scholarly journals 859 Tuning the tumor microenvironment by reprogramming TREM1+ myeloid cells to unleash anti-tumor immunity in solid tumors

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A900-A900
Author(s):  
Nadine Jahchan ◽  
Hanna Ramoth ◽  
Vladi Juric ◽  
Erin Mayes ◽  
Shilpa Mankikar ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Tumor Microenvironment ◽  
Tumor Immunity ◽  
Single Agent ◽  
Myeloid Cells ◽  
Mouse Tumor ◽  
Syngeneic Mouse ◽  
Tumor Tissues ◽  
Mouse Tumor Models

BackgroundThe tumor microenvironment (TME) often contains high levels of suppressive myeloid cells that contribute to innate checkpoint inhibitor (CPI) resistance. Pionyr’s Myeloid Tuning approach involves altering the composition and/or the function of myeloid cells in the TME. Myeloid reprogramming alters the function of immunosuppressive myeloid cells to acquire an immunostimulatory phenotype. Triggering receptor expressed on myeloid cells-1 (TREM1) is an immunoglobulin superfamily cell surface receptor enriched on tumor-associated myeloid cells. To investigate the potential of TREM1 modulation as an anti-cancer therapeutic strategy, Pionyr developed an afucosylated humanized anti-TREM1 monoclonal antibody termed PY159 and characterized it in pre-clinical and translational biomarker assays described below.MethodsPY159 responses in human whole blood and dissociated primary tumor cells in vitro were evaluated by flow cytometry and measurement of secreted cytokines and chemokines by MSD. TREM1 expression in human tumors was validated by scRNAseq, flow cytometry, and immunohistochemistry (IHC). In vivo efficacy and pharmacodynamic studies of a surrogate anti-mouse TREM1 antibody, termed PY159m, were evaluated using syngeneic mouse tumor models, either as a single-agent or in combination with anti-PD-1. To select tumor types and patients most likely to benefit from PY159 therapy, Pionyr developed qualitative and quantitative monoplex and multiplex IHC assays that detect TREM1 expression levels in human tumor tissues.ResultsPY159 treatment in vitro induced signaling, upregulated monocyte activation markers, and induced proinflammatory cytokines. In human tumors, TREM1 was detected on tumor-associated neutrophils, tumor-associated macrophages, and monocytic myeloid-derived suppressive cells. The surrogate PY159m anti-mouse TREM1 antibody exhibited anti-tumor efficacy in several syngeneic mouse tumor models, both as single-agent and in combination with anti-PD-1. Screening for TREM1 expression in tumor tissues demonstrated that TREM1+ tumor associated myeloid cells were highly enriched in the TME of multiple solid tumor indications. The monoplex and multiplex IHC assays offered insights into the localization of TREM1+ myeloid cells and their spatial relationship with other immune cells present in the TME to determine what immune composition will be more favorable for response to PY159 therapy.ConclusionsCollectively, the available nonclinical data support PY159 as a TREM1 agonist that reprograms myeloid cells and unleashes anti-tumor immunity. PY159 safety and efficacy are currently being evaluated in first-in-human clinical trial (NCT04682431) involving select advanced solid tumors patients resistant and refractory to standard of care therapies alone and in combination with a CPI. The TREM1 IHC assay is successfully being used on FFPE archival tumor tissues from enrolled patients to determine TREM1 expression levels.

scholarly journals P02.11 TREM1 agonist PY159 promotes myeloid cell reprogramming and unleashes anti-tumor immunity

2021 ◽  
Vol 9 (Suppl 1) ◽  
pp. A12.2-A13
Author(s):  
V Juric ◽  
E Mayes ◽  
M Binnewies ◽  
P Canaday ◽  
T Lee ◽  
...  
Keyword(s):  
Tumor Immunity ◽  
Single Agent ◽  
Myeloid Cells ◽  
Human Tumors ◽  
Mouse Tumor ◽  
Neutrophil Chemotaxis ◽  
Syngeneic Mouse ◽  
Cytokines And Chemokines ◽  
Part Time

