scholarly journals Overexpression of Rorγt in CAR T Cells Improves Persistence and Reduces Exhaustion

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2801-2801
Author(s):  
Jennifer Cimons ◽  
Mark Eric Kohler ◽  
Michael Yarnell ◽  
Terry J. Fry

Abstract Although T cells modified with a chimeric antigen receptor (CAR) are highly effective, durability of remissions may be limited by the poor persistence of adoptively transferred CAR T cells in patients. Growing evidence supports the idea that the pre-infusion phenotype of CAR T cells affects the efficacy of CAR T cell therapies, in part due to the increased ability of certain subsets of CAR T cells to persist long-term. Studies using conventional T cells have suggested that adoptive transfer of T cells programmed to have Th17/Tc17 effector functions can increase the anti-tumor efficacy and persistence of transferred cells when compared to adoptive transfer of non-Th17/Tc17 cells. However, standard CAR formats currently in clinical use that contain either a CD28 or 4-1BB costimulatory domain fail to generate substantial numbers of Th17/Tc17-like cells. Thus, few studies have investigated whether Th17/Tc17 CAR T cells could enhance the efficacy of CAR T cell therapies. We generated a multi-cistronic lentiviral construct encoding ROR-related Orphan Receptor gamma (RORγt), a key lineage-specifying transcription factor involved in Th17/Tc17 differentiation, followed by a murine CAR targeting CD19 that contains a CD28 costimulatory domain (1928z). RORγt expression did not hinder degranulation in response to CAR antigen upon co-culture with E2aPbx, a murine acute lymphoblastic leukemia cell line. Significantly higher numbers of RORγt-1928z CAR T cells produce IL-17 compared to 1928z CAR T cells (p<0.0001) suggesting that RORγt expression is sufficient to program type-17 effector functions in CAR T cells. To determine the impact of RORγt overexpression on CAR T cell phenotype and persistence in vivo, we adoptively transferred 1x10 6 1928z or RORγt-1928z CAR T cells into leukemia-bearing C57Bl6/J recipients and analyzed CAR T cells from the bone marrow at days 4, 11, and 31. As early as day 4 post-transfer, RORγt-1928z CAR T cells were present at significantly higher numbers than 1928z CAR T cells, and remained higher through Day 31 (0.16% of the bone marrow for 1928z CAR T cells vs 0.84% of the bone marrow for RORγt-1928z CARs; p= 0.0012, n=5 mice per group. The RORγt-1928z CAR T cells were enriched for an effector/effector memory phenotype (CD62L-) compared to 1928z CAR T cells, which were mostly of a central memory phenotype (CD62L+). Interestingly, the RORγt-1928z CAR T cells were enriched for IL-7Rα+ cells and expressed more IL7Rα than their 1928z CAR T cell counterparts (p=0.0012), suggesting an increased capacity for self-renewal in RORγt-1928z CAR T cells. Previous work from our lab has demonstrated that CAR T cells that persist after leukemia clearance have an exhausted phenotype, with increased expression of PD1 and a reduced functionality 1. After leukemia clearance, RORγt-1928z CAR T cells expressed lower levels of PD1 than their 1928z counterparts (p<0.0001). Finally, 1928z CAR T cells form a population of Eomes hiPD1 hi cells, associated with terminal exhaustion, that is absent in the RORγt-1928z CAR T cells. Taken together, our preliminary data demonstrates that overexpression of RORγt is sufficient to program type-17 effector functions in CAR T cells and suggests that RORγt overexpression can enhance the ability of CAR T cells to persist and self-renew, and prevent terminal exhaustion. RORγt overexpression may enhance persistence of CAR T cells and durability of remissions in hematologic malignancies. Furthermore, RORγt overexpression may also be a strategy to enhance CAR T cell efficacy against solid tumors, where an immunosuppressive microenvironment contributes to T cell dysfunction. Yinmeng Yang, Mark Eric Kohler, Terry J. Fry; Effect of Chronic Endogenous Antigen Stimulation on CAR T Cell Persistence and Memory Formation. Blood2017; 130 (Supplement 1): 166. doi: https://doi.org/10.1182/blood.V130.Suppl_1.166.16 Disclosures Fry: Sana Biotechnology: Current Employment, Current equity holder in publicly-traded company.

