scholarly journals Early Clinical Experience of CD19 x CD22 Dual Specific CAR T Cells for Enhanced Anti-Leukemic Targeting of Acute Lymphoblastic Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 278-278 ◽  
Author(s):  
Rebecca Gardner ◽  
Colleen Annesley ◽  
Olivia Finney ◽  
Corinne Summers ◽  
Adam J. Lamble ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Dose Level ◽  
T Cell Subsets ◽  
Preclinical Testing ◽  
Car T Cells ◽  
Car T Cell ◽  
Dual Specificity ◽  
Car T

Abstract Introduction: Advances in chimeric antigen receptor (CAR) T cell therapy have yielded complete remission (CR) rates in relapsed/refractory B-ALL (rrB-ALL) of 70-95%. However, disease recurrence after CD19 or CD22 CAR therapy is greater than 50% at 1 year, and approximately half of recurrences are due to antigen escape. To reduce antigen escape and optimize the durability of remission, we sought to design a CAR T cell product with dual specificity that is capable of simultaneously targeting both CD19 and CD22. Preclinical testing of our bi-specific CAR showed a preference for signaling through CD22 over the CD19 CAR. In contrast, dual transduced T cells signaled through both the CD19 and CD22 CAR with lytic activity and cytokine production similar to single transduced CAR T cells of the same specificity. Therefore, we opted to move forward with dual transduced T cells for clinical use. We are currently testing SCRI-CAR19x22v1 in PLAT-05 (NCT03330691), a phase 1 clinical trial for pediatric and young adult patients with CD19+CD22+ rrB-ALL, with the primary objectives to determine the feasibility of manufacturing products with dual specificity, to assess the safety of the cryopreserved product infusion, and to describe the full toxicity profile. Methods: Subjects undergo apheresis, after which the CD4 and CD8 T cell subsets are immunomagnetically selected and seeded at a prescribed ratio for co-culture in a closed-system G-Rex bioreactor. Following anti-CD3xCD28 bead stimulation, T cells are transduced with two separate SIN lentiviral vectors that direct the expression of a CD19-specific FMC63scFv:IgG4hinge:CD28tm:4-1BB:ζ CAR with an Her2tG tag and expression of a CD22-specific m971scFv:IgG4hinge:CH2(L235D)-CH3:CD28tm:4-1BB:ζ CAR with an EGFRt tag, creating three distinct populations of CAR T cells (anti-CD19, anti-CD22, and anti-CD19x 22). Transduced cells are expanded in serum free media formulation with IL-7, IL-15, and IL-21. Following lymphodepleting chemotherapy, cryopreserved products are thawed and infused at the protocol-prescribed dose level. Cytokine release syndrome (CRS) is graded according to Lee et al. (Blood 2014) and is treated according to our early intervention strategy of tocilizumab and dexamethasone for persistent, mild CRS. Results: Seven subjects (ages 1-26 yr) with rrB-ALL have been enrolled with 4 treated at dose level 1 (1 x 106 CAR T cells/kg) and 3 treated at dose level 2 (3 x 106 CAR T cells/kg). The mean culture time was 7.9 days (range 7-11) and subjects received infusions with a mean CD8:CD4 ratio of 1.7 (range 0.2 - 3.1). CD8 CAR composition, on average, consisted of 21.6 % CD19 CAR, 37.8 % CD22 CAR, and 40.6 % CD22xCD19 CAR T cells. CD4 CAR composition, on average, consisted of 25.8 % CD19 CAR, 30.6 % CD22 CAR, and 43.6 % CD22xCD19 CAR T cells (Figure). Peak engraftment occurred between days 7 and 14 for all patients and was predominantly composed of the CD19 CAR population with median peak values for CD19 CAR, CD22 CAR, and CD19xCD22 CAR T cell populations of 9.1%, 1.2%, and 2.4%, respectively. A CR was achieved in 5/7 (71%) subjects by day 21, 4 of which were minimal residual disease negative. The two subjects without a CR did not exhibit evidence of CAR T cell engraftment; one had previously received CD19 CAR T cells, and the other had progressive disease and pursued alternative therapy at day 10. Therapy was well tolerated with no dose limiting toxicities. CRS occurred in 5 subjects (Grade 1) with 2 of these subjects experiencing mild neurotoxicity (Grade 1). Four subjects received tocilizumab +/- dexamethasone, and two of these received multiple doses of dexamethasone. Conclusions: Preclinical testing showed superior efficacy against both CD19 and CD22 when using two separate CARs and dual transduction, compared to a single bi-specific CAR. Preliminary analysis of PLAT-05 supports feasibility of product manufacturing, and toxicity and response rates that are consistent with the reported CD19 CAR T cell experience. While the infused SCRI-CAR19x22v1 products consist of a near-uniform distribution of the 3 distinct populations, we observed selective in vivo expansion of the CD19 CAR T cell population. Further investigation is required to understand the mechanism of CD19 CAR dominance in vivo. Continued accrual of subjects is ongoing to further assess the impact of dual antigen targeting on the prevention of antigen escape and the potential to provide a more durable remission. Figure. Figure. Disclosures Park: Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees. Jensen:Juno Therapeutics, Inc.: Consultancy, Patents & Royalties, Research Funding.

