Efficacy Of CAR-T Research Articles

Management of Secondary Immunodeficiency Following T-Cell-Engaging Immunotherapeutic Agents in B-Cell Non-Hodgkin Lymphoma: Implications for Early-Line Treatment Strategies

Anti-CD19 chimeric antigen receptor (CAR) T-cell and anti-CD20 bispecific antibody therapies (BsAbs) are rapidly moving to earlier treatment lines for patients with B-cell non-Hodgkin lymphoma (B-NHL). The rapid pace of the advancement of these T-cell-engaging therapies is juxtaposed by a lack of a comprehensive understanding of the scope and kinetics of immunodeficiency following these treatments. We review emerging studies detailing the safety and efficacy of CD19 CAR-T and CD20 BsAbs in earlier lines for B-NHL, as well as a discussion of the limited knowledge of immune recovery following these treatments. We integrate the limited consensus prevention and management recommendations, advocating that the management of secondary immunodeficiency following these transformative therapies is an urgent unmet need in immune oncology research. A collaboration between hematologists/oncologists and immunologists in the management of these patients is critical to optimize patient care.

Preclinical assessment of the efficacy of B7-H3 CAR-T in renal cell carcinoma

B7-H3 is a type I transmembrane protein that belongs to the B7 immune checkpoint protein family, is aberrantly expressed in cancer cells, but rarely expressed in normal tissues, making it an attractive target for cancer therapy. Here, we found B7-H3 is highly expressed in the renal cell carcinoma (RCC) tumor tissues and RCC cell lines, but is undetectable in normal renal tissues. Therefore, we engineered second-generation CAR-T cells targeting B7-H3, incorporating either CD28 or 4–1BB co-stimulatory domains. Both CAR-T cell variants demonstrated potent antitumor activity against RCC tumors in vitro and in metastatic and orthotopic RCC mouse models. Furthermore, the B7-H3 CAR-T cells exhibited remarkable proliferation and robust cytokine release when co-cultured with RCC cancer cells. These findings demonstrated that targeting B7-H3 by CAR-T cells potentially offering a new treatment option for RCC patients.

Tigit: The Potential Mechanisms of Relapse in Multiple Myeloma Following Anti-BCMA CAR-T Therapy and a Promising Target for Improving CAR-T Efficacy

Tigit: The Potential Mechanisms of Relapse in Multiple Myeloma Following Anti-BCMA CAR-T Therapy and a Promising Target for Improving CAR-T Efficacy

Afatinib boosts CAR-T cell antitumor therapeutic efficacy via metabolism and fate reprogramming

BackgroundChimeric antigen receptor T (CAR-T) cell therapy has been shown remarkable efficacy in the treatment of hematological malignancies in recent years. However, a considerable proportion of patients would experience tumor...

Role of bridging RT in relapsed/refractory diffuse large B-cell lymphoma undergoing CAR-T therapy: a multicenter study.

The optimization of bridging regimen before chimeric antigen receptor (CAR)-T cell therapy in diffuse large B-cell lymphoma (DLBCL) may impact CAR-T efficacy and outcome. This retrospective study evaluates CAR-T outcome after bridging with radiotherapy (RT) and other bridging strategies. Among 148 patients with relapsed/refractory DLBCL who underwent leukapheresis for CAR-T manufacturing, 31 received RT-bridging, 84 chemotherapy (CT), 33 no-bridging or steroid-only. CAR-T cell were infused in 96.8% of RT-group, 89.2% of CT-group and 78.8% of no-bridge-group (p = 0.079). Response to bridging was generally poor, but patients receiving RT had a significant reduction in LDH levels between pre- and post-bridging (p = 0.05). The one-year PFS was 51.2% in the RT-group, 28.2% in the CT-group, and 47.6% in the no-bridge-group (p = 0.044, CT-bridging vs RT-bridging); 1-year OS was 86.7% in the RT-group, 52.7% in the CT-group and 69% in the no-bridge-group (p = 0.025, CT-bridging vs RT-bridging). We observed a higher incidence of ICANS in patients who received CT than in others (20.0% CT-group, 3.3% RT-group, 7.7% no-bridge group; p = 0.05). In conclusion, RT-bridging is associated with lower drop-out rate and CAR-T toxicity, and it might be preferred to other bridging strategies for patients with localized disease or for those with one prevalent symptomatic site.