2021 ◽  
Vol 9 (6) ◽  
pp. e002140
Author(s):  
Giulia Pellizzari ◽  
Olivier Martinez ◽  
Silvia Crescioli ◽  
Robert Page ◽  
Ashley Di Meo ◽  
...  

BackgroundCancer immunotherapy with monoclonal antibodies and chimeric antigen receptor (CAR) T cell therapies can benefit from selection of new targets with high levels of tumor specificity and from early assessments of efficacy and safety to derisk potential therapies.MethodsEmploying mass spectrometry, bioinformatics, immuno-mass spectrometry and CRISPR/Cas9 we identified the target of the tumor-specific SF-25 antibody. We engineered IgE and CAR T cell immunotherapies derived from the SF-25 clone and evaluated potential for cancer therapy.ResultsWe identified the target of the SF-25 clone as the tumor-associated antigen SLC3A2, a cell surface protein with key roles in cancer metabolism. We generated IgE monoclonal antibody, and CAR T cell immunotherapies each recognizing SLC3A2. In concordance with preclinical and, more recently, clinical findings with the first-in-class IgE antibody MOv18 (recognizing the tumor-associated antigen Folate Receptor alpha), SF-25 IgE potentiated Fc-mediated effector functions against cancer cells in vitro and restricted human tumor xenograft growth in mice engrafted with human effector cells. The antibody did not trigger basophil activation in cancer patient blood ex vivo, suggesting failure to induce type I hypersensitivity, and supporting safe therapeutic administration. SLC3A2-specific CAR T cells demonstrated cytotoxicity against tumor cells, stimulated interferon-γ and interleukin-2 production in vitro. In vivo SLC3A2-specific CAR T cells significantly increased overall survival and reduced growth of subcutaneous PC3-LN3-luciferase xenografts. No weight loss, manifestations of cytokine release syndrome or graft-versus-host disease, were detected.ConclusionsThese findings identify efficacious and potentially safe tumor-targeting of SLC3A2 with novel immune-activating antibody and genetically modified cell therapies.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3921-3921 ◽  
Author(s):  
Cesar Sommer ◽  
Hsin-Yuan Cheng ◽  
Yik Andy Yeung ◽  
Duy Nguyen ◽  
Janette Sutton ◽  
...  

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.


Author(s):  
Aaron J Harrison ◽  
Xin Du ◽  
Bianca von Scheidt ◽  
Michael H Kershaw ◽  
Clare Y Slaney

Abstract Co-stimulation is a fundamental component of T cell biology and plays a key role in determining the quality of T cell proliferation, differentiation and memory formation. T cell-based immunotherapies, such as chimeric antigen receptor (CAR) T cell immunotherapy, are no exception. Solid tumours have largely been refractory to CAR T cell therapy owing to an immunosuppressive microenvironment which limits CAR T cell persistence and effector function. In order to eradicate solid cancers, increasingly sophisticated strategies are being developed to deliver these vital co-stimulatory signals to CAR T cells, often specifically within the tumour microenvironment. These include designing novel co-stimulatory domains within the CAR or other synthetic receptors, arming CAR T cells with cytokines or using CAR T cells in combination with agonist antibodies. This review discusses the evolving role of co-stimulation in CAR T cell therapies and the strategies employed to target co-stimulatory pathways in CAR T cells, with a view to improve responses in solid tumours.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4275-4275 ◽  
Author(s):  
Kai Sun ◽  
Xuejun Zhang ◽  
Zhen Wang ◽  
Yuqing Chen ◽  
Lei Zhang ◽  
...  

