IMMU-10. ENGINEERED PD-L1 RECEPTORS AUGMENT ANTI-TUMOR ACTIVITY OF HER2 CAR T CELLS IN HIGH GRADE GLIOMA

Abstract INTRODUCTION Immunotherapy with engineered CAR T cells is a promising new therapy for glioblastoma, for which predictive and prognostic biomarkers are needed to inform effective intervention. Recently, our group analyzed standard-of-care (SOC) MRI images of long-term and short-term glioblastoma survivors and identified six intratumoral “habitats” of which “Habitat 6” was correlated with survival at diagnosis in high-grade glioma. Based on the MRI characteristics of “Habitat 6”, viz. high enhancement and high edema, we hypothesized that it could be a marker of tumor immune infiltrates. We are studying longitudinal changes in tumor “habitat” composition on MRIs of subjects with recurrent high-grade glioma treated with CAR T cells engineered to target IL13Ra2. METHODS MRI scans of the brain were acquired in 6 subjects at 3.0 T at baseline and various times before and after initiation of CAR T cell therapy. FLAIR, T1W and T1W-CE MRI images were registered to T2W images and six intratumoral “habitats” were computed as per our recently published methodology. The six habitats generated at the end of the tumor segmentation process were: “Habitat 1” (low FLAIR, low enhancement), “Habitat 2” (high FLAIR, low enhancement), “Habitat 3” (low FLAIR, medium enhancement), “Habitat 4” (high FLAIR, medium enhancement), “Habitat 5” (low FLAIR, high enhancement), and “Habitat 6” (high FLAIR, high enhancement). RESULTS Analysis of temporal changes in the six “habitats” shows an initial increase in both “Habitat 4” and “Habitat 6” following CAR T cell therapy initiation. Subjects with higher absolute volumes of “Habitat 6” at the baseline (pre-treatment) showed longer overall survival. Overall survival is a function of absolute “Habitat 6” volume at baseline, its direction of change immediately post-therapy, the duration of any increase in “Habitat 6” post-treatment, and the “Habitat 6” to “Habitat 4” ratio. Additional subjects are being evaluated to further understand these preliminary observations.

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IMMU-16. INTRA-TUMOURAL IL-12 DELIVERY ENABLES CAR T-CELL IMMUNOTHERAPY FOR HIGH-GRADE GLIOMA

Neuro-Oncology ◽

10.1093/neuonc/noaa222.372 ◽

2020 ◽

Vol 22 (Supplement_3) ◽

pp. iii363-iii363

Author(s):

Giulia Agliardi ◽

Anna Rita Liuzzi ◽

Alastair Hotblack ◽

Donatella De Feo ◽

Nicolás Núñez ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Therapy ◽

High Grade Glioma ◽

High Grade ◽

T Cell Therapy ◽

Car T Cells ◽

Car T Cell ◽

Car T Cell Therapy ◽

Car T

Abstract Treatment with T-cells redirected to tumour specificity with a chimeric antigen receptor (CAR) may be well suited to treat intracranial tumours due to the ability of T-cells to access the central nervous system and migrate to infiltrative sites of disease. In adult glioblastoma, a case report of local and distant eradication of intracranial and spinal tumour deposits following intraventricular infusion of IL13Ra2-CAR T-cells indicates the potential of this approach. However, in contrast to the sustained complete remissions observed in haematological malignancies, in the majority of patients with glioblastoma CAR T-cell therapy has not resulted in clinical benefit. Tumour heterogeneity and the highly immune inhibitory tumour microenvironment (TME) are likely key barriers to achieving durable anti-tumour immunity. Here use intra-tumoural administration of IL-12 to enable CAR T-cell immunity. We employed CAR-T cells targeting the tumour-specific epidermal growth factor variant III (EGFRvIII). In an immunocompetent orthotopic mouse model of high-grade glioma, we show that CAR-T cells alone failed to control fully established tumour, but when combined with a single, locally delivered dose of IL-12, durable antitumor responses were achieved. IL-12 not only boosted cytotoxicity of CAR T-cells, but also reshaped the TME driving increased infiltration of proinflammatory CD4+ T-cells, decreased numbers of regulatory T-cells (Tregs) and activation of the myeloid compartment. Critically, immunotherapy enabling benefits of IL-12 were achieved with minimal systemic effects. Our findings show that local delivery of IL-12 is an effective adjuvant for CAR-T cell therapy for high-grade glioma. Assessment of application in high-risk childhood brain tumours is ongoing.