A Customizable Platform to Integrate CAR and Conditional Expression of Immunotherapeutics in T Cells.

The potential of chimeric antigen receptor (CAR)-based immunotherapy as a promising therapeutic approach is often hindered by the presence of highly immunosuppressive tumor microenvironments (TME). Combination therapies with either co-administration or built-in expression of additional TME-modulating therapeutic molecules to potentiate the functions of CAR-T cells can cause systemic toxicities due to the lack of control over the delivery of biologics. Here, we present a proof-of-concept engineered platform in human Jurkat T cells that combines CAR with a therapeutic gene circuit capable of sensing β-galactosidase (a reported cancer-associated signal) and subsequently activate the production of customized therapeutic gene products. We have demonstrated the integration of the chemically induced proximity (CIP) and associated signal sensing technologies with CAR in this study. A β-galactosidase-activatable prodrug was designed by conjugating a galactose moiety with a CIP inducer abscisic acid (ABA). We showed that Jurkat T cells engineered with CAR and the ABA-inducible genetic circuits can respond to recombinant β-galactosidase to drive the production and secretion of various immunotherapeutics including an anti-cancer agent, an immunomodulatory cytokine, and immune checkpoint inhibitors. Our design is highly modular and could be adapted to sense different cancer-related signals to locally produce antitumor therapeutics that can potentially boost CAR-T efficacy and persistence.

Mesenchymal stem cell infusion for enhancing hematopoietic recovery and addressing cytopenias in CAR-T cell therapy

BackgroundChimeric antigen receptor (CAR)-T therapy has emerged as a promising treatment for hematologic malignancies. However, cytopenia remains one of the most frequent and challenging adverse effects of this therapy.MethodsWe conducted a retrospective analysis of 26 patients with relapsed/refractory aggressive B-cell lymphoma who received CAR-T therapy at our center. Subsequently, to investigate measures to address cytopenias following CAR-T therapy, we isolated and generated murine CAR-T cells and bone marrow-derived mesenchymal stem cells (MSCs), establishing a murine syngeneic CAR-T therapy model. We assessed the impact of MSC infusion on hematopoietic recovery post-CAR-T therapy by evaluating complete blood count, bone marrow hematopoietic stem cells and their subpopulations, bone marrow histomorphology, and hematopoiesis-related genes.ResultsAll patients experienced cytopenias to varying degrees, with complete lineage involvement in half of the patients. Grade ≥ 3 cytopenias were observed in 88.46% of the patients. CAR-T therapy was associated with a higher incidence of biphasic, late-onset, or prolonged cytopenias. Survival analysis indicated that neutropenia and lymphopenia tended to be associated with better prognosis, whereas thrombocytopenia tended to be related to poorer outcomes. Through animal experiments, we discovered that MSCs infusion boosted HSCs and their long-term subpopulations, enhancing hematopoietic recovery, particularly in the megakaryocyte lineage, and mitigating bone marrow damage. Importantly, both in vitro and in vivo experiments demonstrated that MSCs did not compromise the activity or antitumor efficacy of CAR-T cells.ConclusionsOur findings propose MSCs infusion as a promising strategy to address cytopenias, particularly thrombocytopenia, after CAR-T therapy. This approach could help overcome certain limitations of cellular immunotherapy by enhancing hematopoietic recovery without compromising the efficacy of CAR-T cells.HighlightsCytopenia is a frequently observed adverse effect following CAR-T therapy, and it is often characterized by biphasic and prolonged patterns.MSCs play a critical role in promoting hematopoietic recovery and mitigating bone marrow damage in a murine model of CAR-T therapyThe activity and antitumor efficacy of CAR-T cells were not impaired by MSCs.Graphical

Histone marks identify novel transcription factors that parse CAR-T subset-of-origin, clinical potential and expansion.

