scholarly journals Cyclophosphamide and Fludarabine Conditioning Chemotherapy Induces a Key Homeostatic Cytokine Profile in Patients Prior to CAR T Cell Therapy

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4426-4426 ◽  
Author(s):  
Adrian Bot ◽  
John M. Rossi ◽  
Yizhou Jiang ◽  
Lynn Navale ◽  
Yueh-wei Shen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Fold Increase ◽  
Employment Equity ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Equity Ownership

Abstract This study is supported in part by funding from the Cooperative Research and Development Agreement (CRADA) between the National Cancer Institute and Kite Pharma Introduction: CAR-engineered autologous T-cell therapy has shown promising activity in relapsed/refractory B-cell malignancies in an ongoing phase 1 study (Kochenderfer et al. J Clin Oncol 2014). Lymphodepleting conditioning chemotherapy is critical for optimal CAR T-cell activity in animal models. We evaluated the effects of conditioning chemotherapy on cytokine and chemokine levels in patients dosed with anti-CD19 CAR T cells. Methods: In this National Cancer Institute clinical trial (NCT00924326), patients with relapsed/refractory B-cell malignancies received conditioning with cyclophosphamide and fludarabine daily for 3 days starting on day -5; followed by anti-CD19 CAR T cells engineered with a CAR comprising CD28 and CD3-zeta signaling domains. Forty one cytokines, chemokines and immune response related markers were measured in the blood of patients pre (day -5) and post conditioning (day 0) by using EMD Millipore Luminex® xMAP® multiplex assays. Data acquisition and analysis were performed using a Luminex 200™ instrument and xPONENT® 3.1 data analysis software. Increases in cytokine and chemokine levels were analyzed pre- and post- conditioning, and the fold-changes in cytokine and chemokine levels were analyzed relative to clinical outcome subsequent to infusion with anti-CD19 CAR T cells. Analyses were performed with the Wilcoxon rank sum test adjusted for multiplicity with a Bonferroni correction, using a nominal level of 0.006 for significance. Results: Samples from 15patients have been evaluated. There were significant increases pre- to post-conditioning in the levels of interleukin 15 (IL-15; p=0.001), interleukin 7 (IL-7; p=0.0002), and monocyte chemoattractant protein-1 (MCP-1; p<0.0025) in blood, five days after the initiation of conditioning chemotherapy. Levels of interferon-gamma induced protein 10 (IP-10) were elevated post-conditioning, but did not meet the threshold for significance (p=0.048). Compared with baseline, levels of IL-15 increased on average 13 fold and levels of IL-7, IP-10 and MCP-1, about 2 fold. Comparison of the fold-increases in IL-15 upon conditioning between responders and non-responders approached significance (p=0.01), but did not meet the threshold after multiplicity adjustment. Larger fold-change increases for responders versus non-responders were also observed with placental growth factor (PLGF) (median fold increase 2.6 v. 1.6, average fold increase 32 v 4.2), C-reactive protein (CRP) (median fold increase 3.5 v 2.4, average fold increase 6.6 v. 2.0), IP-10 (median fold increase 2.1 v. 0.7, average fold increase 2.6 v. 2.8), and interleukin 10 (IL-10) (median fold increase 1.8 v. 0.4, average fold increase 3.1 v. 2.0), but did not meet the threshold for significance. In addition to ongoing analysis of conditioning-mediated cytokine induction and clinical response, we are evaluating the impact of conditioning chemotherapy dose on cytokine levels, as well as the relationship between conditioning-related cytokines and CAR T-cell expansion and persistence. Conclusions: The data obtained to date support the hypothesis that cytokines such as IL-15 play a key role in the clinical outcomes to anti-CD19 CAR T-cell therapy. Our results demonstrate that conditioning chemotherapy significantly increases the levels of homeostatic cytokines known to regulate T-cell expansion, as well as specific pro-inflammatory cytokines and chemokines. Optimization of conditioning chemotherapy is critical to the activity of CAR T-cell therapies. Disclosures Bot: Kite Pharma: Employment, Equity Ownership. Rossi:Amgen: Equity Ownership; Kite Pharma: Employment, Equity Ownership. Jiang:Kite Pharma: Employment, Equity Ownership. Navale:Amgen: Equity Ownership; Kite Pharma: Employment, Equity Ownership. Shen:Kite Pharma: Employment, Equity Ownership. Sherman:Amgen: Equity Ownership; Kite Pharma: Employment, Equity Ownership. Mardiros:Kite Pharma: Employment, Equity Ownership. Yoder:Kite Pharma: Employment, Equity Ownership. Go:Amgen: Equity Ownership; Kite Pharma: Employment, Equity Ownership. Rosenberg:Kite Pharma: Other: CRADA between Surgery Branch-NCI and Kite Pharma. Wiezorek:Kite Pharma: Employment, Equity Ownership, Other: Officer of Kite Pharma. Chang:Kite Pharma: Employment, Equity Ownership, Other: Officer of Kite Pharma. Roberts:Kite Pharma: Employment, Equity Ownership, Other: Officer of Kite Pharma.