BackgroundTumor-associated myeloid cells can impede productive anti-tumor immunity. One strategy for targeting immunosuppression is myeloid reprogramming, which drives immunosuppressive myeloid cells to acquire an immunostimulatory phenotype. Triggering receptor expressed on myeloid cells-1 (TREM1) is an immunoglobulin superfamily cell surface receptor expressed on neutrophils and subsets of monocytes and tissue macrophages. TREM1 associates with DAP12 adaptor and induces proinflammatory signaling, amplifies innate immune responses, and is implicated in the development of acute and chronic inflammatory diseases. TREM1 is also enriched in tumors, specifically on tumor-associated myeloid cells. To investigate the potential of TREM1 modulation as an anti-cancer therapeutic strategy, we developed PY159, an afucosylated humanized anti-TREM1 monoclonal antibody, and characterized it in the pre-clinical assays described below.Materials and MethodsAn FcγR binding ELISA and a Jurkat TREM1/DAP12 NFAT-luciferase reporter cell line were used to assess PY159 binding to human FcγRs and TREM1 signaling, respectively. PY159 responses in human whole blood in vitro were evaluated by flow cytometry, transcriptional analysis of sorted leukocyte subsets, and measurement of secreted cytokines/chemokines by MSD. A Transwell system was used to evaluate PY159 effects on neutrophil chemotaxis. TREM1 expression in human tumors was validated by scRNAseq, immunohistochemistry, and flow cytometry. Anti-tumor efficacy of a surrogate anti-mouse TREM1 antibody, PY159m, was evaluated using syngeneic mouse tumor models, either as a single agent or in combination with anti-PD-1.ResultsPY159 afucosylation increased its binding affinity for FcγR and its ability to activate TREM1/DAP12 signaling. In human blood assays, PY159 treatment did not induce depletion of TREM1-expressing cells. Rather, it upregulated monocyte activation markers, promoted neutrophil chemotaxis, and induced proinflammatory cytokines and chemokines, which was dependent on PY159 afucosylation. In human tumors, TREM1 was detected on tumor-associated neutrophils, tumor-associated macrophages, and monocytic myeloid-derived suppressive cells. PY159 induced proinflammatory cytokines and chemokines in dissociated human tumors in vitro, demonstrating that PY159 can reprogram tumor-associated myeloid cells. A surrogate anti-mouse TREM1 antibody, PY159m, exhibited anti-tumor efficacy in several syngeneic mouse tumor models, both as single-agent and in combination with anti-PD-1.ConclusionsThese results show that PY159 is a TREM1 agonist that reprograms myeloid cells and unleashes anti-tumor immunity. PY159 safety and efficacy are currently being evaluated in first-in-human clinical trial (NCT04682431) involving patients resistant and refractory to standard of care therapies.Disclosure InformationV. Juric: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. E. Mayes: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. M. Binnewies: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. P. Canaday: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. T. Lee: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. S. Dash: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. J.L. Pollack: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. J. Rudolph: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. V. Huang: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. X. Du: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. N. Jahchan: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. A.J. Ramoth: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. S. Mankikar: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. M. Norng: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. C. Santamaria: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. K.P. Baker: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc. L. Liang: A. Employment (full or part-time); Significant; Pionyr Immunotherapeutics Inc.

705 Anti-tumor activity of CB-668, a potent, selective and orally bioavailable small-molecule inhibitor of the immuno-suppressive enzyme Interleukin 4 (IL-4)-Induced Gene 1 (IL4I1)

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A747-A747
Author(s):  
Andrew MacKinnon ◽  
Deepthi Bhupathi ◽  
Jason Chen ◽  
Tony Huang ◽  
Weiqun Li ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Tumor Microenvironment ◽  
Immune Cell ◽  
Interleukin 4 ◽  
Mouse Tumor ◽  
Syngeneic Mouse ◽  
Molecule Inhibitor ◽  
Anti Tumor Activity ◽  
Mouse Tumor Models