scholarly journals Exhausted CLL T Cells Mediated By PD1 Expression an Important Mechanism for CD19 CAR Efficacy in CLL in the Adoptive Transfer TCL1 Mouse Model

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4537-4537
Author(s):  
Robin Sanderson ◽  
Arantxa Romero-Toledo ◽  
John G. Gribben
Keyword(s):  
T Cells ◽  
T Cell ◽  
Adoptive Transfer ◽  
Research Funding ◽  
Complete Response ◽  
T Cell Subsets ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Abstract Background: The first two autologous CD19 chimeric antigen receptor T (CAR T) cells targeting CD19 have now been approved for the treatment of ALL and refractory lymphomas. Despite impressive responses in these diseases, results remain inconsistent in chronic lymphocytic leukaemia (CLL). It is unknown if this reflects CAR design or an effect of the underlying function of CLL T cells. These 2nd generation CAR T cells require CD28 or 41BB co-stimulatory signalling domains, but these have not been compared directly in humans. Pre-clinical models afford the opportunity to do this, however, modelling of CAR T cells has mostly been performed in vitro or using immunodeficient mice, limiting the ability to study more complex immune biology. CLL is associated with a tumour supportive microenvironment and T cells exhibit multiple functional defects and features of exhaustion. These T cell defects in CLL are closely recapitulated in Eμ-TCL1 (TCL1) mice, and induced in healthy mice by adoptive transfer (AT) of murine CLL cells. We aimed to demonstrate the effect of CLL T cell dysfunction on CAR T cell efficacy and compare CD28 and 41BB directly. Methods: Immunocompetent C57BL/6 mice (WT) received AT of pooled 20 x106 TCL1 cells from fully leukemic TCL1 mice from the same background. Syngeneic donor CAR T cells were either pooled spleens from WT mice or WT mice given AT CLL with CLL load >80%. Both groups were aged matched (approx. 3 months). Splenoctyes were enriched for CD3+ with magnetic beads then activated with anti CD3/CD28 Dynabeads (Thermofisher) and rIL-2 (Roche). They were transduced with retroviral supernatant from either SFG-m19BBmZ-GFP (CD19-41BB) or MSGV-1D3-28Z-1.3mut (CD19-CD28) and cultured for 4 days when they were injected into 48 mice in total. Mice were given 100mg/kg intraperitoneal cyclophosphamide on D-1 followed by 6-8 x106 CAR T cells (or untransduced T cells). Mice were bled weekly to assess CLL load and T cell subsets and were culled when they appeared sick or peripheral blood (PB) CLL>70%. Results: CAR T cells derived from WT and AT T cells exhibit different phenotypes. WT CAR T cells proliferate more readily in culture and exhibit significantly higher transduction efficiencies in the CD8 subset although CD4 transduction is preserved. Following activation and transduction WT CAR T cells have a CD4: CD8 ratio of 1:1 whilst those from AT are heavily skewed to CD8. In both groups >90% T cells are CD44+. PD1+ expression in both CD4 and CD8 subsets is significantly higher in AT compared to WT CAR T cells. Mice treated with the CD19 -41BB CAR derived from WT and AT T cells or untransduced T cells did not respond, whereas 100% of mice treated with CD19-CD28 CAR derived from WT T cells had a complete response with loss of normal B cells 1 week post CAR T cells injection compared to 50% of mice treated with CD19-CD28 from AT T cells. All non-responding mice were culled at week 8 due to progressive leukaemia as were control mice treated with untransduced T cells. All mice with an established response had a continued complete response for 5 weeks following CAR T cell injection. Half of these mice were culled for phenotypic comparison and the other half observed for survival analysis. Those mice that responded and culled at week 8 had equal spleen size (0.1g) to age matched WT mice controls whilst non-responding mice had significantly larger spleens (0.5-3.3g). CAR T cells were only detectable in the PB +1 week post injection. In the PB there was restoration of CD4: CD8 ratios in responding mice compared to leukemic mice. PD1 expression in the spleen and bone marrow in CD3+CD8+ and CD4+ T cells normalised in responding mice compared to non-responding mice. Conclusion: AT of TCL1 CLL into immunocompetent mice is a viable model to study in vivo CAR T cell function and the host immune response. CAR T cells derived from WT T cells lead to a complete response in all of the mice but this response is significantly reduced if T cells exposed to CLL are used. Time to relapse for these responding mice has not been reached. We postulate that failure of the CD19 -41BB CAR in vivo relates to rejection of the GFP construct. There are significant differences in PD1 expression between WT and AT derived CAR T cells, which suggest strategies to repair exhausted T cells may improve the clinical response to CAR T cells in CLL. This provides the rationale for our on going studies of PD1/PDL1 blocking drugs in combination with CAR T cells in this immunocompetent pre-clinical model. Disclosures Gribben: Medical Research Council: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Acerta Pharma: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Honoraria; Pharmacyclics: Honoraria; NIH: Research Funding; Kite: Honoraria; TG Therapeutics: Honoraria; Wellcome Trust: Research Funding; Cancer Research UK: Research Funding; Unum: Equity Ownership; Roche: Honoraria; Abbvie: Honoraria.

