131 Coupled CAR® technology strengthens adoptive T cell therapy by promoting rapid expansion

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A144-A144
Author(s):  
Zhiyuan Cao ◽  
Chengfei Pu ◽  
Xianyang Jiang ◽  
Xiaogang Shen ◽  
Ruihong Zhu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Solid Tumors ◽  
Solid Tumor ◽  
Cell Expansion ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T

BackgroundCAR T therapy has achieved remarkable results in the treatment of hematological tumors such as leukemia, lymphoma, and multiple myeloma. However, there remains challenges in treating solid tumors. These challenges include physical barriers, tumor microenvironment immunosuppression, tumor heterogeneity and target specificity. Especially, due to tumor microenvironmental barriers, CAR T cells are not effectively exposed to tumor antigens and cannot activate co-stimulation signals on CAR molecules, thus conventional CAR T cell therapy has thus far shown weak cell expansion in solid tumor patients, achieved little or no therapeutic responses. Here, we developed CAR T cells based on a novel CoupledCAR® technology to overcome the lack of persistence of solid tumor CAR T cells in vivo.MethodsWe designed a ‘CoupledCAR’ lentivirus vector containing a single-chain variable fragment (scFv) targeting human TSHR. The lentivirus was produced by transfecting HEK-293T cells with ‘CoupledCAR’ lentiviral vectors and viral packaging plasmids. Patient‘s CD3 T cells were cultured in X-VIVO medium containing 125U/mL 1interleukin-2 (IL-2), and transduced with ‘CoupledCAR’ lentivirus at certain MOI. Transduction efficiency and was evaluated at 7 to 9 days after ‘CoupledCAR’ lentivirus transduction, and quality controls for fungi, bacteria, mycoplasma, chlamydia, and endotoxin were performed. After infusion, serial peripheral blood samples were collected, and the expansion and the cytokine release of CART cells were detected by FACS and QPCR. The evaluation of response level for patients were performed at month 1,month 3,and month 6 by PET/CT.ResultsWe used prostatic acid phosphatase (PAP) as an exemplary CAR target for prostate cancer and demonstrated that our CoupledCAR® significantly enhanced the expansion of PAP CAR T cells in vitro and in vivo. Further, we observed that this expansion showed more memory-like phenotypes, and caused little exhaustion of PAP CAR T cells. Also, we find coupled solid tumor CAR T cells have stronger tumor killing ability. We demonstrated this simple expansion to enable the persistence of solid tumor CAR T cells and can be further applied to other kinds of T cell therapy like TCR T and TILs.ConclusionsWe developed a novel platform technology (CoupledCAR®) that allows solid tumor CAR T cells to rapidly expand. This initial CAR T cell expansion enabled enhanced trafficking and infiltration of the tumor tissue whereby further cell expansion occurred and thereby achieved tumor clearance. We have carried clinical trials and obtained early promising clinical data. We will further verify the safety and efficacy of this technology in the treatment of different kinds of solid tumors in the clinic research.

139 Establishment of canine CAR T cells treatment model for solid tumor immunotherapy development

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A152-A153
Author(s):  
Shihong Zhang ◽  
Karan Kohli ◽  
R Graeme Black ◽  
Brian Hayes ◽  
Cassandra Miller ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Solid Tumors ◽  
Solid Tumor ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Signaling Domain