BackgroundTumors evade destruction by the immune system through multiple mechanisms including altering metabolism in the tumor microenvironment. Metabolic control of immune responses occurs through depletion of essential nutrients or accumulation of toxic metabolites that impair immune cell function and promote tumor growth. The secreted enzyme interleukin 4 (IL-4)-induced gene 1 (IL4I1) is an L-phenylalanine oxidase that catabolizes phenylalanine and produces phenyl-pyruvate and hydrogen peroxide. IL4I1 regulates several aspects of adaptive immunity in mice, including inhibition of cytotoxic T cells through its production of hydrogen peroxide (reviewed in1). In human tumors, IL4I1 expression is significantly elevated relative to normal tissues and is notably high in ovarian tumors and B cell lymphomas. Motivated by the hypothesis that IL4I1 is an immuno-metabolic enzyme that suppresses anti-tumor immunity, we discovered CB-668, the first known small-molecule inhibitor of IL4I1.MethodsIL4I1 enzymatic activity was measured using an HRP-coupled enzyme assay. RNA in-situ hybridization was carried out on the RNAScope platform. Syngeneic mouse tumor models were used to evaluate the anti-tumor activity of CB-668. The level of phenyl-pyruvate in tumor homogenates was measured by LC/MS.ResultsOur clinical candidate, CB-668 is a potent and selective non-competitive inhibitor of IL4I1 (IC50 = 15 nM). CB-668 has favorable in vitro ADME properties and showed low clearance and high oral bioavailability in rodents. Twice-daily oral administration of CB-668 was well-tolerated in mice and resulted in single-agent anti-tumor activity in the syngeneic mouse tumor models B16-F10, A20, and EG7. Oral CB-668 administration reduced the levels of phenyl-pyruvate in the tumor, consistent with inhibition of IL4I1 enzymatic activity. Anti-tumor activity of CB-668 was immune cell-mediated since efficacy was abrogated in CD8-depleted mice, and CB-668 treatment caused increased expression of pro-inflammatory immune genes in the tumor. Moreover, CB-668 had no direct anti-proliferative activity on tumor cells grown in vitro (IC50 > 50 µM). CB-668 also favorably combined with anti-PD-L1 therapy to reduce tumor growth in the B16-F10 tumor model.ConclusionsThese data support an immune-mediated anti-tumor effect of IL4I1 inhibition by CB-668, and suggest inhibition of IL4I1 represents a novel strategy for cancer immuno-therapy.ReferencesMolinier-Frenkel V, Prévost-Blondel A, and Castellano F. The IL4I1 Enzyme: A New Player in the Immunosuppressive Tumor Microenvironment. Cells 2019;8:1–9.

scholarly journals 778 Modulating tumor microenvironment with arginase-1 specific T cells

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A813-A813
Author(s):  
Evelina Martinenaite ◽  
Mia Aaboe Jørgensen ◽  
Rasmus Erik Johansson Mortensen ◽  
Shamaila Munir Ahmad ◽  
Stine Emilie Weis-Banke ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Microenvironment ◽  
Memory T Cells ◽  
Ethics Committee ◽  
Mouse Tumor ◽  
Immune Modulators ◽  
Arginase 1 ◽  
Mouse Tumor Models

BackgroundIO112 is an immune modulatory cancer therapy under preclinical development to target arginase-1-expressing tumor cells and immune inhibitory myeloid cells, such as myeloid derived suppressor cells (MDSCs), and tumor associated macrophages (TAMs). Arginase-1 acts as a metabolic immune regulator at the tumor site by reducing availability of L-arginine to the infiltrating immune cells thus reducing T cell functionality and proliferation. Previously, we demonstrated that IO112 triggers activation of spontaneous CD4+ and CD8+ T-cell responses against arginase-1, found in both cancer patients and healthy individuals.1 These T cells are present in the memory T cell compartment, and are activated in arginase-1 inducing conditions, such as presence of TH2 cytokines IL-4 or IL-13 in vitro.2 3 In this study we aimed to explore the role of arginase-1-specific T cells as immune modulators in immune homeostasis and tumor microenvironment for the development of IO112 immunomodulatory therapy.MethodsHuman arginase-1-specific T cells were isolated and expanded for functional characterization of reactivity against arginase-1 expressing target cells as well as subsequent phenotyping of the targeted arginase-1 positive cells. Syngeneic C57BL/6 mouse tumor models were used to assess the therapeutic efficacy of IO112.ResultsWe show that arginase-1-specific memory T cells specifically recognize arginase-1 expressing cells, such as mRNA transfected autologous dendritic cells (DCs) and B cells as well as M2 polarized macrophages in vitro. In addition, activated arginase-1-specific T cells produce pro-inflammatory cytokines IFNγ and TNFα. Secretion of TH1 cytokines by these T cells suggests that they may act as potent immune modulators in the tumor microenvironment, since many arginase-1 expressing myeloid cells are not terminally differentiated and they can be re-polarized to an immunostimulatory, M1-like phenotype. We also observed that targeting of M2-polarized arginase-1 expressing monocytic leukemia cell line THP-1 with arginase-1-specific CD4+ T cells induces upregulation of PD-L1 on the THP-1 cells. Furthermore, we demonstrate anti-tumor activity of IO112 in syngeneic mouse tumor models (B16 and MC38), both as monotherapy and in combination with anti-PD-1 treatment. The therapeutic effect was associated with increased immune infiltration in the IO112-treated mice compared to the control.ConclusionsWe demonstrate that arginase-1 specific T cells can influence the polarization of arginase-1-expressing immune cells. Our study provides evidence that IO112 immune therapy against arginase-1 is an attractive way of modulating the immune suppressive tumor microenvironment for therapeutic benefit. With this rationale, we are currently undertaking Investigational New Drug (IND) application enabling studies to explore this approach in a clinical setting.ReferencesMartinenaite E, Mortensen REJ, Hansen M, Holmström MO, Ahmad SM, Jørgensen NGD, Met Ö, Donia M, Svane IM, Andersen MH. Frequent adaptive immune responses against arginase-1. Oncoimmunology 2018;7(3):e1404215.Martinenaite E, Ahmad SM, Svane IM, Andersen MH. Peripheral memory T cells specific for Arginase-1. Cell Mol Immunol 2019;16(8):718–719.Martinenaite E, Ahmad SM, Bendtsen SK, Jørgensen MA, Weis-Banke SE, Svane IM, Andersen MH. Arginase-1-based vaccination against the tumor microenvironment: the identification of an optimal T-cell epitope. Cancer Immunol Immunother 2019;68(11):1901–1907.Ethics ApprovalThis study was approved by the Scientific Ethics Committee for The Capital Region of Denmark and Danish Ethics Committee on experimental animal welfare.

