaterials being studied for therapeutic potential, and review the literature on ANCs of each class. Special focus is given to emerging applications including ANCs addressing the blood-brain barrier, ANCs delivering nucleic acids, and light-activated ANCs. While many disease targets are related to cancer, ANCs are also under development to address autoimmune, neurological, and infectious diseases. While important challenges remain, ANCs are poised to become a next-generation therapeutic technology.

Overcoming immunotherapy resistance in glioblastoma: challenges and emerging strategies

Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults, characterized by rapid proliferation, extensive infiltration, and significant intratumoral heterogeneity. Despite advancements in conventional treatments, including surgery, radiotherapy, and chemotherapy, the prognosis for GBM patients remains poor, with a median survival of approximately 15 months. Immunotherapy has emerged as a promising alternative; however, the unique biological and immunological features, including its immunosuppressive tumor microenvironment (TME) and low mutational burden, render it resistant to many immunotherapeutic strategies. This review explores the key challenges in GBM immunotherapy, focusing on immune evasion mechanisms, the blood-brain barrier (BBB), and the TME. Immune checkpoint inhibitors and CAR-T cells have shown promise in preclinical models but have limited clinical success due to antigen heterogeneity, immune cell exhaustion, and impaired trafficking across the BBB. Emerging strategies, including dual-targeting CAR-T cells, engineered immune cells secreting therapeutic molecules, and advanced delivery systems to overcome the BBB, show potential for enhancing treatment efficacy. Addressing these challenges is crucial for improving GBM immunotherapy outcomes.

Engineered T cells and macrophages: two arms to seize solid tumors

Following the breakthroughs of CAR T cells in the treatment of several hematological malignancies, clinical trials based on genetically modified immune cells are exponentially increasing. Redirecting T cell cytotoxicity against solid tumors via CARs, however, encountered several barriers that require the engineering of additional functions to improve safety, migration, efficacy, and persistence in solid tumors. Complementary strategies tried to harness macrophage properties such as cancer cell phagocytosis, cytokine release, and antigen presentation to induce broader antitumorigenic immune response. While providing a comprehensive overview on the latest technologies in the cell-based immunotherapy realm, we propose that engineering synthetic interplay between immune cells will be the next breakthrough to drive safer and more effective living therapeutics.

Potent and durable control of mesothelin-expressing tumors by a novel T cell-secreted bi-specific engager

BACKGROUND

The glycosylphosphatidylinositol-anchored cell surface protein mesothelin (MSLN) shows elevated expression in many malignancies and is an established clinical-stage target for antibody-directed therapeutic strategies. Of these, the harnessing of autologous patient T cells via engineered anti-MSLN chimeric antigen receptors (CAR-T) is an approach garnering considerable interest. Although generally shown to target tumor MSLN safely, CAR-T trials have failed to deliver the impressive curative or response metrics achieved for hematological malignancies using the same technology. A need exists, therefore, for improved anti-MSLN molecules and/or more optimal ways to leverage immune effector cells.

METHODS

We performed ELISA, label-free kinetic binding assays, FACS, Western blotting, and transient recombinant MSLN expression to characterize the recognition properties of a novel CAR-active human scFv clone, LABC-13F08. To investigate T cell redirection, we conducted kinetic IncuCyte co-culture killing assays using transduced primary T cells and MSLN+ target cell lines and assessed levels of activation markers and effector cytokines. The antitumor potential of LABC-13F08 formatted as a bispecific engager (BiTE) was evaluated in vivo using transduced human primary T cells and immunocompromised NSG mice xenografted with ovarian, mesothelioma, and pancreatic MSLN+ tumor cell lines.

RESULTS

The LABC-13F08 scFv is highly unusual and distinct from existing (pre)clinical anti-MSLN antibody fragments, exhibiting an absolute requirement for divalent cations to drive MSLN recognition. As a monovalent BiTE, LABC-13F08 demonstrates robust in vitro potency. Additionally, primary human T cells engineered for constitutive secretion of the 13F08 BiTE exhibit strong antitumor activity toward in vivo ovarian and mesothelioma xenograft models and show encouraging levels of monotherapy control in a challenging pancreatic model. LABC-13F08 BiTE secreted from engineered T cells (BiTE-T) can both recruit non-engineered bystander T cells and also induce activation-dependent MSLN-independent bystander killing of cells lacking cognate antigen. To address safety concerns, 13F08 BiTE-T cells can be rapidly targeted for clearance via a molecular "off" switch.

CONCLUSIONS

The novel LABC-13F08 scFv exhibits a mode of binding to MSLN which is not observed in typical anti-MSLN antibodies. Efficacious targeting by a T cell secreted engager would represent a clinically differentiated approach for the treatment of MSLN+ tumors.

Mesothelin-targeted CAR-T cells secreting NKG2D-BiTEs exhibit potent efficacy against triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype with poor prognosis and limited treatment options. Chimeric antigen receptor (CAR)-T cell therapy holds promise, but its efficacy is hindered by tumor antigen escape and heterogeneity. To address these challenges, we developed a novel bispecific T cell engagers CAR-T (BiTEs CAR-T) targeting Mesothelin (MSLN) and secreting NKG2D-Bispecific T cell Engagers (BiTEs) to engage NKG2D ligands (NKG2DL). Analysis of TNBC tissues using The Cancer Genome Atlas and tumor microarrays revealed high but weakly correlated expression of MSLN and NKG2DL, making them ideal targets for dual engagement. To reduce immunogenicity and enhance stability, we used a nanobody and the natural receptor NKG2D as antigen-binding domains instead of traditional scFvs in the CAR construct. The secreted BiTEs could promote the cytotoxicity of untransduced T cells against NKG2DL + tumor cells. In vitro, BiTEs CAR-T cells exhibited superior cytotoxicity, T cell activation, and cytokines production against heterogeneous target cells compared to MSLN CAR-T. In vivo, BiTEs CAR-T cells demonstrated potent antitumor activity in zebrafish and murine TNBC models, significantly reducing tumor burden and prolonging survival without detectable toxicity. These findings suggest that BiTE CAR-T cells offer a highly promising therapeutic strategy for TNBC by addressing antigen heterogeneity and immune escape mechanisms, with promising translational potential for clinical application.

