EXTH-53. ANTI-ROBO1 CAR T CELLS EFFECTIVELY TARGET MALIGNANT BRAIN CANCER

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi175-vi175
Author(s):  
Chirayu R Chokshi ◽  
Benjamin Brakel ◽  
Martin A Rossotti ◽  
Chitra Venugopal ◽  
Sabra Salim ◽  
...  

Abstract No standardized treatment exists for patients with recurrent glioblastoma (GBM). Given the aggressive nature of the disease and difficulty in modeling tumor recurrence, minimal efforts have been made to design rational therapies against it. The roundabout guidance receptor 1 (ROBO1) protein is involved in axonal guidance during neurodevelopment and is aberrantly upregulated in glioma where it mediates glioma cell migration. Here, we present that ROBO1 is highly expressed on the surface of malignant and treatment-refractory brain tumor initiating cells (BTICs), prompting the development of an anti-ROBO1 CAR-T cell therapy. Using the binding region of a single-domain antibody targeting ROBO1, we developed second-generation anti-ROBO1 CAR-T cells specific and effective against ROBO1-expressing BTICs. Upon antigen exposure, anti-ROBO1 CAR-T cells upregulated markers of activation and degranulation. Additionally, treatment of orthotopic and patient-derived brain tumor xenograft models with anti-ROBO1 CAR-T cells resulted in reduced tumor burden and prolonged survival, demonstrating the therapy’s therapeutic potential for treating neoplastic brain malignancies.

Cancers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 139 ◽  
Author(s):  
Jing Cui ◽  
Herui Wang ◽  
Rogelio Medina ◽  
Qi Zhang ◽  
Chen Xu ◽  
...  

Chimeric antigen receptor (CAR)-engineered T cells represent a promising modality for treating glioblastoma. Recently, we demonstrated that CAR-T cells targeting carbonic anhydrase IX (CAIX), a protein involved in HIF-1a hypoxic signaling, is a promising CAR-T cell target in an intracranial murine glioblastoma model. Anti-CAIX CAR-T cell therapy is limited by its suboptimal activation within the tumor microenvironment. LB-100, a small molecular inhibitor of protein phosphatase 2A (PP2A), has been shown to enhance T cell anti-tumor activity through activation of the mTOR signaling pathway. Herein, we investigated if a treatment strategy consisting of a combination of LB-100 and anti-CAIX CAR-T cell therapy produced a synergistic anti-tumor effect. Our studies demonstrate that LB-100 enhanced anti-CAIX CAR-T cell treatment efficacy in vitro and in vivo. Our findings demonstrate the role of LB-100 in augmenting the cytotoxic activity of anti-CAIX CAR-T cells and underscore the synergistic therapeutic potential of applying combination LB-100 and CAR-T Cell therapy to other solid tumors.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Liat Rousso-Noori ◽  
Ignacio Mastandrea ◽  
Shauli Talmor ◽  
Tova Waks ◽  
Anat Globerson Levin ◽  
...  

AbstractGlioblastoma is considered one of the most aggressive malignancies in adult and pediatric patients. Despite decades of research no curative treatment is available and it thus remains associated with a very dismal prognosis. Although recent pre-clinical and clinical studies have demonstrated the feasibility of chimeric antigen receptors (CAR) T cell immunotherapeutic approach in glioblastoma, tumor heterogeneity and antigen loss remain among one of the most important challenges to be addressed. In this study, we identify p32/gC1qR/HABP/C1qBP to be specifically expressed on the surface of glioma cells, making it a suitable tumor associated antigen for redirected CAR T cell therapy. We generate p32 CAR T cells and find them to recognize and specifically eliminate p32 expressing glioma cells and tumor derived endothelial cells in vitro and to control tumor growth in orthotopic syngeneic and xenograft mouse models. Thus, p32 CAR T cells may serve as a therapeutic option for glioblastoma patients.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 2522-2522
Author(s):  
Hong-jiu Dai ◽  
Bin Sun ◽  
Dong Yang ◽  
Hui Xu ◽  
Jingjing Zhu ◽  
...  