BackgroundChimeric antigen receptor (CAR) T cell therapy has transformed therapy for hematological malignancies but has not yet been established as standard of care for any solid tumors. One obstacle for human solid tumor immunotherapy research is the lack of clinically relevant, immunocompetent animal models. In this study, we sought to establish CAR T cells for naturally occurring canine sarcomas in client owned animals as a model for human CAR T cell therapy.MethodsArchived FFPE, freshly isolated canine solid tumor samples as well as tumor lines were tested for B7H3 expression by immunohistochemistry (IHC) and flow cytometry analysis. We designed CARs using the scFv from the human B7H3-specific antibody MGA271 and confirmed the cross-reactivity to canine B7H3 (construct information see figure 1A). A truncated EGFR (tEGFR) was included in the construct to allow for IHC and flow cytometry testing for the presence of CAR T cells. Killing efficiency was evaluated using 3D tumor spheroid killing assays to monitor dynamics. Safety of the CAR products following lymphodepletion was confirmed in two healthy dogs (figure 1B).ResultsCanine solid tumors were confirmed to be B7H3 positive in almost all cases. Using the GALV-pseudotyped retrovirus system, transduction was efficient with up to 70% CAR+ cells. Post-transduction expansion was over 100 folds. B7H3 CAR transduced canine T cells were able to eliminate B7H3+ canine tumor spheroids effectively (figure 2). Safety of the CAR T cells (dose: 1 × 109/m2) were confirmed in both healthy animals following cyclophosphamide lymphodepletion. After week 6, cetuximab was given to the subjects to deplete EGFR+ cells. Subject 2 experienced fever after CAR T cell administration. Both dogs showed elevated serum ALP and ALT levels and returned to normal (figure 3). No other treatment-related adverse events were observed. Information of the CAR T cell products can be found in table 1.Abstract 139 Figure 1Construct information and safety trial design(A) Four 2nd generation CAR constructs were generated. Two B7H3 CARs were candidates for the treatment, and two HER2 CARs served as controls, as they have been shown to kill canine cancer cells. The CARs are consisted of a single chain variable fragment (scFv, either B7H3-specific MGA271 or HER2-specific FRP5), a short hinge, a transmembrane domain (tm), a canine costimulatory signaling domain (either canine CD28 or 4-1BB) and canine CD3? signaling domain. Truncated EGFR is added in the construct for CAR+ T cell detection and facilitate the depletion of CAR T cells in vivo as a safety measure. (B) Blood from the subjects were drawn 3 weeks prior to the treatment for CAR T cell production. Cyclophosphamide (Cy, 400 mg/m2) and Fludarabine (Flu, 10 mg/m2) were given to the subjects for 2 days for lymphodepletion. CAR T cells (1 × 109/m2) and cetuximab (200 mg/m2) were given to the subjects as indicated. Blood, lymph node (LN) and bone marrow (BM) aspirates were collected for CAR T cell homing and persistence analysisAbstract 139 Figure 2Killing of canine OSA spheroids by canine CAR T ce(A) Scheme of tumor cell spheroid forming and killing. The loss of GFP can be measured for cytotoxicity readout (B) FRP5 and MGA271 CAR T cells can effectively kill canine cancer spheroids. Experiments were done in triplicates and error bars indicate SDAbstract 139 Figure 3Dynamics of peripheral lymphocytes, serum ALP and Current treatment regimen effectively decreased peripheral lymphocytes number after cyclophosphamide and fludarabine administration (D-4 and D-3) and increased serum ALP and ALT level after CAR T cell infusion (D0). Dashed line in both graphs show the upper limit of ALP and ALT levels, which are both 68U/LAbstract 139 Table 1Infused CAR T cell product informationBoth subjects are adult male beagle mixConclusionsWe demonstrated that, similar to human cancers, B7H3 is a target in canine solid tumors. We successfully generated canine B7H3 specific CAR T cell products that are highly efficient at killing canine 3D tumor spheroids using a production protocol that closely models human CAR T cell production procedure and confirmed the safety in vivo. We plan to test and optimize various approaches to enhance CAR T cell efficacy for solid tumor treatment both in vitro and in canine sarcoma patients.Ethics ApprovalThe study was approved by Fred Hutchinson Cancer Research Center‘s Institutional Animal Care and Use Committee (IACUC), approval number PROTO201900860

scholarly journals First-in-Human Study of ET019003, a Next Generation Anti-CD19 T-Cell Therapy, in Patients with Relapsed/Refractory Diffuse Large B Cell Lymphoma (r/r DLBCL)