Abstract Introduction: CD19-specific CAR-T cells have shown promise in the treatment of relapsed or refractory Ph+ ALL. It remains to be established whether allogeneic CAR-T cells have clinical activity in patients with relapsed CML lymphoid blast crisis with a history of allo-HSCT. Here we report our experience in two cases of allogeneic CAR-T cell therapy for treatment of relapse after allo-HSCT in patients with refractory CML lymphoid blast crisis. Methods: For manufacture of allogeneic CAR-T cells, peripheral blood mononuclear cells were collected from the same stem cell donor. Lentiviral construction and generation of CAR-T cells, clinical protocol design, assessment and management of cytokine release syndrome (CRS), were performed as described in our previous report (Leukemia. 2017;31:2587-2593). Fludarabine and cyclophosphamide had been administered for lymphocyte depletion before allogeneic CAR-T cells infusion. Patients: Patient 1 was a 52-year-old woman with refractory CML lymphoid blast crisis, who had a relapse after undergoing allo-HSCT from her daughter (HLA-10/10). Her initial examinations of peripheral blood and bone marrow were consistent with the diagnosis of CML lymphoid blast crisis. Cytogenetics and molecular analysis confirmed the presence of t(9;22)(q34;q11) and BCR-ABL1 210 fusion protein. In February 2017, examination of bone marrow revealed a further increase of lymphoblasts to 83.2%. In addition, ABL1 kinase mutations (Y253H and E255K/V) were identified. The patient underwent HLA 10/10-matched allo-HSCT without acute GVHD. A remission with a negative test for BCR-ABL1 210 and 99.62% donor chimerism had been achieved, then she had a lymphoblastic relapse occurred 2 months after allo-HSCT. Consistently, BCR-ABL1 210 turned positive, and chimerism analysis showed 67.4% donor chimerism. 3 weeks after relapse, allogeneic CAR-T cells were infused at the dose of 5×106 /kg CD19-specific CAR-T cells. Patient 2 was a 39-year-old male patient with relapsed CML lymphoid blast crisis with a history of allo-HSCT. He had received a diagnosis of CML chronic phase 7 years earlier. Bone marrow revealed a karyotype of 46, XY, t(3;9;22)(q27;q34;q11) and BCR-ABL mRNA transcript. From April 2011 to September 2012, the patient was treated with nilotinib. In September 2012, bone marrow examination revealed 78% lymphoblasts, thus the diagnosis of CML lymphoid blast crisis was established. In December 2012, the patient underwent HLA 7/10-matched sibling allo-HSCT (from his brother) without evidence of GVHD and maintained CR for 2 years. In December 2014, the patient developed bone marrow relapse (lymphoblast 9.5%) and extramedullary leukemia (testicular involvement) harboring the BCR-ABL-T315I mutation. During 2014 to 2018, the patient received multiple courses of CIKs, HDMTX and DLI, but failed to achieve CR. In March 2018, the patient received healthy donor derived allogeneic CAR19 T cells (2×105/kg) therapy. Result: Before CAR-T cells infusion, both patients with refractory CML lymphoid blast crisis had a relapse after successful allo-HSCT. Approximately 1 month after CAR-T cells infusion, a persistent morphologic remission, a recovering BM, and complete absence of BCR-ABL mRNA transcripts confirmed morphologic and molecular remission in both patients. Consistent with this, flow cytometry could not detect blasts or CD19+ B lineage cells. Patient 1 did not experience toxicities and allogeneic CAR-T cell therapy was well tolerated. Patient 2 developed severe CRS (Gr 4) including high-grade fevers (>40°C), hypotension, hypoxia, mental status changes, and seizures. These episodes ran for approximately 1 week before they were halted by treatment with steroids plus tocilizumab, and plasma exchange. The toxicity of allogeneic CAR-T cells is correlated with high levels of IL-6, IFN-γ, TNF-a, and CRP. Conclusion: The clinical outcomes from these 2 patients demonstrate the in vivo efficacy of allogeneic CD19-targeted T cells to induce clinical, morphology and molecular remissions as well as B cell aplasia in adults with relapsed CML lymphoid blast crisis with a history of allo-HSCT. The efficacy of allogeneic CAR-T cell therapy may not always be related to the risk of severe CRS. The degree of HLA matching may have a major impact on the prevention of CRS after allogeneic CAR-T cell therapy. Fully HLA-matched-pair may increase the safety and efficacy of the allogeneic CAR-T cell therapy. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 7-7
Author(s):  
Rui Zhang ◽  
Juan Xiao ◽  
Zhouyang Liu ◽  
Yuan Sun ◽  
Sanfang Tu ◽  
...  