T cells in the microenvironment of solid pediatric tumors: the case of neuroblastoma

Neuroblastoma (NB) is an immunologically "cold" tumor with poor or no inflamed substrates as most of solid pediatric tumors (SPT). Consistent data indicate that NB tumor microenvironment (TME) is dominated by myeloid cells, with little (but variable) T cell infiltration. The obstacles to lymphocyte infiltration and to their anti-tumor activity are due to different tumor immune evasion strategies, including loss of HLA Class I molecules, high expression of immune checkpoint molecular ligands leading to exhaustion of T effector (and NK) cells, induction of T regulatory, myeloid and stromal cells and secretion of immunosuppressive mediators. In odds with adult solid tumors, NB displays weak immunogenicity caused by intrinsic low mutational burden and scant expression of neoepitopes in the context of MHC-class I antigens which, in turn, are particularly poorly expressed on NB cells, thus inducing low anti-tumor T cell responses. In addition, NB is generated from embryonal cells and is the result of transcriptional abnormalities and not of the accumulation of genetic mutations over time, thus further explaining the low immunogenicity. The poor expression of immunogenic molecules on tumor cells is associated with the high production of immunosuppressive factors which further downregulate lymphocyte infiltration and activity, thus explaining the limited efficacy of new drugs in NB, as immune checkpoint inhibitors. This review is focused on examining the role of T effector and regulatory cells infiltrating TME of NB, taking into account their repertoire, phenotype, function, plasticity and, importantly, predictive value for defining novel targets for therapy.

Strategies to Overcome Antigen Heterogeneity in CAR-T Cell Therapy

Chimeric antigen receptor (CAR) gene-modified T-cell therapy has achieved significant success in the treatment of hematological malignancies. However, this therapy has not yet made breakthroughs in the treatment of solid tumors and still faces issues of resistance and relapse in hematological cancers. A major reason for these problems is the antigenic heterogeneity of tumor tissues. This review outlines the antigenic heterogeneity encountered in CAR-T cell therapy and the corresponding strategies to address it. These strategies include using combination therapy to increase the abundance of target antigens, optimizing the structure of CARs to enhance sensitivity to low-density antigens, developing multi-targeted CAR-T cells, and reprogramming the TME to activate endogenous immunity. These approaches offer new directions for overcoming tumor antigenic heterogeneity in CAR-T cell therapy.

Targeting HLA-E-overexpressing cancers with a NKG2A/C switch receptor

BACKGROUND

Human leukocyte antigen (HLA)-E is overexpressed by a large proportion of solid tumors, including malignant glioblastoma, and acts as a major checkpoint for NKG2A+ CD8+ T cells and natural killer (NK) cells in the tumor microenvironment and circulation. This axis operates alongside PD-L1 to inhibit effector responses by T and NK cells.

METHODS

We engineered a chimeric A/C switch receptor, combining the high HLA-E binding affinity of the NKG2A receptor ectodomain with the activating signaling of the NKG2C receptor endodomain. The cytotoxic function of A/C switch-transduced NK and T cells was evaluated against tumor cells with varying levels of HLA-E expression. In vivo efficacy was assessed using a xenograft model of glioblastoma.

FINDINGS

A/C switch-transduced NK and T cells exhibited superior and specific cytotoxicity against tumor cells with medium to high HLA-E expression. A/C switch-expressing human T cells demonstrated enhanced anti-tumor function in a glioblastoma xenograft model. The activity of the modified T cells was governed by an equilibrium between A/C switch levels and HLA-E expression, creating a therapeutic window to minimize on-target, off-tumor toxicities. Normal cells remained insensitive to A/C switch T cells, even after interferon (IFN)-γ pretreatment to induce HLA-E expression.

CONCLUSIONS

The A/C switch receptor effectively targets tumor cells expressing high levels of HLA-E, either alone or in combination with other engineered specificities, to overcome the suppressive NKG2A/HLA-E checkpoint. This approach offers a promising therapeutic strategy with a favorable safety profile for targeting HLA-E-overexpressing tumors.

FUNDING

This work was funded by The Research Council of Norway, the Norwegian Cancer Society, and the National Cancer Institute.

CD70 CAR T cells secreting an anti-CD33/anti-CD3 dual-targeting antibody overcome antigen heterogeneity in AML

ABSTRACT

CD70 has emerged as a promising target in acute myeloid leukemia (AML), and we have previously demonstrated the potency of an optimized CD70-targeted ligand-based chimeric antigen receptor (CAR). However, here, we identify in vivo CD70 antigen escape as a limitation of single-antigen targeting. Combination targeting of CD70 and CD33 may overcome AML antigen heterogeneity. We hypothesized that modifying our CD70 CAR platform to secrete a bispecific T-cell engaging antibody molecule (TEAM) targeting CD33 (7033) would create a therapeutic window whereby AML heterogeneity could be addressed without increasing tissue toxicity. We found that CD33 TEAMs mediated specific cytotoxicity across AML cell lines, including CD33 or CD70 single-antigen knockout tumors. 7033 CAR T cells eradicated tumor in an in vivo mixed tumor model of CD70 antigen escape and outperformed the previously optimized CD70 CAR in a patient-derived xenograft. In vivo gene expression profiling of CAR T cells revealed enhanced 7033 CAR T-cell pathway scoring for persistence, activation, and T-cell receptor signaling. Additionally, CD33 TEAMs successfully redirected T cells isolated from patients with AML to activate, secrete cytokines, and kill tumor targets despite exposure to substantial prior cytotoxic therapies. In summary, our findings demonstrate the feasibility of our 7033 CAR to overcome AML heterogeneity and leverage the bystander T cells of patients; this approach warrants further study in patients with this dire clinical need.

Pooled screening for CAR function identifies novel IL-13Rα2-targeted CARs for treatment of glioblastoma

BACKGROUND

Chimeric antigen receptor (CAR) therapies have demonstrated potent efficacy in treating B-cell malignancies, but have yet to meaningfully translate to solid tumors. Nonetheless, they are of particular interest for the treatment of glioblastoma, which is an aggressive form of brain cancer with few effective therapeutic options, due to their ability to cross the highly selective blood-brain barrier.

METHODS

Here, we use our pooled screening platform, CARPOOL, to expedite the discovery of CARs with antitumor functions necessary for solid tumor efficacy. We performed selections in primary human T cells expressing a library of 1.3×106 third generation CARs targeting IL-13Rα2, a cancer testis antigen commonly expressed in glioblastoma. Selections were performed for cytotoxicity, proliferation, memory formation, and persistence on repeated antigen challenge.

RESULTS

Each enriched CAR robustly produced the phenotype for which it was selected, and one enriched CAR triggered potent cytotoxicity and long-term proliferation on in vitro tumor rechallenge. It also showed significantly improved persistence and comparable tumor control in a microphysiological human in vitro model and a xenograft model of human glioblastoma, but also demonstrated increased off-target recognition of IL-13Rα1.

CONCLUSION

Taken together, this work demonstrates the utility of extending CARPOOL to diseases beyond hematological malignancies and represents the largest exploration of signaling combinations in human primary cells to date.