scholarly journals Preclinical Evaluation of ALLO-819, an Allogeneic CAR T Cell Therapy Targeting FLT3 for the Treatment of Acute Myeloid Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3921-3921 ◽  
Author(s):  
Cesar Sommer ◽  
Hsin-Yuan Cheng ◽  
Yik Andy Yeung ◽  
Duy Nguyen ◽  
Janette Sutton ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Target Cells ◽  
Employment Equity ◽  
T Cell Therapy ◽  
Cell Therapies ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Equity Ownership

Autologous chimeric antigen receptor (CAR) T cells have achieved unprecedented clinical responses in patients with B-cell leukemias, lymphomas and multiple myeloma, raising interest in using CAR T cell therapies in AML. These therapies are produced using a patient's own T cells, an approach that has inherent challenges, including requiring significant time for production, complex supply chain logistics, separate GMP manufacturing for each patient, and variability in performance of patient-derived cells. Given the rapid pace of disease progression combined with limitations associated with the autologous approach and treatment-induced lymphopenia, many patients with AML may not receive treatment. Allogeneic CAR T (AlloCAR T) cell therapies, which utilize cells from healthy donors, may provide greater convenience with readily available off-the-shelf CAR T cells on-demand, reliable product consistency, and accessibility at greater scale for more patients. To create an allogeneic product, the TRAC and CD52 genes are inactivated in CAR T cells using Transcription Activator-Like Effector Nuclease (TALEN®) technology. These genetic modifications are intended to minimize the risk of graft-versus-host disease and to confer resistance to ALLO-647, an anti-CD52 antibody that can be used as part of the conditioning regimen to deplete host alloreactive immune cells potentially leading to increased persistence and efficacy of the infused allogeneic cells. We have previously described the functional screening of a library of anti-FLT3 single-chain variable fragments (scFvs) and the identification of a lead FLT3 CAR with optimal activity against AML cells and featuring an off-switch activated by rituximab. Here we characterize ALLO-819, an allogeneic FLT3 CAR T cell product, for its antitumor efficacy and expansion in orthotopic models of human AML, cytotoxicity in the presence of soluble FLT3 (sFLT3), performance compared with previously described anti-FLT3 CARs and potential for off-target binding of the scFv to normal human tissues. To produce ALLO-819, T cells derived from healthy donors were activated and transduced with a lentiviral construct for expression of the lead anti-FLT3 CAR followed by efficient knockout of TRAC and CD52. ALLO-819 manufactured from multiple donors was insensitive to ALLO-647 (100 µg/mL) in in vitro assays, suggesting that it would avoid elimination by the lymphodepletion regimen. In orthotopic models of AML (MV4-11 and EOL-1), ALLO-819 exhibited dose-dependent expansion and cytotoxic activity, with peak CAR T cell levels corresponding to maximal antitumor efficacy. Intriguingly, ALLO-819 showed earlier and more robust peak expansion in mice engrafted with MV4-11 target cells, which express lower levels of the antigen relative to EOL-1 cells (n=2 donors). To further assess the potency of ALLO-819, multiple anti-FLT3 scFvs that had been described in previous reports were cloned into lentiviral constructs that were used to generate CAR T cells following the standard protocol. In these comparative studies, the ALLO-819 CAR displayed high transduction efficiency and superior performance across different donors. Furthermore, the effector function of ALLO-819 was equivalent to that observed in FLT3 CAR T cells with normal expression of TCR and CD52, indicating no effects of TALEN® treatment on CAR T cell activity. Plasma levels of sFLT3 are frequently increased in patients with AML and correlate with tumor burden, raising the possibility that sFLT3 may act as a decoy for FLT3 CAR T cells. To rule out an inhibitory effect of sFLT3 on ALLO-819, effector and target cells were cultured overnight in the presence of increasing concentrations of recombinant sFLT3. We found that ALLO-819 retained its killing properties even in the presence of supraphysiological concentrations of sFLT3 (1 µg/mL). To investigate the potential for off-target binding of the ALLO-819 CAR to human tissues, tissue cross-reactivity studies were conducted using a recombinant protein consisting of the extracellular domain of the CAR fused to human IgG Fc. Consistent with the limited expression pattern of FLT3 and indicative of the high specificity of the lead scFv, no appreciable membrane staining was detected in any of the 36 normal tissues tested (n=3 donors). Taken together, our results support clinical development of ALLO-819 as a novel and effective CAR T cell therapy for the treatment of AML. Disclosures Sommer: Allogene Therapeutics, Inc.: Employment, Equity Ownership. Cheng:Allogene Therapeutics, Inc.: Employment, Equity Ownership. Yeung:Pfizer Inc.: Employment, Equity Ownership. Nguyen:Allogene Therapeutics, Inc.: Employment, Equity Ownership. Sutton:Allogene Therapeutics, Inc.: Employment, Equity Ownership. Melton:Allogene Therapeutics, Inc.: Employment, Equity Ownership. Valton:Cellectis, Inc.: Employment, Equity Ownership. Poulsen:Allogene Therapeutics, Inc.: Employment, Equity Ownership. Djuretic:Pfizer, Inc.: Employment, Equity Ownership. Van Blarcom:Allogene Therapeutics, Inc.: Employment, Equity Ownership. Chaparro-Riggers:Pfizer, Inc.: Employment, Equity Ownership. Sasu:Allogene Therapeutics, Inc.: Employment, Equity Ownership.