BACKGROUND: Allogeneic haematopoietic stem cell transplantation (allo-HCT) is a standard treatment for relapsed/refractory B-cell acute lymphoblastic leukemia (r/r B-ALL). However ~30-40% of patients (pts) still relapse after HCT. We report a cohort of 20 r/rB-ALL pts, who relapsed after HCT, and enrolled in the CAR2.0 study receiving one or two types of CAR-T cells targeting various B-ALL antigens. METHOD: Pts with r/r B-ALL who relapsed after allo-HCT and did not have significant active comorbiditeis, were enrolled in the study. The target antigens were determined based on immunostaining of each pt's leukemia cells, and CAR-T infusions included a single, or a combination of CAR-Ts targeting the following antigens: CD19, CD22, CD123 and CD38. T cells were collected from pts (N=4) or their allogeneic donors (N=16) and transduced with an apoptosis-inducible, safety-engineered lentiviral CAR with the following intracellular signaling domains: CD28/CD27/CD3ζ-iCasp9 (4SCAR). Pts received cyclophosphamide/fludarabine lymphodepleting therapy before infusion of 0.2-5.8x106 CAR-T/kg per infusion. In addition to disease response, we carefully monitored the quality of apheresis cells, efficiency of gene transfer, T cell proliferation rate, CAR-T infusion dose, and the CAR-T copy number in peripheral blood. RESULTS: Among the 20 enrolled pts, 11 were <18 years of age, and 7 were BCR- ABL (P190) positive. Before CAR-T treatment, 7 pts had ≤grade 2 active graft-versus-host disease (GVHD), and 13 pts received chemotherapy or targeted therapy after their relapse post HCT. Six pts had extramedullary relapse and 2 of them also had bone marrow relapse. The tumor burden in bone marrow ranged from minimal residual disease (MRD) negative to 66% of blasts, based on flow cytometry before CAR-T therapy. Five pts had >10% blasts in bone marrow, 8 pts had <3% blasts, and 7 pts had MRD negative bone marrow (summarized in the Table below). Based on the GVHD history, chimerism state and the available T-cell sources, 16 pts used allogeneic HCT donor T-cells for CAR-T preparation. All pts were full donor chimeras prior to CAR-T infusion, except one pt who had 41% donor cells in bone marrow. Eleven pts received a single CD19 CAR-T infusion, with a mean dose of 1.6x106 CAR-T/kg, and ten achieved an MRD remission and one had progressive disease (PD) within 60 days by flow cytometry. The remaining 9 pts received 2 CAR-Ts (CD19 plus CD22, CD123 or CD38 CAR-Ts) given on the same day, and resulted in 8 CR and 1 PD within 60 days. After CAR-T infusion, no cytokine release syndrome (CRS) was observed in 8 pts, and 12 pts experienced CRS of grade 1, which was consistent with the previously described low toxicity profile of the 4SCAR design. Acute GVHD ≤ grade 2 developed in 5 pts within one month following CAR-T cell infusion but all responded well to supportive care and/or cyclosporine infusion. The 2 pts who developed PD after CAR-T infusion included the one with 41% donor chimerism and had grade 2 GVHD and active infections before CAR-T infusion. The other pt with PD following CAR-T had severe bone marrow suppression, low leukocyte count, infections and was transfusion dependent before enrollment. This emphasizes the need for controlling comorbidities before infusion of CAR-T cells. In summary, total 18 patients (90%) achieved negative MRD remission within 2 months of therapy with acceptable CRS. Four pts relapsed (after being in remission for 3 months) and 14 pts are in continued remission, 6 of which for > 1 year. None of these 20 pts received a second HCT after CAR-T infusion. GVHD developed in 5/16 (31%) pts after donor source CAR-T cell infusion within one month, but all responded well to treatment. CONCLUSION: This study focuses on CAR-T cell therapy following relapse after HCT. While the expanded study is ongoing, we present results of the first 20 pts. Use of donor-derived or recipient-derived CAR-T products in pts who relapsed after allo-HCT is well tolerated and it may prolong life expectancy of these pts while maintaining good quality of life. Table Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2625-2625
Author(s):  
Olga Molostova ◽  
Larisa Shelikhova ◽  
Dina Schneider ◽  
Rimma Khismatullina ◽  
Yakov Muzalevsky ◽  
...  

