scholarly journals P857 ONM-500 – a novel STING-activating therapeutic nanovaccine platform for cancer immunotherapy

2020 ◽  
Vol 8 (Suppl 1) ◽  
pp. A7-A8
Author(s):  
Jason Miller ◽  
Min Luo ◽  
Hua Wang ◽  
Zhaohui Wang ◽  
Xinliang Ding ◽  
...  
Keyword(s):  
T Cell ◽  
Cancer Immunotherapy ◽  
T Cell Activation ◽  
Cell Activation ◽  
Subcutaneous Administration ◽  
Full Length ◽  
Tumor Models ◽  
Hpv16 E6 ◽  
E6 And E7

BackgroundEfficacy of cancer vaccines requires the induction of tumor antigen-specific cytotoxic T-lymphocytes (CTL) to effectively clear established tumors. Orchestration of antigen presentation, co-stimulatory signaling, and innate cytokine signals are necessary steps for tumor-specific T-cell activation. The ONM-500 nanovaccine platform1-2 utilizes a novel pH-sensitive polymer that forms an antigen-encapsulating nanoparticle and functions both as a carrier for antigen delivery of both peptide and protein antigens to dendritic cells and acts as an adjuvant, activating the stimulator on interferon genes (STING) pathway and generating a CD8+ CTL response. Peptide antigens have translational challenges due to complex formulations and/or HLA-type-specific antigen sequence recognition, processing and presentation. Full-length protein antigens alleviate HLA subtype limitation, allowing coverage of multi-immunogenic T cell epitopes in patients. Pairing ONM-500 adjuvant with the full-length E6 and E7 oncoproteins from human papillomavirus (HPV) cancers shows great potential to treat HPV-associated cancer in patients.MethodsBased on the previously demonstrated STING-dependent T cell activation by ONM-500 [1], the nanovaccine was formulated with full-length HPV16 E6 and E7 proteins (recombinant), and the nanoparticle properties and antigen loading were characterized. In vivo lymph node accumulation following subcutaneous administration was evaluated using fluorescent nanovaccines. Direct binding of ONM-500 to recombinant human STING (CTD) was evaluated using isothermal titration calorimetry (ITC) compared to the endogenous ligand 2’,3’-cGAMP. Antitumor efficacy was evaluated in multiple syngeneic tumor models, including the TC-1 model which overexpresses HPV16 E6 and E7 with the ONM-500 vaccine in combination with anti-PD-1 checkpoint inhibitor. Long-term anti-tumor memory was evaluated in a follow-up rechallenge study after 60 days in tumor-free animals.ResultsCharacterization of ONM-500 nanovaccine shows reproducible particle chemi-physical properties and antigen loading. The nanoparticle size substantiates the effective lymph node accumulation for antigen cross-presentation in dendritic cells following subcutaneous administration. ITC studies with human STING demonstrated effective binding by ONM-500 adjuvant. The nanovaccine anti-tumor efficacy was previously demonstrated in melanoma, colorectal, and HPV-associated syngeneic tumor models. In TC-1 tumors, ONM-500 nanovaccine containing full-length E6/E7 protein showed 100% overall survival at 55 days (figure 1). Tumor growth inhibition was also improved over E7 antigen peptide formulated nanovaccine. A rechallenge study demonstrated long-term antigen-specific anti-tumor memory response.Abstract P857 Figure 1ConclusionsONM-500 STING-activating nanovaccines effectively deliver antigens in vivo to lymph nodes to elicit antigen-specific CTL response. The anti-tumor efficacy in multiple tumor models demonstrates the potential of ONM-500 as a general STING agonist cancer vaccine platform, and full-length E6/E7 incorporated ONM-500 is being developed for HPV-associated cancers.Ethics ApprovalAll animal procedures were performed with ethical compliance and approval by the Institutional Animal Care and Use Committee of the University of Texas Southwestern Medical Center (Protocol No. 2017-101954) and Pennsylvania State College of Medicine (Protocol No. 47682).ReferencesLuo M, Wang H, Wang Z, Cai H, Lu Z, Li Y, Du M, Huang G, Wang C, Chen X, Porembka MR, Lea J, Frankel AE, Fu YX, Chen ZJ, Gao J. A STING-activating nanovaccine for cancer immunotherapy. Nat Nanotechnol 2017; 12:648–654.Luo M, Liu Z, Zhang X, Han C, Samandi LZ, Dong C, Sumer BD, Lea J, Fu YX, Gao J. Synergistic STING activation by PC7A nanovaccine and ionizing radiation improves cancer immunotherapy. J Control Release 2019; 28:154–160.

Bispecific anti-PD-1/PD-L1 antibody CTX-8371 to promote cellular clustering and PD-1 shedding, antitumor activity and tolerability.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e15056-e15056
Author(s):  
Diana I. Albu ◽  
Yan Qin ◽  
Xianzhe Wang ◽  
Vivian Li ◽  
Taeg Kim ◽  
...  
Keyword(s):  
T Cell ◽  
Transgenic Mice ◽  
T Cell Activation ◽  
Cell Activation ◽  
Mouse Tumor ◽  
Tumor Models ◽  
Cynomolgus Monkeys ◽  
Range Finding