Chimeric antigen receptor-modified T cell (CAR-T) immunotherapy has revolutionised blood cancer treatment. Parsing the genetic underpinnings of T cell quality and CAR-T efficacy is challenging. Transcriptomics inform CAR-T state, but the nature of dynamic transcription during activation hinders identification of transiently or minimally expressed genes, such as transcription factors, and over-emphasises effector and metabolism genes. Here we explore whether analyses of transcriptionally repressive and permissive histone methylation marks describe CAR-T cell functional states and therapeutic potential beyond transcriptomic analyses. Histone mark analyses improve identification of differences between naïve, central memory, and effector memory CD8 + T cell subsets of human origin, and CAR-T derived from these subsets. We find important differences between CAR-T manufactured from central memory cells of healthy donors and of patients. By examining CAR-T products from a clinical trial in lymphoma (NCT01865617), we find a novel association between the activity of the transcription factor KLF7 with in vivo CAR-T accumulation in patients and demonstrate that over-expression of KLF7 increases in vitro CAR-T proliferation and IL-2 production. In conclusion, histone marks provide a rich dataset for identification of functionally relevant genes not apparent by transcriptomics.

Parametric optimization and comparative study of machine learning and deep learning algorithms for breast cancer diagnosis.

Breast Cancer is the leading form of cancer found in women and a major cause of increased mortality rates among them. However, manual diagnosis of the disease is time-consuming and often limited by the availability of screening systems. Thus, there is a pressing need for an automatic diagnosis system that can quickly detect cancer in its early stages. Data mining and machine learning techniques have emerged as valuable tools in developing such a system. In this study we investigated the performance of several machine learning models on the Wisconsin Breast Cancer (original) dataset with a particular emphasis on finding which models perform the best for breast cancer diagnosis. The study also explores the contrast between the proposed ANN methodology and conventional machine learning techniques. The comparison between the methods employed in the current study and those utilized in earlier research on the Wisconsin Breast Cancer dataset is also compared. The findings of this study are in line with those of previous studies which also highlighted the efficacy of SVM, Decision Tree, CART, ANN, and ELM ANN for breast cancer detection. Several classifiers achieved high accuracy, precision and F1 scores for benign and malignant tumours, respectively. It is also found that models with hyperparameter adjustment performed better than those without and boosting methods like as XGBoost, Adaboost, and Gradient Boost consistently performed well across benign and malignant tumours. The study emphasizes the significance of hyperparameter tuning and the efficacy of boosting algorithms in addressing the complexity and nonlinearity of data. Using the Wisconsin Breast Cancer (original) dataset, a detailed summary of the current status of research on breast cancer diagnosis is provided.

Mapping Transmission Dynamics and Drug Resistance Surveillance in the Cyprus HIV-1 Epidemic (2017-2021).

