Claudin18.2-specific CAR T cells in gastrointestinal cancers: phase 1 trial interim results

Inconsistent Reporting and Definitions of Time-to-Event Endpoints in CAR T Clinical Trials: A Review

Clinical trials evaluating chimeric antigen receptor T-cell therapy (CAR T) commonly report time-to-event (TTE) endpoints. However, definitions are not necessarily comparable across studies and variability can lead to misinterpretation of results or inappropriate comparisons across products and studies. Amid the rapidly increasing number of published CAR T trials-many of which were used for regulatory approval-this study aims to summarize the variation in the use and reporting of TTE endpoints in CAR T trials. We include CAR T trials published January 2008 to January 2023 on PubMed that reported at least one of these TTE endpoints: overall survival (OS), progression-free survival (PFS), duration of response/remission (DOR), disease-free survival, event-free survival (EFS), relapse-free survival (RFS), time to relapse, time to progression, or time to treatment failure. We abstracted and summarized endpoint definitions, including the time origin, events, competing events, and censoring. We assessed the completeness of endpoint reporting, overall and by subgroups such as study phase, publication year, and the journal's impact factor. We included 116 publications in the analysis. The most frequently reported TTEs were OS (83%,), PFS (56%), DOR (55%), and EFS (23%). Complete reporting of endpoints was poor overall: 32%, 24%, 25%, and 56% for OS, PFS, DOR, and EFS respectively. Complete reporting was lower in articles published before 2018, in lower impact factor journals, and in phase I trials. There was also a large variability in TTE definitions among those reported. For example, among 64 studies reporting DOR, 48% used the date of response as the time origin while 20% used the date of infusion, and 31% did not report a time origin. There is substantial heterogeneity and incompleteness of TTE endpoint definitions in CAR T trials that could impact the interpretation of the study results. Improving TTE reporting, by stating the time origin, event(s) of interest, competing event(s) if any, and censoring, is required to ensure valid assessment of clinical benefit and cross-trial comparison.

Advancements and challenges in CAR T cell therapy for pediatric brain tumors: A review

Chimeric Antigen Receptor (CAR) T cell therapy represents a groundbreaking advancement in immunotherapy, initially gaining FDA approval for treating hematological malignancies. This therapy has shown promising results in solid tumors, particularly in pediatric brain tumors, which are the leading cause of cancer-related death in children. CAR T cells are engineered to target specific antigens on tumor cells, thereby reducing off-target effects and increasing the cytotoxic impact on cancer cells. Over the years, CAR T cell technology has evolved through five generations, each enhancing the structure, functionality, and safety of these cells. Despite these advancements, the application of CAR T cells in solid tumors, especially within the central nervous system (CNS), faces significant challenges. These include the physical barrier posed by the blood-brain barrier (BBB), the immunosuppressive tumor microenvironment (TME), and the heterogeneity of tumor antigens. The review discusses several promising antigenic targets for CAR T cells in pediatric brain tumors, such as HER2, EphA2, IL-13Rα2, and Survivin, which have been explored in recent clinical trials. These trials have shown early promise in improving patient outcomes, though the risks of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) remain concerns. The future of CAR T cell therapy lies in overcoming these barriers through innovative approaches like "Armored CARs" or TRUCKs, designed to modulate the TME and improve CAR T cell efficacy in solid tumors. Additionally, combination therapies and safety switches in next-generation CAR T cells are being explored to enhance therapeutic potential while minimizing adverse effects.

Prognostic role of claudin-18.2 in intrahepatic cholangiocarcinoma

Claudins are key components of tight junctions, essential for maintaining cellular adhesion, regulating intercellular molecule transport, and preserving cell polarity. Altered claudin expression can lead to tight junction dysfunction, potentially disrupting signaling pathways and contributing to the development of epithelial cancers. This study aims to explore the understudied role of CLDN18.2 in intrahepatic cholangiocarcinoma and its relationship with clinical outcomes. We analyzed tissue samples from 182 patients who underwent curative surgery for intrahepatic cholangiocarcinoma. Our research examined the relationship between CLDN18.2 expression and various clinical factors, including patient characteristics, pathological findings, and survival metrics such as overall survival (OS), disease-free survival (DFS), metastasis-free survival (MeFS), and local recurrence-free survival (LRFS). Overexpression of CLDN18.2 showed significant associations with R1 resection (p = 0.032) and advanced T stage (p = 0.043). Univariate analysis revealed that high CLDN18.2 expression was correlated with poorer OS (p = 0.0002), DFS (p < 0.0001), LRFS (p < 0.0001), and MeFS (p < 0.0001). Multivariate analysis further confirmed that high CLDN18.2 expression was independently associated with worse OS (p = 0.015), DFS (p < 0.001), LRFS (p < 0.001), and MeFS (p < 0.001). Overexpression of CLDN18.2 was associated with unfavorable clinical prognosis and adverse pathological features in intrahepatic cholangiocarcinoma. These findings suggest that CLDN18.2 could serve as a potential prognostic biomarker for intrahepatic cholangiocarcinoma.

Advances in Immunotherapy and Targeted Therapy for Gastric Cancer: A Comprehensive Review

Gastric cancer remains one of the most prevalent and lethal malignancies worldwide, characterized by poor survival rates, particularly in advanced stages. In recent years, a paradigm shift in gastric cancer treatment has been witnessed with the introduction of immunotherapy and targeted therapies. This review provides a detailed examination of current immunotherapeutic strategies, including adoptive cell therapy (ACT), immune checkpoint inhibitors (ICIs), and cancer vaccines. Additionally, it explores advancements in targeted therapies, focusing on the human epidermal growth factor receptor 2 (HER2) and vascular endothelial growth factor receptor (VEGFR) signaling pathways, as well as emerging targets such as claudin 18.2. Clinical trials investigating chimeric antigen receptor T-cell (CAR-T) therapy, T-cell receptor-engineered T-cell (TCR-T) therapy, and natural killer (NK) cell-based treatments have shown promise, particularly when combined with conventional chemotherapeutic regimens. However, challenges such as cytokine release syndrome, immune-related toxicities, and scalability issues remain significant. The combination of immunotherapy with targeted therapies represents a promising approach to enhance treatment outcomes. Future directions emphasize the need to overcome resistance mechanisms and refine treatment strategies to improve efficacy while reducing adverse effects. This review aims to elucidate the current landscape of immunotherapy and targeted therapy in gastric cancer and to explore their potential in shaping the future of clinical management for this devastating disease.

New approaches of chimeric antigen receptor (CAR)-immune cell-based therapy in gastric cancer; highlight CAR-T and CAR-NK

One characteristic that makes gastric cancer (GC) against other cancers is the intricate immune system's reaction, particularly to tenacious inflammation. Consequently, the immunological function is essential to the growth of this malignancy. Tumor immunotherapy has yielded several encouraging outcomes, but despite this, different patients continue to not respond to treatment, and a far larger number become resistant to it. Also, activated CAR-T cells express a majority of immunological checkpoint factors, containing PD1, CTLA4, and LAG3, which counteracts the anti-tumor actions of CAR-T cells. Moreover, cytokine release syndrome is one of the possible adverse responses of CAR-T cell therapy. Therefore, producing universal allogeneic T lymphocytes with potent anti-tumor activity is essential. This study demonstrates current research on this cutting-edge technology, including the composition and mode of action of CAR-NK and CAR-T cells in GC. Also, in this study, we examined recent studies about various specific GC biomarkers that target CAR-T cells and CAR-NK cells.

Claudin 18.2 expression profile in primary tumors and their ovarian metastases: implications for targeted therapy

BACKGROUND

Claudin 18.2 (CLDN18.2), a tight junction protein predominantly expressed in the normal gastric epithelium, has recently emerged as a potential therapeutic target in various solid tumors. Despite growing interest, comprehensive data on CLDN18.2 expression across primary tumors from different organs and their corresponding metastatic lesions remain limited.

METHODS

This study analyzed CLDN18.2 expression in 102 patients with primary adenocarcinomas from various organs and their corresponding ovarian metastatic carcinomas and in 81 cases of primary ovarian mucinous tumors using immunohistochemistry. We evaluated the association of CLDN18.2 expression with clinicopathologic features and survival outcomes.

RESULTS

The highest CLDN18.2 positivity rate was observed in gastric adenocarcinomas (40%, 12/30), followed by cervical adenocarcinomas (20%, 1/5) and colorectal adenocarcinomas (4%, 2/50). Notably, primary ovarian mucinous tumors showed remarkably high expression rates, reaching 77% overall and 100% in mucinous borderline tumors. In contrast, adenocarcinomas of the appendix and breast lacked CLDN18 expression. While CLDN18.2 expression was generally maintained during metastasis, some variations in expression patterns were observed, particularly in gastric cancers (13%, 4/30). Our analysis found no significant correlation between CLDN18.2 expression and overall survival in the patient cohort.