Reconfiguring the immune system to target cancer: Therapies based on T cells, cytokines, and vaccines

Over the years, extensive research has been dedicated to performing in-depth analysis of cancer to uncover the intricate details of its nature - including the types of cancer, causative agents, stimulators of disease progression, factors contributing to poor prognosis, and efficient therapies to restrict the metastatic aggressiveness. This chapter highlights the mechanisms through which different arms of the host immune system - namely cytokines, lymphocytes, antigen-presenting cells (APCs) -can be mobilized to eradicate cancer. Most malignant tumors are either poorly immunogenic, or are harbored in a highly immuno-suppressive microenvironment. This is why reinforcing the host's anti-tumor defenses, through infusion of pro-inflammatory cytokines, tumor antigen-loaded APCs, and anti-tumor cytotoxic cells has emerged as a viable treatment option against cancer. The chapter also highlights the ongoing preclinical and clinical studies in different malignancies and the outcome of various therapies. Although these methods are not foolproof, and antigen escape variants can still evade or develop resistance to customized therapies, they achieve disease stabilization in several cases when conventional treatments fail. In many instances, combination therapies involving cytokines, T cells, and vaccinations prove more effective than monotherapies. The limitations of the current therapies are also discussed, along with ongoing modifications aimed at improving efficacy.

CAR-engineered NK cells versus CAR T cells in treatment of glioblastoma; strength and flaws

Glioblastoma (GBM) is a highly aggressive primary brain tumor that carries a grim prognosis. Because of the dearth of treatment options available for treatment of GBM, Chimeric Antigen Receptor (CAR)-engineered T cell and Natural Killer (NK) therapy could provide alternative strategies to address the challenges in GBM treatment. In these approaches, CAR T and NK cells are engineered for cancer-specific immunotherapy by recognizing surface antigens independently of major histocompatibility complex (MHC) molecules. However, the efficacy of CAR T cells is hindered by GBM's downregulation of its targeted antigens. CAR NK cells face similar challenges, but, in contrast, they offer advantages as off-the-shelf allogeneic products, devoid of graft-versus-host disease (GVHD) risk as well as anti-cancer activity beyond CAR specificity, potentially reducing the risk of relapse or resistance. Despite CAR T cell therapies being extensively studied in clinical settings, the use of CAR-modified NK cells in GBM treatment remains largely in the preclinical stage. This review aims to discuss recent advancements in NK cell and CAR T cell therapies for GBM, including methods for introducing CARs into both NK cells and T cells, addressing manufacturing challenges, and providing evidence supporting the efficacy of these approaches from preclinical and early-phase clinical studies. The comprehensive evaluation of CAR-engineered NK cells and CAR T cells seeks to identify the optimal therapeutic approach for GBM, contributing to the development of effective immunotherapies for this devastating disease.

Progress and Challenges in HIV-1 Vaccine Research: A Comprehensive Overview

The development of an effective HIV-1 vaccine remains a formidable challenge in biomedical research. Despite significant advancements in our understanding of HIV biology and pathogenesis, progress has been impeded by factors such as the virus's genetic diversity, high mutation rates, and its ability to establish latent reservoirs. Recent innovative approaches, including mosaic vaccines and mRNA technology to induce broadly neutralizing antibodies, have shown promise. However, the efficacy of these vaccines has been modest, with the best results achieving approximately 30% effectiveness. Ongoing research emphasizes the necessity of a multifaceted strategy to overcome these obstacles and achieve a breakthrough in HIV-1 vaccine development. This review summarizes current approaches utilized to further understand HIV-1 biology and to create a global vaccine. We discuss the impact of these approaches on vaccine development for other diseases, including COVID-19, influenza, and Zika virus. Additionally, we highlight the specific limitations faced with each approach and present the methods researchers employ to overcome these challenges. These innovative techniques, which have demonstrated preclinical and clinical success, have advanced the field closer to the ultimate goal of developing a global HIV-1 vaccine. Leveraging these advancements will enable significant strides in combating HIV-1 and other infectious diseases, ultimately improving global health outcomes.

A Bi-Specific T Cell-Engaging Antibody Shows Potent Activity, Specificity, and Tumor Microenvironment Remodeling in Experimental Syngeneic and Genetically Engineered Models of GBM

BACKGROUND

Bispecific T cell-engagers (BTEs) are engineered antibodies that redirect T cells to target antigen-expressing tumors. BTEs targeting tumor-specific antigens such as interleukin 13 receptor alpha 2 (IL13Rα2) and EGFRvIII have been developed for glioblastoma (GBM). However, there is limited mechanistic understanding of the action of BTE since prior studies were mostly conducted in immunocompromised animal models. To close this gap, the function of BTEs was assessed in the immunosuppressive glioma microenvironment (TME) of orthotopic and genetically engineered mouse models (GEMM) with intact immune systems.

METHODS

A BTE that bridges CD3 epsilon on murine T cells to IL13Rα2-positive GBM cells was developed and the therapeutic mechanism investigated in immunocompetent mouse models of GBM. Multi-color flow cytometry, single-cell RNA sequencing (scRNA-Seq), multiplex immunofluorescence, and multiparametric magnetic resonance imaging (MRI) across multiple pre-clinical models of GBM were used to evaluate the mechanism and action and response.

RESULTS

BTE-mediated interactions between murine T cells and GBM cells triggered T cell activation and antigen-dependent killing of GBM cells. BTE treatment significantly extended the survival of mice bearing IL13Rα2-expressing orthotopic glioma and de novo forming GBM in the GEMM. Quantified parametric MR imaging validated the survival data showing a reduction in glioma volume and decreased glioma viability. Flow cytometric and scRNA-seq analyses of the TME revealed robust increases in activated and memory T cells and decreases in immunosuppressive myeloid cells in the brains of mice following BTE treatment.

CONCLUSIONS

Our data demonstrate that the survival benefits of BTEs in preclinical models of glioma are due to the ability to engage the host immune system in direct killing, induction of immunological memory, and modulation of the TME. These findings provide a deeper insight into the mechanism of BTE actions in GBM.

Sodium valproate enhances efficacy of NKG2D CAR-T cells against glioblastoma

Chimeric antigen receptor T-cell (CAR-T) therapies have shown promise in glioblastoma clinical studies, but responses remain inconsistent due to heterogeneous tumor antigen expression and immune evasion post-treatment. NKG2D CAR-T cells have demonstrated a favorable safety profile in patients with hematologic tumors, and showed robust antitumor efficacy in various xenograft models, including glioblastoma. However, malignant glioma cells evade immunological surveillance by reducing NKG2D ligands expression or cleavage. To enhance the effectiveness of NKG2D CAR-T therapy, we investigated the potential of combining NKG2D CAR-T with approved drugs that cross the blood-brain barrier and augment NKG2D ligands expression in glioma cells. We found that sodium valproate (VPA), an antiepileptic drug, significantly increased surface NKG2D ligands expression on glioblastoma cells at a sublethal concentration. VPA treatment enhanced the susceptibility of glioblastoma cells to NKG2D CAR-T mediated cytotoxicity in both 2D monolayer and 3D tumor spheroid models in vitro. Moreover, VPA-treated glioblastoma cells stimulated CAR-T cells to produce higher levels of inflammatory cytokines (IL-2, IFN-γ, and IL-6). Mechanistically, VPA upregulated NKG2D ligands expression via the PI3K/Akt signaling pathway. Additionally, VPA treatment augmented the antitumor activity of NKG2D CAR-T cells in a glioblastoma xenograft model in vivo. These preclinical results suggest that combining VPA with NKG2D CAR-T therapy represents a promising strategy for improving glioblastoma treatment, warranting further clinical investigation.