The human immunodeficiency virus type 1 (HIV-1) epidemic has been a major public health threat on a global scale since the early 1980s. Despite the introduction of combination antiretroviral therapy (cART), the incidence of new HIV-1 infections continues to rise in some regions around the world. Thus, with the continuous transmission of HIV-1 and the lack of a cure, it is imperative for molecular epidemiological studies to be performed, to monitor the infection and ultimately be able to control the spread of this virus. This work provides a comprehensive molecular epidemiological analysis of the HIV-1 infection in Cyprus, through examining 305 HIV-1 sequences collected between 9 March 2017 and 14 October 2021. Employing advanced statistical and bioinformatic techniques, the research delved deeply into understanding the transmission dynamics of the HIV-1 epidemic in Cyprus, as well as the monitoring of HIV-1's genetic diversity and the surveillance of transmitted drug resistance. The characterization of Cyprus's HIV-1 epidemic revealed a diverse landscape, comprising 21 HIV-1 group M pure subtypes and circulating recombinant forms (CRFs), alongside numerous uncharacterized recombinant strains. Subtypes A1 and B emerged as the most prevalent strains, followed by CRF02_AG. The findings of this study also revealed high levels of transmitted drug resistance (TDR) patterns, raising concerns for the efficacy of cART. The demographic profiles of individuals involved in HIV-1 transmission underscored the disproportionate burden borne by young to middle-aged Cypriot males, particularly those in the MSM community, who reported contracting the virus in Cyprus. An assessment of the spatiotemporal evolutionary dynamics illustrated the global interconnectedness of HIV-1 transmission networks, implicating five continents in the dissemination of strains within Cyprus: Europe, Africa, Asia, North America, and Oceania. Overall, this study advances the comprehension of the HIV-1 epidemic in Cyprus and highlights the importance of understanding HIV-1's transmission dynamics through continuous surveillance efforts. Furthermore, this work emphasizes the critical role of state-of-the-art bioinformatics analyses in addressing the challenges posed by HIV-1 transmission globally, laying the groundwork for public health interventions aimed at curbing its spread and improving patient outcomes.

Dual targeting chimeric antigen receptor cells enhance antitumour activity by overcoming T cell exhaustion in pancreatic cancer.

Although our previous data indicated that claudin 18 isoform 2 (CLDN18.2)-targeted chimeric antigen receptor(CAR)T cells displayed remarkable clinical efficacy in CLDN18.2-positive gastric cancer, their efficacy is limited in pancreatic ductal adenocarcinoma (PDAC). The tumour microenvironment (TME) is one of the main obstacles to the efficacy of CAR-T and remodelling the TME may be a possible way to overcome this obstacle. The TME of PDAC is characterized by abundant cancer-related fibroblasts (CAFs), which hinder the infiltration and function of CLDN18.2-targeted CAR-T cells. The expression of fibroblast activation protein alpha (FAP) is an important feature of active CAFs, providing potential targets for eliminating CAFs. In this study, we generated 10 FAP/CLDN 18.2 dual-targeted CAR-T cells and evaluated their anti-tumour ability in vitro and in vivo. Compared with conventional CAR-T cells, some dual-targeted CAR-T cells showed improved therapeutic effects in mouse pancreatic cancers. Further, dual-targeted CAR-T cells with better anti-tumour effect could suppress the recruitment of myeloid-derived suppressor cells (MDSCs) to improve the immunosuppressive TME, which contributes to the survival of CD8+ T cells. Moreover, dual-targeted CAR-T cells reduced the exhaustion of T cells in transforming TGF-β dependent manner. The dual-targeted CAR-T cells obtained enhancement of T effector function, inhibition of T cell exhaustion, and improvement of tumour microenvironment. Our findings provide a theoretical rationale for dual-targeted FAP/CLDN 18.2 CAR-T cells therapy in PDAC.

C-JUN overexpressing CAR-T cells in acute myeloid leukemia: preclinical characterization and phase I trial

Chimeric antigen receptor (CAR) T cells show suboptimal efficacy in acute myeloid leukemia (AML). We find that CAR T cells exposed to myeloid leukemia show impaired activation and cytolytic function, accompanied by impaired antigen receptor downstream calcium, ZAP70, ERK, and C-JUN signaling, compared to those exposed to B-cell leukemia. These defects are caused in part by the high expression of CD155 by AML. Overexpressing C-JUN, but not other antigen receptor downstream components, maximally restores anti-tumor function. C-JUN overexpression increases costimulatory molecules and cytokines through reinvigoration of ERK or transcriptional activation, independent of anti-exhaustion. We conduct an open-label, non-randomized, single-arm, phase I trial of C-JUN-overexpressing CAR-T in AML (NCT04835519) with safety and efficacy as primary and secondary endpoints, respectively. Of the four patients treated, one has grade 4 (dose-limiting toxicity) and three have grade 1–2 cytokine release syndrome. Two patients have no detectable bone marrow blasts and one patient has blast reduction after treatment. Thus, overexpressing C-JUN endows CAR-T efficacy in AML.