SBT6050, a HER2-directed TLR8 therapeutic, as a systemically administered, tumor-targeted human myeloid cell agonist.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 3110-3110
Author(s):  
Heather Metz ◽  
Monica Childs ◽  
Jamie Brevik ◽  
Damion Winship ◽  
Ty Brender ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Cytokine Production ◽  
Single Agent ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Clinical Development ◽  
Innate Immune ◽  
Mouse Tumor ◽  
Systemic Delivery ◽  
Mouse Tumor Models

3110 Background: Solid tumors are replete with myeloid cells which, when activated, drive potent anti-tumor responses. Clinical development of systemically administered myeloid cell agonists, however, has been hindered by acute toxicities due to peripheral activation of the targeted cell types. Intratumoral administration, the route of delivery typically used for innate immune/myeloid cell agonists, is limited by tumor accessibility and a dependence on abscopal responses. A systemically delivered myeloid cell agonist with tumor-localized activity has the potential to overcome challenges encountered with other innate immune/myeloid cell agonists in clinical development. Methods: SBT6050 is a novel therapeutic comprised of a potent toll-like receptor (TLR) 8 agonist payload conjugated to a HER2-directed monoclonal antibody. Delivery of the payload into the endosome of human myeloid cells, where TLR8 resides, requires the co-engagement of HER2 on tumor cells and Fc gamma receptor on human myeloid cells. Thus, SBT6050 is designed for systemic delivery and tumor-targeted activation of human myeloid cells. Results: Studies with human immune cells show that SBT6050 potently induces, in a HER2-dependent manner, multiple anti-tumor immune activities due to its direct activation of myeloid cells and the subsequent induction of T and NK cell cytolytic activity. SBT6050 is designed to activate human myeloid cells only in the presence of HER2-positive tumor cells with moderate (2+ by IHC) or high (3+ by IHC) expression levels. Tumor-localized activity has been demonstrated in mouse models using a SBT6050 mouse surrogate. Systemic delivery results in robust single agent efficacy in multiple mouse tumor models, even those engineered to lack T cells, without accompanying peripheral cytokine production. Trastuzumab and SBT6050 bind to distinct epitopes on HER2 and enhanced activity is observed when the two agents are combined. Conclusions: SBT6050 is a systemically administered, tumor-targeted myeloid cell agonist that demonstrates single agent efficacy in multiple mouse tumor models without peripheral cytokine production. A first-in-human study with SBT6050 is expected to begin this year for patients with HER2-expressing solid tumors.

scholarly journals P03.31 Skin dendritic cells in melanoma are key for successful checkpoint blockade therapy