109 Dominant-negative TGFβ receptor 2 enhances GPC3-targeting CAR-T cell efficacy against hepatocellular carcinoma

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A121-A121
Author(s):  
Nina Chu ◽  
Michael Overstreet ◽  
Ryan Gilbreth ◽  
Lori Clarke ◽  
Christina Gesse ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Flow Cytometry ◽  
T Cells ◽  
T Cell ◽  
Dominant Negative ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

BackgroundChimeric antigen receptors (CARs) are engineered synthetic receptors that reprogram T cell specificity and function against a given antigen. Autologous CAR-T cell therapy has demonstrated potent efficacy against various hematological malignancies, but has yielded limited success against solid cancers. MEDI7028 is a CAR that targets oncofetal antigen glypican-3 (GPC3), which is expressed in 70–90% of hepatocellular carcinoma (HCC), but not in normal liver tissue. Transforming growth factor β (TGFβ) secretion is increased in advanced HCC, which creates an immunosuppressive milieu and facilitates cancer progression and poor prognosis. We tested whether the anti-tumor efficacy of a GPC3 CAR-T can be enhanced with the co-expression of dominant-negative TGFβRII (TGFβRIIDN).MethodsPrimary human T cells were lentivirally transduced to express GPC3 CAR both with and without TGFβRIIDN. Western blot and flow cytometry were performed on purified CAR-T cells to assess modulation of pathways and immune phenotypes driven by TGFβ in vitro. A xenograft model of human HCC cell line overexpressing TGFβ in immunodeficient mice was used to investigate the in vivo efficacy of TGFβRIIDN armored and unarmored CAR-T. Tumor infiltrating lymphocyte populations were analyzed by flow cytometry while serum cytokine levels were quantified with ELISA.ResultsArmoring GPC3 CAR-T with TGFβRIIDN nearly abolished phospho-SMAD2/3 expression upon exposure to recombinant human TGFβ in vitro, indicating that the TGFβ signaling axis was successfully blocked by expression of the dominant-negative receptor. Additionally, expression of TGFβRIIDN suppressed TGFβ-driven CD103 upregulation, further demonstrating attenuation of the pathway by this armoring strategy. In vivo, the TGFβRIIDN armored CAR-T achieved superior tumor regression and delayed tumor regrowth compared to the unarmored CAR-T. The armored CAR-T cells infiltrated HCC tumors more abundantly than their unarmored counterparts, and were phenotypically less exhausted and less differentiated. In line with these observations, we detected significantly more interferon gamma (IFNγ) at peak response and decreased alpha-fetoprotein in the serum of mice treated with armored cells compared to mice receiving unarmored CAR-T, demonstrating in vivo functional superiority of TGFβRIIDN armored CAR-T therapy.ConclusionsArmoring GPC3 CAR-T with TGFβRIIDN abrogates the signaling of TGFβ in vitro and enhances the anti-tumor efficacy of GPC3 CAR-T against TGFβ-expressing HCC tumors in vivo, proving TGFβRIIDN to be an effective armoring strategy against TGFβ-expressing solid malignancies in preclinical models.Ethics ApprovalThe study was approved by AstraZeneca’s Ethics Board and Institutional Animal Care and Use Committee (IACUC).

Combinatorial Antigen Targeting Strategy for Acute Myeloid Leukemia

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 22-23
Author(s):  
Pinar Ataca Atilla ◽  
Mary K McKenna ◽  
Norihiro Watanabe ◽  
Maksim Mamonkin ◽  
Malcolm K. Brenner ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Tumor Control ◽  
Publicly Traded ◽  