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2870-2870 ◽  
Author(s):  
Pengcheng He ◽  
Hong Liu ◽  
Haibo Liu ◽  
Mina Luo ◽  
Hui Feng ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Cell Expansion ◽  
T Cell Therapy ◽  
Car T ◽  
Equity Ownership ◽  
T Cell Expansion ◽  
The Absolute

Background : CD19-targeted CAR-T therapies have shown promising efficacy in treating B-cell malignancies. However, treatment-related toxicities, such as cytokine-release syndrome (CRS) and CAR T-cell-related encephalopathy syndrome (CRES), have been one of the major obstacles limiting the use of CAR-T therapies. How to minimize occurrence and severity of toxicity while maintaining efficacy is a major focus for T-cell therapies in development. ET019003 is a next generation CD19-targeted T-cell therapy developed by Eureka Therapeutics, built on the proprietary ARTEMISTM T-cell platform. The ET019003 construct is optimized with the co-expression of an ET190L1 Antibody-TCR (Xu et al, 2018) and novel co-stimulation molecule. We are conducting a First-in-human (FIH) study of ET019003 T cells in CD19+ r/r DLBCL patients. Methods: This FIH study aims to evaluate the safety and efficacy of ET019003 T-cell therapy in CD19+ patients with r/r DLBCL. As of July 2019, six subjects were administered ET019003 T cells. These subjects were pathologically confirmed with DLBCL that is CD19+ (by immunohistochemistry), whose disease have progressed or relapsed after 2-5 lines of prior therapies. All were high-risk patients with rapid tumor progression and heavy tumor burden. Each subject had a Ki67 proliferative index over 60%, 2/6 of the subjects had a Ki67 proliferative index over 90%. Moreover, 5/6 of the subjects had extra-nodal involvement. Following a 3-day preconditioning treatment with Fludarabine (25mg/m2/day)/ Cyclophosphamide (250mg/m2/day), patients received i.v. infusions of ET019003 T cells at an initial dose of 2-3×106 cells/kg. Additional doses at 3×106 cells/kg were administered at 14 to 30-day intervals. Adverse events were monitored and assessed based on CTCAE 5.0. Clinical responses were assessed based on Lugano 2014 criteria. Results: As of July 2019, six subjects have received at least one ET019003 T-cell infusion, and four subjects have received two or more ET019003 T-cell infusions. No Grade 2 or higher CRS was observed in the six subjects. One subject developed convulsions and cognitive disturbance. This subject had lymphoma invasion in the central nervous system before ET019003 T-cell therapy. The subject was treated with glucocorticoid and the symptoms resolved within 24 hours. Other adverse events included fever (6/6, 100%), fatigue (3/6, 50%), thrombocytopenia (3/6, 50%), diarrhea (2/6, 33%), and herpes zoster (1/6, 17%). ET019003 T-cell expansion in vivo (monitored by flow cytometry and qPCR) was observed in all six subjects after first infusion. The absolute peak value of detected ET019003 T cells ranged between 26,000 - 348,240 (median 235,500) per ml of peripheral blood. Tmax (time to reach the absolute peak value) was 6 - 14 days (median 7.5 days). For the four subjects who received multiple ET019003 T-cell infusions, the absolute peak values of detected ET019003 T cells after the second infusion were significantly lower than the absolute peak values achieved after the first infusion. For the two subjects who received three or more infusions of ET019003 T cells, no significant ET019003 T-cell expansion in vivo was observed after the third infusion. All six subjects completed the evaluation of clinical responses at 1 month after ET019003 T-cell therapy. All subjects responded to ET019003 T cells and achieved either a partial remission (PR) or complete response (CR). Conclusions: Preliminary results from six CD19+ r/r DLBCL patients in a FIH study show that ET019003 T-cell therapy is safe with robust in vivo T-cell expansion. The clinical study is on-going and we are monitoring safety as well as duration of response in longer follow-up. Reference: Xu et al. Nature Cell Discovery, 2018 Disclosures Liu: Eureka Therapeutics: Employment, Equity Ownership. Chang:Eureka Therapeutics: Equity Ownership. Liu:Eureka Therapeutics: Employment, Equity Ownership.