Autologous transplant vs. CAR-T therapy in patients with DLBCL treated while in complete remission

In patients with relapsed DLBCL in complete remission (CR), autologous hematopoietic cell transplantation (auto-HCT) and CAR-T therapy are both effective, but it is unknown which modality provides superior outcomes. We compared the efficacy of auto-HCT vs. CAR-T in patients with DLBCL in a CR. A retrospective observational study comparing auto-HCT (2015–2021) vs. CAR-T (2018–2021) using the Center for International Blood & Marrow Transplant Research registry. Median follow-up was 49.7 months for the auto-HCT and 24.7 months for the CAR-T cohort. Patients ages 18 and 75 with a diagnosis of DLBCL were included if they received auto-HCT (n = 281) or commercial CAR-T (n = 79) while in a CR. Patients undergoing auto-HCT with only one prior therapy line and CAR-T patients with a previous history of auto-HCT treatment were excluded. Endpoints included Progression-free survival (PFS), relapse rate, non-relapse mortality (NRM) and overall survival (OS). In univariate analysis, treatment with auto-HCT was associated with a higher rate of 2-year PFS (66.2% vs. 47.8%; p < 0.001), a lower 2-year cumulative incidence of relapse (27.8% vs. 48% ; p < 0.001), and a superior 2-year OS (78.9% vs. 65.6%; p = 0.037). In patients with early (within 12 months) treatment failure, auto-HCT was associated with a superior 2-year PFS (70.9% vs. 48.3% ; p < 0.001), lower 2-year cumulative incidence of relapse (22.8% vs. 45.9% ; p < 0.001) and trend for higher 2-year OS (82.4% vs. 66.1% ; p = 0.076). In the multivariable analysis, treatment with auto-HCT was associated with a superior PFS (hazard ratio 1.83; p = 0.0011) and lower incidence of relapse (hazard ratio 2.18; p < 0.0001) compared to CAR-T. In patients with relapsed LBCL who achieve a CR, treatment with auto-HCT is associated with improved clinical outcomes compared to CAR-T. These data support the consideration of auto-HCT in select patients with LBCL achieving a CR in the relapsed setting.

Multidimensional analysis reveals predictive markers for CAR-T efficacy.

Multidimensional analysis reveals predictive markers for CAR-T efficacy.

Efficacy and safety of bendamustine-containing bridging therapy in R/R LBCL patients receiving CD19 CAR T-cells.

Bridging therapy (BT) after leukapheresis is required in most relapsed/refractory (R/R) large B-cell lymphoma (LBCL) patients receiving chimeric antigen receptor (CAR) T cells. Bendamustine-containing regimens are a potential BT option. We aimed to assess if this agent had a negative impact on CAR-T outcomes when it was administered as BT. We included R/R LBCL patients from six centers who received systemic BT after leukapheresis from February 2019 to September 2022; patients who only received steroids or had pre-apheresis bendamustine exposure were excluded. Patients were dividedinto two BT groups, with and without bendamustine. Separate safety and efficacy analyses were carried out for axi-cel and tisa-cel. Of 243 patients who received BT, bendamustine (benda) was included in 62 (26%). There was a higher rate of BT progressors in the non-benda group (62% vs. 45%, p = 0.02). Concerning CAR-T efficacy, complete responses were comparable for benda versus non-benda BT cohorts with axi-cel (70% vs. 53%, p = 0.12) and tisa-cel (44% vs. 36%, p = 0.70). Also, 12-month progression-free and overall survival were not significantly different between BT groups with axi-cel (56% vs. 43% and 71% vs. 63%) and tisa-cel (25% vs. 26% and 52% vs. 48%); there were no differences when BT response was considered. CAR T-cell expansion for each construct was similar between BT groups. Regarding safety, CRS G ≥3 (6% vs. 6%, p = 0.79), ICANS G ≥3 (15% vs. 17%, p = 0.68), severe infections, and neutropenia post-infusion were comparable among BT regimens. BT with bendamustine-containing regimens is safe for patients requiring disease control during CAR T-cell manufacturing.