Advisory Committees ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Introduction: Efforts to safely and effectively treat acute myeloid leukemia (AML) by targeting a single leukemia associated antigen with chimeric antigen receptor T (CAR T) cells have had limited success. We determined whether combinatorial expression of chimeric antigen receptors directed to two different AML associated antigens would augment tumor eradication and prevent relapse in targets with heterogeneous expression of myeloid antigens. Methods: We generated CD123 and CD33 targeting CARs; each containing a 4-1BBz or CD28z endodomain. We analyzed the anti-tumor activity of T cells expressing each CAR alone or in co-transduction with a CLL-1 CAR with CD28z endodomain and CD8 hinge previously optimized for use in our open CAR-T cell trial for AML (NCT04219163). We analyzed CAR-T cell phenotype, expansion and transduction efficacy by flow cytometry and assessed function by in vitro and in vivo activity against AML cell lines expressing high, intermediate or low levels of the target antigens (Molm 13= CD123 high, CD33 high, CLL-1 intermediate, KG1a= CD123 low, CD33 low, CLL-1 low and HL60= CD123 low, CD33 intermediate, CLL-1 intermediate/high) For in vivo studies we used NOD.SCID IL-2Rg-/-3/GM/SF (NSGS) mice with established leukemia, determining antitumor activity by bioluminescence imaging. Results: We obtained high levels of gene transfer and expression with both single (CD33.4-1BBʓ, CD123.4-1BBʓ, CD33.CD28ʓ, CD123.CD28ʓ, CLL-1 CAR) and double transduction CD33/CD123.4-1BBʓ or CD33/CD123.CD28ʓ) although single-transductants had marginally higher total CAR expression of 70%-80% versus 60-70% after co-transduction. Constructs containing CD28 co-stimulatory domain exhibited rapid expansion with elevated peak levels compared to 41BB co-stim domain irrespective of the CAR specificity. (p<0.001) (Fig 1a). In 72h co-culture assays, we found consistently improved anti-tumor activity by CAR Ts expressing CLL-1 in combination either with CD33 or with CD123 compared to T cells expressing CLL-1 CAR alone. The benefit of dual expression was most evident when the target cell line expressed low levels of one or both target antigens (e.g. KG1a) (Fig 1b) (P<0.001). No antigen escape was detected in residual tumor. Mechanistically, dual expression was associated with higher pCD3ʓ levels compared to single CAR T cells on exposure to any given tumor (Fig 1c). Increased pCD3ʓ levels were in turn associated with augmented CAR-T degranulation (assessed by CD107a expression) in both CD4 and CD8 T cell populations and with increased TNFα and IFNɣ production (p<0.001 Fig 1d). In vivo, combinatorial targeting with CD123/CD33.CD28ʓ and CLL-1 CAR T cells improved tumor control and animal survival in lines (KG1a, MOLM13 and HL60) expressing diverse levels of the target antigens (Fig 2). Conclusion: Combinatorial targeting of T cells with CD33 or CD123.CD28z CARs and CLL-1-CAR improves CAR T cell activation associated with superior recruitment/phosphorylation of CD3ʓ, producing enhanced effector function and tumor control. The events that lead to increased pCD3ʓ after antigen engagement in the dual transduced cells may in part be due to an overall increase in CAR expression but may also reflect superior CAR recruitment after antigen engagement. We are now comparing the formation, structure, and stability of immune synapses in single and dual targeting CARs for AML. Disclosures Brenner: Walking Fish: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Membership on an entity's Board of Directors or advisory committees; Tumstone: Membership on an entity's Board of Directors or advisory committees; Tessa Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: Founder; Maker Therapeutics: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Other: Founder; Memmgen: Membership on an entity's Board of Directors or advisory committees; Allogene: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees. Atilla:Bluebird Bio: Membership on an entity's Board of Directors or advisory committees; Tumstone: Membership on an entity's Board of Directors or advisory committees; Tessa Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: founder; Marker Therapeuticsa: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Other: Founder, Patents & Royalties; Allogene: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Walking Fish: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Memgen: Membership on an entity's Board of Directors or advisory committees; KUUR: Membership on an entity's Board of Directors or advisory committees.