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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 ◽

10.1182/blood-2019-129998 ◽

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.

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Abstract LB-182: Differential modulation of the PD-1 pathway impacts the anti-tumor activity of CAR T cells

10.1158/1538-7445.am2017-lb-182 ◽

2017 ◽

Author(s):

Regina J. Lin ◽

Anne-Sophie Gautron ◽

Laurent Poirot ◽

Oi Kwan Wong ◽

Barbra Sasu ◽

...

Keyword(s):

T Cells ◽

Differential Modulation ◽

Car T Cells ◽

Car T ◽

Anti Tumor Activity

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CD19-Redirected Chimeric Antigen Receptor T (CART19) Cells Induce a Cytokine Release Syndrome (CRS) and Induction of Treatable Macrophage Activation Syndrome (MAS) That Can Be Managed by the IL-6 Antagonist Tocilizumab (toc).

Blood ◽

10.1182/blood.v120.21.2604.2604 ◽

2012 ◽

Vol 120 (21) ◽

pp. 2604-2604 ◽

Cited By ~ 1

Author(s):

Stephan A. Grupp ◽

David L Porter ◽

David T Teachey ◽

David M. Barrett ◽

Anne Chew ◽

...

Keyword(s):

Cell Proliferation ◽

T Cells ◽

T Cell ◽

Chimeric Antigen Receptor ◽

Tumor Lysis Syndrome ◽

Antigen Receptor ◽

Car T Cells ◽

Car T ◽

Anti Tumor Activity

Abstract Abstract 2604 We previously reported on CART19 cells expressing a chimeric antigen receptor (CAR) with intracellular activation and costimulatory domains. Infusion of these cells results in 100 to 100,000× in vivo proliferation, tumor lysis syndrome followed by durable antitumor activity, and prolonged persistence in pts with B cell tumors. Here we report that in vivo proliferation of CART19 cells and potent anti-tumor activity is associated with CRS, leading to hemophagocytic lymphohistiocytosis (HLH), also termed MAS. We propose that MAS/HLH is a unique biomarker that is associated with and may be required for potent anti-tumor activity. Autologous T cells were lentivirally transduced with a CAR composed of anti-CD19 scFv/4-1BB/CD3-zeta, activated/expanded ex-vivo with anti-CD3/anti-CD28 beads, and then infused into ALL or CLL pts with persistent disease after 2–8 prior treatments. CART19 anti ALL activity was also modeled in a xenograft mouse model with high level of human ALL/human T cell engraftment and simultaneous detection of CAR T cells and ALL using 2-color bioluminescent imaging. We describe updated results of 10 pts who received CART19 cells elsewhere at ASH (Porter, et al), including 9 pts with CLL and 1 pediatric pt with relapsed refractory ALL. 6/9 evaluable pts had a CR or PR, including 4 sustained CRs. While there was no acute infusional toxicity, all responding pts also developed CRS. All had high fevers, as well as grade 3 or 4 hypotension/hypoxia. CRS preceded peak blood expression of CART19 cells, and then increased in intensity until the CART19 cell peak (D10–31 after infusion). The ALL pt experienced the most significant toxicity, with grade 4 hypotension and respiratory failure. Steroid therapy on D6 resulted in no improvement. On D9, noting high levels of TNFa and IL-6 (peak increases above baseline: IFNg at 6040x; IL-6 at 988x; IL-2R at 56x, IL-2 at 163× and TNFa at 17x), we administered TNFa and IL-6 antagonists entanercept and toc. This resulted in resolution of fever and hypotension within 12hr and a rapid wean from ventilator support to room air. These interventions had no apparent impact on CART19 cell expansion or efficacy: peak of CAR T cells (2539 CAR+ cells/uL; 77% of CD3 cells by flow) occurred on D11, and D23 bone marrow showed CR with negative MRD, compared to her initial on-study marrow which showed 65% blasts. Although she had no history of CNS ALL, spinal fluid showed detectable CART19 cells (21 lymphs/mcL; 78% CAR+). At 4mo post infusion, this pt remains in CR, with 17 CART19 cells/uL in the blood and 31% CAR+ CD3 cells in the marrow. Clinical assessment of subsequent responding patients shows all had evidence of MAS/HLH including dramatic elevations of ferritin and histologic evidence of HLH. Peak ferritin levels range from 44,000 to 605,000, preceding and continuing with peak T cell proliferation. Other consistent findings include rapid onset hepatosplenomegaly unrelated to disease and moderate DIC. Subsequently, 3 CLL patients have also been treated with toc, also with prompt and striking resolution of high fevers, hypotension and hypoxia. 1 received toc on D10 and achieved a CR accompanied by CART19 expansion. 1 had rapid resolution of CRS following toc administration on day 9 and follow up for response is too short. A 3rd CLL pt received toc on D3 for early fevers and had no CART-19 proliferation and no response. To model the timing of cytokine blockade, xenografts using bioluminescent primary pediatric ALL were established and then treated with extra cells from the clinical manufacture. The CART19 cells proliferated and resulted in prolonged survival. Cytokine blockade prior to T cell infusion with toc and/or etanercept abrogated disease control with less in vivo proliferation of infused CART19 cells, confirming the result seen in the one pt given early toc (D3). The optimal time and threshold to trigger cytokine blockade is currently being tested in these models. CART19 T cells can produce massive in-vivo expansion, long-term persistence, and anti-tumor efficacy, but can also induce significant CRS with features suggestive of MAS/HLH that responds rapidly to cytokine blockade. Given prior to initiation of significant CART19 proliferation, blockade of TNFa and/or IL-6 may interfere with proliferation and effector function, but if given at a point where cell proliferation is underway, toc may ameliorate the symptoms that we have observed correlate with robust clinical responses. Disclosures: Off Label Use: tocilizumab for cell therapy toxicity. Levine:University of Pennsylvania: financial interest due to intellectual property and patents in the field of cell and gene therapy. Conflict of interest is managed in accordance with University of Pennsylvania policy and oversight Patents & Royalties; TxCell: Consultancy, Membership on an entity's Board of Directors or advisory committees. Kalos:University of Pennsylvania: Patents & Royalties. June:Novartis: Research Funding, institution owned patents have been licensed by Novartis, institution owned patents have been licensed by Novartis Patents & Royalties.

