Engineered IL13 variants direct specificity of IL13Rα2-targeted CAR T cell therapy

Expanding the Therapeutic Reach of Chimeric Antigen Receptor T-Cells and Bispecific T-Cell Engagers Across Solid Tumors

The introduction of T-cell-based therapeutics in hematologic malignancies has led to improvements in outcomes for patients with acute leukemia, lymphoma, and multiple myeloma. To date, the Food and Drug Administration (FDA) has approved seven chimeric antigen receptor-T (CAR-T) cell therapies and seven bispecific T-cell engagers (BiTEs) across a variety of hematologic malignancies; however, the extension of CAR-T therapies and BiTEs to the solid tumor arena has been somewhat limited. In this review, we discuss the landmark data that led to the commercialization of four novel FDA-approved T-cell-based therapeutics in solid malignancies, including tarlatamab for small cell lung cancer, afamitresgene autoleucel for synovial sarcoma, lifileucel for metastatic melanoma, and tebentafusp for metastatic uveal melanoma. We discuss the targetable antigen landscape of CAR-T therapies and BiTEs under investigation in solid malignancies. We explore the translational potential for various CARs under active investigation, including human epidermal growth factor receptor 2-directed CARs in breast cancer, prostate stem cell antigen-directed CARs for prostate cancer, epidermal growth factor receptor (EGFR)-IL13Ra2 and EGFR-vIII CARs for glioblastoma, and GD2-directed CARs for neuroblastoma. We glean from lessons learned for existing CAR-T therapies and BiTEs for hematologic malignancies and emphasize solutions toward facilitating the clinical rollout of T-cell-based therapies in solid tumors, including scalability to meet the growing needs of clinical oncology. Some solutions include addressing on-target, off-tumor toxicity; improving the manufacturing of CARs; optimizing the tissue-specific tumor microenvironment by combating immune desert tumors; and discovering natural tumor neoantigens and non-self-epitopes generated by tumor-specific mutations. These concepts can help provide transformative benefits for patients with solid malignancies in the coming years.

Spatial Control of CAR T Cell Activation Using Tumor-Homing Polymers

CAR T cell therapies often lack specificity, leading to issues ranging from inadequate antigen targeting to off-tumor toxicities. To counter that lack of specificity, we expanded tumor targeting capabilities with universal CAR and spatially defined CAR T cell engagement with targets through a combination of synthetic biology and biomaterial approaches. We developed a novel framework, called "In situ Mobilization: Polymer Activated Cell Therapies" (IMPACT) for polymer-mediated, anatomical control of IF-THEN gated CAR T cells. With IMPACT, a regulated payload such as a BiTE or tumor-targeting CAR will only be expressed after engineered cells engage a tumor-localizing polymer ("IF" condition). In this first demonstration of IMPACT, we engineered CAR T cells to respond to fluorescein that is displayed by an injectable polymer that binds to and is retained in fibrin deposits in tumor microenvironments. This interaction then drives selective and conditional expression of a protein within tumors ("THEN" condition). Here, we develop the polymer and CAR T cell infrastructure of IMPACT and demonstrate tumor-localized CAR T cell activation in a murine tumor model after the intravenous administration of polymer and engineered T cells.

Association of epigenetic landscapes with heterogeneity and plasticity in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis. Due to a lack of clear symptoms, patients often present with advanced disease, with limited clinical intervention options. The high mortality rate of PDAC is, however, also a result of several other factors that include a high degree of heterogeneity and treatment resistant cellular phenotypes. Molecular subtypes of PDAC have been identified that are thought to represent cellular phenotypes at the tissue level. The epigenetic landscape is an important factor that dictates these subtypes. Permissive epigenetic landscapes serve as drivers of molecular heterogeneity and cellular plasticity in developing crypts as well as metaplastic lesions. Drawing parallels with other cancers, we hypothesize that epigenetic permissiveness is a potential driver of cellular plasticity in PDAC. In this review will explore the epigenetic alterations that underlie PDAC cell states and relate them to cellular plasticity from other contexts. In doing so, we aim to highlight epigenomic drivers of PDAC heterogeneity and plasticity and, with that, offer some insight to guide pre-clinical research.

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.