scholarly journals AAV-Mediated In Vivo CAR Gene Therapy for Targeting Human T Cell Leukemia

2021 ◽  
Author(s):  
Waqas Nawaz ◽  
Bilian Huang ◽  
Shijie Xu ◽  
Yanlei Li ◽  
Linjing Zhu ◽  
...  
Keyword(s):  
Gene Therapy ◽  
T Cells ◽  
T Cell ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Car T Cells ◽  
Car T Cell ◽  
Human T Cell ◽  
Car T

AbstractChimeric antigen receptor (CAR) T cell therapy is the most active field in immuno-oncology and brings substantial benefit to patients with B cell malignancies. However, the complex procedure for CAR T cell generation hampers its widespread applications. Here, we describe a novel approach in which human CAR T cells can be generated within the host upon injecting an Adeno-associated virus (AAV)vector carrying the CAR gene, which we call AAV delivering CAR gene therapy (ACG). Upon single infusion into a humanized NCG tumor mouse model of human T cell leukemia, AAV generates sufficient numbers of potent in vivo CAR cells, resulting in tumor regression; these in vivo generated CAR cells produce antitumor immunological characteristics. This instantaneous generation of in vivo CAR T cells may bypass the need for patient lymphodepletion, as well as the ex vivo processes of traditional CAR T cell production, which may make CAR therapy simpler and less expensive. It may allow the development of intricate, individualized treatments in the form of on-demand and diverse therapies.Significance StatementAAV can generate enough CAR cells within the host. That act as a living drug, distributed throughout the body, and persist for weeks, with the ability to recognize and destroy tumor cells.