Engineered T cells secreting αB7-H3-αCD3 bispecific engagers for enhanced anti-tumor activity against B7-H3 positive multiple myeloma: a novel therapeutic approach

BACKGROUND

Multiple myeloma (MM) is an incurable plasma cell malignancy with increasing global incidence. Chimeric antigen receptor (CAR) T-cell therapy targeting BCMA has shown efficacy in relapsed or refractory MM, but it faces resistance due to antigen loss and the tumor microenvironment. Bispecific T-cell engaging (BITE) antibodies also encounter clinical challenges, including short half-lives requiring continuous infusion and potential toxicities.

METHODS

To address these issues, we developed a lentiviral system to engineer T cells that secrete αB7-H3-αCD3 bispecific engager molecules (αB7-H3-αCD3 ENG-T cells). We evaluated their effectiveness against MM cells with varying B7-H3 expression levels, from B7-H3neg to B7-H3high.

RESULTS

The αB7-H3-αCD3 ENG-T cells demonstrated significant anti-tumor activity against MM cell lines expressing B7-H3. SupT-1 cells (B7-H3neg) served as controls and exhibited minimal cytotoxicity from αB7-H3-αCD3 ENG T cells. In contrast, these engineered T cells showed dose-dependent killing of B7-H3-expressing MM cells: NCI-H929 (B7-H3low), L-363 (B7-H3medium), and KMS-12-PE (B7-H3high). For NCI-H929 cells, cytotoxicity reached 38.5 ± 7.4% (p = 0.0212) and 54.0 ± 9.2% (p = 0.0317) at effector-to-target (E:T) ratios of 5:1 and 10:1, respectively. Against L-363 cells, cytotoxicity was 56.6 ± 3.2% (p < 0.0001) and 71.4 ± 5.2% (p = 0.0002) at E:T ratios of 5:1 and 10:1, respectively. For KMS-12-PE cells, significant cytotoxic effects were observed even at an E:T ratio of 1:1, with 27.2 ± 3.7% (p = 0.0004), 44.4 ± 3.7% (p < 0.0001), and 68.6 ± 9.2% (p = 0.0004) cytotoxicity at E:T ratios of 1:1, 5:1, and 10:1, respectively.

CONCLUSIONS

These results indicate that αB7-H3-αCD3 ENG T cells could be a promising therapy for B7-H3-positive MM. They may enhance current MM treatments and improve overall outcomes. Additional preclinical and clinical research is required to fully assess their therapeutic potential.

Advances in CAR T cell therapy: antigen selection, modifications, and current trials for solid tumors

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the treatment of hematologic malignancies, achieving remarkable clinical success with FDA-approved therapies targeting CD19 and BCMA. However, the extension of these successes to solid tumors remains limited due to several intrinsic challenges, including antigen heterogeneity and immunosuppressive tumor microenvironments. In this review, we provide a comprehensive overview of recent advances in CAR T cell therapy aimed at overcoming these obstacles. We discuss the importance of antigen identification by emphasizing the identification of tumor-specific and tumor-associated antigens and the development of CAR T therapies targeting these antigens. Furthermore, we highlight key structural innovations, including cytokine-armored CARs, protease-regulated CARs, and CARs engineered with chemokine receptors, to enhance tumor infiltration and activity within the immunosuppressive microenvironment. Additionally, novel manufacturing approaches, such as the Sleeping Beauty transposon system, mRNA-based CAR transfection, and in vivo CAR T cell production, are discussed as scalable solution to improve the accessibility of CAR T cell therapies. Finally, we address critical therapeutic limitations, including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), and suboptimal persistence of CAR T cells. An examination of emerging strategies for countering these limitations reveals that CRISPR-Cas9-mediated genetic modifications and combination therapies utilizing checkpoint inhibitors can improve CAR T cell functionality and durability. By integrating insights from preclinical models, clinical trials, and innovative engineering approaches, this review addresses advances in CAR T cell therapies and their performance in solid tumors.

Cell-Based Therapies in GI Cancers: Current Landscape and Future Directions

Cell-based therapies have become integral to the routine clinical management of hematologic malignancies. Tumor-infiltrating lymphocyte (TIL) therapy has demonstrated efficacy in immunogenic solid tumors, such as melanoma. However, in the GI field, evidence supporting the clinical success of cell-based therapies is still awaited. CLDN18.2, a key tight junction molecule in stomach epithelium, has emerged as a promising target for gastric cancer (GC) treatment. Because of its lineage-specific expression, significant efforts have been made to develop chimeric antigen receptor T-cell (CAR-T) therapies targeting CLDN18.2. These therapies have shown encouraging tumor shrinkage in patients with heavily pretreated GC. However, durable responses remain uncommon. CAR-T exhaustion driven by immune-suppressive cells in the tumor microenvironment, along with the heterogeneous expression of target molecules, poses significant challenges. In addition, managing on-target, off-tumor toxicities remains a critical issue in therapies targeting tissue-associated antigens. Next-generation CARs are expected to address these resistance mechanisms. Furthermore, adoptive macrophage and natural killer cell therapies hold promise for not only their efficacy but also for the ease off-the-shelf production. Advanced neoantigen prediction and identification of optimal T-cell activation targets could facilitate the clinical application of TIL and T-cell receptor-T therapies in GI cancers. Cell-based therapies might have the potential to transform the treatment landscape for GI cancers.

Engineered Cellular Therapies for the Treatment of Thoracic Cancers

Thoracic malignancies (lung cancers and malignant pleural mesothelioma) are prevalent worldwide and are associated with high morbidity and mortality. Effective treatments are needed for patients with advanced disease. Cell therapies are a promising approach to the treatment of advanced cancers that make use of immune effector cells that have the ability to mediate antitumor immune responses. In this review, we discuss the prospect of chimeric antigen receptor-T (CAR-T) cells, natural killer (NK) cells, T cell receptor-engineered (TCR-T) cells, and tumor-infiltrating lymphocytes (TILs) as treatments for thoracic malignancies. CAR-T cells and TILs have proven successful in several hematologic cancers and advanced melanoma, respectively, but outside of melanoma, results have thus far been unsuccessful in most other solid tumors. NK cells and TCR-T cells are additional cell therapy platforms with their own unique advantages and challenges. Obstacles that must be overcome to develop effective cell therapy for these malignancies include selecting an appropriate target antigen, combating immunosuppressive cells and signaling molecules present in the tumor microenvironment, persistence, and delivering a sufficient quantity of antitumor immune cells to the tumor. Induced pluripotent stem cells (iPSCs) offer great promise as a source for both NK and T cell-based therapies due to their unlimited expansion potential. Here, we review clinical trial data, as well as recent basic scientific advances that offer insight into how we may overcome these obstacles, and provide an overview of ongoing trials testing novel strategies to overcome these obstacles.