CONCLUSION

The preserved expression of CLDN18.2 in metastatic tumors underscores its potential utility as a target for therapeutic approaches. Our findings emphasize the importance of evaluating CLDN18.2 status in both primary and metastatic tumors to refine therapeutic strategies.

CAR T or NK cells targeting mismatched HLA-DR molecules in acute myeloid leukemia after allogeneic hematopoietic stem cell transplant

Acute myeloid leukemia (AML)-specific target antigens are difficult to identify. Here we demonstrate that HLA-DRB1 can serve as a leukemia-specific target of chimeric antigen receptor (CAR) T cells in patients with AML after allogeneic hematopoietic stem cell transplantation (allo-HCT). We identified KG2032 as a monoclonal antibody specifically bound to AML cells in about half of patients, but not to normal leukocytes other than B lymphocytes. KG2032 reacted with a subset of HLA-DRB1 molecules, specifically those in which the 86th amino acid was not aspartic acid. KG2032 reacted minimally with nonhematopoietic tissues. These results indicate that KG2032 reactivity is highly specific for AML cells in patients who carry KG2032-reactive HLA-DRB1 alleles and who received allo-HCT from a donor carrying KG2032-nonreactive HLA-DRB1 alleles. KG2032-derived CAR T or natural killer cells showed significant anti-leukemic activity in preclinical models in female mice, suggesting that they may cure patients with AML who are incurable with allo-HCT.

Tonic signaling in CAR-T therapy: the lever long enough to move the planet

Chimeric antigen receptor (CAR) T-cell therapy has shown remarkable efficacy in treating hematological malignancies and is expanding into other indications such as autoimmune diseases, fibrosis, aging and viral infection. However, clinical challenges persist in treating solid tumors, including physical barriers, tumor heterogeneity, poor in vivo persistence, and T-cell exhaustion, all of which hinder therapeutic efficacy. This review focuses on the critical role of tonic signaling in CAR-T therapy. Tonic signaling is a low-level constitutive signaling occurring in both natural and engineered antigen receptors without antigen stimulation. It plays a pivotal role in regulating immune cell homeostasis, exhaustion, persistence, and effector functions. The "Peak Theory" suggests an optimal level of tonic signaling for CAR-T function: while weak tonic signaling may result in poor proliferation and persistence, excessively strong signaling can cause T cell exhaustion. This review also summarizes the recent progress in mechanisms underlying the tonic signaling and strategies to fine-tune the CAR tonic signaling. By understanding and precisely modulating tonic signaling, the efficacy of CAR-T therapies can be further optimized, offering new avenues for treatment across a broader spectrum of diseases. These findings have implications beyond CAR-T cells, potentially impacting other engineered immune cell therapies such as CAR-NK and CAR-M.

Pancreatic cancer: failures and hopes-a review of new promising treatment approaches

Pancreatic cancer is a challenging disease with limited treatment options and a high mortality rate. Just few therapy advances have been made in recent years. Tumor microenvironment, immunosuppressive features and mutational status represent important obstacles in the improvement of survival outcomes. Up to now, first-line therapy did achieve a median overall survival of less than 12 months and this discouraging data lead clinicians all over the world to focus their efforts on various fields of investigation: 1) sequential cycling of different systemic therapy in order to overcome mechanisms of resistance; 2) discovery of new predictive bio-markers, in order to target specific patient population; 3) combination treatment, in order to modulate the tumor microenvironment of pancreatic cancer; 4) new modalities of the delivery of drugs in order to pass the physical barrier of desmoplasia and tumor stroma. This review shows future directions of treatment strategies in advanced pancreatic cancer through a deep analysis of these recent macro areas of research.

CAR-γδ T Cells Targeting Claudin18.2 Show Superior Cytotoxicity Against Solid Tumor Compared to Traditional CAR-αβ T Cells

BACKGROUND

Claudin18.2 (CLDN18.2) is highly expressed during the development of various malignant tumors, especially gastric cancer, and CAR-T cells targeting CLDN18.2 have therapeutic potential. However, their dependence on the major histocompatibility complex (MHC) for antigen recognition limits their application. Human Gamma Delta (γδ) T cells, with strong MHC-independent cytotoxicity to most solid tumors both in vivo and in vitro, are emerging as ideal cells for the generation of robust universal CLDN18.2 CAR-T cells to treat solid tumors. Our aim was to construct a universal CAR-γδ T cell targeting CLDN18.2.

METHODS

We constructed novel CAR-CLDN18.2-γδ T cells by lentiviral infection and compared their superior efficacy in the treatment of CLDN18.2-positive solid tumors in vivo and in vitro.

RESULTS

CD3ζ expression was verified in HEK293T cells after lentiviral transfection of CLDN18.2 CAR, and the lentivirus was packaged and concentrated to a titer of 4.90 × 108 TU/mL. Primary γδ T cells and αβ T cells were infected with efficiencies of approximately 31.76 ± 4.122% and 44.13 ± 4.436%, respectively. CAR-CLDN18.2-γδ T cells exhibited specific cytotoxicity against CLDN18.2-positive gastric cancer cells and secreted relatively high levels of Granzyme-B, Perforin-1, and IFN-γ. CAR-γδ T cells also showed superior cytotoxicity to target cells compared to classical CAR-αβ T cells in vitro. Finally, the antitumor activity of γδ T-CAR-CLDN18.2 cells was evaluated in tumor-bearing NSG mice, and CAR-CLDN18.2-γδ T cells significantly inhibited tumor growth and prolonged the survival of the mice.

CONCLUSIONS

Our results demonstrate that universal CAR-CLDN18.2-γδ T cell is promising for the treatment of CLDN18.2-positive solid tumor and provide insights for the development of more universal CAR-γδ T-cell strategies for tumor immunotherapy.

Chimeric Antigen Receptor-T Cells in Colorectal Cancer: Pioneering New Avenues in Solid Tumor Immunotherapy

Colorectal cancer (CRC) remains a major global health burden, being one of the most prevalent cancers with high mortality rates. Despite advances in conventional treatment modalities, patients with metastatic CRC often face limited options and poor outcomes. Chimeric antigen receptor-T (CAR-T) cell therapy, initially successful in hematologic malignancies, presents a promising avenue for treating solid tumors, including CRC. This review explores the potential of CAR-T cell therapy in CRC by analyzing clinical trials and highlighting prominent CRC-specific targets. We discuss the challenges such as immunosuppressive microenvironment, tumor heterogeneity, and physical barriers that limit CAR-T efficacy. Emerging strategies, such as logic-gated and dual-targeting CAR-T cells, offer practical solutions to overcome these hurdles. Furthermore, we explore the combination of CAR-T cell therapy with immune checkpoint inhibitors to enhance T-cell persistence and tumor infiltration. As the field continues to evolve, CAR-T cell therapies hold significant potential for revolutionizing the treatment landscape of CRC.

The Chimeric Antigen Receptor T Cell Target Claudin 6 Is a Marker for Early Organ-Specific Epithelial Progenitors and Is Expressed in Some Pediatric Solid Tumor Entities

Background/Objectives: The oncofetal membrane protein Claudin 6 (CLDN6) is an attractive target for T cell-based therapies. There is a lack of detailed analyses on the age-dependent expression of CLDN6 in normal tissues is lacking, which limits the expansion of CLDN6 CAR-T cell clinical trials to pediatric populations. Methods: We analyzed CLDN6 expression in extracranial solid tumors and normal tissues of children using RNA-sequencing data from over 500 pediatric solid tumor samples, qRT-PCR and immunohistochemistry (IHC) in more than 100 fresh-frozen tumor samples and, approximately, 250 formalin-fixed paraffin-embedded (FFPE) samples. We examined normal tissue expression via qRT-PCR in 32 different infant tissues and via IHC in roughly 290 tissues from donors across four age groups, as well as in fetal autopsy samples. Results: In fetal tissues, we detected CLDN6 expression primarily in the epithelial cells of several organs, including the skin, lungs, kidneys, intestinal tract, and pancreas, but not in undifferentiated blastemal cells. Postnatally, we found CLDN6-positive epithelial progenitors only during the first few weeks of life. In older-age groups, isolated clusters of CLDN6-positive progenitors were present, but in scarce quantities. In tumor tissues, we found strong and homogeneous CLDN6 expression in desmoplastic small round cell tumors and germ cell tumors. Wilms tumors demonstrated heterogeneous CLDN6 expression, notably absent in the blastemal component. Conclusions: These findings highlight an organ-specific presence of CLDN6-positive epithelial precursors that largely disappear in terminally differentiated epithelia within weeks after birth. Therefore, our data support CLDN6 as a viable therapeutic target in pediatric patients and justify their inclusion in basket studies for anti-CLDN6-based therapies.