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Suppression of 4.1R enhances the potency of NKG2D-CAR T cells against pancreatic carcinoma via activating ERK signaling pathway

Oncogenesis ◽

10.1038/s41389-021-00353-8 ◽

2021 ◽

Vol 10 (9) ◽

Author(s):

Yaoxin Gao ◽

Haizhen Lin ◽

Dandan Guo ◽

Sijia Cheng ◽

Ying Zhou ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Pancreatic Carcinoma ◽

Signaling Pathway ◽

Xenograft Model ◽

Erk Signaling ◽

Dependent Manner ◽

Car T Cells ◽

Car T ◽

Anti Tumor Activity

AbstractPancreatic carcinoma (PC) is one of the most common malignancies. Chimeric antigen receptor (CAR)-modified T cells has achieved remarkable efficacy in the treatment of hematological malignancies. However, lack of tumor-specific targets and the existence of inhibitory factors limit the function of CAR T cells when treating solid tumors. 4.1R has been reported to suppress the anti-tumor activity of T cell responses. In this study, we investigated the anti-tumor activity of 4.1R deletion in natural killer group 2D (NKG2D)-CAR T cells against PC. The CAR T cells were obtained by transfecting T cells with lentiviral vector carrying NKG2D-CAR, NC-NKG2D-CAR, or KD2-NKG2D-CAR. In vitro, NKG2D-CAR T cells showed higher cytotoxicity than Mock T cells. However, compared to NKG2D-CAR T cells, furtherly higher cytotoxicity against PC cells in a dose-dependent manner was found in KD2-NKG2D-CAR T cells. In addition, the proliferation rate and cytotoxic activity of KD2-NKG2D-CAR T cells were significantly higher than those of NKG2D-CAR T cells. Besides, the inhibitory receptors PD-1 and TIM-3 were expressed in lower level on KD2-NKG2D-CAR T cells. In vivo, KD2-NKG2D-CAR T cells suppressed tumor growth more effectively in a xenograft model compared to NKG2D-CAR T cells. Mechanistically, 4.1R regulated CAR T cell function via activating ERK signaling pathway. Therefore, the study provides a new idea to enhance the anti-tumor efficiency of CAR T therapy.