Multimodal targeting chimeras enable integrated immunotherapy leveraging tumor-immune microenvironment

Although immunotherapy has revolutionized cancer treatment, its efficacy is affected by multiple factors, particularly those derived from the complexity and heterogeneity of the tumor-immune microenvironment (TIME). Strategies that simultaneously and synergistically engage multiple immune cells in TIME remain highly desirable but challenging. Herein, we report a multimodal and programmable platform that enables the integration of multiple therapeutic modules into single agents for tumor-targeted co-engagement of multiple immune cells within TIME. We developed the triple orthogonal linker (T-Linker) technology to integrate various therapeutic small molecules and biomolecules as multimodal targeting chimeras (Multi-TACs). The EGFR-CD3-PDL1 Multi-TAC facilitated T-dendritic cell co-engagement to target solid tumors with excellent efficacy, as demonstrated in vitro, in several humanized mouse models and in patient-derived tumor models. Furthermore, Multi-TACs were constructed to coordinate T cells with other immune cell types. The highly modular and programmable feature of our Multi-TACs may find broad applications in immunotherapy and beyond.

CAR-T cell therapy: Advances in digestive system malignant tumors

Malignant tumors of the digestive system have had a notoriously dismal prognosis throughout history. Immunotherapy, radiotherapy, surgery, and chemotherapy are the primary therapeutic approaches for digestive system cancers. The rate of recurrence and metastasis, nevertheless, remains elevated. As one of the immunotherapies, chimeric antigen receptor T cell (CAR-T) therapy has demonstrated a promising antitumor effect in hematologic cancer. Despite undergoing numerous clinical trials, the ineffective antitumor effect and adverse effects of CAR-T cell therapy in the treatment of digestive system cancers continue to impede its clinical translation. It is necessary to surmount the restricted options for targeting proteins, the obstacles that impede CAR-T cell infiltration into solid tumors, and the limited survival time in vivo. We examined and summarized the developments, obstacles, and countermeasures associated with CAR-T therapy in digestive system cancers. Emphasis was placed on the regulatory functions of potential antigen targets, the tumor microenvironment, and immune evasion in CAR-T therapy. Thus, our analysis has furnished an all-encompassing comprehension of CAR-T cell therapy in digestive system cancers, which will generate tremendous enthusiasm for subsequent in-depth research into CAR-T-based therapies in digestive system cancers.

CAR-T cell therapy for the treatment of adult high-grade gliomas

Treatment for malignant primary brain tumors, including glioblastoma, remains a significant challenge despite advances in therapy. CAR-T cell immunotherapy represents a promising alternative to conventional treatments. This review discusses the landscape of clinical trials for CAR-T cell therapy targeting brain tumors, highlighting key advancements like novel target antigens and combinatorial strategies designed to address tumor heterogeneity and immunosuppression, with the goal of improving outcomes for patients with these aggressive cancers.

Next-generation immunotherapy: igniting new hope for lung cancer

Adoption of immunotherapy has completely transformed the treatment landscape of cancer. Patients with advanced cancer treated with immunotherapy may benefit from durable tumor response and long-term survival. The most widely used immunotherapy in solid tumors is anti-programmed-death (ligand) protein (PD-(L)1), which is now an integral part of non-small cell lung cancer (NSCLC) treatment irrespective of histological cell types and tumor stage. However, the vast majority of patients with advanced NSCLC treated with anti-PD-(L)1 still develop therapeutic resistance, and the prognosis after anti-PD-(L)1 resistance is poor. Resistance mechanisms to PD-1 blockade are often complex and encompass a combination of defects within the cancer-immunity cycle. These defects include failure in antigen presentation and T-cell priming, presence of co-inhibitory immune checkpoints, inability of immune cells to infiltrate the tumor, and presence of immunosuppressive tumor microenvironment. Recently, advances in drug design, genomic sequencing, and gene editing technologies have led to development of next-generation immunotherapies that may potentially overcome these resistance mechanisms. In this review, we will discuss the anti-PD-(L)1 resistance mechanism landscape in NSCLC and four novel modalities of immunotherapy in detail, namely novel immune checkpoint inhibitor and targeted therapy combinations, bispecific antibodies, cancer vaccine, and cell therapy. These novel therapeutics have all demonstrated early clinical data in NSCLC treatment and may work synergistically with each other to restore anticancer immunity. In addition, we share our perspectives on the future promises and challenges in the transformation of these novel immunotherapies to standard clinical care.

CAR T-cell therapy for gliomas

PURPOSE OF REVIEW

To review the landscape of chimeric antigen receptor T-cell (CAR T) therapy for gliomas as seen in recently published trials and discuss on-going challenges with new cancer immunotherapy treatments.

RECENT FINDINGS

Given how CAR T therapy has revolutionized the treatment of several hematologic malignancies, there has been increasing interest in using immunotherapy, and particularly CAR T therapy for gliomas. Within the past decade, several first in human trials have published early patient experiences showing treatment is generally well tolerated but with limited efficacy, which may be improving with newer evolutions in CAR T design to overcome known resistance mechanisms in glioma treatment.

SUMMARY

CAR T therapy is a promising avenue of treatment for high-grade gliomas, which have a universally poor prognosis as well as limited therapeutics. There are a growing number of CAR T clinical trials for CNS tumors and thus, an understanding of their treatment strategies, toxicity management, and overcoming resistance mechanisms will be important for both clinical practice and to identify areas for future research.

Regional and intratumoral adoptive T-cell therapy

Adoptive T-cell therapies (ACTs) including tumor-infiltrating lymphocytes and engineered T cells (transgenic T-cell receptor and chimeric antigen receptor T cells), have made an important impact in the field of cancer treatment over the past years. Most of these therapies are typically administered systemically in approaches that facilitate the elimination of hematologic malignancies. Therapeutical efficacy against solid tumors, however, with the exception of tumor-infiltrating lymphocytes against melanoma, remains limited due to several barriers preventing lymphocyte access to the tumor bed. Building upon the experience of regional administration in other immunotherapies, the regional administration of adoptive cell therapies is being assessed to overcome this challenge, granting a first round of access of the transferred T cells to the tumor niche and thereby ensuring their activation and expansion. Intralesional and intracavitary routes of delivery have been tested with promising antitumor objective responses in preclinical and clinical studies. Additionally, several strategies are being developed to further improve T-cell activity after reinfusing them back to the patient such as combinations with other immunotherapy agents or direct engineering of the transferred T cells, achieving long-term immune memory. Clinical trials testing different regional adoptive T-cell therapies are ongoing but some issues related to methodology of administration and correct selection of the target antigen to avoid on-target/off-tumor side-effects need to be further evaluated and improved. Herein, we discuss the current preclinical and clinical landscape of intratumoral and locoregional delivery of adoptive T-cell therapies.