Reprogramming tumor-associated macrophages in gastric cancer: a pathway to enhanced immunotherapy

Gastric cancer (GC) remains a significant global health concern due to its poor prognosis and limited therapeutic options, particularly in advanced stages. Tumor microenvironment (TME), particularly tumor-associated macrophages (TAMs), plays a key role in tumor progression, immune evasion, and therapy resistance. TAMs exhibit plasticity, shifting between pro-inflammatory M1 and immunosuppressive M2 phenotypes, with the latter predominating in GC and contributing to poor outcomes. Recent therapeutic advancements focus on targeting TAMs, including inhibiting M2 polarization, reprogramming TAMs to M1 phenotypes, and combining TAM-targeted approaches with immune checkpoint inhibitors. Innovations in nanotechnology, metabolic reprogramming, and targeting key pathways such as interleukin-6 and C-C motif ligand 2/C-C motif chemokine receptor 2 further enhance these strategies. However, challenges remain, including the spatial and functional heterogeneity of TAMs within the TME and the need for selective targeting to avoid disrupting immune homeostasis. Ongoing research on TAM origins, functions, and interactions within the TME is crucial for developing precise and effective therapies. These advances hold promise not only for improving outcomes in GC but also for addressing other cancers with similarly complex microenvironments.

Adoptive cell therapy against tumor immune evasion: mechanisms, innovations, and future directions

Tumors employ a range of strategies to evade detection and eradication by the host's immune system. These include downregulating antigen expression, altering antigen presentation processes, and inhibiting immune checkpoint pathways. etc. Adoptive Cell Therapy (ACT) represents a strategy that boosts anti-tumor immunity. This is achieved by amplifying or genetically engineering immune cells, which are either sourced from the patient or a donor, in a laboratory setting. Subsequently, these cells are reintroduced into the patient to bolster their immune response against cancer. ACT has successfully restored anti-tumor immune responses by amplifying the activity of T cells from patients or donors. This review focuses on the mechanisms underlying tumor escape, including alterations in tumor cell antigens, the immunosuppressive tumor microenvironment (TME), and modulation of immune checkpoint pathways. It further explores how ACT can avddress these factors to enhance therapeutic efficacy. Additionally, the review discusses the application of gene-editing technologies (such as CRISPR) in ACT, highlighting their potential to strengthen the anti-tumor capabilities of T cells. Looking forward, the personalized design of ACT, combined with immune checkpoint inhibitors and targeted therapies, is expected to significantly improve treatment outcomes, positioning this approach as a key strategy in the field of cancer immunotherapy.

Infections in Patients with Solid Tumors Undergoing Adoptive Cellular Therapy

Adoptive cellular therapy (ACT) is an increasingly widely used treatment approach for malignancy. While infectious complications of ACT have been well described in patients with hematologic malignancies, limited data are available on the epidemiology of infections in patients with solid tumors. The purpose of this study was to describe the epidemiology of infections occurring within the first 180 days in adult patients with solid tumors treated with ACT and to identify risk factors predisposing these patients to infection. Data on 132 adult patients with solid tumors undergoing ACT between August 2014 and November 2021 at Memorial Sloan Kettering Cancer Center were collected. Infections were documented from the day of ACT infusion through day 180 postinfusion. Overall, 28 of 132 patients (21.2%) experienced 33 infections within the first 30 days of ACT, and 17 of 131 surviving patients (13%) were diagnosed with 24 infections between day 31 and day 180. Infection-related mortality was low. The majority of infections were bacterial. While male gender, older age, Eastern Cooperative Oncology Group (ECOG) performance status (PS) at time of ACT infusion, tocilizumab receipt, and cytokine release syndrome treated with tocilizumab were associated with shorter time to first infection on univariable analysis, only ECOG PS and tocilizumab receipt remained independent risk factors in the multivariable analysis. The proportion of patients with solid tumors experiencing early or late infections after ACT was lower compared to that reported among patients with B cell malignancies after chimeric antigen receptor T cell therapy. Most observed infections were primarily bacterial with low infection-related mortality; the incidence of viral and fungal infections was low. Based on the low frequency and timing of infections relative to neutropenia, antibacterial and antifungal prophylaxis are not likely to be beneficial. ECOG PS ≥2 and tocilizumab receipt were identified as significant predictors for infection after ACT, likely signaling an individual's debilitated state that predisposes to infection. Additional work to parse out confounders is needed to better identify risk factors for infection.

Overcoming chimeric antigen receptor-T (CAR-T) resistance with checkpoint inhibitors: Existing methods, challenges, clinical success, and future prospects : A comprehensive review

Immune checkpoint blockade is, as of today, the most successful form of cancer immunotherapy, with more than 43 % of cancer patients in the US eligible to receive it; however, only up to 12.5 % of patients respond to it. Similarly, adoptive cell therapy using bioengineered chimeric antigen receptorT (CAR-T) cells and T-cell receptor (TCR) cells has provided excellent responses against liquid tumours, but both forms of immunotherapy have encountered challenges within a tumour microenvironment that is both lacking in tumour-specific T-cells and is strongly immunosuppressive toward externally administered CAR-T and TCR cells. This review focuses on understanding approved checkpoint blockade and adoptive cell therapy at both biological and clinical levels before delving into how and why their combination holds significant promise in overcoming their individual shortcomings. The advent of next-generation checkpoint inhibitors has further strengthened the immune checkpoint field, and a special section explores how these inhibitors can address existing hurdles in combining checkpoint blockade with adoptive cell therapy and homing in on our cancer target for long-term immunity.

Exploring the therapeutic efficacy difference in claudin18.2-targeted cell therapy revealed by single-cell sequencing

Chimeric antigen receptor T cell (CAR T) therapy has been successfully used to treat hematological malignancies. Nonetheless, its application to solid tumors remains challenging. Our previous analysis of the ongoing clinical trial (NCT03874897) demonstrated promising results in patients with advanced CLDN18.2-positive gastric cancer who received CT041 CAR T treatment. Here, we collected peripheral blood and ascites from five patients from the clinical trial 3 and 7 days (d) after CT041 infusion. Patients with a high proportion of naïve-like T cells were more likely to benefit from CT041 treatment. We found that high expression of CLDN18 in ascites epithelial cells correlated with a favorable prognosis, whereas ascites epithelial cells with high MYC expression and strong interactions between tumor cells and T cells were adverse prognostic factors for CT041 treatment. These findings may provide theoretical evidence for the screening of populations that can benefit from CAR T therapy and improve the efficacy of CAR T therapy.

Non-small cell lung cancer and the tumor microenvironment: making headway from targeted therapies to advanced immunotherapy

Over the past decades, significant progress has been made in the understanding of non-small cell lung cancer (NSCLC) biology and tumor progression mechanisms, resulting in the development of novel strategies for early detection and wide-ranging care approaches. Since their introduction, over 20 years ago, targeted therapies with tyrosine kinase inhibitors (TKIs) have revolutionized the treatment landscape for NSCLC. Nowadays, targeted therapies remain the gold standard for many patients, but still they suffer from many adverse effects, including unexpected toxicity and intrinsic acquired resistance mutations, which lead to relapse. The adoption of immune checkpoint inhibitors (ICIs) in 2015, has offered exceptional survival benefits for patients without targetable alterations. Despite this notable progress, challenges remain, as not all patients respond favorably to ICIs, and resistance to therapy can develop over time. A crucial factor influencing clinical response to immunotherapy is the tumor microenvironment (TME). The TME is pivotal in orchestrating the interactions between neoplastic cells and the immune system, influencing tumor growth and treatment outcomes. In this review, we discuss how the understanding of this intricate relationship is crucial for the success of immunotherapy and survey the current state of immunotherapy intervention, with a focus on forthcoming and promising chimeric antigen receptor (CAR) T cell therapies in NSCLC. The TME sets major obstacles for CAR-T therapies, creating conditions that suppress the immune response, inducing T cell exhaustion. To enhance treatment efficacy, specific efforts associated with CAR-T cell therapy in NSCLC, should definitely focus TME-related immunosuppression and antigen escape mechanisms, by combining CAR-T cells with immune checkpoint blockades.

Targeted therapy and immunotherapy for gastric cancer: rational strategies, novel advancements, challenges, and future perspectives

Gastric cancer (GC) is one of the most common malignant tumors worldwide, and its treatment has been a focus of medical research. Herein we systematically review the current status of and advancements in targeted therapy and immunotherapy for GC, which have emerged as important treatment strategies in recent years with great potential, and summarize the efficacy and safety of such treatments. Targeted therapies against key targets in GC, including epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), and vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR), have shown remarkable therapeutic efficacies by inhibiting tumor progression and/or blood supply. In particular, markable breakthroughs have been made in HER2-targeting drugs for HER2-positive GC patients. To address intrinsic and acquired resistances to HER2-targeting drugs, novel therapeutic agents including bispecific antibodies and antibody-drug conjugates (ADC) targeting HER2 have been developed. Immunotherapy enhances the recognition and elimination of cancer cells by activating body anticancer immune system. Programmed cell death protein 1 (PD-1) and programmed cell death-ligand 1 (PD-L1) antibodies are the most commonly used immunotherapeutic agents and have been used with some success in GC treatment. Innovative immunotherapy modalities, including adoptive immune cell therapy, tumor vaccines, and non-specific immunomodulators therapy, and oncolytic viruses have shown promise in early-stage clinical trials for GC. Clinical trials have supported that targeted therapy and immunotherapy can significantly improve the survival and quality of life of GC patients. However, the effects of such therapies need to be further improved and more personalized, with advancement in researches on tumor immune microenvironment. Further studies remain needed to address the issues of drug resistance and adverse events pertaining to such therapies for GC. The combined application of such therapies and individualized treatment strategies should be further explored with novel drugs developed, to provide more effective treatments for GC patients.