scholarly journals Phase I Study of AUTO3, a Bicistronic Chimeric Antigen Receptor (CAR) T-Cell Therapy Targeting CD19 and CD22, in Pediatric Patients with Relapsed/Refractory B-Cell Acute Lymphoblastic Leukemia (r/r B-ALL): Amelia Study

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2620-2620 ◽  
Author(s):  
Persis J Amrolia ◽  
Robert Wynn ◽  
Rachael E Hough ◽  
Ajay Vora ◽  
Denise Bonney ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Employment Equity ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T ◽  
Equity Ownership

Introduction CAR T-cell therapies directed against CD19 or CD22 have shown remarkable activity in r/r B-ALL but relapse due to target antigen down-regulation/loss has been the major cause of treatment failure. To address this, we developed AUTO3, a CAR T-cell therapy designed to target CD19 and CD22 simultaneously. Preliminary results of this study showed an acceptable safety profile and encouraging efficacy in pediatric r/r B-ALL (all 6 patients treated in active doses ≥3 x 106 CAR T-cells/ Kg achieved complete remission (CR) with negative minimal residual disease (MRD) (Amrolia et al, Blood 2018 132:279). Here we present the updated results of CAR naïve patients treated at the active doses. Methods & Patients We constructed a bicistronic retroviral vector encoding both an anti-CD19 CAR and an anti-CD22 CAR. This second-generation CAR incorporated an OX40 co-stimulatory domain for the CD19 CAR and a 41BB for the CD22 CAR. The cell product was manufactured on a semi-automated/closed process. Patients (aged 1‒24 years) with high risk relapsed (IBFM criteria) or refractory B-ALL, adequate performance score/organ function, an absolute lymphocyte count ≥0.5 x 109/L are eligible. Patients with CNS Grade 3 disease, active graft versus host disease are excluded. Patients receive lymphodepletion with 30 mg/m2/day fludarabine x 4 days and 500 mg/m2/day cyclophosphamide x 2 days prior to AUTO3 infusion. Three dose levels were explored (1 x 106, 3 x 106, and 5 x 106 cells/kg), CAR T cells are infused as a single (for <25% blasts) or split (for ≥25% blasts) dose based on leukemia burden. Bridging therapy is allowed during the manufacturing period. The primary endpoint is the frequency of dose-limiting toxicities (DLTs) and key secondary endpoints include morphological/MRD negative CR rate, disease-free survival, overall survival, as well as AUTO3 levels and persistence in blood and bone marrow. Results As of the data cut-off date (June 17, 2019), 10 patients received AUTO3 at 3 x 106 cells/Kg (n= 5, of whom 1 received split dose) or 5 x 106 CAR T-cells/Kg (n= 5, all of them received single infusion). The median transduction efficiency was 15.5% (range 8.6‒39.3%). Median age was 8.5 years (range 5‒16 years) and 5 (50%) patients had prior haemopoietic stem cell transplant (HSCT). One patient (10%) had prior anti-CD19 CAR-T cells. The disease burden at Day ‒7 ranged from 0 to 38% (median 7.5%) blasts. Among the 10 treated patients, 2 have not completed the 30 days post-infusion DLT observation period as of the cut-off date. No deaths or DLTs were