2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A35.2-A36
Author(s):  
N Prokopi ◽  
CH Tripp ◽  
B Tummers ◽  
JC Crawford ◽  
M Efremova ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cells ◽  
Tumor Microenvironment ◽  
Mouse Model ◽  
Tumor Growth ◽  
Tumor Immunity ◽  
Cd8 T Cells ◽  
Checkpoint Blockade ◽  
And Function

BackgroundImmunotherapy of cancer by checkpoint blockade has significantly improved the survival of melanoma patients. However, in patients with tumors that are poorly infiltrated by effector T cells the clinical results are not encouraging. Therefore, combination approaches that enhance pre-existing anti-tumor immunity and reset the patients‘ immunological status are urgently needed. In this study we used the tg(Grm1)EPv melanoma mouse model that reflects a non-immunogenic tumor microenvironment. In this mouse model, spontaneous melanoma development is driven by the ectopic expression of the metabotropic glutamate receptor-1 in melanocytes, which confers to them a hyperproliferative and anti-apoptotic phenotype. The same alteration has been shown to be present in 40% of melanoma patient samples. The aim of our study was to investigate whether enhancing dendritic cell (DC) numbers and function in the tg(Grm1)EPv mouse model could restore responsiveness to checkpoint blockade.Material and MethodsWe used multicolor flow cytometry, gene expression analysis by RNA-seq and microarray to analyze tumors and tumor-draining lymph nodes (tdLN). With various immunological in vitro and in vivo assays we determined the functional role of DC in tumor immunity.ResultsA loss of skin DC has previously been reported for primary melanoma lesions and we here show that melanoma progression in the tg(Grm1)EPv mouse model coincides with a gradual decrease in the skin cDC2 subset and an upregulation of the inhibitory ligands PD-L1 and galectin-9. Monotherapy with anti-PD-L1 could not delay tumor growth, suggesting that this is a good model to study resistance to checkpoint blockade. We hypothesized that by boosting DC numbers and function we would restore responsiveness to checkpoint blockade. By administering a treatment consisting of systemic Flt3L and intratumoral polyI:C/anti-CD40, we were able to rescue the numbers and function of skin cDC2. Analysis of the treated tumors by flow cytometry showed that the DC boost regimen led to an increased tumor infiltration of activated CD4+ and CD8+T cells. An in vitro T cell proliferation assay revealed that dermal cDC2 that had migrated to the tdLN, played a crucial role in this process, since these were able to cross-present endogenous gp100 antigen more efficiently than migratory Langerhans cells and dermal cDC1. CD4+ and CD8+T cells recruited in the tumors of the DC boost treated mice, expressed PD-1 and TIM-3. Therefore, combination therapy with checkpoint blockade of these molecules resulted in increased cytotoxic activity within the tumor and eventually delay of tumor growth.ConclusionsOur results demonstrate that skin DC shape the tumor microenvironment upon immunotherapy and thus, therapies that aim to enhance responsiveness to checkpoint blockade may well benefit from a component that boosts the numbers and the function of skin DC.Disclosure InformationN. Prokopi: None. C.H. Tripp: None. B. Tummers: None. J.C. Crawford: None. M. Efremova: None. K. Hutter: None. L. Bellmann: None. G. Cappellano: None. L. Boon: None. D. Ortner: None. Z. Trajanoski: None. S. Chen: None. T. de Gruijl: None. D.R. Green: None. P. Stoitzner: None.

MDNA11 is a long-acting IL-2 superkine that potentiates durable immune response in mouse tumor models and non-human primates.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e14546-e14546
Author(s):  
Minh D. To ◽  
Fahar Merchant ◽  
Nina Merchant
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Single Agent ◽  
Mouse Tumor ◽  
Tumor Models ◽  
Toxicology Study ◽  
Long Acting ◽  
Mouse Tumor Models