Introduction CD19 CAR-T cell products were recently approved as therapy for B-lineage malignancies. We initiated an IIT trial where manufacture of CAR-T cells was performed locally using a unique CD19 CAR with potent anti-leukemic effects. Patients and methods A total of 37 pts with relapsed/refractory B-acute lymphoblastic leukemia (12 female, 25 male, median age 10 y) were screened, 27 pts were enrolled for a trial, 10 were eligible for compassionate use of CD19 CAR-T cell therapy. Sixteen patients had relapsed B-ALL after haploidentical HSCT, 19 pts refractory relapse, 2 induction failure, 13 patients had previous blinatumomab infusion. Eighteen patients had >20% blast cells, median bone marrow leukemia burden for patients with full blown disease was 89%, 19 pts had minimal residual disease (MRD) >0.1% in BM, 3 had skeletal involvement with multiple mass lesions, one had CNS involvement. The CliniMACS Prodigy T cell transduction (TCT) process was used to produce CD19 CAR-T cells. The automated production included CD4/CD8 selection, CD3/CD28 stimulation with MACS GMP T Cell TransAct and transduced with lentiviral vector expressing the CD19CAR gene (second generation CD19.4-1BB zeta with alternate transmembrane domain derived from the TNF superfamily) (Lentigen, Miltenyi Biotec company). T cells were expansion over 10 days in the presence of serum-free TexMACS GMP Medium supplemented with MACS GMP IL-7 and IL-15. Final product was administered without cryopreservation to the patients after fludarabine/cyclophosphamide preconditioning. All patients received prophylactic tocilizumab at 8mg/kg before CAR-T cell infusion. Patients did not receive HSCT as consolidation after CAR-T therapy. Results Thirty-five manufacturing cycles were successful. Median transduction efficacy was 60% (20-80). Median expansion of T cells was x 46 (18-51). CD4:CD8 ratio in the final product was 0.73. The cell products were administered at a dose of 3*106/kg of CAR-T cells in 4 pts, 1*106/kg in 9 pts, 0.5*106/kg in 14 pts, 0.1*106/kg in 8 pts. Two patients received 0.1*106/kg of CAR-T cells produced from haploidentical donors. The cytokine release syndrome (CRS) occurred in 22 (59%) pts and was mostly mild and moderate: grade I - 15 pts, grade II- 4 pts, grade III - 2 pt, grade IV - 1 pt. CAR-T cell related encephalopathy occurred in 15 (40%). Grade I-II neurotoxicity developed in 10 pts, grade III - in 2 pt, grade IV - 1 pt, grade V - 2 pt. In one patient with grade V neurotoxicity concomitant K. pneumonia encephalitis was documented. Severe (grade 3-5) CRS and neurotoxicity were associated exclusively with large leukemia burden (>20% in the bone marrow) at enrollment, p=0,002. Thirty-one patient was evaluable for response at day 28. Four pts had persistent leukemia. In 27 (87%) cases Flow MRD-negative remission was achieved. Disease relapse after initial response was registered in 9 (33%) cases (7 patients had CD19 negative, 2 had CD19 positive relapse). At the moment of reporting, 10 patients have died (3 due to sepsis, 1 due to brain edema, 1 due to brain edema and K. pneumonia encephalitis, 5 due to progression of disease or relapse). Twenty-seven pts are alive, 19 in complete remission with a median follow up of 223 days (41-516 days). Conclusion CliniMACS Prodigy TCT process is a robust CAR-T cell manufacturing platform that enables rapid and flexible provision of CAR-T cells to patients in need. Significant toxicity of CD19 CAR-T cells was associated exclusively with high leukemia burden at enrollment. In the absence of HSCT consolidation relapse rate exceeds 30%. Disclosures Schneider: Lentigen Technology, A Miltenyi Biotec Company: Employment. Preussner:Miltenyi Biotec: Employment. Rauser:Miltenyi Biotec: Employment. Orentas:Lentigen Technology Inc., a Miltenyi Biotec Company: . Dropulic:Lentigen Technology, A Miltenyi Biotec Company: Employment. Maschan:Miltenyi Biotec: Other: lecture fee.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. SCI-37-SCI-37 ◽  
Author(s):  
James N. Kochenderfer