2522 Background: Medulloblastoma (MB) is a cancerous malignant brain tumor, that most often occurs in young children. Standard-of-care therapies for treating pediatric MB have long-term side effects, even in children who are cured. Recently people are exploring the potential of chimeric antigen receptor T (CAR-T) cell therapy in brain tumor, yet the clinical outcome is limited. It's reported that NKG2D ligands are wildly expressed in MB cells, which supports NKG2D system might play an important role in MB therapy. Here, we take advantage of NKG2D-specific CAR-T cells (KD-025) for MB treatment. Methods: HTB186, HTB185 and HTB187 MB cell lines as well as MB cancer patient samples were evaluated for NKG2D ligands expression. The KD-025 showed antigen-specific stimulation by cytokine secretion and target cell lysis. HTB186 cells, which stably express luciferase protein, were used to establish in vivo subcutaneous and xenograft models in NSG mice. Mice received a single treatment of 10 million KD-025 intravenously. Results: NKG2D ligands were detected on HTB186 and HTB187 cells and most of screened BM patient samples. The KD-025 was generated with CD8 hinge region and transmembrane region, 4-1BB costimulatory region and CD3 zeta region. The KD-025 expression was > 50% on the surface of T cells confirmed by flow cytometry. Co-incubation of KD-025 with HTB186 cells specifically upregulates TNF-α, IFN-γ, IL-10 and IL-2 cytokines and strongly lysis tumor cells even at low E:T ratio (70-80% at 8:1). Strikingly, KD-025 markedly eliminated xenograft tumors in vivo and did not exhibit significant treatment-related toxicity in the treated mice. Regarding to T cell persistence, the CAR-T cells are barely detectable 24 days after injection, which is comparable with CD19 CAR in our experiments as well as published data. No obvious pathological changes were found in the tested organs. Conclusions: Our work with the KD-025 contributes to the growing body of research committed to discovering a novel therapy for MB. NKG2D ligands are highly expressed on human MB samples. KD-025 potently respond to MB and eliminate tumor in a xenograft mouse model with no obvious safety issues. The results support future clinical trial of KD-025 in patients with MB, where the need for effective treatment is great.


2021 ◽  
Vol 12 (12) ◽  
Author(s):  
Jie Xu ◽  
Qingtao Meng ◽  
Hao Sun ◽  
Xinwei Zhang ◽  
Jun Yun ◽  
...  

AbstractChimeric antigen receptor (CAR) - T cell therapy is a new class of cellular immunotherapies, which has made great achievements in the treatment of malignant tumors. Despite improvements in colorectal cancer (CRC) therapy, treatment of many patients fails because of metastasis and recurrence. The human epidermal growth factor receptor 2 (HER2) is a substantiated target for CAR-T therapy, and has been reported recently to be over-expressed in CRC, which may provide a potential therapeutic target for CRC treatment. Herein, HER2 was a promising target of metastatic colorectal cancer (mCRC) in CAR-T therapy as assessed by flow cytometry and tissue microarray (TMA) with 9-year survival follow-up data. Furthermore, HER2-specific CAR-T cells exhibited strong cytotoxicity and cytokine-secreting ability against CRC cells in vitro. Moreover, through the tumor-bearing model of the NOD-Prkdcem26cd52Il2rgem26Cd22/Nju (NCG) mice, HER2 CAR-T cells showed signs of effectively preventing CRC progression in three different xenograft models. Notably, HER2 CAR-T cells displayed greater aggressiveness in HER2+ CRC in the patient-derived tumor xenograft (PDX) models and had potent immunotherapeutic capacity for mCRC in the metastatic xenograft mouse models. In conclusion, our studies provide scientific evidence that HER2 CAR-T cells represent an emerging immunotherapy for the treatment of mCRC.


Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 404
Author(s):  
Vicky Mengfei Qin ◽  
Criselle D’Souza ◽  
Paul J. Neeson ◽  
Joe Jiang Zhu

Chimeric antigen receptors (CAR) are genetically engineered receptors that can recognise specific antigens and subsequently activate downstream signalling. Human T cells engineered to express a CAR, also known as CAR-T cells, can target a specific tumour antigen on the cell surface to mediate a cytotoxic response against the tumour. CAR-T cell therapy has achieved remarkable success in treating hematologic malignancies, but not in solid tumours. Currently, extensive research is being carried out to make CAR-T cells a therapy for solid tumours. To date, most of the research interest in the field has focused on cytotoxic T lymphocytes as the carrier of CAR products. However, in addition to T cells, the CAR design can be introduced in other immune cells, such as natural killer (NK)/NKT cells, γδ T cells, mucosal-associated invariant T (MAIT) cells, dendritic cells (DC), macrophages, regulatory T cells (Treg), B cells, etc. Some of the CAR-engineered immune cells, such as CAR- γδ T and CAR-NK/NK-T cells, are directly involved in the anti-tumour response, demonstrated in preclinical studies and/or clinical trials. CAR-Tregs showed promising therapeutic potential in treating autoimmune diseases. In particular, B cells engineered with chimeric receptors can be used as a platform for long-term delivery of therapeutic proteins, such as recombinant antibodies or protein replacement, in an antigen-specific manner. CAR technology is one of the most powerful engineering platforms in immunotherapy, especially for the treatment of cancers. In this review, we will discuss the recent application of the CAR design in non-CAR-T cells and future opportunities in immunotherapy.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Laura Castelletti ◽  
Dannel Yeo ◽  
Nico van Zandwijk ◽  
John E. J. Rasko