IMMU-22. B7-H3 NANOBODY CAR-T AND SOLUBLE TREM2 GENETICALLY ENGINEERED MYELOID CELL THERAPY IN MURINE SYNGENEIC GLIOBLASTOMA

Abstract BACKGROUND Myeloid immunosuppression can be a major impediment to CAR-T cell therapy for CNS tumors. Importantly, CAR-T cells are often evaluated in immunocompromised mice which cannot accurately recapitulate the tumor immune response or tumor microenvironment. CNS tumor macrophages express TREM2, an important driver of immunosuppression. This study combines B7-H3 targeting nanobody CAR-T cells which are cross reactive in humans and mice (currently being evaluated for clinical development) with genetically engineered myeloid cells (GEMys) expressing soluble TREM2 (sTREM2) in a syngeneic mouse model of glioblastoma (GBM), with the aim of blocking TREM2-mediated immunosuppression to enhance CAR-T cell function. METHODS Syngeneic murine GBM, designed to mimic human GBM and generated at the Center for Advanced Preclinical Research (CAPR), was used for all studies. B7-H3 nanobody CAR-T cells were generated from mouse splenic T cells. In vitro tumor killing assays were performed by xCELLigence. sTREM2 GEMys were generated from bone marrow progenitor cells using lentiviral transduction. For in vivo studies, mice underwent orthotopic implantation of tumors and placement of an MRI-compatible, permanent catheter-port system for serial intracerebroventricular (ICV) administration of cell therapies. Mice were treated with CAR-T and/or GEMy therapies, evaluated weekly for tumor burden by MRI, and were monitored for survival. RESULTS Syngeneic GBM expression of B7-H3 was confirmed by flow cytometry, immunofluorescence, and western blot. B7-H3 nanobody CAR-T cells demonstrated effective killing of GBM by xCELLigence. sTREM2 GEMys were successfully generated and confirmed to produce sTREM2. Cell therapies were successfully infused ICV via the implanted catheter-port system, demonstrating safety and feasibility of this model for serial ICV cellular therapy. CONCLUSIONS B7-H3 nanobody CAR-T cells were validated against syngeneic GBM, and we have demonstrated safety and feasibility of ICV catheter administration of cellular therapies in vivo. Future studies will continue to evaluate in vivo timing and efficacy of CAR-T and GEMy therapy.

A Review of CAR-T Combination Therapies for Treatment of Gynecological Cancers.

CAR-T cell therapy offers a promising way for prolonged cancer remission, specifically in the case of blood cancers. However, its application in the treatment of solid tumors still faces many limitations. This review paper provides a comprehensive overview of the challenges and strategies associated with CAR-T cell therapy for solid tumors, with a focus on gynecological cancer. This study discusses the limitations of CAR-T therapy for solid tumor treatment, such as T cell exhaustion, stromal barrier, and antigen shedding. Additionally, it addresses possible approaches to increase CAR-T efficacy in solid tumors, including combination therapies with checkpoint inhibitors and chemotherapy, as well as the novel approach of combining CAR-T with oncolytic virotherapy. Given the lack of comprehensive research on CAR-T combination therapies for treating gynecological cancers, this review aims to provide insights into the current landscape of combination therapies for solid tumors and highlight the potential of such an approach in gynecology.