Multiple myeloma (MM) is a usually incurable malignancy of plasma cells. While the therapy of MM has improved greatly in the past 15 years, therapies with novel mechanisms of action are needed for MM. Allogeneic stem cell transplantation has been shown to have a potent anti-myeloma effect, and allogeneic donor lymphocyte infusions can cause remissions of MM. These results from allogeneic transplantation show that MM can be vulnerable to cellular immunotherapies, but allogeneic transplants have substantial rates of mortality and morbidity. Anti-CD19 CAR T cells have been shown to have powerful activity against B-cell malignancies. The success of anti-CD19 CAR T cells against B-cell malignancies has motivated investigators to develop genetically-modified T-cell therapies for MM. CD19 has been targeted as a therapy for multiple myeloma. A clinical trial of anti-CD19 CAR T cells for MM is underway. Part of the rationale for targeting CD19 is that CD19 might be expressed on a myeloma stem cell, which might be a mature B cell. The NY-ESO antigen has been targeted by human-leukocyte-antigen-restricted T cells in a clinical trial enrolling MM patients. B-cell maturation antigen (BCMA) is expressed by most cases of MM. We conducted the first-in-humans clinical trial of CAR T cells targeting BCMA at the National Cancer Institute. T cells expressing the CAR used in this work (CAR-BCMA) specifically recognized BCMA-expressing cells. Twelve patients received CAR-BCMA T cells on this dose-escalation trial. Among the 6 patients treated on the lowest two dose levels, limited anti-myeloma activity and mild toxicity occurred. On the third dose level, one patient obtained a very good partial remission. Two patients were treated on the fourth dose level of 9x106 CAR+T cells/kg bodyweight. Before treatment, the first patient on the fourth dose level had chemotherapy-resistant MM making up 90% of bone marrow cells. After treatment, bone marrow plasma cells became undetectable by flow cytometry, and the patient's MM entered a stringent complete remission that lasted for 17 weeks before relapse. The second patient on the fourth dose level had chemotherapy-resistant MM with 80% bone marrow plasma cells before treatment. Twenty-eight weeks after this patient received CAR-BCMA T-cells, bone marrow plasma cells were undetectable by flow cytometry, and the serum monoclonal protein had decreased by >95%. Both patients treated on the fourth dose level had toxicity consistent with cytokine-release syndrome including fever, hypotension, and dyspnea. Both patients also had prolonged cytopenias. In summary, our findings demonstrated strong anti-myeloma activity of CAR-BCMA T cells. One of the best attributes of the CAR T-cell field is that there are multiple avenues for improving CAR T-cell therapies. New CAR designs are being tested. Any part of the CAR might be improved including development of new fully-human single chain variable fragments (scFv) for the antigen-recognition component of the CAR, testing different hinge and transmembrane domains, and defining the optimal costimulatory moieties. Another avenue for improving CAR T-cell therapies is improving T-cell culture methods. Optimizing clinical application of CAR T cells, especially enhancing toxicity management, is another important avenue of improving CAR T-cell therapies. Finally, identifying new CAR target antigens is a critically important area of CAR research. In summary, genetically-modified T cells hold great promise to make a profound improvement in the therapy of multiple myeloma. Disclosures Kochenderfer: bluebird bio: Patents & Royalties, Research Funding; Kite Pharma: Patents & Royalties, Research Funding.


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.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A146-A146
Author(s):  
Jihyun Lee ◽  
Areum Park ◽  
Jungwon Choi ◽  
Dae Gwan Yi ◽  
Hee Jung Yang ◽  
...  