scholarly journals 124 Functionalizing CAR T cells for selective proliferation and dual-targeting using the meditope technology

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A133-A133
Author(s):  
Cheng-Fu Kuo ◽  
Yi-Chiu Kuo ◽  
Miso Park ◽  
Zhen Tong ◽  
Brenda Aguilar ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

BackgroundMeditope is a small cyclic peptide that was identified to bind to cetuximab within the Fab region. The meditope binding site can be grafted onto any Fab framework, creating a platform to uniquely and specifically target monoclonal antibodies. Here we demonstrate that the meditope binding site can be grafted onto chimeric antigen receptors (CARs) and utilized to regulate and extend CAR T cell function. We demonstrate that the platform can be used to overcome key barriers to CAR T cell therapy, including T cell exhaustion and antigen escape.MethodsMeditope-enabled CARs (meCARs) were generated by amino acid substitutions to create binding sites for meditope peptide (meP) within the Fab tumor targeting domain of the CAR. meCAR expression was validated by anti-Fc FITC or meP-Alexa 647 probes. In vitro and in vivo assays were performed and compared to standard scFv CAR T cells. For meCAR T cell proliferation and dual-targeting assays, the meditope peptide (meP) was conjugated to recombinant human IL15 fused to the CD215 sushi domain (meP-IL15:sushi) and anti-CD20 monoclonal antibody rituximab (meP-rituximab).ResultsWe generated meCAR T cells targeting HER2, CD19 and HER1/3 and demonstrate the selective specific binding of the meditope peptide along with potent meCAR T cell effector function. We next demonstrated the utility of a meP-IL15:sushi for enhancing meCAR T cell proliferation in vitro and in vivo. Proliferation and persistence of meCAR T cells was dose dependent, establishing the ability to regulate CAR T cell expansion using the meditope platform. We also demonstrate the ability to redirect meCAR T cells tumor killing using meP-antibody adaptors. As proof-of-concept, meHER2-CAR T cells were redirected to target CD20+ Raji tumors, establishing the potential of the meditope platform to alter the CAR specificity and overcome tumor heterogeneity.ConclusionsOur studies show the utility of the meCAR platform for overcoming key challenges for CAR T cell therapy by specifically regulating CAR T cell functionality. Specifically, the meP-IL15:sushi enhanced meCAR T cell persistence and proliferation following adoptive transfer in vivo and protects against T cell exhaustion. Further, meP-ritiuximab can redirect meCAR T cells to target CD20-tumors, showing the versatility of this platform to address the tumor antigen escape variants. Future studies are focused on conferring additional ‘add-on’ functionalities to meCAR T cells to potentiate the therapeutic effectiveness of CAR T cell therapy.

scholarly journals CAR T-cell therapy of solid tumors: promising approaches to modulating antitumor activity of CAR T cells

2019 ◽  
pp. 5-12 ◽  
Author(s):  
Ya.Yu. Kiseleva ◽  
A.M. Shishkin ◽  
A.V. Ivanov ◽  
T.M. Kulinich ◽  
V.K. Bozhenko
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Solid Tumors ◽  
Functional Activity ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Adoptive immunotherapy that makes use of genetically modified autologous T cells carrying a chimeric antigen receptor (CAR) with desired specificity is a promising approach to the treatment of advanced or relapsed solid tumors. However, there are a number of challenges facing the CAR T-cell therapy, including the ability of the tumor to silence the expression of target antigens in response to the selective pressure exerted by therapy and the dampening of the functional activity of CAR T cells by the immunosuppressive tumor microenvironment. This review discusses the existing gene-engineering approaches to the modification of CAR T-cell design for 1) creating universal “switchable” synthetic receptors capable of attacking a variety of target antigens; 2) enhancing the functional activity of CAR T cells in the immunosuppressive microenvironment of the tumor by silencing the expression of inhibiting receptors or by stimulating production of cytokines.