observed. MTD has not yet been reached. The most common grade (Gr) ≥3 adverse events were neutropenia (60%), anaemia (50%), pyrexia (40%), febrile neutropenia (40%) and thrombocytopenia (30%). Eight patients (80%) had Gr 1 cytokine release syndrome (CRS), one (10%) had Gr 2 CRS; no ≥Gr 3 CRS was observed. Only one patient was treated with tocilizumab and none required admission to ICU due to CRS. One patient (10%) experienced Gr 1 neurotoxicity; no ≥ Gr 2 neurotoxicity was reported. Among the 9 CAR naïve patients, 7 (4 in the 3 x 106 cells/Kg dose cohort, 3 in the 5 x 106 cells/Kg dose cohort) had a minimum of 8 weeks' follow up and were evaluable for efficacy analysis. All 7 patients achieved CR/CRi (100%) following AUTO3 infusion as well as molecular negative remission (100%). After a median follow-up of 8 months (range 2-12), emergence of MRD by PCR occurred in four patients, lack of persistence of circulating CAR T-cells was observed in 3 of the 4 patients. Three relapses were reported including one with CD19 negative/CD22 low expression at 1 year after treatment. One patient in ongoing molecular remission proceeded to HSCT. All the remaining 4 patients in ongoing CR/CRi maintain B-cell aplasia. The median CAR T-cell expansion (expressed as vector copy number per microgram of DNA) at peak was 102K (range 56-128). The median persistence of CAR-T cells in blood was 180 days (range 21-330). Updated data with longer follow up and additional patient data will be presented. Conclusion This interim data analysis demonstrates that AUTO3 at ≥3 x 106 cells dose achieved 100% molecular remission rate with a favourable safety profile, no ≥ Gr 3 CRS or ≥ Gr 2 neurotoxicity was reported. The most common cause of relapse was antigen positive relapse due to lack of CAR T cell persistence. Evaluation of patients with a modified manufacturing process is planned. Disclosures Amrolia: UCLB: Patents & Royalties. Clark:Autolus Ltd: Employment, Equity Ownership. Al-Hajj:Autolus Therapeutics: Employment, Equity Ownership. Cordoba:Autolus: Employment, Equity Ownership. Kotsopoulou:Autolus Therapeutics: Employment, Equity Ownership. Khokhar:Autolus Therapeutics: Employment, Equity Ownership. Pule:Autolus: Employment, Equity Ownership, Patents & Royalties. Peddareddigari:Autolus Therapeutics: Employment, Equity Ownership.

scholarly journals Anti-Mesothelin CAR T cell therapy for malignant mesothelioma

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Laura Castelletti ◽  
Dannel Yeo ◽  
Nico van Zandwijk ◽  
John E. J. Rasko
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Malignant Mesothelioma ◽  
Oncolytic Viruses ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

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.

scholarly journals Metabolic and Mitochondrial Functioning in Chimeric Antigen Receptor (CAR)—T Cells

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 ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Chimeric Antigen Receptor ◽  
Metabolic State ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

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.