AbstractMalignant mesothelioma (MM) is a treatment-resistant tumor originating in the mesothelial lining of the pleura or the abdominal cavity with very limited treatment options. More effective therapeutic approaches are urgently needed to improve the poor prognosis of MM patients. Chimeric Antigen Receptor (CAR) T cell therapy has emerged as a novel potential treatment for this incurable solid tumor. The tumor-associated antigen mesothelin (MSLN) is an attractive target for cell therapy in MM, as this antigen is expressed at high levels in the diseased pleura or peritoneum in the majority of MM patients and not (or very modestly) present in healthy tissues. Clinical trials using anti-MSLN CAR T cells in MM have shown that this potential therapeutic is relatively safe. However, efficacy remains modest, likely due to the MM tumor microenvironment (TME), which creates strong immunosuppressive conditions and thus reduces anti-MSLN CAR T cell tumor infiltration, efficacy and persistence. Various approaches to overcome these challenges are reviewed here. They include local (intratumoral) delivery of anti-MSLN CAR T cells, improved CAR design and co-stimulation, and measures to avoid T cell exhaustion. Combination therapies with checkpoint inhibitors as well as oncolytic viruses are also discussed. Preclinical studies have confirmed that increased efficacy of anti-MSLN CAR T cells is within reach and offer hope that this form of cellular immunotherapy may soon improve the prognosis of MM patients.


Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1955
Author(s):  
Feifei Guo ◽  
Jiuwei Cui

Despite remarkable achievements in the treatment of hematologic malignancies, chimeric antigen receptor (CAR)-T cell therapy still faces many obstacles. The limited antitumor activity and persistence of infused CAR-T cells, especially in solid tumors, are the main limiting factors for CAR-T therapy. Moreover, clinical security and accessibility are important unmet needs for the application of CAR-T therapy. In view of these challenges, many potentially effective solutions have been proposed and confirmed. Both the independent and combined strategies of CAR-T therapy have exhibited good application prospects. Thus, in this review, we have discussed the cutting-edge breakthroughs in CAR-T therapy for cancer treatment, with the aim of providing a reference for addressing the current challenges.


Author(s):  
Mariana Torres Mazzi ◽  
Karina Lôbo Hajdu ◽  
Priscila Rafaela Ribeiro ◽  
Martín Hernán Bonamino

Abstract Chimeric antigen receptor (CAR)-T cell therapy represents a breakthrough in the immunotherapy field and has achieved great success following its approval in 2017 for the treatment of B cell malignancies. While CAR-T cells are mostly applied as anti-tumor therapy in the present, their initial concept was aimed at a more general purpose of targeting membrane antigens, thus translating in many potential applications. Since then, several studies have assessed the use of CAR-T cells towards non-malignant pathologies such as autoimmune diseases, infectious diseases and, more recently, cardiac fibrosis and cellular senescence. In this review, we present the main findings and implications of CAR-based therapies for non-malignant conditions.


Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1229
Author(s):  
Ali Hosseini Rad S. M. ◽  
Joshua Colin Halpin ◽  
Mojtaba Mollaei ◽  
Samuel W. J. Smith Bell ◽  
Nattiya Hirankarn ◽  
...  

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized adoptive cell therapy with impressive therapeutic outcomes of >80% complete remission (CR) rates in some haematological malignancies. Despite this, CAR T cell therapy for the treatment of solid tumours has invariably been unsuccessful in the clinic. Immunosuppressive factors and metabolic stresses in the tumour microenvironment (TME) result in the dysfunction and exhaustion of CAR T cells. A growing body of evidence demonstrates the importance of the mitochondrial and metabolic state of CAR T cells prior to infusion into patients. The different T cell subtypes utilise distinct metabolic pathways to fulfil their energy demands associated with their function. The reprogramming of CAR T cell metabolism is a viable approach to manufacture CAR T cells with superior antitumour functions and increased longevity, whilst also facilitating their adaptation to the nutrient restricted TME. This review discusses the mitochondrial and metabolic state of T cells, and describes the potential of the latest metabolic interventions to maximise CAR T cell efficacy for solid tumours.


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