scholarly journals GPRC5D is a target for the immunotherapy of multiple myeloma with rationally designed CAR T cells

2019 ◽  
Vol 11 (485) ◽  
pp. eaau7746 ◽  
Author(s):  
Eric L. Smith ◽  
Kim Harrington ◽  
Mette Staehr ◽  
Reed Masakayan ◽  
Jon Jones ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
B Cell ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell Therapy ◽  
Car T

Early clinical results of chimeric antigen receptor (CAR) T cell therapy targeting B cell maturation antigen (BCMA) for multiple myeloma (MM) appear promising, but relapses associated with residual low-to-negative BCMA-expressing MM cells have been reported, necessitating identification of additional targets. The orphan G protein–coupled receptor, class C group 5 member D (GPRC5D), normally expressed only in the hair follicle, was previously identified as expressed by mRNA in marrow aspirates from patients with MM, but confirmation of protein expression remained elusive. Using quantitative immunofluorescence, we determined that GPRC5D protein is expressed on CD138+ MM cells from primary marrow samples with a distribution that was similar to, but independent of, BCMA. Panning a human B cell–derived phage display library identified seven GPRC5D-specific single-chain variable fragments (scFvs). Incorporation of these into multiple CAR formats yielded 42 different constructs, which were screened for antigen-specific and antigen-independent (tonic) signaling using a Nur77-based reporter system. Nur77 reporter screen results were confirmed in vivo using a marrow-tropic MM xenograft in mice. CAR T cells incorporating GPRC5D-targeted scFv clone 109 eradicated MM and enabled long-term survival, including in a BCMA antigen escape model. GPRC5D(109) is specific for GPRC5D and resulted in MM cell line and primary MM cytotoxicity, cytokine release, and in vivo activity comparable to anti-BCMA CAR T cells. Murine and cynomolgus cross-reactive CAR T cells did not cause alopecia or other signs of GPRC5D-mediated toxicity in these species. Thus, GPRC5D(109) CAR T cell therapy shows potential for the treatment of advanced MM irrespective of previous BCMA-targeted therapy.

scholarly journals Advancing CAR T-Cell Therapy for Solid Tumors: Lessons Learned from Lymphoma Treatment

Cancers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 125 ◽  
Author(s):  
Aleksei Titov ◽  
Aygul Valiullina ◽  
Ekaterina Zmievskaya ◽  
Ekaterina Zaikova ◽  
Alexey Petukhov ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Solid Tumors ◽  
B Cell Lymphoma ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Chimeric antigen receptor (CAR) immunotherapy is one of the most promising modern approaches for the treatment of cancer. To date only two CAR T-cell products, Kymriah® and Yescarta®, have been approved by the Food and Drug Administration (FDA) for the treatment of lymphoblastic leukemia and B-cell lymphoma. Administration of CAR T-cells to control solid tumors has long been envisaged as one of the most difficult therapeutic tasks. The first two clinical trials conducted in sarcoma and neuroblastoma patients showed clinical benefits of CAR T-cells, yet multiple obstacles still hold us back from having accessible and efficient therapy. Why did such an effective treatment for relapsed and refractory hematological malignancies demonstrate only relatively modest efficiency in the context of solid tumors? Is it due to the lucky selection of the “magic” CD19 antigen, which might be one of a kind? Or do lymphomas lack the immunosuppressive features of solid tumors? Here we review the existing knowledge in the field of CAR T-cell therapy and address the heterogeneity of solid tumors and their diverse strategies of immunoevasion. We also provide an insight into prospective developments of CAR T-cell technologies against solid tumors.

scholarly journals New Generation Chimeric Antigen Receptor T-Cell Therapy (CoupledCAR) Induces High Rate Remissions in Solid Tumor

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4631-4631
Author(s):  
Lei Xiao
Keyword(s):  
Clinical Trials ◽  
T Cells ◽  
Thyroid Cancer ◽  
T Cell ◽  
Cell Therapy ◽  
Solid Tumors ◽  
Tumor Cells ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T