Cell-based medicinal products: a review of current research

INTRODUCTION. Cell therapies and tissue-engineered products are aimed at patients with severe conditions (genetic and neurodegenerative disorders, cancers, musculoskeletal injuries, burns, etc.) that lack alternative treatment options. Analysis of clinical efficacy data on cellbased medicinal products is important for understanding their translational potential in personalised medicine.AIM. This study aimed to review key trends in cell therapy, analyse data on approved cell therapies and tissue-engineered products, and assess challenges and prospects for their use.DISCUSSION. This article analyses data on the composition of cell therapies and tissue-engineered products, indications for their use, and the results of clinical studies. Cell-based medicinal products are derived from autologous or allogeneic mesenchymal and limbal stem cells, epithelial cells, chondrocytes, native or genetically engineered haematopoietic stem cells, genetically engineered lymphocytes (CAR-T, CAR-NK), etc. Medicinal products based on cell technologies have been approved in many countries, including the USA (approximately 30), the European Union (approximately 20), Japan (18), South Korea (15), etc. As of today, two cell therapies have been granted marketing authorisation in the Russian Federation. The first is based on CAR-T cells (a gene therapy product), and the other is based on chondrocytes (a cell-based medicinal product); the latter has been developed in Russia. The main advantages of cell therapy products include higher efficacy and fewer adverse drug reactions in comparison with standard treatment modalities. The main challenges of cell therapy include the risks of immune reactions and mutagenesis associated with lentiviral vectors or CRISPR/Cas9 technology, as well as limited efficacy of CAR-T and CAR-NK cells due to immunosuppressive properties of tumour microenvironment.CONCLUSIONS. In comparison with conventional treatment approaches, the use of cell therapies and tissue-engineered products can help effectively eliminate defects in various body tissues, avoid highly invasive surgical interventions, and reduce regeneration time. Thus, ensuring development of similar but at the same time more affordable Russian medicinal products can bring great benefits for the healthcare system of the Russian Federation.

Enhanced anti-ovarian cancer efficacy with MSLN-chimeric antigen receptor T cells secreting anti-CD39 antibody.

e17553 Background: The effectiveness of chimeric antigen receptor (CAR) T cell therapy directed at mesothelin (MSLN) in solid tumors, such as ovarian cancer, is hindered by the immunosuppressive tumor microenvironment (TME), where adenosine plays a crucial role in impairing CAR-T cell function. Preclinical and clinical studies have demonstrated that targeting CD39, a pivotal enzyme catalyzing the conversion of extracellular ATP into adenosine, yields significant antitumor effects. Therefore, combining MSLN CAR-T with an anti-CD39 antibody emerges as a potential therapeutic strategy against cancer. Methods: We have previously designed OriA631, an antibody antagonist targeting CD39 in VHH format. Our preclinical investigation has highlighted the outstanding potential of OriA631, showcasing superior performance in binding affinity, effective inhibition of CD39 enzyme activity, and remarkable in vivo high anti-tumor efficacy. Subsequently, we undertook further engineering of MSLN CAR-T cells to secrete the VHH component of OriA631 (MSLN CAR-T-CD39-VHH) and systematically assessed its antitumor effects in NSG mice. Results: Our data reveals that MSLN CAR-T cells exhibit a significant upregulation of CD39 upon activation by ovarian cancer cells in both in vitro and in the tumor microenvironment (TME). To assess the combined effect of MSLN CAR-T with anti-CD39, B-NDG mice were subcutaneously inoculated with 3x10^6 ovarian cancer cells (SKOV3-MSLNhi-CD39hi). Subsequently, different T cells (1x10^7 cells/mouse) were injected when the tumor reached around 80 mm³, and the groups were divided into Mock T, MSLN CAR-T, MSLN CAR-T-CD39-VHH, and MSLN CAR-T in combination with locally injected CD39 Ab (OriA631). The data demonstrated that MSLN CAR-T inhibited tumor growth from approximately 1000mm³ (Mock T group) to 300mm³ at day 30 relative to T cell injection. Tumors in the MSLN CAR-T in combination with OriA631 group were around 100mm³, suggesting a significant combination anti-tumor efficacy of MSLN CAR-T in conjunction with CD39 targeting. Furthermore, MSLN CAR-T-CD39-VHH, where MSLN CAR-T cells secrete the VHH component of OriA631, completely eliminated the tumor at day 18 with no relapse during the experimental period. This result underscores the superior anti-tumor efficacy of MSLN CAR-T-CD39-VHH, with the high level of VHH component of CD39 Ab observed in the TME. Importantly, the low or undetectable level of VHH component of CD39 Ab in the serum also indicates the safety of the product. Conclusions: Our study introduces the innovative therapeutic agent MSLN CAR-T-CD39-VHH, showcasing superior anti-tumor efficacy and the potential for reduced antibody-associated side effects. These findings strongly endorse the application of MSLN CAR-T-CD39-VHH as a promising and impactful therapeutic approach for the treatment of ovarian cancer.