IMMU-45. COMBINATION OF EGFRVIII CAR T-CELL THERAPY AND PARACRINE GAM MODULATION FOR THE TREATMENT OF GBM

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi102-vi103
Author(s):  
Tomás A Martins ◽  
Marie-Françoise Ritz ◽  
Tala Shekarian ◽  
Philip Schmassmann ◽  
Deniz Kaymak ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Differential Expression Analysis ◽  
Dependent Manner ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Abstract The GBM immune tumor microenvironment mainly consists of protumoral glioma-associated microglia and macrophages (GAMs). We have previously shown that blockade of CD47, a ‘don't eat me’-signal overexpressed by GBM cells, rescued GAMs' phagocytic function in mice. However, monotherapy with CD47 blockade has been ineffective in treating human solid tumors to date. Thus, we propose a combinatorial approach of local CAR T cell therapy with paracrine GAM modulation for a synergistic elimination of GBM. We generated humanized EGFRvIII CAR T-cells by lentiviral transduction of healthy donor human T-cells and engineered them to constitutively release a soluble SIRPγ-related protein (SGRP) with high affinity towards CD47. Tumor viability and CAR T-cell proliferation were assessed by timelapse imaging analysis in co-cultures with endogenous EGFRvIII-expressing BS153 cells. Tumor-induced CAR T-cell activation and degranulation were confirmed by flow cytometry. CAR T-cell secretomes were analyzed by liquid chromatography-mass spectrometry. Immunocompromised mice were orthotopically implanted with EGFRvIII+ BS153 cells and treated intratumorally with a single CAR T-cell injection. EGFRvIII and EGFRvIII-SGRP CAR T-cells killed tumor cells in a dose-dependent manner (72h-timepoint; complete cytotoxicity at effector-target ratio 1:1) compared to CD19 controls. CAR T-cells proliferated and specifically co-expressed CD25 and CD107a in the presence of tumor antigen (24h-timepoint; EGFRvIII: 59.3±3.00%, EGFRvIII-SGRP: 52.6±1.42%, CD19: 0.1±0.07%). Differential expression analysis of CAR T-cell secretomes identified SGRP from EGFRvIII-SGRP CAR T-cell supernatants (-Log10qValue/Log2fold-change= 3.84/6.15). Consistent with studies of systemic EGFRvIII CAR T-cell therapy, our data suggest that intratumoral EGFRvIII CAR T-cells were insufficient to eliminate BS153 tumors with homogeneous EGFRvIII expression in mice (Overall survival; EGFRvIII-treated: 20%, CD19-treated: 0%, n= 5 per group). Our current work focuses on the functional characterization of SGRP binding, SGRP-mediated phagocytosis, and on the development of a translational preclinical model of heterogeneous EGFRvIII expression to investigate an additive effect of CAR T-cell therapy and GAM modulation.

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 Feasibility, and Efficacy of Donor-Derived cd19-Targeted Car t-Cell Therapy in Refractory/Relapsed(r/r)b-Cell Acute Lymphoblastic Leukemia (b-all) Patients

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 4-6
Author(s):  
Xian Zhang ◽  
Junfang Yang ◽  
Wenqian Li ◽  
Gailing Zhang ◽  
Yunchao Su ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T ◽  
Grade 3