New Generation Chimeric Antigen Receptor T-Cell Therapy ( CoupledCAR ) Induces High Rate Remissions in Solid Tumor Yu Liu1,Song Li2,Youli Luo3,Haixia Song4,Chengfei Pu5, Zhiyuan Cao 5, Cheng Lu5,Yang Hang5,Xi Huang5,Xiaogang Shen5 ,Xiaojun Hu3 , Renbin Liu1,Xiuwen Wang2,Junjie Mao3,Shihong Wei4 ,Zhao Wu5and Lei Xiao5* 1.The Third Affiliated Hospital, SUN YAT-SEN University 2.Qilu Hospital of Shandong University 3.The Fifth Affiliated Hospital, SUN YAT-SEN University 4.Gansu Procincial Cancer Hospital 5.Innovative Cellular Therapeutics *Corresponding to: Lei Xiao, [email protected] Chimeric antigen receptor (CAR) T cell therapy made significant progress for treating blood cancer such as leukemia, lymphoma, and myeloma. However, the therapy faces many challenges, such as physical barrier, tumor microenvironment immunosuppression, tumor heterogeneity, target specificity, and cell expansion in vivo for treatment of solid tumors Conventional CAR T cell therapy showed weak CAR T expansion in patients and thus achieved no or little response for treating solid tumors. Here, we generated "CoupledCAR" T cells including an anti-TSHR CAR molecule. Compared with conventional CART cells,these "CoupledCAR" T cells successfully improved the expansion of CART cells more than 100 times and enhanced CAR T cells' migration ability, allowing the CAR T cells to resist and infiltrate the tumor microenvironment and killed tumor cells. To verify the effect of "CoupledCAR" T cells on solid tumors, we have completed several clinical trials for different solid tumors, including two patients with thyroid cancer. Immunohistochemistry (IHC) results showed that thyroid stimulating hormone receptors (TSHR) were highly expressed in thyroid cancer cells. In vitro co-culture experiments showed that TSHR CAR T cells specifically recognized and killed TSHR-positive tumor cells. Animal experiments showed that TSHR CAR T cells inhibited the proliferation of TSHR-positive tumor cells. Therefore, we designed "CoupledCAR" T cells expressing a binding domain against TSHR. Further,we did clinical trials of two group patients that were successfully treated using conventional TSHR CAR T cells and the "CoupledCAR" T cells, respectively. In the first group using conventional TSHR CAR T cells, patients showed weak cell expansion and less migration ability. In the group using TSHR "CoupledCAR" T cells, patients showed rapid expansion of CAR T cells and killing of tumor cells. One month after infusion (M1), the patient was evaluated as PR(Partial Response): the lymph node metastasis disappeared, and thoracic paratracheal tumors decreased significantly. Three months after infusion (M3), the patient was evaluated as a durable response, and the tumor tissue was substantially smaller than M1. Further, two patients with colonrectal cancer were enrolled in this trial and infused "CoupledCAR" T cells. One patient achieved PR and the other one achieved SD (Stable Disease). Therefore, "CoupledCAR" T cells can effectively promote expansion, migration and killing ability of CAR T cells in patients with thyroid cancer. "CoupledCAR" T cell technology is a technological platform, which may be used to treat other cancer types. Next, we are recruiting more patients with solid tumors in clinical trials using "CoupledCAR" T cells. Disclosures No relevant conflicts of interest to declare.

scholarly journals The roles of T cell competition and stochastic extinction events in chimeric antigen receptor T cell therapy

2021 ◽  
Vol 288 (1947) ◽  
Author(s):  
Gregory J. Kimmel ◽  
Frederick L. Locke ◽  
Philipp M. Altrock
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

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.

scholarly journals Efficient elimination of primary B-ALL cells in vitro and in vivo using a novel 4-1BB-based CAR targeting a membrane-distal CD22 epitope

2020 ◽  
Vol 8 (2) ◽  
pp. e000896
Author(s):  
Talia Velasco-Hernandez ◽  
Samanta Romina Zanetti ◽  
Heleia Roca-Ho ◽  
Francisco Gutierrez-Aguera ◽  
Paolo Petazzi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
T Cell Therapy ◽  
High Affinity ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