e14546 Background: The efficacy and safety of recombinant human IL-2 (rhIL-2; Proleukin) to treat certain cancers is limited by a short half-life, marked toxicity and selective high affinity binding to IL2Ra over IL2Rb, resulting in preferential activation of suppressive Tregs. In contrast, MDNA11 has been engineered as a long-acting IL-2 superkine with high affinity IL2Rb receptor selectivity, resulting in preferential anti-cancer effector immune cell activation. Methods: MDNA11 was characterized in both in vitro and in vivo studies including assessment of receptor binding kinetics using BLI/Octet, receptor-mediated signaling in human PMBCs, efficacy in syngeneic mouse tumor models including memory response, as well as safety and PK/PD assessments in non-human primates (NHP). Results: Unlike rhIL-2, MDNA11 does not bind to human IL2Ra but demonstrates a 30-fold higher affinity binding to human IL2Rb. This selectivity resulted in enhanced in vitro STAT5 signaling in human NK and resting CD8 T cells with diminished signaling in Tregs; validation studies in humanized mice are ongoing. In CT26 and MC38 syngeneic tumor models, MDNA11 demonstrates potent and durable efficacy as monotherapy following a Q1W dose schedule for 2 weeks. Synergy with anti-PD1 and anti-CTLA4 immune checkpoint inhibitors (ICIs) was observed and a robust immune memory response developed in all mice with complete tumor clearance. These mice were protected against relapse and tumor re-challenges for up to 8 months without any further treatment, and showed the presence of antigen-specific CD8 T cells. In binding studies with IL-2 receptors of different species, MDNA11 showed highly similar affinity towards human and cynomolgus IL2Rb, confirming the latter as a highly relevant model for toxicology study. MDNA11 was well tolerated in cynomolgus monkeys up to 0.6 mg/kg, while inducing durable (≥10 days) proliferation and expansion of NK and CD8 T cells. Effects on Tregs were minimal and there was no eosinophilia and hypotension (associated with vascular leak syndrome). At high doses of MDNA11, the most common clinical observations were transient loss of appetite and diarrhea. There was modest increase in levels of IFNg and TNFa, but no sign of cytokine release syndrome. Dosing did not trigger development of anti-drug antibodies or histopathologic evidence of pulmonary edema (a major IL-2 induced toxicity). Conclusions: MDNA11 is a long-acting IL-2 superkine that exhibits robust efficacy in mouse tumor models as a single agent and was synergistic in combination with ICIs (anti-CTLA4 and anti-PD1). In NHP, MDNA11 demonstrates selective immune effector cell activation and a favorable safety profile. These data constitute a strong framework for the design of a pivotal GLP toxicology study to further support the planned clinical study of MDNA11 either as a single agent or in combination with ICIs.

scholarly journals 695 Oral delivery of a microbial extracellular vesicle induces potent anti-tumor immunity in mice

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A737-A737
Author(s):  
Loise Francisco-Anderson ◽  
Loise Francisco-Anderson ◽  
Mary Abdou ◽  
Michael Goldberg ◽  
Erin Troy ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Growth ◽  
Extracellular Vesicles ◽  
Tumor Immunity ◽  
Extracellular Vesicle ◽  
The Body ◽  
Checkpoint Inhibition ◽  
Small Intestinal ◽  
The Impact

BackgroundThe small intestinal axis (SINTAX) is a network of anatomic and functional connections between the small intestine and the rest of the body. It acts as an immunosurveillance system, integrating signals from the environment that affect physiological processes throughout the body. The impact of events in the gut in the control of tumor immunity is beginning to be appreciated. We have previously shown that an orally delivered single strain of commensal bacteria induces anti-tumor immunity preclinically via pattern recognition receptor-mediated activation of innate and adaptive immunity. Some bacteria produce extracellular vesicles (EVs) that share molecular content with the parent bacterium in a particle that is roughly 1/1000th the volume in a non-replicating form. We report here an orally-delivered and gut-restricted bacterial EV which potently attenuates tumor growth to a greater extent than whole bacteria or checkpoint inhibition.MethodsEDP1908 is a preparation of extracellular vesicles produced by a gram-stain negative strain of bacterium of the Oscillospiraceae family isolated from a human donor. EDP1908 was selected for its immunostimulatory profile in a screen of EVs from a range of distinct microbial strains. Its mechanism of action was determined by ex vivo analysis of the tumor microenvironment (TME) and by in vitro functional studies with murine and human cells.ResultsOral treatment of tumor-bearing mice with EDP1908 shows superior control of tumor growth compared to checkpoint inhibition (anti-PD-1) or an intact microbe. EDP1908 significantly increased the percentage of IFNγ and TNF producing CD8+ CTLs, NK cells, NKT cells and CD4+ cells in the tumor microenvironment (TME). EDP1908 also increased tumor-infiltrating dendritic cells (DC1 and DC2). Analysis of cytokines in the TME showed significant increases in IP-10 and IFNg production in mice treated with EDP1908, creating an environment conducive to the recruitment and activation of anti-tumor lymphocytes.ConclusionsThis is the first report of striking anti-tumor effects of an orally delivered microbial extracellular vesicle. These data point to oral EVs as a new class of immunotherapeutic drugs. They are particularly effective at harnessing the biology of the small intestinal axis, acting locally on host cells in the gut to control distal immune responses within the TME. EDP1908 is in preclinical development for the treatment of cancer.Ethics ApprovalPreclinical murine studies were conducted under the approval of the Avastus Preclinical Services’ Ethics Board. Human in vitro samples were attained by approval of the IntegReview Ethics Board; informed consent was obtained from all subjects.