Suppressive immune microenvironment and CART therapy for glioblastoma: Future prospects and challenges

Glioblastoma, a highly malignant intracranial tumor, has acquired slow progress in treatment. Previous clinical trials involving targeted therapy and immune checkpoint inhibitors have shown no significant benefits in treating glioblastoma. This ineffectiveness is largely due to the complex immunosuppressive environment of glioblastoma. Glioblastoma cells exhibit low immunogenicity and strong heterogeneity and the immune microenvironment is replete with inhibitory cytokines, numerous immunosuppressive cells, and insufficient effective T cells. Fortunately, recent Phase I clinical trials of CART therapy for glioblastoma have confirmed its safety, with a small subset of patients achieving survival benefits. However, CART therapy continues to face challenges, including blood-brain barrier obstruction, antigen loss, and an immunosuppressive tumor microenvironment (TME). This article provides a detailed examination of glioblastoma's immune microenvironment, both from intrinsic and extrinsic tumor cell factors, reviews current clinical and basic research on multi-targets CART treatment, and concludes by outlining the key challenges in using CART cells for glioblastoma therapy.

Linker-specific monoclonal antibodies present a simple and reliable detection method for scFv-based CAR NK cells

Chimeric antigen receptor (CAR) T cell therapies have demonstrated significant successes in treating cancer. Currently, there are six approved CAR T cell products available on the market that target different malignancies of the B cell lineage. However, to overcome the limitations of CAR T cell therapies, other immune cells are being investigated for CAR-based cell therapies. CAR natural killer (NK) cells can be applied as allogeneic cell therapy, providing an economical, safe, and efficient alternative to autologous CAR T cells. To improve CAR research and future in-patient monitoring of cell therapeutics, a simple, reliable, and versatile CAR detection reagent is crucial. As most existing CARs contain a single-chain variable fragment (scFv) with either a Whitlow or a G4S linker site, linker-specific monoclonal antibodies (mAbs) can detect a broad range of CARs. This study demonstrates that these linker-specific mAbs can detect different CAR NK cells in vitro, spiked in whole blood, and within patient-derived tumor spheroids with high specificity and sensitivity, providing an effective and almost universal alternative for scFv-based CAR detection. Additionally, we confirm that linker-specific antibodies can be used for functional testing and enrichment of CAR NK cells, thereby providing a useful research tool to fast-track the development of novel CAR-based therapies.

Harnessing cytokines to optimize chimeric antigen receptor-T cell therapy for gastric cancer: Current advances and innovative strategies

Enormous patients with gastric cancer (GC) are insensitive to chemotherapy and targeted therapy without the chance of radical surgery, so immunotherapy may supply a novel choice for them. Chimeric antigen receptor (CAR)-T cell therapy has the advantages of higher specificity, stronger lethality, and longer-lasting efficacy, and it has the potential for GC in the future. However, its application still faces numerous obstacles in terms of accuracy, efficacy, and safety. Cytokines can mediate the migration, proliferation, and survival of immune cells, regulate the duration and strength of immune responses, and are involved in the occurrence of severe side effects in CAR-T cell therapy. The expression levels of specific cytokines are associated with the genesis, invasion, metastasis, and prognosis of GC. Applications of cytokines and their receptors in CAR-T cell therapy have emerged, and various cytokines and their receptors have contributed to improving CAR-T cell anti-tumor capabilities. Large amounts of central cytokines in this therapy include chemokines, interleukins (ILs), transforming growth factor-β (TGF-β), and colony-stimulating factors (CSFs). Meanwhile, researchers have explored the combination therapy in treating GC, and several approaches applied to other malignancies can also be considered as references. Therefore, our review comprehensively outlines the biological functions and clinical significance of cytokines and summarizes current advances and innovative strategies for harnessing cytokines to optimize CAR-T cell therapy for GC.