Backgrounds As CAR T-cell therapy is a highly personalized therapy, process of generating autologous CAR-T cells for each patient is complex and can still be problematic, particularly for heavily pre-treated patients and patients with significant leukemia burden. Here, we analyzed the feasibility and efficacy in 37 patients with refractory/relapsed (R/R) B-ALL who received CAR T-cells derived from related donors. Patients and Methods From April 2017 to May 2020, 37 R/R B-ALL patients with a median age of 19 years (3-61 years), were treated with second-generation CD19 CAR-T cells derived from donors. The data was aggregated from three clinical trials (www.clinicaltrials.gov NCT03173417; NCT02546739; and www.chictr.org.cn ChiCTR-ONC-17012829). Of the 37 patients, 28 were relapsed following allogenic hematopoietic stem cell transplant (allo-HSCT) and whose lymphocytes were collected from their transplant donors (3 HLA matched sibling and 25 haploidentical). For the remaining 9 patients without prior transplant, the lymphocytes were collected from HLA identical sibling donors (n=5) or haploidentical donors (n=4) because CAR-T cells manufacture from patient samples either failed (n=5) or blasts in peripheral blood were too high (&gt;40%) to collect quality T-cells. The median CAR-T cell dose infused was 3×105/kg (1-30×105/kg). Results For the 28 patients who relapsed after prior allo-HSCT, 27 (96.4%) achieved CR within 30 days post CAR T-cell infusion, of which 25 (89.3%) were minimal residual disease (MRD) negative. Within one month following CAR T-cell therapy, graft-versus-host disease (GVHD) occurred in 3 patients including 1 with rash and 2 with diarrhea. A total of 19 of the 28 (67.9%) patients had cytokine release syndrome (CRS), including two patients (7.1%) with Grade 3-4 CRS. Four patients had CAR T-cell related neurotoxicity including 3 with Grade 3-4 events. With a medium follow up of 103 days (1-669days), the median overall survival (OS) was 169 days (1-668 days), and the median leukemia-free survival (LFS) was 158 days (1-438 days). After CAR T-cell therapy, 15 patients bridged into a second allo-HSCT and one of 15 patients (6.7%) relapsed following transplant, and two died from infection. There were 11 patients that did not receive a second transplantation, of which three patients (27.3%) relapsed, and four parents died (one due to relapse, one from arrhythmia and two from GVHD/infection). Two patients were lost to follow-up. The remaining nine patients had no prior transplantation. At the time of T-cell collection, the median bone marrow blasts were 90% (range: 18.5%-98.5%), and the median peripheral blood blasts were 10% (range: 0-70%). CR rate within 30 days post CAR-T was 44.4% (4/9 cases). Six patients developed CRS, including four with Grade 3 CRS. Only one patient had Grade 3 neurotoxicity. No GVHD occurred following CAR T-cell therapy. Among the nine patients, five were treated with CAR T-cells derived from HLA-identical sibling donors and three of those five patients achieved CR. One patient who achieved a CR died from disseminated intravascular coagulation (DIC) on day 16. Two patients who achieved a CR bridged into allo-HSCT, including one patient who relapsed and died. One of two patients who did not response to CAR T-cell therapy died from leukemia. Four of the nine patients were treated with CAR T-cells derived from haploidentical related donors. One of the four cases achieved a CR but died from infection on day 90. The other three patients who had no response to CAR T-cell therapy died from disease progression within 3 months (7-90 days). Altogether, seven of the nine patients died with a median time of 19 days (7-505 days). Conclusions We find that manufacturing CD19+ CAR-T cells derived from donors is feasible. For patients who relapse following allo-HSCT, the transplant donor derived CAR-T cells are safe and effective with a CR rate as high as 96.4%. If a patient did not have GVHD prior to CAR T-cell therapy, the incidence of GVHD following CAR T-cell was low. Among patients without a history of transplantation, an inability to collect autologous lymphocytes signaled that the patient's condition had already reached a very advanced stage. However, CAR T-cells derived from HLA identical siblings can still be considered in our experience, no GVHD occurred in these patients. But the efficacy of CAR T-cells from haploidentical donors was very poor. Disclosures No relevant conflicts of interest to declare.

scholarly journals Allogeneic Hematopoietic Cell Transplantation Is Critical to Maintain Remissions after CD19-CAR T-Cell Therapy for Pediatric ALL: A Single Center Experience