BackgroundThere are few therapeutic options available for patients with B-cell acute lymphoblastic leukemia (B-ALL) relapsing as CD19– either after chemotherapy or CD19-targeted immunotherapies. CD22-chimeric antigen receptor (CAR) T cells represent an attractive addition to CD19-CAR T cell therapy because they will target both CD22+CD19– B-ALL relapses and CD19– preleukemic cells. However, the immune escape mechanisms from CD22-CAR T cells, and the potential contribution of the epitope binding of the anti-CD22 single-chain variable fragment (scFv) remain understudied.MethodsHere, we have developed and comprehensively characterized a novel CD22-CAR (clone hCD22.7) targeting a membrane-distal CD22 epitope and tested its cytotoxic effects against B-ALL cells both in in vitro and in vivo assays.ResultsConformational epitope mapping, cross-blocking, and molecular docking assays revealed that the hCD22.7 scFv is a high-affinity binding antibody which specifically binds to the ESTKDGKVP sequence, located in the Ig-like V-type domain, the most distal domain of CD22. We observed efficient killing of B-ALL cells in vitro, although the kinetics were dependent on the level of CD22 expression. Importantly, we show an efficient in vivo control of patients with B-ALL derived xenografts with diverse aggressiveness, coupled to long-term hCD22.7-CAR T cell persistence. Remaining leukemic cells at sacrifice maintained full expression of CD22, ruling out CAR pressure-mediated antigen loss. Finally, the immunogenicity capacity of this hCD22.7-scFv was very similar to that of other CD22 scFv previously used in adoptive T cell therapy.ConclusionsWe report a novel, high-affinity hCD22.7 scFv which targets a membrane-distal epitope of CD22. 4-1BB-based hCD22.7-CAR T cells efficiently eliminate clinically relevant B- CD22high and CD22low ALL primary samples in vitro and in vivo. Our study supports the clinical translation of this hCD22.7-CAR as either single or tandem CD22–CD19-CAR for both naive and anti-CD19-resistant patients with B-ALL.

Quality Assessment of Pre-Clinical Studies of Chimeric Antigen Receptor T-Cell Therapy Products: A Point of Focus On Safety

2021 ◽  
Vol 16 ◽  
Author(s):  
Vikas Maharshi ◽  
Diksha Diksha ◽  
Pooja Gupta
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Chimeric Antigen Receptor ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Background: Serious adverse reactions have been reported with the use of chimeric antigen receptor (CAR) T-cell therapy in clinical setting despite the success of these products in pre-clinical stages of development. Objective: We evaluated the quality of available pre-clinical safety data of CAR T-cell therapy products. Methods: A 21 items safety-checklist was designed specifically for CAR T-cell. Literature was searched using search/MeSH terms in PubMed (October 2019 – February 2020). Studies were screened from title and abstract. Original pre-clinical researches related to CAR T-cell anti-cancer therapy were included. Results: Of the search results, 152 studies (3 in vivo, 39 in vitro, and 110 combined) were included. Only 7.9% studies were specifically designed to evaluate/ improve product safety. Eleven studies included target antigen(s) and no study included co-stimulatory molecule(s) expressed exclusively by tumor tissue and/or CAR T-cells. One study used CRISPR-Cas9 for CAR gene insertion. The use of switch-off mechanism and purity assessment of CAR T-cell products were reported in 13.2% and 8.6% studies respectively. Of the 149 studies with in vivo component, immuno-competent animal models were used in 24.8%. Measurement of blood pressure, temperature, body weight and serum cytokines were reported in 0, 2.7, 29.2 and 27.4% studies respectively. The tissue distribution and CAR T-cells persistence were reported in 26.5% studies. Conclusion: Majority of the checklist parameters were not reported in the pre-clinical publications to be adequately predictive of the safety of CAR T-cells in a clinical setting.

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