CAR-T Cells in the Treatment of Nervous System Tumors

Chimeric antigen receptor T cells (CAR-Ts) have shown a remarkable efficacy in hematological malignancies but limited responses in solid tumors. Among solid tumors, CAR-T cell therapy has been particularly explored in brain tumors. CAR-T cells have shown a limited clinical efficacy in various types of brain tumors due to several factors that have hampered their activity, including tumor antigen heterogeneity, the limited access of CAR-T cells to brain tumor cells, limited CAR-T cell trafficking and in vivo persistence and the presence of a highly immunosuppressive tumor microenvironment. Despite these considerations, some recent studies have shown promising antitumor activity of GD2-CAR-T cells on diffuse midline gliomas and neuroblastomas and of CARv3-TEAM-E cells in glioblastomas. However, strategies are required to improve the effect of CAR-T cells in brain tumors, including advanced CAR-T cell design with multiple antigenic targeting and incorporation of combination therapies.

Adoptive Cell Therapy for Solid Tumors: Current Status in Melanoma and Next-Generation Therapies

Lifileucel or TIL has recently been FDA approved for metastatic melanoma patients as first cell therapy for a solid tumor. We discuss roll-out of TIL as new SOC and other upcoming new cell therapies.

Targeting Interleukin-13 Receptor α2 and EphA2 in Aggressive Breast Cancer Subtypes with Special References to Chimeric Antigen Receptor T-Cell Therapy

Breast cancer (BCA) remains the leading cause of cancer-related mortality among women worldwide. This review delves into the therapeutic challenges of BCA, emphasizing the roles of interleukin-13 receptor α2 (IL-13Rα2) and erythropoietin-producing hepatocellular receptor A2 (EphA2) in tumor progression and resistance. Highlighting their overexpression in BCA, particularly in aggressive subtypes, such as Her-2-enriched and triple-negative breast cancer (TNBC), we discuss the potential of these receptors as targets for chimeric antigen receptor T-cell (CAR-T) therapies. We examine the structural and functional roles of IL-13Rα2 and EphA2, their pathological significance in BCA, and the promising therapeutic avenues their targeting presents. With an in-depth analysis of current immunotherapeutic strategies, including the limitations of existing treatments and the potential of dual antigen-targeting CAR T-cell therapies, this review aims to summarize potential future novel, more effective therapeutic interventions for BCA. Through a thorough examination of preclinical and clinical studies, it underlines the urgent need for targeted therapies in combating the high mortality rates associated with Her-2-enriched and TNBC subtypes and discusses the potential role of IL-13Rα2 and EphA2 as promising candidates for the development of CAR T-cell therapies.

Engineering the IL-4/IL-13 axis for targeted immune modulation

The structurally and functionally related interleukin-4 (IL-4) and IL-13 cytokines play pivotal roles in shaping immune activity. The IL-4/IL-13 axis is best known for its critical role in T helper 2 (Th2) cell-mediated Type 2 inflammation, which protects the host from large multicellular pathogens, such as parasitic helminth worms, and regulates immune responses to allergens. In addition, IL-4 and IL-13 stimulate a wide range of innate and adaptive immune cells, as well as non-hematopoietic cells, to coordinate various functions, including immune regulation, antibody production, and fibrosis. Due to its importance for a broad spectrum of physiological activities, the IL-4/IL-13 network has been targeted through a variety of molecular engineering and synthetic biology approaches to modulate immune behavior and develop novel therapeutics. Here, we review ongoing efforts to manipulate the IL-4/IL-13 axis, including cytokine engineering strategies, formulation of fusion proteins, antagonist development, cell engineering approaches, and biosensor design. We discuss how these strategies have been employed to dissect IL-4 and IL-13 pathways, as well as to discover new immunotherapies targeting allergy, autoimmune diseases, and cancer. Looking ahead, emerging bioengineering tools promise to continue advancing fundamental understanding of IL-4/IL-13 biology and enabling researchers to exploit these insights to develop effective interventions.

