Pharmacology of Chimeric Antigen Receptor–Modified T Cells

2021 ◽  
Vol 61 (1) ◽  
pp. 805-829
Author(s):  
Edward Z. Song ◽  
Michael C. Milone

Cell-based immunotherapies using T cells that are engineered to express a chimeric antigen receptor (CAR-T cells) are an effective treatment option for several B cell malignancies. Compared with most drugs, CAR-T cell products are highly complex, as each cell product is composed of a heterogeneous mixture of millions of cells. The biodistribution and kinetics of CAR-T cells, following administration, are unique given the ability of T cells to actively migrate as well as replicate within the patient. CAR-T cell therapies also have multiple mechanisms of action that contribute to both their antitumor activity and their toxicity. This review provides an overview of the unique pharmacology of CAR-T cells, with a focus on CD19-targeting and B cell maturation antigen (BCMA)-targeting CAR-T cells.

2020 ◽  
Author(s):  
L Nicolas Gonzalez Castro ◽  
Jorg Dietrich

Abstract Adoptive cell therapies (ACT) are a group of cancer immunotherapies that involve the infusion of engineered immune cells targeting specific tumor antigens, with chimeric antigen receptor (CAR) T-cells at the vanguard of this revolution in cancer therapy. Several CAR T-cell products have been approved for the treatment of leukemia and lymphoma and many more are currently undergoing evaluation in clinical trials for the treatment of other liquid and solid malignancies. Despite their remarkable effectiveness, as with other immunotherapies, CAR T-cells are frequently associated with systemic and neurologic toxicity. There has been a major effort by many institutions to develop specific protocols to guide management of treatment associated toxicities (e.g., cytokine release syndrome, CRS). However, neurotoxic effects of CAR T-cell therapies are more difficult to evaluate and treat, not easily lending themselves to an algorithmic approach to diagnosis and management. Given the steadily expanding use of CAR T-cell therapies for various malignancies, it is of critical importance for neuro-oncologists to be familiar with the clinical presentation and management principles of CAR T-cell-associated neurotoxicity. Here we present key principles for the evaluation and management of patients affected by CAR T-cell associated neurotoxicity based on the most recent evidence.


2019 ◽  
Vol 14 (1) ◽  
pp. 60-69
Author(s):  
Manxue Fu ◽  
Liling Tang

Background: Chimeric Antigen Receptor (CAR) T cell immunotherapy, as an innovative method for tumor immunotherapy, acquires unprecedented clinical outcomes. Genetic modification not only provides T cells with the antigen-binding function but also endows T cells with better immunological functions both in solid and hematological cancer. However, the CAR T cell therapy is not perfect because of several reasons, such as tumor immune microenvironment, and autologous limiting factors of CAR T cells. Moreover, the safety of CAR T cells should be improved.Objective:Recently many patents and publications have reported the importance of CAR T cell immunotherapy. Based on the patents about CAR T cell immunotherapy, we conclude some methods for designing the CAR which can provide information to readers.Methods:In this review, we collect recent patents and publications, summarize some specific antigens for oncotherapy from patents and enumerate some approaches to conquering immunosuppression and reinforcing the immune response of CAR T cells. We also sum up some strategies for improving the safety of CAR T cell immunotherapy.Results:CAR T cell immunotherapy as a neotype cellular immunotherapy has been proved effective in oncotherapy and authorized by FDA. Improvements in CAR designing enhance functions of CAR T cells.Conclusion:This review, summarizing antigens and approaches to overcome defects of CAR T cell immunotherapy from patents and publications, might contribute to a broad readership.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Chunyi Shen ◽  
Zhen Zhang ◽  
Yi Zhang

Immunotherapy, especially based on chimeric antigen receptor (CAR) T cells, has achieved prominent success in the treatment of hematological malignancies. However, approximately 30-50% of patients will have disease relapse following remission after receiving CD19-targeting CAR-T cells, with failure of maintaining a long-term effect. Mechanisms underlying CAR-T therapy inefficiency consist of loss or modulation of target antigen and CAR-T cell poor persistence which mostly results from T cell exhaustion. The unique features and restoration strategies of exhausted T cells (Tex) have been well described in solid tumors. However, the overview associated with CAR-T cell exhaustion is relatively rare in hematological malignancies. In this review, we summarize the characteristics, cellular, and molecular mechanisms of Tex cells as well as approaches to reverse CAR-T cell exhaustion in hematological malignancies, providing novel strategies for immunotherapies.