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

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

T cell landscape in the microenvironment of human solid tumors

T cells are the main effectors involved in anti-tumor immunity, mediating most of the adaptive response towards cancer. After priming in lymph nodes, tumor antigens-specific naïve T lymphocytes proliferate and differentiate into effector CD4+ and CD8+ T cells that migrate from periphery into tumor sites aiming to eliminate cancer cells. Then while most effector T cells die, a small fraction persists and recirculates as long-lived memory T cells which generate enhanced immune responses when re-encountering the same antigen. A number of T (and non-T) cell subsets, stably resides in non-lymphoid peripheral tissues and may provide rapid immune response independently of T cells recruited from blood, against the reemergence of cancer cells. When tumor grows, however, tumor cells have evaded immune surveillance of effector cells (NK and CTL cells) which are exhausted, thus favoring the local expansion of T (and non-T) regulatory cells. In this review, the current knowledge of features of T cells present in the tumor microenvironment (TME) of solid adult and pediatric tumors, the mechanisms upregulating immune-checkpoint molecules and transcriptional and epigenetic landscapes leading to dysfunction and exhaustion of T effector cells are reviewed. The interaction of T cells with cancer- or TME non-neoplastic cells and their secreted molecules shape the T cell profile compromising the intrinsic plasticity of T cells and, therefore, favoring immune evasion. In this phase regulatory T cells contribute to maintain a high immunosuppressive TME thus facilitating tumor cell proliferation and metastatic spread. Despite the advancements of cancer immunotherapy, many tumors are unresponsive to immune checkpoint inhibitors, or therapeutical vaccines or CAR T cell-based adoptive therapy: some novel strategies to improve these T cell-based treatments are lastly proposed.

Bispecific antibody therapy for lymphoma

The rapid development of novel therapeutics in B-cell Non-Hodgkin's lymphoma (B-NHL) over the past decade has presented a critical inflection point for the field. Bispecific antibodies are one such therapeutic class emerging as an effective, off-the-shelf option for B-NHL. In this review, we focus primarily on Diffuse Large B-cell Lymphoma (DLBCL), highlighting the evolution, comparison, tolerability, ongoing challenges, and future potential of bispecific antibodies that are currently approved or in clinical trials for B-NHL. With the number of anti-lymphoma drugs increasing every year, it is important to optimize clinical trial analysis and design so that outcomes, toxicities, and predictors thereof can be understood and compared amongst therapeutic classes to ensure that patients get the safest and most effective treatments for them at the most appropriate line of therapy.

Armoring chimeric antigen receptor (CAR) T cells as micropharmacies for cancer therapy

Chimeric antigen receptor (CAR)-T-cell therapy has emerged as a powerful weapon in the fight against cancer. However, its efficacy is often hindered by challenges such as limited tumor penetration, antigen escape, and immune suppression within the tumor microenvironment. This review explores the potential of armored CAR-T cells, or 'micropharmacies', in overcoming these obstacles and enhancing the therapeutic outcomes of adoptive T-cell (ATC) therapy. We delve into the engineering strategies behind these advanced therapies and the mechanisms through which they improve CAR-T-cell efficacy. Additionally, we discuss the latest advancements and research findings in the field, providing a comprehensive understanding of the role of armored CAR-T cells in cancer treatment. Ultimately, this review highlights the promising future of integrating micropharmacies into ATC therapy, paving the way for more effective and targeted cancer treatments.

Logic-gated and contextual control of immunotherapy for solid tumors: contrasting multi-specific T cell engagers and CAR-T cell therapies

CAR-T cell and T cell engager therapies have demonstrated transformational efficacy against hematological malignancies, but achieving efficacy in solid tumors has been more challenging, in large part because of on-target/off-tumor toxicities and sub-optimal T cell anti-tumor cytotoxic functions. Here, we discuss engineering solutions that exploit biological properties of solid tumors to overcome these challenges. Using logic gates as a framework, we categorize the numerous approaches that leverage two inputs instead of one to achieve better cancer selectivity or efficacy in solid tumors with dual-input CAR-Ts or multi-specific TCEs. In addition to the "OR gate" and "AND gate" approaches that leverage dual tumor antigen targeting, we also review "contextual AND gate" technologies whereby continuous cancer-selective inputs such a pH, hypoxia, target density, tumor proteases, and immune-suppressive cytokine gradients can be creatively incorporated in therapy designs. We also introduce the notion of "output directionality" to distinguish dual-input strategies that mechanistically impact cancer cell killing or T cell fitness. Finally, we contrast the feasibility and potential benefits of the various approaches using CAR-T and TCE therapeutics and discuss why the promising "IF/THEN" and "NOT" gate types pertain more specifically to CAR-T therapies, but can also succeed by integrating both technologies.

Enhancing anti-EGFRvIII CAR T cell therapy against glioblastoma with a paracrine SIRPγ-derived CD47 blocker

A significant challenge for chimeric antigen receptor (CAR) T cell therapy against glioblastoma (GBM) is its immunosuppressive microenvironment, which is densely populated by protumoral glioma-associated microglia and macrophages (GAMs). Myeloid immune checkpoint therapy targeting the CD47-signal regulatory protein alpha (SIRPα) axis induces GAM phagocytic function, but CD47 blockade monotherapy is associated with toxicity and low bioavailability in solid tumors. In this work, we engineer a CAR T cell against epidermal growth factor receptor variant III (EGFRvIII), constitutively secreting a signal regulatory protein gamma-related protein (SGRP) with high affinity to CD47. Anti-EGFRvIII-SGRP CAR T cells eradicate orthotopic EGFRvIII-mosaic GBM in vivo, promoting GAM-mediated tumor cell phagocytosis. In a subcutaneous CD19+ lymphoma mouse model, anti-CD19-SGRP CAR T cell therapy is superior to conventional anti-CD19 CAR T. Thus, combination of CAR and SGRP eliminates bystander tumor cells in a manner that could overcome main mechanisms of CAR T cell therapy resistance, including immune suppression and antigen escape.

Advances in CAR-T therapy for central nervous system tumors

The application of chimeric antigen receptor T-cell therapy in central nervous system tumors has significantly advanced; however, challenges pertaining to the blood-brain barrier, immunosuppressive microenvironment, and antigenic heterogeneity continue to be encountered, unlike its success in hematological malignancies such as acute lymphoblastic leukemia and diffuse large B-cell lymphomas. This review examined the research progress of chimeric antigen receptor T-cell therapy in gliomas, medulloblastomas, and lymphohematopoietic tumors of the central nervous system, focusing on chimeric antigen receptor T-cells targeting antigens such as EGFRvIII, HER2, B7H3, GD2, and CD19 in preclinical and clinical studies. It synthesized current research findings to offer valuable insights for future chimeric antigen receptor T-cell therapeutic strategies for central nervous system tumors and advance the development and application of this therapeutic modality in this domain.