Expansion of endogenous T cells in CSF of pediatric CNS tumor patients undergoing locoregional delivery of IL13R〿2-targeting CAR T cells: an interim analysis

Outcomes for pediatric brain tumor patients remain poor, and there is optimism that chimeric antigen receptor (CAR) T cell therapy can improve prognosis. Here, we present interim results from the first six pediatric patients treated on an ongoing phase I clinical trial (NCT04510051) of IL13BBζ-CAR T cells delivered weekly into the lateral cerebral ventricles, identifying clonal expansion of endogenous CAR-negative CD8+ T cells in the cerebrospinal fluid (CSF) over time. Additionally, of the five patients evaluable for disease response, three experienced transient radiographic and/or clinical benefit not meeting protocol criteria for response. The first three patients received CAR T cells alone; later patients received lymphodepletion before the first infusion. There were no dose limiting toxicities (DLTs). Aside from expected cytopenias in patients receiving lymphodepletion, serious adverse events possibly attributed to CAR T cell infusion were limited to one episode of headache and one of liver enzyme elevation. One patient withdrew from treatment during the DLT period due to a Grade 3 catheter-related infection and was not evaluable for disease response, although this was not attributed to CAR T cell infusion. Importantly, scRNA- and scTCR-sequence analyses provided insights into CAR T cell interaction with the endogenous immune system. In particular, clonally expanded endogenous CAR- T cells were recovered from the CSF, but not the peripheral blood, of patients who received intraventricular IL13BBζ-CAR T cell therapy. Additionally, although immune infiltrates in CSF and post-therapy tumor did not generally correlate, a fraction of expanded T cell receptors (TCRs) was seen to overlap between CSF and tumor. This has important implications for what samples are collected on these trials and how they are analyzed. These initial findings provide support for continued investigation into locoregionally-delivered IL13BBζ-CAR T cells for children with brain tumors.

Exploring CAR-T Cell Therapy Side Effects: Mechanisms and Management Strategies

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the treatment of malignancies, especially hematological tumors, but toxicities have tempered its success. The main impediments to the development of CAR-T cell therapies are the following: cytokine release syndrome (CRS), immune-effector-cell-associated neurotoxicity syndrome (ICANS), tumor lysis syndrome (TLS), and on-target/off-tumor toxicity (OTOT). This review summarizes these side effects' underlying mechanisms and manifestations over time. It provides potential prevention and treatment according to the consensus grading, stressing the significance of establishing strategies that anticipate, reduce, and navigate the beginning of these side effects. It is essential to fully comprehend the mechanisms underlying these toxicities to create efficient treatment and preventive approaches.

Small-Molecule Compounds Boost CAR-T Cell Therapy in Hematological Malignancies

OPINION STATEMENT

Although chimeric antigen receptor T cell immunotherapy has been successfully applied in patients with hematological malignancies, several obstacles still need to be overcome, such as high relapse rates and side effects. Overcoming the limitations of CAR-T cell therapy and boosting the efficacy of CAR-T cell therapy are urgent issues that must be addressed. The exploration of small-molecule compounds in combination with CAR-T cell therapies has achieved promising success in pre-clinical and clinical studies in recent years. Protein kinase inhibitors, demethylating drugs, HDAC inhibitors, PI3K inhibitors, immunomodulatory drugs, Akt inhibitors, mTOR inhibitors, and Bcl-2 inhibitors exhibited potential synergy in combination with CAR-T cell therapy. In this review, we will discuss the recent application of these combination therapies for improved outcomes of CAR-T cell therapy.

CAR T cells: engineered immune cells to treat brain cancers and beyond

Malignant brain tumors rank among the most challenging type of malignancies to manage. The current treatment protocol commonly entails surgery followed by radiotherapy and/or chemotherapy, however, the median patient survival rate is poor. Recent developments in immunotherapy for a variety of tumor types spark optimism that immunological strategies may help patients with brain cancer. Chimeric antigen receptor (CAR) T cells exploit the tumor-targeting specificity of antibodies or receptor ligands to direct the cytolytic capacity of T cells. Several molecules have been discovered as potential targets for immunotherapy-based targeting, including but not limited to EGFRvIII, IL13Rα2, and HER2. The outstanding clinical responses to CAR T cell-based treatments in patients with hematological malignancies have generated interest in using this approach to treat solid tumors. Research results to date support the astounding clinical response rates of CD19-targeted CAR T cells, early clinical experiences in brain tumors demonstrating safety and evidence for disease-modifying activity, and the promise for further advances to ultimately assist patients clinically. However, several variable factors seem to slow down the progress rate regarding treating brain cancers utilizing CAR T cells. The current study offers a thorough analysis of CAR T cells' promise in treating brain cancer, including design and delivery considerations, current strides in clinical and preclinical research, issues encountered, and potential solutions.