2020 ◽  
Vol 94 (10) ◽  
Author(s):  
Matthew T. Ollerton ◽  
Edward A. Berger ◽  
Elizabeth Connick ◽  
Gregory F. Burton

ABSTRACT The major obstacle to a cure for HIV infection is the persistence of replication-competent viral reservoirs during antiretroviral therapy. HIV-specific chimeric antigen receptor (CAR) T cells have been developed to target latently infected CD4+ T cells that express virus either spontaneously or after intentional latency reversal. Whether HIV-specific CAR-T cells can recognize and eliminate the follicular dendritic cell (FDC) reservoir of HIV-bound immune complexes (ICs) is unknown. We created HIV-specific CAR-T cells using human peripheral blood mononuclear cells (PBMCs) and a CAR construct that enables the expression of CD4 (domains 1 and 2) and the carbohydrate recognition domain of mannose binding lectin (MBL) to target native HIV Env (CD4-MBL CAR). We assessed CAR-T cell cytotoxicity using a carboxyfluorescein succinimidyl ester (CFSE) release assay and evaluated CAR-T cell activation through interferon gamma (IFN-γ) production and CD107a membrane accumulation by flow cytometry. CD4-MBL CAR-T cells displayed potent lytic and functional responses to Env-expressing cell lines and HIV-infected CD4+ T cells but were ineffective at targeting FDC bearing HIV-ICs. CD4-MBL CAR-T cells were unresponsive to cell-free HIV or concentrated, immobilized HIV-ICs in cell-free experiments. Blocking intercellular adhesion molecule-1 (ICAM-1) inhibited the cytolytic response of CD4-MBL CAR-T cells to Env-expressing cell lines and HIV-infected CD4+ T cells, suggesting that factors such as adhesion molecules are necessary for the stabilization of the CAR-Env interaction to elicit a cytotoxic response. Thus, CD4-MBL CAR-T cells are unable to eliminate the FDC-associated HIV reservoir, and alternative strategies to eradicate this reservoir must be sought. IMPORTANCE Efforts to cure HIV infection have focused primarily on the elimination of latently infected CD4+ T cells. Few studies have addressed the unique reservoir of infectious HIV that exists on follicular dendritic cells (FDCs), persists in vivo during antiretroviral therapy, and likely contributes to viral rebound upon cessation of antiretroviral therapy. We assessed the efficacy of a novel HIV-specific chimeric antigen receptor (CAR) T cell to target both HIV-infected CD4+ T cells and the FDC reservoir in vitro. Although CAR-T cells eliminated CD4+ T cells that express HIV, they did not respond to or eliminate FDC bound to HIV. These findings reveal a fundamental limitation to CAR-T cell therapy to eradicate HIV.


2017 ◽  
Vol 13 (01) ◽  
pp. 28 ◽  
Author(s):  
Andrew Fesnak ◽  
Una O’Doherty ◽  
◽  

Adoptive transfer of chimeric antigen receptor (CAR) T cells is a powerful targeted immunotherapeutic technique. CAR T cells are manufactured by harvesting mononuclear cells, typically via leukapheresis from a patient’s blood, then activating, modifying the T cells to express a transgene encoding a tumour-specific CAR, and infusing the CAR T cells into the patient. Gene transfer is achieved through the use of retroviral or lentiviral vectors, although non-viral delivery systems are being investigated. This article discusses the challenges associated with each stage of this process. Despite the need for a consistent end product, there is inherent variability in cellular material obtained from critically ill patients who have been exposed to cytotoxic therapy. It is important to carefully select target antigens to maximise effect and minimise toxicity. Various types of CAR T cell toxicity have been documented: this includes “on target, on tumour”, “on target, off tumour” and “off target” toxicity. A growing body of clinical evidence supports the efficacy and safety of CAR T cell therapy; CAR T cells targeting CD19 in B cell leukemias are the best-studied therapy to date. However, providing personalised therapy on a large scale remains challenging; a future aim is to produce a universal “off the shelf” CAR T cell.