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 Next Generation NKG2D-based CAR T-cells (CYAD-02): Co-expression of a Single shRNA Targeting MICA and MICB Improves Cell Persistence and Anti-Tumor Efficacy in vivo

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3931-3931
Author(s):  
Martina Fontaine ◽  
Benjamin Demoulin ◽  
Simon Bornschein ◽  
Susanna Raitano ◽  
Steve Lenger ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Next Generation ◽  
Activated T Cells ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Anti Tumor Activity ◽  
Nkg2d Receptor

Background The Natural Killer Group 2D (NKG2D) receptor is a NK cell activating receptor that binds to eight different ligands (NKG2DL) commonly over-expressed in cancer, including MICA and MICB. The product candidate CYAD-01 are chimeric antigen receptor (CAR) T-cells encoding the full length human NKG2D fused to the intracellular domain of CD3ζ. Data from preclinical models have shown that CYAD-01 cells specifically target solid and hematological tumors. Encouraging preliminary results from the Phase I clinical trial THINK, assessing CYAD-01 safety, showed initial signals of objective clinical responses in patients with r/r AML and MDS. The clinical development of CAR T-cells has been limited by several challenges including achieving sufficient numbers of cells for clinical application. We have previously shown that NKG2D ligands are transiently expressed on activated T cells and that robust cell yields are generated through the addition of a blocking antibody and a PI3K inhibitor during cell manufacture. Here, we investigated the ability of an optimized short hairpin RNA (shRNA) technology to modulate NKG2DL expression on CYAD-01 cells and to determine if there is an increase in the anti-tumor activity of NKG2D-based CAR T-cells (termed CYAD-02). Methods Molecular and cellular analyses identified MICA and MICB as the key NKG2DL expressed on activated T-cells and highly likely to participate in driving fratricide. In silico analysis and in vitro screening allowed the identification of a single shRNA targeting the conserved regions of MICA and MICB, thus downregulating both MICA and MICB expression. The selected shRNA was incorporated in the NKG2D-based CAR vector, creating the next-generation NKG2D-based CAR T-cell candidate, CYAD-02. In addition, truncated versions of the NKG2D receptor were generated to explore the mechanisms of action of NKG2D receptor activity in vivo. The in vivo persistence and anti-tumor activity of CYAD-02 cells was evaluated in an aggressive preclinical model of AML. Results Injection of CAR T-cells bearing truncated forms of the NKG2D-CAR in immunosuppressed mice resulted in similar persistence to the control T-cells. In contrast, CYAD-01 cells had reduced persistence, suggesting that the recognition of the NKG2DL by the NKG2D receptor could contribute to this effect. Analysis of cell phenotype upon CAR T-cell activation showed that MICA and MICB were transiently expressed on T-cells during manufacturing. These results collectively suggested that downregulating MICA and MICB expression in CYAD-01 cells could be a mean to increase CAR T-cell persistence in vivo. Candidate shRNA were screened for efficient targeting of both MICA and MICB at the mRNA and protein level. T-cells transduced with a single vector encoding for the NKG2D-based CAR and the selected shRNA targeting MICA and MICB (CYAD-02) demonstrated 3-fold increased expansion during in vitro culture in the absence of the blocking antibody used to increase cell yield during manufacture. When injected into immunosuppressed mice, CYAD-02 cells generated with the Optimab process showed 10-fold higher engraftment one week after injection and potent anti-tumor activity resulting in 2.6-fold increase of mouse survival in an aggressive AML model. Conclusions By using a single vector encoding the NKG2D-based CAR next to a shRNA targeting MICA and MICB and combined with improved cell culture methods, CYAD-02, the next-generation of NKG2D-based CAR T-cells, demonstrated enhanced in vivo persistence and anti-tumor activity. Following FDA acceptance of the IND application, a Phase 1 dose-escalation trial evaluating the safety and clinical activity of CYAD-02 for the treatment of r/r AML and MDS is scheduled to start in early 2020. Disclosures Fontaine: Celyad: Employment. Demoulin:Celyad: Employment. Bornschein:Celyad: Employment. Raitano:Celyad: Employment. Machado:Horizon Discovery: Employment. Moore:Avvinity Therapeutics: Employment, Other: Relationship at the time the work was performed; Horizon Discovery: Employment, Equity Ownership, Other: Relationship at the time the work was performed; Centauri Therapeutics: Consultancy, Other: Current relationship. Sotiropoulou:Celyad: Employment. Gilham:Celyad: Employment.