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Beyond the Cell Surface: Targeting Intracellular Negative Regulators to Enhance T cell Anti-Tumor Activity

International Journal of Molecular Sciences ◽

10.3390/ijms20235821 ◽

2019 ◽

Vol 20 (23) ◽

pp. 5821 ◽

Cited By ~ 6

Author(s):

Sitaram ◽

Uyemura ◽

Malarkannan ◽

Riese

Keyword(s):

T Cells ◽

T Cell ◽

Cell Function ◽

Cell Activity ◽

Sh2 Domain ◽

Extracellular Proteins ◽

Car T Cells ◽

Car T ◽

Src Homology ◽

Anti Tumor Activity

It is well established that extracellular proteins that negatively regulate T cell function, such as Cytotoxic T-Lymphocyte-Associated protein 4 (CTLA-4) and Programmed Cell Death protein 1 (PD-1), can be effectively targeted to enhance cancer immunotherapies and Chimeric Antigen Receptor T cells (CAR-T cells). Intracellular proteins that inhibit T cell receptor (TCR) signal transduction, though less well studied, are also potentially useful therapeutic targets to enhance T cell activity against tumor. Four major classes of enzymes that attenuate TCR signaling include E3 ubiquitin kinases such as the Casitas B-lineage lymphoma proteins (Cbl-b and c-Cbl), and Itchy (Itch), inhibitory tyrosine phosphatases, such as Src homology region 2 domain-containing phosphatases (SHP-1 and SHP-2), inhibitory protein kinases, such as C-terminal Src kinase (Csk), and inhibitory lipid kinases such as Src homology 2 (SH2) domain-containing inositol polyphosphate 5-phosphatase (SHIP) and Diacylglycerol kinases (DGKs). This review describes the mechanism of action of eighteen intracellular inhibitory regulatory proteins in T cells within these four classes, and assesses their potential value as clinical targets to enhance the anti-tumor activity of endogenous T cells and CAR-T cells.

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EXTH-20. SYNGENEIC B7-H3-SPECIFIC CAR T-CELLS HAVE POTENT ANTI-BRAIN TUMOR ACTIVITY VIA LOCAL OR SYSTEMIC DELIVERY

Neuro-Oncology ◽

10.1093/neuonc/noaa215.374 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii91-ii91

Author(s):

Dalia Haydar ◽

Zhongzhen Yi ◽

Haley Houke ◽

Martine F Roussel ◽

Chris DeRenzo ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Brain Tumors ◽

Tumor Cells ◽

Systemic Delivery ◽

Car T Cells ◽

Car T ◽

Anti Tumor Activity ◽

Gl261 Glioma

Abstract BACKGROUND We and others have identified B7-H3 (CD276) as a promising target for CAR T-cell-based immunotherapies for pediatric brain tumors. So far, B7-H3-CAR T cells have only been studied in xenograft models for brain tumors, which do not recapitulate the immunosuppressive tumor microenvironment (TME). To overcome this obstacle, we decided to adapt the immune competent GL261 murine glioma model which mimics human disease and host immune barriers. METHODS To evaluate their safety and efficacy, murine B7-H3-CAR T-cells were generated using retroviral particles encoding a 2nd generation B7-H3-CAR with a CD28.z signaling domain. Expansion, persistence, and anti-tumor activity were evaluated in vitro and in vivo. Components of the brain TME were then evaluated using flow cytometry and immunostaining. RESULTS B7-H3-CAR T cells only killed B7-H3+ tumor cells, secreted significant levels of IFNγ and IL-2 in an antigen-dependent manner and expanded an average of 85-fold in repeat stimulation assay with B7-H3+ tumor cells in contrast to control CAR T-cells. In vivo, intratumoral (2x106) or systemic (3x106) injection of syngeneic B7-H3-CAR T-cells into mice with orthotopic GL261 glioma induced complete regression in 60% of treated mice resulting in a significant survival advantage. Mice showed no evidence of acute or long-term toxicities related to CAR T-cell infusions. We confirmed this encouraging safety profile by systemic administration of a high dose (1x107) B7-H3-CAR T-cells and performing histological analyses of all major organs on day 14 post T-cell injection, which showed no notable signs of injury or on-target/off-tumor toxicities. CONCLUSIONS We successfully generated syngeneic B7-H3-CAR T-cells and have demonstrated that these cells have potent anti-tumor activity in the immune competent GL261 glioma model via local or systemic delivery without apparent toxicities. Our study paves the way for future testing of B7-H3-CAR T-cells in early phase clinical studies.

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