scholarly journals 843 Development and engineering of human sialidase for degradation of immunosuppressive sialoglycans to treat cancer

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A884-A884
Author(s):  
Li Peng ◽  
Lizhi Cao ◽  
Sujata Nerle ◽  
Robert LeBlanc ◽  
Abhishek Das ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Cells ◽  
First Generation ◽  
Single Agent ◽  
Mouse Tumor ◽  
Cytokine Release ◽  
Tumor Models ◽  
Cell Immunity ◽  
Mouse Tumor Models

BackgroundSialoglycans, a type of glycans with a terminal sialic acid, have emerged as a critical glyco-immune checkpoint that impairs antitumor response by inhibiting innate and adaptive immunity. Upregulation of sialoglycans on tumors has been observed for decades and correlates with poor clinical outcomes across many tumor types. We previously showed that targeted desialylation of tumors using a bifunctional sialidase x antibody molecule, consisting of sialidase and a tumor-associated antigen (TAA)-targeting antibody, has led to robust single-agent efficacy in mouse tumor models. In addition to tumor cells, most immune cells present substantially more abundant sialoglycans than non-hematological healthy cells, which may also contribute to immunosuppression. Therefore, we studied the impact of immune cell desialylation and evaluated the therapeutic potential of a newly developed sialidase-Fc fusion (Bi-Sialidase), which lacks a TAA-targeting moiety and consists of engineered human neuraminidase 2 (Neu2) and human IgG1 Fc region, in preclinical mouse tumor models.MethodsThe first generation Neu2 variant was further optimized to improve titers and stability to constructed Bi-Sialidase. Bi-Sialidase’s desialylation potency and impact on immune responses were studied in vitro using various human immune functional assays, including T-cell activation, allogeneic mixed lymphocyte reaction, antibody-dependent cellular cytotoxicity, macrophages polarization/activation, neutrophil activation, and peripheral blood mononuclear cell (PBMC) cytokine release assays. We evaluated its antitumor efficacy in mouse tumor models. Bi-Sialidase’s safety profile was characterized by conducting rat and non-human primate (NHP) toxicology studies.ResultsThe optimized Bi-Sialidase achieved a titer of 2.5 g/L from a 15-day fed-batch Chinese hamster ovary cell culture; in contrast, the wild-type and first-generation Neu2 had no production or a low titer (<0.1 g/L) under similar conditions, respectively. We demonstrated that Bi-Sialidase led to dose-dependent desialylation of immune cells and potentiated T-cell immunity, without impacting NK, macrophage, or neutrophil activation by desialylating immune cells. Activated and exhausted T cells upregulated surface sialoglycans and Bi-Sialidase-mediated desialylation reinvigorated exhausted-like T cells as measured by IFNg production. Bi-Sialidase treatment also enhanced DC priming and activation of naïve T cells by desialylating both T cells and DCs. Furthermore, Bi-Sialidase showed single-agent antitumor activity in multiple mouse tumor models, including MC38, CT26, A20, and B16F10. Importantly, Bi-Sialidase did not cause cytokine release in human PBMC assays and was tolerated to up to 100 mg/kg in rats and NHPs, demonstrating a wide safety margin.ConclusionsBi-Sialidase with an optimized Neu2 offers a novel immunomodulatory approach to enhancing T-cell immunity by desialylating immunosuppressive sialoglycans for cancer treatment.

scholarly journals 323 Immunogenic syngeneic model MC38-OVA for the preclinical evaluation of immune evasion and checkpoint blockade

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A348-A348
Author(s):  
Jessie Wang ◽  
Kaixia Lian ◽  
Jia Zheng ◽  
Chenpan Nie ◽  
Annie An ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Immunity ◽  
Immune Evasion ◽  
Syngeneic Mouse ◽  
Ifn Γ ◽  
Draining Lymph Nodes ◽  
Syngeneic Tumors