scholarly journals Efficacy and Safety of JWCAR029 in Adult Patients with Relapsed and Refractory B-Cell Non-Hodgkin Lymphoma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4187-4187 ◽  
Author(s):  
Zixun Yan ◽  
Wen Wang ◽  
Zhong Zheng ◽  
Ming Hao ◽  
Su Yang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Hodgkin Lymphoma ◽  
Dose Level ◽  
Car T Cells ◽  
Car T Cell ◽  
Non Hodgkin Lymphoma ◽  
Car T

Abstract Introduction JWCAR029 is a novel CD19-directed 4-1BB stimulated chimeric antigen receptor T (CAR-T) cell type, which is different from JWCAR017 with independent production of CD4 and CD8 T cells and transfusion in non-fixed ratio. We conducted a single arm, open-label, dose escalation Phase I trial of JWCAR029 in relapsed and refractory B-cell non-Hodgkin lymphoma (NCT03355859). Methods From January to July 2018, 10 patients have been enrolled in this trial, including eight diffused large B cell lymphoma (DLBCL) and two MALT lymphoma, with median age of 47 years (range 32 to 59 years). All the patients received immunochemotherapy as induction and more than two lines of salvage treatment. Two patients received bridging chemotherapy after T-cell collection due to rapid tumor progression, followed by re-evaluation before CAR-T cell infusion. Lymphodepletion preconditioning was accomplished by fludarabine 25mg/m2/d and cyclophosphamide 250mg/m2/d on Day-4 to D-2, followed by CAR-T cell infusion on Day0. JWCAR029 was administrated as a single infusion in escalation dose levels, from 2.5×107 CAR-T cells (dose level 1, DL1) to 5.0×107 CAR-T cells (dose level 2, DL2) and to 1.0×108 CAR-T cells (dose level 3, DL3) according to mTPI-2 algorithm. Circulating blood count, serum biochemistry, and coagulation status were follow-up after infusion. Cytokines were assessed on a Luminex platform. Tumor evaluation was performed on Day 29 by PET-CT. PK data were detected by flow cytometry and real-time quantitative polymerase chain reaction system. All the adverse events were recorded. The study was approved by the Shanghai Rui Jin Hospital Review Board with informed consent obtained in accordance with the Declaration of Helsinki. Results The demographic characteristics of the patients were demonstrated in Table 1. Among six evaluable patients (3 of DL1 and 3 of DL2), the ORR was 100% on Day 29, including four complete remission and 2 partial remission. Cytokine release syndrome (CRS) was 100% in Gr 1, with main symptoms as fever (<39.0 degrees), fatigue, and muscle soreness. No neurotoxicity was observed. Four of the six patients with fever >38.0 degrees used prophylactic IL-6 Inhibitor (8mg/kg, ACTEMRA, two patients administered twice). No patients received steroids. The CRS showed no difference between dose level groups (p>0.99). Adverse effects included leukopenia (Gr 3-4: 83.3%, Gr 1-2: 16.7%), hypofibrinogenemia (Gr 1: 16.7%, Gr 2-4: 0%), liver dysfunction (Gr 1: 33.3%, Gr 2-4: 0%), elevated CRP (Gr 1: 83.3%, Gr 2-4: 0%), ferritin (Gr 1-2: 83.3%, Gr 2-4: 0%), or IL-6 (Gr 1-2:100%, Gr 3-4: 0%, Table 2). Conclusion Although long-term follow-up was needed, the preliminary data of six patients in this trial have demonstrated high response rates and safety of JWCAR029 in treating relapsed and refractory B-cell non-Hodgkin lymphoma. Disclosures Hao: JW Therapeutics: Employment, Equity Ownership.