Oncolytic virus and CAR-T cell therapy in solid tumors

Adoptive immunotherapy with T cells, genetically modified to express a tumor-reactive chimeric antigen receptor (CAR), is an innovative and rapidly developing life-saving treatment for cancer patients without other therapeutic opportunities. CAR-T cell therapy has proven effective only in hematological malignancies. However, although by now only a few clinical trials had promising outcomes, we predict that CAR-T therapy will eventually become an established treatment for several solid tumors. Oncolytic viruses (OVs) can selectively replicate in and kill cancer cells without harming healthy cells. They can stimulate an immune response against the tumor, because OVs potentially stimulate adaptive immunity and innate components of the host immune system. Using CAR-T cells along with oncolytic viruses may enhance the efficacy of CAR-T cell therapy in destroying solid tumors by increasing the tumor penetrance of T cells and reducing the immune suppression by the tumor microenvironment. This review describes recent advances in the design of oncolytic viruses and CAR-T cells while providing an overview of the potential combination of oncolytic virotherapy with CAR-T cells for solid cancers. In this review, we will focus on the host-virus interaction in the tumor microenvironment to reverse local immunosuppression and to develop CAR-T cell effector function.

Revolutionizing cancer treatment: an in-depth exploration of CAR-T cell therapies

Cancer is a leading cause of fatality worldwide. Due to the heterogeneity of cancer cells the effectiveness of various conventional cancer treatment techniques is constrained. Thus, researchers are diligently investigating therapeutic approaches like immunotherapy for effective tumor managements. Immunotherapy harnesses the inherent potential of patient's immune system to achieve desired outcomes. Within the realm of immunotherapy, CAR-T (Chimeric Antigen Receptor T) cells, emerges as a revolutionary innovation for cancer therapy. The process of CAR-T cell therapy entails extracting the patient's T cells, altering them with customized receptors designed to specifically recognize and eradicate the tumor cells, and then reinfusing the altered cells into the patient's body. Although there has been significant progress with CAR-T cell therapy in certain cases of specific B-cell leukemia and lymphoma, its effectiveness is hindered in hematological and solid tumors due to the challenges such as severe toxicities, restricted tumor infiltration, cytokine release syndrome and antigen escape. Overcoming these obstacles requires innovative approaches to design more effective CAR-T cells, which require a competent and diverse team to develop and implement. This comprehensive review addresses numerous therapeutic issues and provides a strategic solution while providing a deep understanding of the structural intricacies and production processes of CAR-T cells. In addition, this review explores the practical aspects of CAR-T cell therapy in clinical settings.

Revolutionizing the treatment for nasopharyngeal cancer: the impact, challenges and strategies of stem cell and genetically engineered cell therapies

Nasopharyngeal carcinoma (NPC) is a distinct malignancy of the nasopharynx and is consistently associated with the Epstein-Barr virus (EBV) infection. Its unique anatomical location and complex aetiology often result in advanced-stage disease at first diagnosis. While radiotherapy (RT) and chemotherapy have been the mainstays of treatment, they often fail to prevent tumour recurrence and metastasis, leading to high rates of treatment failure and mortality. Recent advancement in cell-based therapies, such as chimeric antigen receptor (CAR)-T cell therapy, have shown great promise in hematological malignancies and are now being investigated for NPC. However, challenges such as targeting specific tumour antigens, limited T cell persistence and proliferation, and managing treatment-related toxicities must be addressed. Extensive research is needed to enhance the effectiveness and safety of these therapies, paving the way for their integration into standard clinical practice for better management of NPC and a better quality of life for human health.

State of the art and perspectives of chimeric antigen receptor T cells cell therapy for neuroblastoma

Neuroblastoma (NB) is a solid, neuroendocrine pediatric solid tumor with divergent clinical behavior. Patients with high-risk diseases have poor prognoses despite complex multimodal therapy, which requires the search for new therapeutic approaches. Chimeric antigen receptor T cells (CAR-T) have led to dramatic improvements in the survival of cancer patients, most notably those with hematologic malignancies. Early-phase clinical trials of CAR-T cell therapy for NB have proven safe and feasible, but limited clinical efficacy. At the same time, multiple experimental and preclinical studies have shown that the most common in clinical trials single 2nd or 3rd generation CAR structure is not sufficient for a complete response in solid tumors. Here, we review the recent advances and future perspectives associated with engineered receptors, including several antigens binding, armored CAR-T of 4th and 5th generation and CAR-T cell combination strategies with other immunotherapy. We also summarize the results and shortcomings of ongoing clinical trials of CAR-T therapy for NB.

A dual-targeting approach with anti-IL10R CAR-T cells engineered to release anti-CD33 bispecific antibody in enhancing killing effect on acute myeloid leukemia cells

BACKGROUND

Immunotherapies, including chimeric antigen receptor (CAR) T cells and bispecific antibodies (BsAbs), encounter several challenges in the management of acute myeloid leukemia (AML), including limited persistence of these treatments, antigen loss and resistance of leukemia stem cells (LSCs) to therapy.

METHODS

Here, we proposed a novel dual-targeting approach utilizing engineered anti-IL10R CAR-T cells to secrete bispecific antibodies targeting CD33. This innovative strategy, rooted in our previous research which established a connection between IL-10 and the stemness of AML cells, designed to improve targeting efficiency and eradicate both LSCs and AML blasts.

RESULTS

We first demonstrated the superior efficacy of this synergistic approach in eliminating AML cell lines and primary cells expressing different levels of the target antigens, even in cases of low CD33 or IL10R expression. Furthermore, the IL10R CAR-T cells that secret anti-CD33 bsAbs (CAR.BsAb-T), exhibited an enhanced activation and induction of cytotoxicity not only in IL10R CAR-T cells but also in bystander T cells, thereby more effectively targeting CD33-positive tumor cells. Our in vivo experiments provided additional evidence that CAR.BsAb-T cells could efficiently redirect T cells, reduce tumor burden, and demonstrate no significant toxicity. Additionally, delivering bsAbs locally to the tumor sites through this strategy helps mitigate the pharmacokinetic challenges typically associated with the rapid clearance of prototypical bsAbs.

CONCLUSIONS

Overall, the engineering of a single-vector targeting IL10R CAR, which subsequently secretes CD33-targeted bsAb, addresses the issue of immune escape due to the heterogeneous expression of IL10R and CD33, and represents a promising progress in AML therapy aimed at improving treatment outcomes.

EGFRVIII and EGFR targeted chimeric antigen receptor T cell therapy in glioblastoma

Glioblastoma is the most common primary brain tumor. Although there have been significant advances in surgical techniques, chemo and immunotherapies, and radiation therapy, outcomes continue to be devastating for these patients with minimal improvements in survival. Chimeric antigen receptor T cell therapy is a revolutionary approach that is a new pillar in the treatment of cancer. CAR T cell therapy has produced remarkable results in hematological malignancies; however, multiple limitations currently prevent it from being a first-line therapy, especially for solid tumors. Epidermal growth factor receptor is classically amplified in glioblastoma, and a variant, EGFR variant III, is expressed on glioblastoma, making it an exciting potential target for CAR T cell therapy. Although preclinical has exciting potential, clinical data has been heterogeneous. In this review, we assess the state of field of EGFR-targeted CAR T cells.