Overcoming immunotherapy resistance in gastric cancer: insights into mechanisms and emerging strategies

Gastric cancer (GC) remains a leading cause of cancer-related mortality worldwide, with limited treatment options in advanced stages. Immunotherapy, particularly immune checkpoint inhibitors (ICIs) targeting PD1/PD-L1, has emerged as a promising therapeutic approach. However, a significant proportion of patients exhibit primary or acquired resistance, limiting the overall efficacy of immunotherapy. This review provides a comprehensive analysis of the mechanisms underlying immunotherapy resistance in GC, including the role of the tumor immune microenvironment, dynamic PD-L1 expression, compensatory activation of other immune checkpoints, and tumor genomic instability. Furthermore, the review explores GC-specific factors such as molecular subtypes, unique immune evasion mechanisms, and the impact of Helicobacter pylori infection. We also discuss emerging strategies to overcome resistance, including combination therapies, novel immunotherapeutic approaches, and personalized treatment strategies based on tumor genomics and the immune microenvironment. By highlighting these key areas, this review aims to inform future research directions and clinical practice, ultimately improving outcomes for GC patients undergoing immunotherapy.

TBK1 Targeting Is Identified as a Therapeutic Strategy to Enhance CAR T-Cell Efficacy Using Patient-Derived Organotypic Tumor Spheroids

Novel therapeutic strategies are needed to improve the efficacy of chimeric antigen receptor (CAR) T cells as a treatment of solid tumors. Multiple tumor microenvironmental factors are thought to contribute to resistance to CAR T-cell therapy in solid tumors, and appropriate model systems to identify and examine these factors using clinically relevant biospecimens are limited. In this study, we examined the activity of B7-H3-directed CAR T cells (B7-H3.CAR-T) using 3D microfluidic cultures of patient-derived organotypic tumor spheroids (PDOTS) and then confirmed the activity of B7-H3.CAR T cells in PDOTS. Although B7-H3 expression in PDOTS was associated with B7-H3.CAR-T sensitivity, mechanistic studies revealed dynamic upregulation of co-inhibitory receptors on CAR T-cells following target cell encounter that led to CAR T-cell dysfunction and limited efficacy against B7-H3-expressing tumors. PD-1 blockade restored CAR T-cell activity in monotypic and organotypic tumor spheroids with improved tumor control and upregulation of effector cytokines. Given the emerging role of TANK-binding kinase 1 (TBK1) as an immune evasion gene, we examined the effect of TBK1 inhibition on CAR T-cell efficacy. Similar to PD-1 blockade, TBK1 inhibition restored CAR T-cell activity in monotypic and organotypic tumor spheroids, prevented CAR T-cell dysfunction, and enhanced CAR T-cell proliferation. Inhibition or deletion of TBK1 also enhanced the sensitivity of cancer cells to immune-mediated killing. Taken together, our results demonstrate the feasibility and utility of ex vivo profiling of CAR T cells using PDOTS and suggest that targeting TBK1 could be used to enhance CAR T-cell efficacy by overcoming tumor-intrinsic and -extrinsic resistance mechanisms.

Claudin 18.2-targeting antibody-drug conjugate CMG901 in patients with advanced gastric or gastro-oesophageal junction cancer (KYM901): a multicentre, open-label, single-arm, phase 1 trial

BACKGROUND

CMG901 is a novel first-in-class antibody-drug conjugate with a humanised anticlaudin 18.2 antibody linked to microtubule-disrupting agent monomethyl auristatin E. We aimed to assess the antitumour activity and safety of CMG901 in patients with advanced gastric or gastro-oesophageal junction cancer and other solid tumours.

METHODS

KYM901 is a multicentre, open-label, single-arm, phase 1 trial consisting of dose-escalation and dose-expansion stages. Patients with advanced solid tumours, including gastric or gastro-oesophageal junction and pancreatic cancers, were recruited from 31 hospital sites in China. Eligible patients were aged 18 years or older, were refractory to standard therapy or had no available standard-of-care regimen, and had an Eastern Cooperative Oncology Group performance status score of 0-1, a life expectancy of at least 3 months, and at least one measurable lesion. Patients received intravenous CMG901 every 3 weeks (0·3-3·4 mg/kg in dose escalation and 2·2-3·0 mg/kg in dose expansion) until disease progression, unacceptable toxic effects, initiation of new antitumour therapy, study withdrawal, or death. Primary endpoints were adverse events and dose-limiting toxic effects in the dose-escalation phase, and objective response rate and recommended phase 2 dose in the dose-expansion phase. Confirmed objective response was defined as a partial or complete response that was verified by follow-up imaging at least 4 weeks after the initial assessment. Safety was assessed in all patients who received at least one dose of CMG901 with at least one post-dose safety evaluation. Antitumour activity was assessed in all patients who received at least one dose of CMG901 (full analysis set) and in all CMG901-treated patients with at least one post-dose imaging evaluation and no major protocol deviations (efficacy analysis set). Dose-expansion data for patients with pancreatic cancer will be published separately. Due to small sample sizes, results in patients with other solid tumours (n=2) are not planned for publication. This ongoing trial is registered with ClinicalTrials.gov, NCT04805307.

FINDINGS

Between Dec 24, 2020, and Feb 23, 2023, 27 patients were enrolled in the dose-escalation phase (median age 57·0 years [IQR 48·0-63·0]; 14 [52%] male, 13 [48%] female) and 107 patients with gastric or gastro-oesophageal junction cancer in the dose-expansion phase (median age 56·0 years [44·0-64·0]; 57 [53%] male, 50 [47%] female). As of Feb 24, 2024, one dose-limiting toxic effect (grade 3 pancreatitis) occurred at 2·2 mg/kg, and the maximum tolerated dose was not reached in the dose-escalation phase. All 27 patients reported at least one treatment-emergent adverse event, most frequently vomiting (19 [70%]), decreased appetite (16 [59%]), proteinuria (16 [59%]), and anaemia (15 [56%]), and five (19%) had drug-related grade 3 or worse treatment-emergent adverse events. In 107 patients, grade 3 or worse treatment-emergent adverse events occurred in 73 (68%) patients and serious adverse events occurred in 54 (50%) patients in dose expansion. The most common grade 3-4 adverse events were neutrophil count decreased (22 [21%]), anaemia (15 [14%]), and vomiting (11 [10%]). One treatment-related death was reported. At median follow-up of 9·0 months (IQR 4·4-12·9), among 113 patients with gastric or gastro-oesophageal junction cancer in the 2·2-3·0 mg/kg cohort full analysis set across both the dose-escalation and dose-expansion phases, the confirmed objective response rate was 28% (95% CI 20-38; 32 of 113 patients). In the 109 patients included in the efficacy analysis set, the confirmed objective response rate was 29% (95% CI 21-39; 32 of 109 patients). Based on overall safety, activity, and pharmacokinetics of CMG901, 2·2 mg/kg was the proposed recommended phase 2 dose.

INTERPRETATION

CMG901 showed a manageable safety profile and had promising antitumour activity in patients with advanced gastric or gastro-oesophageal junction cancer.

FUNDING

KYM Biosciences.

Combinational CAR T-cell therapy for solid tumors: Requisites, rationales, and trials

Chimeric antigen receptor (CAR) T-cell therapy has achieved potent antitumor efficacy in hematological malignancies; however, because of limitations in CAR T-cell recruitment, infiltration, activation, and functional persistence in the tumor, its efficacy in solid tumors has been suboptimal. To overcome these challenges, combinational strategies that include chemotherapy, radiation therapy, or immune checkpoint inhibitor agent therapy with CAR T-cell therapy are being investigated. The established functional characteristics of the abovementioned therapies provide a rationale for the use of a combinational approach with CAR T cells. Chemotherapy reshapes the peritumoral stroma, decreases the immunosuppressive cell population, and promotes a proinflammatory milieu, all of which allow for increased recruitment, infiltration, and accumulation of CAR T cells. Radiation therapy promotes a chemokine gradient, which augments tumor infiltration by CAR T cells and further increases expression of tumor-associated antigens, allowing for increased activation of CAR T cells. Immune checkpoint inhibitor agent therapy inactivates T-cell exhaustion pathways-most notably, the PD1/PDL1 pathway-thereby improving the functional persistence of CAR T cells and promoting endogenous immunity. In this review, we discuss the requisites and rationales for combinational therapy, and we review 25 ongoing phase I and II clinical trials, of which 4 use chemotherapy, 3 use radiation therapy, 11 use immunotherapy, and 7 use another agent. While safety, efficacy, and improved outcomes are the primary goals of these ongoing studies, the knowledge gained from them will help pave the way for subsequent studies focused on optimizing combinational regimens and identifying predictive biomarkers.