scholarly journals A Preclinical Embryonic Zebrafish Xenograft Model to Investigate CAR T Cells in Vivo

Cancers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 567 ◽  
Author(s):  
Susana Pascoal ◽  
Benjamin Salzer ◽  
Eva Scheuringer ◽  
Andrea Wenninger-Weinzierl ◽  
Caterina Sturtzel ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cellular Therapy ◽  
Xenograft Model ◽  
Model Systems ◽  
Preclinical Model ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Chimeric antigen receptor (CAR) T cells have proven to be a powerful cellular therapy for B cell malignancies. Massive efforts are now being undertaken to reproduce the high efficacy of CAR T cells in the treatment of other malignancies. Here, predictive preclinical model systems are important, and the current gold standard for preclinical evaluation of CAR T cells are mouse xenografts. However, mouse xenograft assays are expensive and slow. Therefore, an additional vertebrate in vivo assay would be beneficial to bridge the gap from in vitro to mouse xenografts. Here, we present a novel assay based on embryonic zebrafish xenografts to investigate CAR T cell-mediated killing of human cancer cells. Using a CD19-specific CAR and Nalm-6 leukemia cells, we show that live observation of killing of Nalm-6 cells by CAR T cells is possible in zebrafish embryos. Furthermore, we applied Fiji macros enabling automated quantification of Nalm-6 cells and CAR T cells over time. In conclusion, we provide a proof-of-principle study that embryonic zebrafish xenografts can be used to investigate CAR T cell-mediated killing of tumor cells. This assay is cost-effective, fast, and offers live imaging possibilities to directly investigate CAR T cell migration, engagement, and killing of effector cells.

scholarly journals Targeting glycosylation of PD-1 to enhance CAR-T cell cytotoxicity

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaojuan Shi ◽  
Daiqun Zhang ◽  
Feng Li ◽  
Zhen Zhang ◽  
Shumin Wang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Inhibitory Effects ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

AbstractAsparagine-linked (N-linked) glycosylation is ubiquitous and can stabilize immune inhibitory PD-1 protein. Reducing N-linked glycosylation of PD-1 may decrease PD-1 expression and relieve its inhibitory effects on CAR-T cells. Considering that the codon of Asparagine is aac or aat, we wondered if the adenine base editor (ABE), which induces a·t to g·c conversion at specific site, could be used to reduce PD-1 suppression by changing the glycosylated residue in CAR-T cells. Our results showed ABE editing altered the coding sequence of N74 residue of PDCD1 and downregulated PD-1 expression in CAR-T cells. Further analysis showed ABE-edited CAR-T cells had enhanced cytotoxic functions in vitro and in vivo. Our study suggested that the single base editors can be used to augment CAR-T cell therapy.

scholarly journals Enhanced CAR-T activity against established tumors by polarizing human T cells to secrete interleukin-9

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Lintao Liu ◽  
Enguang Bi ◽  
Xingzhe Ma ◽  
Wei Xiong ◽  
Jianfei Qian ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antitumor Activity ◽  
Effector Memory ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Ifn Γ

AbstractCAR-T cell therapy is effective for hematologic malignancies. However, considerable numbers of patients relapse after the treatment, partially due to poor expansion and limited persistence of CAR-T cells in vivo. Here, we demonstrate that human CAR-T cells polarized and expanded under a Th9-culture condition (T9 CAR-T) have an enhanced antitumor activity against established tumors. Compared to IL2-polarized (T1) cells, T9 CAR-T cells secrete IL9 but little IFN-γ, express central memory phenotype and lower levels of exhaustion markers, and display robust proliferative capacity. Consequently, T9 CAR-T cells mediate a greater antitumor activity than T1 CAR-T cells against established hematologic and solid tumors in vivo. After transfer, T9 CAR-T cells migrate effectively to tumors, differentiate to IFN-γ and granzyme-B secreting effector memory T cells but remain as long-lived and hyperproliferative T cells. Our findings are important for the improvement of CAR-T cell-based immunotherapy for human cancers.

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