2021 ◽  
Vol 288 (1947) ◽  
Author(s):  
Gregory J. Kimmel ◽  
Frederick L. Locke ◽  
Philipp M. Altrock

Chimeric antigen receptor (CAR) T cell therapy is a remarkably effective immunotherapy that relies on in vivo expansion of engineered CAR T cells, after lymphodepletion (LD) by chemotherapy. The quantitative laws underlying this expansion and subsequent tumour eradication remain unknown. We develop a mathematical model of T cell–tumour cell interactions and demonstrate that expansion can be explained by immune reconstitution dynamics after LD and competition among T cells. CAR T cells rapidly grow and engage tumour cells but experience an emerging growth rate disadvantage compared to normal T cells. Since tumour eradication is deterministically unstable in our model, we define cure as a stochastic event, which, even when likely, can occur at variable times. However, we show that variability in timing is largely determined by patient variability. While cure events impacted by these fluctuations occur early and are narrowly distributed, progression events occur late and are more widely distributed in time. We parameterized our model using population-level CAR T cell and tumour data over time and compare our predictions with progression-free survival rates. We find that therapy could be improved by optimizing the tumour-killing rate and the CAR T cells' ability to adapt, as quantified by their carrying capacity. Our tumour extinction model can be leveraged to examine why therapy works in some patients but not others, and to better understand the interplay of deterministic and stochastic effects on outcomes. For example, our model implies that LD before a second CAR T injection is necessary.


Author(s):  
Paolo Strati ◽  
Shabnum Patel ◽  
Loretta Nastoupil ◽  
Michelle A. Fanale ◽  
Catherine M. Bollard ◽  
...  

Immune-based treatment strategies, such as checkpoint inhibition and chimeric antigen receptor (CAR) T cells, have started a new frontier for treatment in non-Hodgkin lymphoma (NHL). Checkpoint inhibition has been most successful in Hodgkin lymphoma, where higher expression of PD-L1 is correlated with better overall response rate. Combinations of checkpoint inhibition with various chemotherapy or biologics are in clinical trials, with initially promising results and manageable safety profiles. CAR T-cell therapies that target CD19 are a promising and attractive therapy for B-cell NHLs, with a product approved by the US Food and Drug Administration in 2017. Changes in the target, hinge, or costimulatory domain can dramatically alter the persistence and efficacy of the CAR T cells. The ZUMA trials from Kite used CD19-(CD28z) CAR T cells, whereas the TRANSCEND studies from Juno and the JULIET studies from Novartis used CD19-(4-1BBz) CARs. Despite the recent successes with CAR T-cell clinical trials, major concerns associated with this therapy include cytokine release syndrome, potential neurotoxicities, B-cell aplasia, loss of tumor antigen leading to relapse, and cost and accessibility of the treatment. Although first-generation CAR T-cell therapies have failed in solid malignancies, newer second- and third-generation CAR T cells that target antigens other than CD19 (such as mesothelin or B-cell maturation antigen) are being studied in clinical trials for treatment of lung cancer or multiple myeloma. Overall, immune-based treatment strategies have given oncologists and patients hope when there used to be none, as well as a new basket of tools yet to come with further research and development.


Author(s):  
Bill X. Wu ◽  
No-Joon Song ◽  
Brian P. Riesenberg ◽  
Zihai Li

Abstract The use of chimeric antigen receptor (CAR) T cell technology as a therapeutic strategy for the treatment blood-born human cancers has delivered outstanding clinical efficacy. However, this treatment modality can also be associated with serious adverse events in the form of cytokine release syndrome. While several avenues are being pursued to limit the off-target effects, it is critically important that any intervention strategy has minimal consequences on long term efficacy. A recent study published in Science Translational Medicine by Dr. Hudecek’s group proved that dasatinib, a tyrosine kinase inhibitor, can serve as an on/off switch for CD19-CAR-T cells in preclinical models by limiting toxicities while maintaining therapeutic efficacy. In this editorial, we discuss the recent strategies for generating safer CAR-T cells, and also important questions surrounding the use of dasatinib for emergency intervention of CAR-T cell mediated cytokine release syndrome.