BackgroundThe development of immuno-oncology (I/O) therapeutics has revolutionized the cancer treatment landscape. Despite this achievement, the mechanism behind limited responses is poorly understood. Tumor immune evasion has been reported to arise through the loss of tumor necrosis factor (TNF) signaling, interferon-γ (IFN-γ) signaling, and antigen presentation pathways, which are crucial to CD8+ T cell-mediated killing. Syngeneic mouse models have been widely used as they have an intact immune system, are easily accessible, and have a vast array of historical data for comparison. However, limited syngeneic models respond to immune checkpoint inhibitors, possibly due to low intrinsic immunogenicity. The expression of ovalbumin (OVA) has previously shown to sufficiently alter the susceptibility of syngeneic tumors to host T cell-mediated responses. In this study, the newly developed OVA-expressing MC38 syngeneic line was characterized for tumor immunity, checkpoint blockade response and response durability.MethodsMurine colon cancer MC38 cells were transduced by lentiviral vector with chicken OVA coding cDNA. A single clone was selected, and OVA expression was confirmed by western blot. The MC38-OVA cells were subcutaneously implanted into immunocompetent mice to evaluate the tumorigenicity and in vivo response to anti-PD-1 antibody treatment. Blood was collected 2 days post final dose of anti-PD-1 treatment for phenotypic analysis by FACS. Spleen and tumor draining lymph nodes were collected at termination for FACS analysis of IFN-γ+ T cells and OVA specific CD8+ T cells. Adoptive transfer was evaluated by challenge studies in both MC38-OVA and MC38 tumor-bearing mice with T cells derived from MC38-OVA mice, anti-PD-1 cured mice and OT-I mice. In vitro killing assays were performed to evaluate the function of adoptive CD3+ T cells transfer.ResultsOVA-expressing MC38 presented complete regression under anti-PD-1 treatment in vivo. T cell expansion was observed after anti-PD-1 treatment in peripheral blood with increased IFN-γ+ T cells in both tumor-draining lymph nodes and spleen. Additionally, anti-PD-1 cured mice generated robust tumor specific memory T cell, which successfully inhibited MC38-OVA and MC38 tumor growth following adoptive transfer. CD3+ T cells from MC38-OVA-bearing mice and OT-I mice showed anti-tumor immunity in vivo. In vitro killing assay demonstrated increased immunity.ConclusionsSyngeneic mouse tumor models are preferred preclinical models for I/O research, despite limited intrinsic immunogenicity. OVA expression in syngeneic tumors largely increased T cell-mediated immunity to enhance antigen-specific T cell responses during tumorigenesis, providing novel immunogenic models for preclinical immunotherapy evaluation.

scholarly journals Nano-encapsulated tryptanthrin derivative for combined anticancer therapy via inhibiting indoleamine 2,3-dioxygenase and inducing immunogenic cell death

Nanomedicine ◽  
2019 ◽  
Vol 14 (18) ◽  
pp. 2423-2440 ◽  
Author(s):  
Canyu Yang ◽  
Bing He ◽  
Qiang Zheng ◽  
Dakuan Wang ◽  
Mengmeng Qin ◽  
...  
Keyword(s):  
Cell Death ◽  
Single Agent ◽  
Tumor Burden ◽  
Antitumor Efficacy ◽  
In Vivo Studies ◽  
Immunogenic Cell Death ◽  
Indoleamine 2,3 Dioxygenase ◽  
Tumor Tissues

Aim: We developed a polycaprolactone-based nanoparticle (NP) to encapsulate tryptanthrin derivative CY-1-4 and evaluated its antitumor efficacy. Materials & methods: CY-1-4 NPs were prepared and evaluated for their cytotoxicity and associated mechanisms, indoleamine 2,3-dioxygenase (IDO)-inhibitory ability, immunogenic cell death (ICD)-inducing ability and antitumor efficacy. Results: CY-1-4 NPs were 123 nm in size. In vitro experiments indicated that they could both induce ICD and inhibit IDO. In vivo studies indicated that a medium dose reduced 58% of the tumor burden in a B16-F10-bearing mouse model, decreased IDO expression in tumor tissues and regulated lymphocytes subsets in spleen and tumors. Conclusion: CY-1-4 is a potential antitumor candidate that could act as a single agent with combined functions of IDO inhibition and ICD induction.

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