A new broom sweeps clean: CLDN16 surpasses the BRAF-V600E mutation as an unrivaled biomarker in papillary thyroid cancer

OBJECTIVE

This study assessed CLDN16 as a potential replacement or improvement biomarker for papillary thyroid cancer (PTC), addressing the limitations associated with the prevalently used BRAF-V600E mutation.

DESIGN

Database analyses, tissue validation, RNA sequencing, and functional assays were conducted to evaluate CLDN16 as a PTC biomarker and its clinical application.

METHODS

CLDN16 expression was examined in PTC and normal thyroid/para-tumor tissues and compared across various cancer types. We evaluated diagnostic accuracy, stability in primary and metastatic sites, and associations with aggressive features. Knockdown experiments were performed to investigate the impact on PTC cell behavior. Additionally, we developed a support vector machine model for diagnosing malignant and high-risk PTCs.

RESULTS

CLDN16 demonstrated high specificity for PTC, with positive detection rates (88.0% in The Cancer Genome Atlas [TCGA] and 88.3% in our center) significantly surpassing BRAF-V600E (47.5% in TCGA and 74.3% in our center). This resulted in superior diagnostic accuracy (ROC-CLDN16 = 0.922 vs ROC-BRAF-V600E = 0.742 in TCGA). CLDN16 exhibited stable expression across primary and metastatic sites and was associated with aggressive features, including extrathyroidal extension and lymph node metastasis. CLDN16 knockdown inhibited migration, invasion, and iodine uptake in PTC cells. Clinically, CLDN16 effectively identified malignancy in BRAF wild patients (94.2%), and combined with BRAF-V600E, achieved 96.9% accuracy. The incorporation of CLDN16 into PTC molecular typing facilitated precise high-risk identification (92.0% accuracy in the training set and 100% in the validation set).

CONCLUSIONS

CLDN16 presents a promising biomarker that could surpass BRAF-V600E, offering effective clinical utility and revolutionizing PTC molecular typing for precise high-risk identification.

A literature review of recent advances in gastric cancer treatment: exploring the cross-talk between targeted therapies

BACKGROUND

Gastric cancer (GC) ranks fourth in global mortality rates and fifth in prevalence, making it one of the most common cancers worldwide. Recent clinical studies have highlighted the potential of immunotherapies as a promising approach to treating GC. This study aims to shed light on the most impactful therapeutic strategies in the context of GC immunotherapy, highlighting both established and emerging approaches.

MAIN BODY

This review examines over 160 clinical studies conducted globally, focusing on the effectiveness of various immunotherapy modalities, including cancer vaccines, adoptive cell therapy, immune checkpoint inhibitors (ICIs), and monoclonal antibodies (mAbs). A comprehensive search of peer-reviewed literature was performed using databases such as Web of Science, PubMed, and Scopus. The selection criteria included peer-reviewed articles published primarily within the last 10 years, with a focus on studies that provided insights into targeted therapies and their mechanisms of action, clinical efficacy, and safety profiles. The findings indicate that these immunotherapy strategies can enhance treatment outcomes for GC, aligning with current treatment guidelines. ICIs like pembrolizumab and nivolumab have shown significant survival benefits in specific GC subgroups. Cancer vaccines and CAR-T cell therapies demonstrate potential, while mAbs targeting HER2 and VEGFR pathways enhance outcomes in combination regimens. We discuss the latest advancements and challenges in targeted therapy and immunotherapy for GC. Given the evolving nature of this field, this research emphasizes significant evidence-based therapies and those currently under evaluation rather than providing an exhaustive overview. Challenges include resistance mechanisms, immunosuppressive tumor environments, and inconsistent results from combination therapies. Biomarker-driven approaches and further research into emerging modalities like CAR-T cells and cancer vaccines are critical for optimizing treatments.

CONCLUSIONS

Immunotherapy is reshaping GC management by improving survival and quality of life. Ongoing research and clinical evaluations are crucial for refining personalized and effective therapies.

Current Landscape of Molecular Biomarkers in Gastroesophageal Tumors and Potential Strategies for Co-Expression Patterns

The treatment of metastasized gastroesophageal adenocarcinoma largely depends on molecular profiling based on immunohistochemical procedures. Therefore, the examination of HER2, PD-L1, and dMMR/MSI is recommended by the majority of clinical practice guidelines, as positive expression leads to different treatment approaches. Data from large phase-III trials and consequent approvals in various countries enable physicians to offer their patients several therapy options including immunotherapy, targeted therapy, or both combined with chemotherapy. The introduction of novel therapeutic targets such as CLDN18.2 leads to a more complex decision-making process as a significant number of patients show positive results for the co-expression of other biomarkers besides CLDN18.2. The aim of this review is to summarize the current biomarker landscape of patients with metastatic gastroesophageal tumors, its direct clinical impact on daily decision-making, and to evaluate current findings on biomarker co-expression. Furthermore, possible treatment strategies with multiple biomarker expression are discussed.

Clinical and molecular characteristics of patients with brain metastasis secondary to pancreatic ductal adenocarcinoma

BACKGROUND

The prognosis for patients with pancreatic ductal adenocarcinoma (PDAC) is poor. Secondary brain metastasis (Br-M) occurs in less than 1% of patients. Clinical characteristics and molecular alterations have not been characterized in this rare patients' subset.

MATERIALS AND METHODS

The Foundry software platform was used to retrospectively query electronic health records for patients with Br-M secondary to PDAC from 2005 to 2023; clinical, molecular, and overall survival (OS) data were analyzed.

RESULTS

Br-M was diagnosed in 44 patients with PDAC. Median follow-up was 78 months; median OS from initial PDAC diagnosis was 47 months. Median duration from PDAC diagnosis to Br-M detection was 24 months; median OS from Br-M diagnosis was 3 months. At Br-M diagnosis, 82% (n = 36) of patients had elevated CA19-9. Lung was the most common preexisting metastatic location (71%) with Br-M, followed by liver (66%). Br-M were most frequently observed in the frontal lobe (34%, n = 15), cerebellar region (23%, n = 10), and leptomeninges (18%, n = 8). KRAS mutations were detected in 94.1% (n = 16) of patients who had molecular data available (n = 17) with KRASG12V being the most frequent subtype 47% (n = 8); KRASG12D in 29% (n = 5); KRASG12R in 18% (n = 3). Patients who underwent Br-M surgical resection (n = 5) had median OS of 8.6 months, while median OS following stereotactic radiosurgery only (n = 11) or whole-brain radiation only (n = 20) was 3.3 and 2.8 months, respectively.

CONCLUSION

Br-M is a late PDAC complication, resulting in an extremely poor prognosis especially in leptomeningeal disease. KRAS was mutated in 94.1% of the patients and the KRASG12V subtype was prevalent.

Immunotherapy in gastric cancer-A systematic review

Background

Gastric Cancer (GC) is the 5th most prevalent and 4th most deadly neoplasm globally. Immunotherapy has emerged as a promising treatment approach in GC, potentially improving positive clinical outcomes while addressing the limitations of conventional therapies. GC immunotherapy modalities consist of adoptive cell therapy (ACT), cancer vaccines, and immune checkpoint inhibitors (ICI).

Objectives

This systematic review aims to provide an overview of the advances in immune-based therapeutic approaches in GC, highlighting the potential of this therapy as a strategy for GC treatment.

Methods

Key studies investigating several immunotherapeutic agents and combination therapies were searched in PUBMED and included in this study. Specific cancer outcomes related to disease progression or survival were analyzed.

Results

After screening 236 studies, the results revealed that immunotherapy, particularly the ICI pembrolizumab, demonstrated promising efficacy in the treatment of GC, as several studies reported improved OS, PFS, and objective response rate with the use of pembrolizumab alone or in combination with other treatment modalities.

Conclusion

Safety analysis showed that immunotherapy was mostly well-tolerated, with manageable adverse events and relatively good safety profiles. Nonetheless, further research is required to understand the mechanisms of tumor resistance better and identify predictive biomarkers that can direct treatment optimization.