Strategies for engineering oncolytic viruses to enhance cancer immunotherapy

Non-small cell lung cancer (NSCLC) is the predominant form of lung cancer and is characterized by rapid metastasis and high mortality, presenting a challenge for early-stage treatment modalities. The heterogeneity of NSCLC's tumor microenvironment (TME) significantly influences the efficacy of anti-PD-1 immune checkpoint inhibitors (ICIs) therapy, leading to varied patient responses. This review characterized different strains of oncolytic viruses in NSCLC and the different gene edits in pre-existing oncolytic viruses. This study also aimed to provide strategies to enhance anti-PD-1 therapy in NSCLC by engineering oncolytic viruses (OVs). This study offers insights into the genomic adaptations necessary for OVs targeting NSCLC, identify genetic determinants of anti-PD-1 response variability, and propose genomic edits to bolster therapy effectiveness. The primary goal of this study is to present a theoretically designed OV with a detailed genomic framework capable of enhancing the response to anti-PD-1 therapy, thereby advancing the field of cancer immunotherapy.

ReCARving the future: bridging CAR T-cell therapy gaps with synthetic biology, engineering, and economic insights

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment of hematologic malignancies, offering remarkable remission rates in otherwise refractory conditions. However, its expansion into broader oncological applications faces significant hurdles, including limited efficacy in solid tumors, safety concerns related to toxicity, and logistical challenges in manufacturing and scalability. This review critically examines the latest advancements aimed at overcoming these obstacles, highlighting innovations in CAR T-cell engineering, novel antigen targeting strategies, and improvements in delivery and persistence within the tumor microenvironment. We also discuss the development of allogeneic CAR T cells as off-the-shelf therapies, strategies to mitigate adverse effects, and the integration of CAR T cells with other therapeutic modalities. This comprehensive analysis underscores the synergistic potential of these strategies to enhance the safety, efficacy, and accessibility of CAR T-cell therapies, providing a forward-looking perspective on their evolutionary trajectory in cancer treatment.

Pre-Clinical Models for CAR T-Cell Therapy for Glioma

Immunotherapy represents a transformative shift in cancer treatment. Among myriad immune-based approaches, chimeric antigen receptor (CAR) T-cell therapy has shown promising results in treating hematological malignancies. Despite aggressive treatment options, the prognosis for patients with malignant brain tumors remains poor. Research leveraging CAR T-cell therapy for brain tumors has surged in recent years. Pre-clinical models are crucial in evaluating the safety and efficacy of these therapies before they advance to clinical trials. However, current models recapitulate the human tumor environment to varying degrees. Novel in vitro and in vivo techniques offer the opportunity to validate CAR T-cell therapies but also have limitations. By evaluating the strengths and weaknesses of various pre-clinical glioma models, this review aims to provide a roadmap for the development and pre-clinical testing of CAR T-cell therapies for brain tumors.

Local therapy in glioma: An evolving paradigm from history to horizons (Review)

Despite the implementation of multimodal treatments after surgery, glioblastoma (GBM) remains an incurable disease, posing a significant challenge in neuro-oncology. In this clinical setting, local therapy (LT), a developing paradigm, has received significant interest over time due to its potential to overcome the drawbacks of conventional therapy options for GBM. The present review aimed to trace the historical development, highlight contemporary advances and provide insights into the future horizons of LT in GBM management. In compliance with the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols criteria, a systematic review of the literature on the role of LT in GBM management was conducted. A total of 2,467 potentially relevant articles were found and, after removal of duplicates, 2,007 studies were screened by title and abstract (Cohen's κ coefficient=0.92). Overall, it emerged that 15, 10 and 6 clinical studies explored the clinical efficiency of intraoperative local treatment modalities, local radiotherapy and local immunotherapy, respectively. GBM recurrences occur within 2 cm of the radiation field in 80% of cases, emphasizing the significant influence of local factors on recurrence. This highlights the urgent requirement for LT strategies. In total, three primary reasons have thus led to the development of numerous LT solutions in recent decades: i) Intratumoral implants allow the blood-brain barrier to be bypassed, resulting in limited systemic toxicity; ii) LT facilitates bridging therapy between surgery and standard treatments; and iii) given the complexity of GBM, targeting multiple components of the tumor microenvironment through ligands specific to various elements could have a synergistic effect in treatments. Considering the spatial and temporal heterogeneity of GBM, the disease prognosis could be significantly improved by a combination of therapeutic strategies in the era of precision medicine.

Glioblastoma stem cell metabolism and immunity

Despite enormous efforts being invested in the development of novel therapies for brain malignancies, there remains a dire need for effective treatments, particularly for pediatric glioblastomas. Their poor prognosis has been attributed to the fact that conventional therapies target tumoral cells, but not glioblastoma stem cells (GSCs). GSCs are characterized by self-renewal, tumorigenicity, poor differentiation, and resistance to therapy. These characteristics represent the fundamental tools needed to recapitulate the tumor and result in a relapse. The mechanisms by which GSCs alter metabolic cues and escape elimination by immune cells are discussed in this article, along with potential strategies to harness effector immune cells against GSCs. As cellular immunotherapy is making significant advances in a variety of cancers, leveraging this underexplored reservoir may result in significant improvements in the treatment options for brain malignancies.

Functional Activity of Cytokine-Induced Killer Cells Enhanced by CAR-CD19 Modification or by Soluble Bispecific Antibody Blinatumomab

Strategies to increase the anti-tumor efficacy of cytokine-induced killer cells (CIKs) include genetic modification with chimeric antigen receptors (CARs) or the addition of soluble T-cell engaging bispecific antibodies (BsAbs). Here, CIKs were modified using a transposon system integrating two distinct anti-CD19 CARs (CAR-MNZ and CAR-BG2) or combined with soluble CD3xCD19 BsAb blinatumomab (CIK + Blina). CAR-MNZ bearing the CD28-OX40-CD3ζ signaling modules, and CAR-BG2, designed on the Tisagenlecleucel CAR sequence (Kymriah®), carrying the 4-1BB and CD3ζ signaling elements, were employed. After transfection and CIK expansion, cells expressed CAR-CD19 to a similar extent (35.9% CAR-MNZ and 17.7% CAR-BG2). In vitro evaluations demonstrated robust proliferation and cytotoxicity (~50% cytotoxicity) of CARCIK-MNZ, CARCIK-BG2, and CIK + Blina against CD19+ target cells, suggesting similar efficacy. All effectors formed an increased number of synapses, activated NFAT and NFkB, and secreted IL-2 and IFN-ɣ upon encountering targets. CIK + Blina displayed strongest NFAT and IFN-ɣ induction, whereas CARCIK-BG2 demonstrated superior synapse formation. All the effectors have shown therapeutic activity in vivo against the CD19+ Daudi tumor model, with CARCIK cells showing a more durable response compared to CIK + Blina, likely due to the short half-life of Blina in this model.