Phase I trial of hypoxia-responsive CEA CAR-T cell therapy in patients with heavily pretreated solid tumor via intraperitoneal or intravenous transfusion.

3514 Background: Chimeric antigen receptor (CAR) T cell therapy has been successful in hematologic malignancies but not in solid tumors. Homing capacity and tumor microenvironment are key issues to limit CAR-T efficacy to solid tumors. Our previous study has shown that hypoxia-responsive CAR-T cells exhibit reduced exhaustion and enhanced efficacy in solid tumors (Cancer Res 2024). Here, we aimed to optimize the administration route by comparing safety and efficacy of our newly established CEA CAR-T through intraperitoneal (I.P.) and intravenous (I.V.) infusions in solid tumor patients who failed to standard therapy. Methods: In this phase I, open-label, dose-escalation clinical trial, eligible patients were CEA positive and relapsed or refractory to at least second-line treatment. CAR-T cells was administered via I.P. or I.V. with dose escalation including low dose of 1-3 x106 CAR+/kg and high dose of 4-6 x106 CAR+/kg. Adverse events were graded by CTCAE 5.0. Tumor responses were evaluated using RECIST 1.1. Results: Between June 2022 to Jan 2024,40 pts were enrolled and infused CAR-T cells, including 35 CRC pts, 3 GC pts, 1 NSCLC pts and 1 BTC pts. There were 16 pts in the I.P. group and 24 pts in the I.V. group. CRS was observed in 62.5% of the pts at grade 1-2, and no ICANS or treatment related death was reported. Grade 1-2 mucositis was reported in 25% of the patients. Immune-mediated diarrhea and colitis of all grades occurred in 32.5% of the patients, including 17.5% grade 3 events. And 100% of patients experienced grade 3-4 hematologic toxicity. In terms of efficacy, the I.P. group displayed a higher objective response rate (ORR) of 25% (4/16), compared to 8% (2/24) in the I.V. group, alongside a superior disease control rate (DCR) of 88% (14/16) in I.P. compared to 67% (16/24) in I.V. group. Notably, within the high-dose group receiving I.P. infusion, the ORR increased to 28.5%. Moreover, the responded patients in the high-dose group all had sustained tumor remission for more than 5 months, including one patient who had a 76% target lesions regression at six months follow up. CAR-T cells demonstrated robust expansion in both the I.P. and I.V. groups, while no significant difference was found in maximum concentration. Conclusions: The CEA CAR-T cell therapy had acceptable toxicity via I.P. or I.V. infusion. We have observed a promising antitumor potential by I.P. infusion and a prolonged tumor remission in high-dose group. Further investigation is needed to highlight these findings and the corresponding mechanisms. Clinical trial information: NCT05396300 . [Table: see text]