Digestive cancers: mechanisms, therapeutics and management

Cancers of the digestive system are major contributors to global cancer-associated morbidity and mortality, accounting for 35% of annual cases of cancer deaths. The etiologies, molecular features, and therapeutic management of these cancer entities are highly heterogeneous and complex. Over the last decade, genomic and functional studies have provided unprecedented insights into the biology of digestive cancers, identifying genetic drivers of tumor progression and key interaction points of tumor cells with the immune system. This knowledge is continuously translated into novel treatment concepts and targets, which are dynamically reshaping the therapeutic landscape of these tumors. In this review, we provide a concise overview of the etiology and molecular pathology of the six most common cancers of the digestive system, including esophageal, gastric, biliary tract, pancreatic, hepatocellular, and colorectal cancers. We comprehensively describe the current stage-dependent pharmacological management of these malignancies, including chemo-, targeted, and immunotherapy. For each cancer entity, we provide an overview of recent therapeutic advancements and research progress. Finally, we describe how novel insights into tumor heterogeneity and immune evasion deepen our understanding of therapy resistance and provide an outlook on innovative therapeutic strategies that will shape the future management of digestive cancers, including CAR-T cell therapy, novel antibody-drug conjugates and targeted therapies.

The high efficacy of claudin18.2-targeted CAR-T cell therapy in advanced pancreatic cancer with an antibody-dependent safety strategy

Pancreatic cancer (PC) is one of the most lethal digestive system tumors. Claudin18.2 is highly expressed in PC tissue and could serve as a suitable target for CAR-T therapy. In the present study, we reported the utilization of tEGFR-expressing claudin18.2-targeted CAR-T cells to treat 3 patients with advanced PC. Intriguingly, all 3 patients achieved disease remission after CAR-T cell infusion, with 1 complete remission (CR) and 2 partial remissions (PRs). However, gastric mucosal injury was observed, which was recognized as on-target off-tumor toxicity (OTOT) and may be due to the expression of claudin18.2 on normal gastric tissues. To control the severe OTOT in patient 3, cyclophosphamide and cetuximab were administered to deplete CAR-T cells, and they successfully controlled OTOT. Single-cell transcriptome and T cell receptor sequencing revealed the objective alterations of CAR-T cell clones after cetuximab treatment. Collectively, the present study showed the robust anti-tumor activity of claudin18.2-targeted CAR-T cells against PC and reported the feasibility of the antibody-dependent safety switch strategy to control the OTOT caused by CAR-T cells in patients. Our study may pave the way for the development of a novel strategy to treat patients with advanced PC in the future.

Preclinical Development of T Cells Engineered to Express a T-Cell Antigen Coupler Targeting Claudin 18.2-Positive Solid Tumors

The T-cell antigen coupler (TAC) is a chimeric receptor that facilitates tumor antigen-specific activation of T cells by co-opting the endogenous T-cell receptor complex in the absence of tonic signaling. Previous data demonstrate that the TAC affords T cells with the ability to induce durable and safe antitumor responses in preclinical models of hematologic and solid tumors. In this study, we describe the preclinical pharmacology and safety of an autologous Claudin 18.2 (CLDN18.2)-directed TAC T-cell therapy, TAC01-CLDN18.2, in preparation for a phase I/II clinical study in subjects with CLDN18.2-positive solid tumors. Following a screen of putative TAC constructs, the specificity, activity, and cytotoxicity of TAC T cells expressing the final CLDN18.2-TAC receptor were evaluated in vitro and in vivo using gastric, gastroesophageal, and pancreatic tumor models as well as human cells derived from normal tissues. CLDN18.2-specific activity and cytotoxicity of CLDN18.2-TAC T cells were observed in coculture with various 2D tumor cultures naturally expressing CLDN18.2 as well as tumor spheroids. These effects occurred in models with low antigen levels and were positively associated with increasing CLDN18.2 expression. CLDN18.2-TAC T cells effectively eradicated established tumor xenografts in mice in the absence of observed off-target or on-target/off-tumor effects, elicited durable efficacy in recursive killing and tumor rechallenge experiments, and remained unreactive in coculture with human cells representing vital organs. Thus, the data demonstrate that CLDN18.2-TAC T cells can induce a specific and long-lasting antitumor response in various CLDN18.2-positive solid tumor models without notable TAC-dependent toxicities, supporting the clinical development of TAC01-CLDN18.2.

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.

Developing CAR T-Cell Therapies for Pediatric Solid Tumors

Chimeric antigen receptor (CAR) T cells have revolutionized the treatment of hematological malignancies, inducing notable and durable clinical responses. However, for solid tumors, including but not limited to pediatric tumors, several peculiar biological features posed substantial challenges for achieving comparable results. Despite sound pre-clinical evidence of the ability of CAR T cells to eradicate solid malignancies, their activity remains suboptimal when facing the in vivo complexity of solid tumors, characterized by antigen heterogeneity, scarce T-cell infiltration, and an immunosuppressive microenvironment. Neuroblastoma was amongst the first tumors to be evaluated as a potential candidate for GD2-targeting CAR T cells, which recently documented promising results in high-risk, heavily pre-treated patients. Moreover, innovative engineering strategies for generating more potent and persistent CAR T cells suggest the possibility to reproduce, and potentially improve, these promising results on a larger scale. In the next years, harnessing the full therapeutic potential of CAR T cells and other immunotherapeutic strategies may open new possibilities for effectively treating the most aggressive forms of pediatric tumors.

The power and the promise of CAR-mediated cell immunotherapy for clinical application in pancreatic cancer

BACKGROUND

Pancreatic cancer, referred to as the "monarch of malignancies," is a neoplastic growth mostly arising from the epithelial cells of the pancreatic duct and acinar cells. This particular neoplasm has a highly unfavorable prognosis due to its marked malignancy, inconspicuous initial manifestation, challenging early detection, rapid advancement, and limited survival duration. Cellular immunotherapy is the ex vivo culture and expansion of immune effector cells, granting them the capacity to selectively target malignant cells using specialized techniques. Subsequently, these modified cells are reintroduced into the patient's organism with the purpose of eradicating tumor cells and providing therapeutic intervention for cancer.

PRESENT SITUATION

Presently, the primary cellular therapeutic modalities employed in the treatment of pancreatic cancer encompass CAR T-cell therapy, TCR T-cell therapy, NK-cell therapy, and CAR NK-cell therapy.

AIM OF REVIEW

This review provides a concise overview of the mechanisms and primary targets associated with various cell therapies. Additionally, we will explore the prospective outlook of cell therapy in the context of treating pancreatic cancer.

Intravenous and intracranial GD2-CAR T cells for H3K27M+ diffuse midline gliomas

H3K27M-mutant diffuse midline gliomas (DMGs) express high levels of the disialoganglioside GD2 (ref. 1). Chimeric antigen receptor-modified T cells targeting GD2 (GD2-CART) eradicated DMGs in preclinical models1. Arm A of Phase I trial no. NCT04196413 (ref. 2) administered one intravenous (IV) dose of autologous GD2-CART to patients with H3K27M-mutant pontine (DIPG) or spinal DMG (sDMG) at two dose levels (DL1, 1 × 106 kg-1; DL2, 3 × 106 kg-1) following lymphodepleting chemotherapy. Patients with clinical or imaging benefit were eligible for subsequent intracerebroventricular (ICV) intracranial infusions (10-30 × 106 GD2-CART). Primary objectives were manufacturing feasibility, tolerability and the identification of maximally tolerated IV dose. Secondary objectives included preliminary assessments of benefit. Thirteen patients enroled, with 11 receiving IV GD2-CART on study (n = 3 DL1 (3 DIPG); n = 8 DL2 (6 DIPG, 2 sDMG)). GD2-CART manufacture was successful for all patients. No dose-limiting toxicities occurred on DL1, but three patients experienced dose-limiting cytokine release syndrome on DL2, establishing DL1 as the maximally tolerated IV dose. Nine patients received ICV infusions, with no dose-limiting toxicities. All patients exhibited tumour inflammation-associated neurotoxicity, safely managed with intensive monitoring and care. Four patients demonstrated major volumetric tumour reductions (52, 54, 91 and 100%), with a further three patients exhibiting smaller reductions. One patient exhibited a complete response ongoing for over 30 months since enrolment. Nine patients demonstrated neurological benefit, as measured by a protocol-directed clinical improvement score. Sequential IV, followed by ICV GD2-CART, induced tumour regressions and neurological improvements in patients with DIPG and those with sDMG.