Author(s):  
Jeremy S. Abramson ◽  
Matthew Lunning ◽  
M. Lia Palomba

Aggressive B-cell lymphomas that are primary refractory to, or relapse after, frontline chemoimmunotherapy have a low cure rate with conventional therapies. Although high-dose chemotherapy remains the standard of care at first relapse for sufficiently young and fit patients, fewer than one-quarter of patients with relapsed/refractory disease are cured with this approach. Anti-CD19 chimeric antigen receptor (CAR) T cells have emerged as an effective therapy in patients with multiple relapsed/refractory disease, capable of inducing durable remissions in patients with chemotherapy-refractory disease. Three anti-CD19 CAR T cells for aggressive B-cell lymphoma (axicabtagene ciloleucel, tisagenlecleucel, and lisocabtagene ciloleucel) are either U.S. Food and Drug Administration approved or in late-stage development. All three CAR T cells produce durable remissions in 33%–40% of treated patients. Differences among these products include the specific CAR constructs, costimulatory domains, manufacturing process, dose, and eligibility criteria for their pivotal trials. Notable toxicities include cytokine release syndrome and neurologic toxicities, which are usually treatable and reversible, as well as cytopenias and hypogammaglobulinemia. Incidences of cytokine release syndrome and neurotoxicity differ across CAR T-cell products, related in part to the type of costimulatory domain. Potential mechanisms of resistance include CAR T-cell exhaustion and immune evasion, CD19 antigen loss, and a lack of persistence. Rational combination strategies with CAR T cells are under evaluation, including immune checkpoint inhibitors, immunomodulators, and tyrosine kinase inhibitors. Novel cell products are also being developed and include CAR T cells that target multiple tumor antigens, cytokine-secreting CAR T cells, and gene-edited CAR T cells, among others.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A149-A149
Author(s):  
Yuan Qin ◽  
Anna Qin ◽  
Anna Musket ◽  
Joseph Lee ◽  
Zhi Yao ◽  
...  

BackgroundHepatocellular carcinoma (HCC) is the leading cause of cancer mortality worldwide. While HBV/HCV infection is the primary cause of HCC, overexpression of MET, the receptor of hepatocyte growth factor (HGF), occurs in 50% HCC patients, and is an indicator of poor prognosis. Although the multi-target MET tyrosine kinase inhibitor cabozantinib is FDA approved for treating advanced HCC, the long-term efficacy versus toxicity remains unknown. Our study is to develop specific MET-targeting chimeric antigen receptor T (CAR-T) cells for treating HCC with MET overexpression.MethodsBased on a well-established anti-MET monoclonal antibody, we synthesized and cloned the single-chain variable fragment (ScFv) sequence into two retroviral based 2nd generation CAR vectors (MET-CAR.CD28.ζ. and MET-CAR.4-1BB.ζ.). A MET-CAR without CD3ζ domain (MET-CARΔ) served as a negative control. To produce MET-CAR-T cells, healthy PBMCs were stimulated with anti-CD3/CD28 antibodies in the presence of IL-7/IL-15 followed by transduction with MET-CAR viral particles. T cell transduction efficacy was determined using flow cytometry. HCC cell lines with variable MET expression from high/positive (MHCC97H, C3A, and JHH5) to MET low/negative (SNU398) were used to determine MET-specific CAR T cells specificity and effector function using MTS assay. We also collected media from the tumor-T cell co-cultures and determined IL-2 and IFNγ secretion using ELISA. Finally, real-time confocal imaging (24 h) was performed to record the progress of MET-CAR T cell mediated killing activity against MHCC97H/mCherry cells.ResultsWe show that both MET-CAR.CD28.ζ and MET-CAR.4-1BB.ζ -T cells significantly killed MHCC97H, C3A, and JHH5 cells in antigen dependent manner. MET-CAR T cell killing is MET dependent as we observed no killing of MET-negative SNU398 cells. In addition, MET-CAR.4-1BB.ζ and MET-CAR.CD28.ζ- T cells secreted IL-2 and IFNγ when co-cultured with MHCC97H, C3A, JHH5 cells, but not SNU398. Confocal imaging studies showed that both MET-specific CAR T cells migrated toward MHCC97H/mCherry cells, formed aggregations, and induced tumor cell death, while MET-CARΔ T cells failed to do so.ConclusionsHere we demonstrate that MET-CAR.4-1BB.ζ and MET-CAR.CD28.ζ- T cells specifically recognize and kill MET-positive HCC cells in vitro. While animal studies are required to validate the efficacy in vivo, our study has produced a novel therapeutic CAR T cell target for treating malignant HCC and other type of cancers with MET overexpression.AcknowledgementsThis independent research was supported by the Gilead Sciences Research Scholars Program in Liver Disease- The Americas, and Department of Defense (DoD) Ideal Award (to QX)Ethics ApprovalThe study was approved by East Tennessee State University’s Ethics Board, approval number #0619.3s.


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