BackgroundChimeric antigen receptor (CAR) -T cell therapies have proven to be effective against various liquid tumors. However, the development of CAR-T against solid tumors has been challenging due to insufficient efficacy and potential on-target off-tumor toxicities caused by low expression of tumor antigens on normal tissues. Testing various affinities of CARs has demonstrated that lower affinity CARs maintain its anti-tumor effect while minimizing safety concerns (1). In order to develop a CAR-T against solid tumors expressing Mucin1, we have screened for Mucin1 binding antibodies and tested their anti-tumor effect in vitro and in vivo. The potential of on-target off-tumor toxicity was also measured in vitro.MethodsAnti-Mucin1 human single chain variable fragments (scFv) were obtained via screening against a scFv display library. Anti-Mucin1 scFvs were incorporated into CARs and in vitro, in vivo functions against various tumor cells expressing Mucin1 were tested. For in vivo studies, tumor bearing NOG mice (HCC1954 cells) received anti-Mucin1 CAR-T cells. Therapeutic efficacy was evaluated by measuring tumor volumes. Potential on-target off-tumor toxicity against Mucin1 on normal cells was tested by investigating the killing effect of anti-Mucin1 CAR-T against cancer cell line (HCC70) and non-tumorigenic breast epithelial cell line (MCF-10A) in co-culture systemsResultsIn vitro activity of anti-Mucin1 CAR-T cells that displayed a range of affinities for Mucin1 (27nM to 320nM) showed similar cytokine secretion levels and cytotoxicity against Mucin-1 expressing tumor cell lines (HCC70 and T47D). Robust anti-tumor activity was also demonstrated in vivo against large tumors (400~500 mm3) with relatively small numbers of CAR-T cells (0.5 x 106 CAR-T cells per mouse). In vivo expansion of CAR-T cells were observed in all scFv-CAR-T cases and accompanied by close to complete regression of tumors within 25 days post CAR-T cell injection. Of the 4 scFv CAR-Ts, 2H08 (with a Kd of 94nM) was tested for activity against normal breast epithelial cells. When 2H08-CAR-T was cocultured with a mixture of HCC70 and MCF-10A cells, they preferentially killed only the Mucin1 overexpressing HCC70 cells leaving MCF-10 cells intact.ConclusionsOur study demonstrates anti-tumor activity of a novel scFv-derived CAR-T recognizing Mucin1 and its effectiveness in large pre-established tumors in vivo. We also demonstrate that 2H08-CAR-T can distinguish between target overexpressing cancer cells and normal epithelial cells, which suggests that by toning down the affinity of CAR against antigen one can improve the safety profile of solid tumor antigen targeting CAR-T cell therapies.ReferenceCastellarin M, Sands C, Da T, Scholler J, Graham K, Buza E, Fraietta J, Zhao Y, June C. A rational mouse model to detect on-target, off-tumor CAR T cell toxicity. JCI Insight 2020; 5:e136012Ethics ApprovalAll experiments were done under protocols approved by the Institutional Animal Care and Use Committee (IACUC) (Study#LGME21-011).ConsentWritten informed consent was obtained from the patient for publication of this abstract and any accompanying images. A copy of the written consent is available for review by the Editor of this journal.


2021 ◽  
Vol 22 (16) ◽  
pp. 8996
Author(s):  
Theresa Haslauer ◽  
Richard Greil ◽  
Nadja Zaborsky ◽  
Roland Geisberger

Chimeric antigen receptor (CAR) T-cells (CAR T-cells) are a promising therapeutic approach in treating hematological malignancies. CAR T-cells represent engineered autologous T-cells, expressing a synthetic CAR, targeting tumor-associated antigens (TAAs) independent of major histocompatibility complex (MHC) presentation. The most common target is CD19 on B-cells, predominantly used for the treatment of lymphoma and acute lymphocytic leukemia (ALL), leading to approval of five different CAR T-cell therapies for clinical application. Despite encouraging clinical results, treatment of other hematological malignancies such as acute myeloid leukemia (AML) remains difficult. In this review, we focus especially on CAR T-cell application in different hematological malignancies as well as strategies for overcoming CAR T-cell dysfunction and increasing their efficacy.


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