SHR-1806, a robust OX40 agonist to promote T cell-mediated antitumor immunity

Anti-CTLA-4 and anti-PD-1/PD-L1 antibodies have significantly revolutionized cancer immunotherapy. However, the persistent challenge of low patient response rates necessitates novel approaches to overcome immune tolerance. Targeting immunostimulatory signaling may have a better chance of success for its ability to enhance effector T cell (Teff) function and expansion for antitumor immunity. Among various immunostimulatory pathways, the evidence underscores the potential of activating OX40-OX40L signaling to enhance CD8+ T cell generation and maintenance while suppressing regulatory T cells (Tregs) within the tumor microenvironment (TME). In this study, we introduce a potent agonistic anti-OX40 antibody, SHR-1806, designed to target OX40 receptors on activated T cells and amplify antitumor immune responses. SHR-1806 demonstrates a high affinity and specificity for human OX40 protein, eliciting FcγR-mediated agonistic effects, T cell activation, antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) activities in vitro. In human OX40 knock-in mice bearing MC38 tumor, SHR-1806 shows a trend toward a higher potency than the reference anti-OX40 antibody produced in-house, GPX4, an analog of pogalizumab, the most advanced drug candidate developed by Roche. Furthermore, SHR-1806 displays promising anti-tumor activity alone or in combination with toll-like receptor 7 (TLR7) agonist or PD-L1 inhibitor in mouse models. Evaluation of SHR-1806 in rhesus monkeys indicates a favorable safety profile and typical pharmacokinetic characteristics. Thus, SHR-1806 emerges as a robust OX40 agonist with promising therapeutic potential.

Global research trends in CAR-T cell therapy for solid tumors: A comprehensive visualization and bibliometric study (2012-2023)

CAR-T cell therapy has emerged as a significant approach for the management of hematological malignancies. Over the past few years, the utilization of CAR-T cells in the investigation and treatment of solid tumors has gained momentum, thereby establishing itself as a prominent area of research. This descriptive study involved the retrieval of articles about CAR-T cell therapy for solid tumors from the Web of Science Core Collection (WoSCC) database. Subsequently, bibliometric analysis and knowledge map analysis were conducted on these articles. The field under consideration is currently experiencing a period of swift advancement, as evidenced by the escalating number of publications in this domain each year. The United States holds an indisputable position as the foremost leader in this particular field, with the University of Pennsylvania emerging as the most active institution. The authors with the highest citation frequency and co-citation frequency are Carl H. June and Shannon L. Maude, respectively. The research hotspots in this field mainly focus on five aspects. Additionally, 10 emerging themes were identified. This study undertakes a comprehensive, systematic, and objective analysis and exploration of the field of CAR-T cell treatment for solid tumors, utilizing bibliometric methods. The findings of this study are expected to serve as a valuable reference and enlightenment for future research endeavors in this particular domain.

PSCA-targeted BPX-601 CAR T cells with pharmacological activation by rimiducid in metastatic pancreatic and prostate cancer: a phase 1 dose escalation trial

Here we report results of a phase 1 multi-institutional, open-label, dose-escalation trial (NCT02744287) of BPX-601, an investigational autologous PSCA-directed GoCAR-T® cell product containing an inducible MyD88/CD40 ON-switch responsive to the activating dimerizer rimiducid, in patients with metastatic pancreatic (mPDAC) or castration-resistant prostate cancer (mCRPC). Primary objectives were to evaluate safety and tolerability and determine the recommended phase 2 dose/schedule (RP2D). Secondary objectives included the assessment of efficacy and characterization of the pharmacokinetics of rimiducid. Thirty-three patients received BPX-601 with or without rimiducid, 24 patients with mPDAC and 9 with mCRPC. Two dose-limiting toxicities and two treatment-related deaths occurred in the highest-dose mCRPC cohort, after which the study was terminated, without determination of the RP2D. Two mCRPC patients experienced partial responses (one unconfirmed), and 56% of mCRPC patients achieved ≥50% reduction in prostate-specific antigen. BPX-601 cell expansion, long-term persistence in peripheral blood, and tumor infiltration were observed. Rimiducid increased circulating inflammatory cytokines/chemokines consistent with GoCAR-T® cell activation. These results suggest that pharmacological activation of GoCAR-T® cells is feasible and may offer a promising avenue to control chimeric antigen receptor-T cell activity with continued dose-optimization to improve tolerability.

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.

Prognostic value of inflammatory and nutritional indexes among patients with unresectable advanced gastric cancer receiving immune checkpoint inhibitors combined with chemotherapy-a retrospective study

Background

Recent studies have revealed that inflammatory factors and nutritional status of patients with advanced gastric cancer (AGC) are related to the efficacy of drug therapy and patient prognosis. This study seeks to evaluate the correlation between inflammatory markers, nutritional status, and clinical outcomes of immune checkpoint inhibitor (ICI)-based therapies among inoperable AGC patients.

Method

This retrospective study included 88 AGC patients who received ICIs combined with chemotherapy. Inflammatory and nutritional indicators from patients before and after two cycles of treatment were collected. Finally, the correlations between these indicators and the clinical response and survival of AGC patients with ICI treatment were examined.

Results

The results revealed that an Eastern Cooperative Oncology Group performance status (ECOG PS) score of 0, neutrophil count to lymphocyte count ratio (NLR) < 2.84, platelet count to lymphocyte count ratio (PLR) < 82.23, lymphocyte count to monocyte count ratio ≥ 2.35, the hemoglobin, albumin, lymphocyte and platelet score (HALP) ≥ 31.17, prognostic nutritional index (PNI) ≥ 46.53, albumin ≥ 41.65, the decreased HALP group and the decreased PNI group were significantly correlated with improved objective response rate. Additionally, an ECOG PS score of 0, NLR < 2.84 and the decreased HALP group was associated with a superior disease control rate. Meanwhile, an ECOG PS score of 0 (progression-free survival (PFS): P = 0.003; overall survival (OS): P = 0.001) and decreased PLR following treatment (PFS: P = 0.011; OS: P = 0.008) were significant independent predictors of PFS and OS. Lastly, a systemic immune inflammation index ≥ 814.8 was also a positive independent predictor of OS among AGC patients.

Conclusion

Our study supports the potential of inflammatory and nutritional factors to serve as predictors of the efficacy and prognosis in patients undergoing ICI-based therapies for AGC. However, further investigations are necessary to validate these findings.

In vivo programmed myeloid cells expressing novel chimeric antigen receptors show potent anti-tumor activity in preclinical solid tumor models

Introduction

The approval of chimeric antigen receptor (CAR) T cell therapies for the treatment of B cell malignancies has fueled the development of numerous ex vivo cell therapies. However, these cell therapies are complex and costly, and unlike in hematological malignancies, outcomes with most T cell therapies in solid tumors have been disappointing. Here, we present a novel approach to directly program myeloid cells in vivo by administering novel TROP2 CAR mRNA encapsulated in lipid nanoparticles (LNPs).

Methods

The CAR comprises a TROP2 specific single-chain variable fragment (scFv) fused to a truncated CD89 which requires association with the FcRγ signal adapter to trigger myeloid-specific cell activation. The mRNA encoding the TROP2 CAR was encapsulated in LNPs. Co-immunoprecipitation, flow cytometry and enzyme-linked immunosorbent assay (ELISA) were used to measure CAR expression and functional activity in vitro. Anti-tumor efficacy of the TROP2 CAR mRNA/LNP was evaluated after intravenous administration in various murine tumor models.

Results

In vitro, transient expression of the TROP2 CAR on monocytes triggers antigen-dependent cytotoxicity and cytokine release. In tumor bearing mice and cynomolgus monkeys, the TROP2 CAR mRNA/LNP are primarily expressed by myeloid cells. In a mouse xenograft model, intravenous administration of TROP2 CAR mRNA/LNP results in tumor growth inhibition and in a B16/F10-OVA immunocompetent melanoma mouse model, anti-tumor efficacy of a gp75-specific CAR correlates with increased number of activated T cells, activation of dendritic cells and a humoral response against B16/F10-OVA melanoma tumors.

Discussions

These findings demonstrate that myeloid cells can be directly engineered in vivo to kill tumor cells and orchestrate an adaptive immune response and guide clinical studies for the treatment of solid tumors.

CAR T Cells and T-Cell Therapies for Cancer: A Translational Science Review

Importance

Chimeric antigen receptor (CAR) T cells are T lymphocytes that are genetically engineered to express a synthetic receptor that recognizes a tumor cell surface antigen and causes the T cell to kill the tumor cell. CAR T treatments improve overall survival for patients with large B-cell lymphoma and progression-free survival for patients with multiple myeloma.

Observations

Six CAR T-cell products are approved by the US Food and Drug Administration (FDA) for 6 hematologic malignancies: B-cell acute lymphoblastic leukemia, large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, chronic lymphocytic leukemia, and multiple myeloma. Compared with standard chemotherapy followed by stem cell transplant, CAR T cells improved 4-year overall survival in patients with large B-cell lymphoma (54.6% vs 46.0%). Patients with pediatric acute lymphoblastic leukemia achieved durable remission after CAR T-cell therapy. At 3-year follow-up, 48% of patients were alive and relapse free. In people with multiple myeloma treated previously with 1 to 4 types of non-CAR T-cell therapy, CAR T-cell therapy prolonged treatment-free remissions compared with standard treatments (in 1 trial, CAR T-cell therapy was associated with progression-free survival of 13.3 months compared with 4.4 months with standard therapy). CAR T-cell therapy is associated with reversible acute toxicities, such as cytokine release syndrome in approximately 40% to 95% of patients, and neurologic disorders in approximately 15% to 65%. New CAR T-cell therapies in development aim to increase efficacy, decrease adverse effects, and treat other types of cancer. No CAR T-cell therapies are FDA approved for solid tumors, but recently, 2 other T lymphocyte-based treatments gained approvals: 1 for melanoma and 1 for synovial cell sarcoma. Additional cellular therapies have attained responses for certain solid tumors, including pediatric neuroblastoma, synovial cell sarcoma, melanoma, and human papillomavirus-associated cancers. A common adverse effect occurring with these T lymphocyte-based therapies is capillary leak syndrome, which is characterized by fluid retention, pulmonary edema, and kidney dysfunction.