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 39-40
Author(s):  
Aimee C Talleur ◽  
Renee M. Madden ◽  
Amr Qudeimat ◽  
Ewelina Mamcarz ◽  
Akshay Sharma ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
T Cell Therapy ◽  
Allogeneic Hct ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

CD19-CAR T-cell therapy has shown remarkable efficacy in pediatric patients with relapsed and/or refractory B-cell acute lymphoblastic leukemia (r/r ALL). Despite high short-term remission rates, many responses are not durable and the best management of patients who achieve a complete response (CR) post-CAR T-cell therapy remains controversial. In particular, it is unclear if these patients should be observed or proceed to consolidative allogeneic hematopoietic cell transplantation (HCT). To address this question, we reviewed the clinical course of all patients (n=22) who received either an investigational CAR T-cell product (Phase I study: SJCAR19 [NCT03573700]; n=12) or tisagenlecleucel (n=10) at our institution. The investigational CD19-CAR T cells were generated by a standard cGMP-compliant procedure using a lentiviral vector encoding a 2nd generation CD19-CAR with a FMC63-based CD19 binding domain, CD8a stalk and transmembrane domain, and 41BB.ζ signaling domain. Patients received therapy between 8/2018 and 3/2020. All products met manufacturing release specifications. Within the entire cohort, median age at time of infusion was 12.3 years old (range: 1.8-23.5) and median pre-infusion marrow burden using flow-cytometry minimal residual disease (MRD) testing was 6.8% (range: 0.003-100%; 1 patient detectable by next-generation sequencing [NGS] only). All patients received lymphodepleting chemotherapy (fludarabine, 25mg/m2 daily x3, and cyclophosphamide, 900mg/m2 daily x1), followed by a single infusion of CAR T-cells. Phase I product dosing included 1x106 CAR+ T-cells/kg (n=6) or 3x106 CAR+ T-cells/kg (n=6). Therapy was well tolerated, with a low incidence of cytokine release syndrome (any grade: n=10; Grade 3-4: n=4) and neurotoxicity (any grade: n=8; Grade 3-4: n=3). At 4-weeks post-infusion, 15/22 (68.2%) patients achieved a CR in the marrow, of which 13 were MRDneg (MRDneg defined as no detectable leukemia by flow-cytometry, RT-PCR and/or NGS, when available). Among the 2 MRDpos patients, 1 (detectable by NGS only) relapsed 50 days after CAR T-cell infusion and 1 died secondary to invasive fungal infection 35 days after infusion. Within the MRDneg cohort, 6/13 patients proceeded to allogeneic HCT while in MRDneg/CR (time to HCT, range: 1.8-2.9 months post-CAR T-cell infusion). All 6 HCT recipients remain in remission with a median length of follow-up post-HCT of 238.5 days (range 19-441). In contrast, only 1 (14.3%) patient out of 7 MRDneg/CR patients who did not receive allogeneic HCT, remains in remission with a follow up of greater 1 year post-CAR T-cell infusion (HCT vs. no HCT: p&lt;0.01). The remaining 6 patients developed recurrent detectable leukemia within 2 to 9 months post-CAR T-cell infusion (1 patient detectable by NGS only). Notably, recurring leukemia remained CD19+ in 4 of 5 evaluable patients. All 4 patients with CD19+ relapse received a 2nd CAR T-cell infusion (one in combination with pembrolizumab) and 2 achieved MRDneg/CR. There were no significant differences in outcome between SJCAR19 study participants and patients who received tisagenlecleucel. With a median follow up of one year, the 12 month event free survival (EFS) of all 22 patients is 25% (median EFS: 3.5 months) and the 12 month overall survival (OS) 70% (median OS not yet reached). In conclusion, infusion of investigational and FDA-approved autologous CD19-CAR T cells induced high CR rates in pediatric patients with r/r ALL. However, our current experience shows that sustained remission without consolidative allogeneic HCT is not seen in most patients. Our single center experience highlights not only the need to explore maintenance therapies other than HCT for MRDneg/CR patients, but also the need to improve the in vivo persistence of currently available CD19-CAR T-cell products. Disclosures Sharma: Spotlight Therapeutics: Consultancy; Magenta Therapeutics: Other: Research Collaboration; CRISPR Therapeutics, Vertex Pharmaceuticals, Novartis: Other: Clinical Trial PI. Velasquez:St. Jude: Patents & Royalties; Rally! Foundation: Membership on an entity's Board of Directors or advisory committees. Gottschalk:Patents and patent applications in the fields of T-cell & Gene therapy for cancer: Patents & Royalties; TESSA Therapeutics: Other: research collaboration; Inmatics and Tidal: Membership on an entity's Board of Directors or advisory committees; Merck and ViraCyte: Consultancy.