Conclusions and Relevance

CAR T-cell therapy is an FDA-approved therapy that has improved progression-free survival for multiple myeloma, improved overall survival for large B-cell lymphoma, and attained high rates of cancer remission for other hematologic malignancies such as acute lymphoblastic leukemia, follicular lymphoma, and mantle cell lymphoma. Recently approved T lymphocyte-based therapies demonstrated the potential for improved outcomes in solid tumor malignancies.

CAR T Cell Nanosymbionts: Revealing the Boundless Potential of a New Dyad

Cancer treatment has traditionally focused on eliminating tumor cells but faces challenges such as resistance and toxicity. A promising direction involves targeting the tumor microenvironment using CAR T cell immunotherapy, which has shown potential for treating relapsed and refractory cancers but is limited by high costs, resistance, and toxicity, especially in solid tumors. The integration of nanotechnology into ICAM cell therapy, a concept we have named "CAR T nanosymbiosis", offers new opportunities to overcome these challenges. Nanomaterials can enhance CAR T cell delivery, manufacturing, activity modulation, and targeting of the tumor microenvironment, providing better control and precision. This approach aims to improve the efficacy of CAR T cells against solid tumors, reduce associated toxicities, and ultimately enhance patient outcomes. Several studies have shown promising results, and developing this therapy further is essential for increasing its accessibility and effectiveness. Our "addition by subtraction model" synthesizes these multifaceted elements into a unified strategy to advance cancer treatment paradigms.

Nanoparticle-mediated universal CAR-T therapy

In recent years, chimeric antigen receptor (CAR)-T cell therapy has been highly successful in treating hematological malignancies, leading to significant advancements in the cancer immunotherapy field. However, the typical CAR-T therapy necessitates the enrichment of patients' own leukocytes for ex vivo production of CAR-T cells, this customized pattern requires a complicated and time-consuming manufacturing procedure, making it costly and less accessible. The off-the-shelf universal CAR-T strategy could reduce manufacturing costs and realize timely drug administration, presenting as an ideal substitute for typical CAR-T therapy. Utilizing nanocarriers for targeted gene delivery is one of the approaches for the realization of universal CAR-T therapy, as biocompatible and versatile nanoparticles could deliver CAR genes to generate CAR-T cells in vivo. Nanoparticle-mediated in situ generation of CAR-T cells possesses multiple advantages, including lowered cost, simplified manufacturing procedure, and shortened administration time, this strategy is anticipated to provide a potentially cost-effective alternative to current autologous CAR-T cell manufacturing, thus facilitating the prevalence and improvement of CAR-T therapy.

Construction and characterization of a novel secreted MsC-CAR-T cell in solid tumors

The CD47-SIRPα signaling has been acknowledged as a significant immune checkpoint and CD47 blocking has been proved as a potential therapeutic strategy for the treatment of solid tumor. However, the potential application of CAR-T cells secreted antibody fragment simultaneously in solid tumor is rarely explored. In this study, we searched bioinformatic databases and investigated the characteristics of CD47 in solid tumors. Then we consulted bioinformatic databases to design, optimize and construct a novel MsC-CAR which could target MAGE-A1 and self-secrete CD47-scFv. The engineering T cells containing MsC-CAR were transfected, verified and characterized. The tumor-inhibitory role of MsC-CART cells was further determined in vitro and in vivo. The results showed that MsC-CARs were successfully constructed and MsC1-CARs demonstrated the preferable features of recognizing MAGE-A1 and secreting CD47-scFv. Engineering T cells transfecting with MsC1-CAR (MsC1-CART cells) exerted the prominent tumor-inhibitory effectiveness, both in different cancer cell lines and LUAD xenograft tumors. The present data highlighted that MsC1-CART cells elaborately combined the adoptive cellular immunotherapy and immune checkpoint inhibitor therapy, may represent a new direction for the treatment of MAGE-A1 positive solid tumors.

Mechanisms underlying dose-limiting toxicities of conventional chemotherapeutic agents

Dose-limiting toxicities (DLTs) are severe adverse effects that define the maximum tolerated dose of a cancer drug. In addition to the specific mechanisms of each drug, common contributing factors include inflammation, apoptosis, ion imbalances, and tissue-specific enzyme deficiencies. Among various DLTs are bleomycin-induced pulmonary fibrosis, doxorubicin-induced cardiomyopathy, cisplatin-induced nephrotoxicity, methotrexate-induced hepatotoxicity, vincristine-induced neurotoxicity, paclitaxel-induced peripheral neuropathy, and irinotecan, which elicits severe diarrhea. Currently, specific treatments beyond dose reduction are lacking for most toxicities. Further research on cellular and molecular pathways is imperative to improve their management. This review synthesizes preclinical and clinical data on the pharmacological mechanisms underlying DLTs and explores possible treatment approaches. A comprehensive perspective reveals knowledge gaps and emphasizes the need for future studies to develop more targeted strategies for mitigating these dose-dependent adverse effects. This could allow the safer administration of fully efficacious doses to maximize patient survival.

[Claudine 18.2: A new therapeutic target in digestive cancers]

Therapies targeting HER2 and immune checkpoint inhibitors have improved survival in patients with metastatic gastric or gastro-oesophageal junction adenocarcinoma, but the prognosis associated with these cancers remains poor. Claudin 18.2 is a tight junction protein expressed in the oeso-gastric mucosa. Some gastric and gastro-oesophageal junction adenocarcinoma overexpress this protein, as well as some pancreatic, ovarian and pulmonary cancers. In pathological context, its epitope may be exposed at the surface of cells and therefore makes it an interesting therapeutic target. Zolbetuximab, a monoclonal antibody targeting claudin 18.2, showed a survival benefit in first line metastatic treatment in patients with claudin 18.2 positive gastric and gastro-oesophageal junction adénocarcinoma, in two phase III studies. CAR T-cells specifically targeting this protein have also shown promising efficacy from the second line of treatment. Considering the probable impact of the expression status of claudin 18.2 in future treatment algorithms, this review aims to present the pathophysiology underlying the targeting of claudin 18.2, summarize state of the art results of anti-claudin 18.2 therapies and discuss future challenges for the management of patients with claudin 18.2 positive gastric and gastro-oesophageal junction adenocarcinoma.

Advances in cell therapy: progress and challenges in hematological and solid tumors

Cell-based therapies harness the endogenous ability of the immune system to fight cancer and have shown promising results in the treatment of hematological malignancies. However, their clinical application beyond B cell malignancies is hampered by numerous hurdles, ranging from relapsed disease to a hostile tumor microenvironment (TME). Recent advances in cell engineering and TME modulation may expand the applicability of these therapies to a wider range of cancers, creating new treatment possibilities. Breakthroughs in advanced gene editing and sophisticated cell engineering, have also provided promising solutions to longstanding challenges. In this review, we examine the challenges and future directions of the most prominent cell-based therapies, including chimeric antigen receptor (CAR)-T cells, tumor-infiltrating lymphocytes (TILs), and natural killer (NK) cells, and emerging modalities. We provide a comprehensive analysis of emerging cell types and combination strategies translated into clinical trials, offering insights into the next generation of cell-based cancer treatments.

CAR T-cells for pediatric solid tumors: where to go from here?

Despite the great success that chimeric antigen receptor (CAR) T-cells have had in patients with B-cell malignancies and multiple myeloma, they continue to have limited efficacy against most solid tumors. Especially in the pediatric population, pre- and post-treatment biopsies are rarely performed due to ethical reasons, and thus, our understanding is still very limited regarding the mechanisms in the tumor microenvironment by which tumor cells exclude effectors and attract immune-suppressive cells. Nevertheless, based on the principles that are known, current T-cell engineering has leveraged some of these processes and created more potent CAR T-cells. The recent discovery of new oncofetal antigens and progress made in CAR design have expanded the potential pool of candidate antigens for therapeutic development. The most promising approaches to enhance CAR T-cells are novel CAR gating strategies, creative ways of cytokine delivery to the TME without enhancing systemic toxicity, and hijacking the chemokine axis of tumors for migratory purposes. With these new modifications, the next step in the era of CAR T-cell development will be the clinical validation of these promising preclinical findings.