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.

The efficacy and safety of anti-CLL1 based CAR-T cells in children with relapsed or refractory acute myeloid leukemia: A multicenter interim analysis.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 10000-10000
Author(s):  
Hui Zhang ◽  
Chaoke Bu ◽  
Zhiyong Peng ◽  
min luo ◽  
Chunfu Li
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Myeloid Leukemia ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T ◽  
Refractory Acute Myeloid Leukemia

10000 Background: Chimeric antigen receptor (CAR)-T cell therapy has demonstrated remarkable success in treating a variety of blood cancers, such as CD19 CAR-T for B-cell malignancies and BCMA CAR-T for myeloid myeloma (MM). However, similar achievement has yet to be replicated in patients with relapsed and refractory acute myeloid leukemia (R/R AML), primarily due to the AML heterogeneity, making it difficult to find an ideal CAR-T target. Previous efforts have targeted single CD33, CD123, LeY, NKG2D, or CD70 receptors, but the overall response rate is very disappointed. To address these challenges, we aim to find an effective target for AML without the need for the hematopoietic stem cells transplant (HSCT). In our study, CLL1 is chosen as a promising target as it is not expressed on normal HSCs, but highly expressed on AML blasts cells and leukemia stem cells (LSCs). Here we report the interim analysis from a Phase I clinical trial using anti-CLL1 based CAR-T cells to treat children with R/R AML. The primary and secondary objectives were to evaluate the safety and anti-AML responses, respectively, with long-term prognosis within those patients who did not receive allogeneic HSCT (allo-HSCT) as an additional objective. Methods: We have generated a 2nd generation of CLL1 CAR-T, the extracellular scFv was derived from a murine CLL1 monoclonal antibody, which was generated by hybridoma technology. Autologous CAR-T cells were manufactured in a cGMP facility. Between Oct 2019 and Jan 2021, 11 pediatric R/R AML patients were infused. CLL1 or CLL1-CD33 dual CAR-T cells were given by a dose at 0.3-1x106/kg with a single dose after lymphodepleting conditioning with cyclophosphamide/fludarabine(Cy/Flu). Results: Of the 11 patients infused, Grade 3-4 hematologic adverse events were observed before and during CAR-T cell infusion, and no dose-limiting toxicities were observed. Meanwhile, grade 1-3 cytokine release syndrome was observed but without any lethal events. All the adverse effects were resolved after guideline-directed intervention. Anti-CLL1 CAR-T cells efficiently expanded in vivo, the median expansion peaking time was at Day 8. For these 11 R/R-AML patients, 10 patients completely responded to anti-CLL1 based CAR-T cell therapy, with CLL1 positive AML blast eliminated within one month. Among the responded 10 patients, 5 patients reached CR/MRD-, 3 patients reached CR/MRD+, 1 patient reached PR and 1 patient showed SD, with only CLL1 negative AML cells. Conclusions: Our study demonstrated that 10/11 patients responded to CLL1 CAR-T cell therapy within one month. For patients showing MRD+ with CLL1 negative AML blast, chemotherapy like Azacitidine, and combined with HSCT may help those patients to reach complete response. These initial results suggested that anti-CLL1 base CAR-T cells can be a well-tolerated and candidate option for treating children with R/R-AML. Clinical trial information: ChiCTR1900027684.

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