e15056 Background: Checkpoint blockade therapies targeting PD-1 and PD-L1 have shown great success for the treatment of various malignancies. However, a substantial fraction of patients with PD-L1-positive tumors remain unresponsive to these therapies. Novel therapy with significantly greater activity than the leading PD-1/PD-L1 inhibitors is expected to bring additional clinical benefit to patients. Here we describe the preclinical evaluation of CTX-8371, which combines anti-PD-1 and anti-PD-L1 monoclonal antibodies in one bispecific tetravalent molecule. Methods: The immune-enhancing activity of CTX-8371 was tested in vitro in T cell activation assays and tumor cell killing assay. CTX-8371 anti-tumor efficacy in vivo was assessed using mouse tumor cells expressing human PD-L1 implanted in transgenic mice humanized at the PD-1 and PD-L1 loci. CTX-8371 anti-tumor activity was also tested in xenograft tumor models. The mechanism of action of CTX-8371 was investigated in vitro using Jurkat cells expressing PD-1 or PD-L1, human PBMCs, and in vivo in tumor-bearing, chimeric PD-1/PD-L1 transgenic mice. CTX-8371 PK was determined in mice using an MSD ELISA-based assay and in cynomolgus monkeys using a qualified ELISA method. Dose range finding and toxicokinetic studies were performed in cynomolgus monkeys. Results: CTX-8371 potently enhanced T cell activation and function in vitro and showed curative efficacy as monotherapy in multiple solid tumor models, isografts or xenografts. Furthermore, CTX-8371 demonstrated superior anti-tumor efficacy compared to Keytruda or atezolizumab in checkpoint inhibitors-sensitive and resistant syngeneic mouse tumor models. Mechanistically, in addition to blocking PD-1 interaction with PD-L1, CTX-8371 bispecific antibody facilitated cell to cell bridging between cells expressing PD-1 and cells expressing PD-L1. Furthermore, we show that simultaneous binding of CTX-8371 to both PD-1 and PD-L1 resulted in long term PD-1 shedding. This suggests that CTX-8371 may prevent or overcome T cell exhaustion within the tumor microenvironment, thus providing additional advantage over existing therapies. Lastly, excellent tolerability was observed in non-human primates given 2 weekly drug infusions at up to 50 mg/kg dose. Conclusions: CTX-8371 displays multiple mechanisms of action over monoclonal PD1/PD-L1 blockade. These unique pharmacological properties of CTX-8371 could explain the enhanced T cell responses to tumor antigens and superior efficacy over current monoclonal antibody therapies. With favorable PK/PD and toxicology profiles in mice and cynomolgus monkeys, CTX-8371 warrants further advancement to clinical testing.

442 ICT01, an anti-BTN3A mAb that activates Vg9Vd2 T cells, plus interleukin-2: a potent and promising combination for cancer immunotherapy

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A468-A468
Author(s):  
Aude de Gassart ◽  
Patrick Brune ◽  
LE Suong ◽  
Sophie Agaugué ◽  
Emmanuel Valentin ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cancer Immunotherapy ◽  
T Cell Activation ◽  
Immune Cells ◽  
Cell Activation ◽  
Human Pbmcs ◽  
Vγ2vδ2 T Cells

Background gdT-cells are attractive targets for cancer immunotherapy given their strong cytolytic and pro-inflammatory cytokine secretion activities, and the association between tumor infiltration and positive prognosis.1 2 ImCheck Therapeutics is developing ICT01, an anti-human butyrophilin-3A (BTN3A/CD277) mAb specifically activating g9d2 T-cells in a phosphoantigen (pAg)-independent manner. ICT01 is currently in a Phase 1/2a study in solid and hematologic tumors (NCT04243499).IL-2 has been shown to expand g9d2 T-cells in vitro and in non-human primates in presence of pAgs.3 4 5 We wanted to characterize the proliferative effects of combining ICT01 with IL-2 on γ9δ2 T-cells as an approach to potentiate g9d2 T-cell mediated cancer immunotherapy.Methods g9d2 T-cell activation and expansion was assessed in vitro in human PBMCs treated with ICT01±IL-2, and in vivo, in the blood of immunocompromised NCG mice engrafted with 20 × 106 human PBMCs and treated with ICT01 (single IV dose, 5 mg/kg on Day 1) ±IL-2 (0.3MIU/kg IP on Day 1–4). A dose-ranging ICT01 (single IV dose, 1 or 5 mg/kg on Day 1)+IL-2 combination (1 MIU SC QD on Days 1–5) study was conducted in cynomolgus monkeys.ResultsIn PBMCs cultures in vitro, ICT01 selectively activated g9d2 T-cells and IL-2 significantly enhanced ICT01-mediated g9d2 T-cell proliferation, this compartment reaching >50% of T-cells after 8 days of treatment versus ~10% with ICT01 alone. This was confirmed in vivo in mice models. Flow cytometry analysis of mice blood revealed a 5.5-fold increase in human g9d2 T-cell number in the combination groups compared to ICT01 or IL-2 alone treated animals, with g9d2 T-cell frequency reaching ~35% of the CD3+ T-cell compartment. In Cynomolgus, a specific expansion and activation of peripheral g9d2 T-cells from ~1–2% at baseline to up to 30% of T cells 7 days post ICT01 administration was observed. No ICT01 effect was observed on other immune cells. Histopathological examinations revealed a trend towards higher numbers of g9d2 T-cells in several organs in ICT01+IL-2 treated monkeys. There was no evidence for a systemic cytokine release syndrome at any time point. Adverse effects with variable severity were observed, most of them being reversible and commonly associated with IL-2 alone, and not reported in the IND-enabling GLP toxicity study with ICT01 monotherapy at doses up to 100 mg/kg.ConclusionsThese results demonstrate the ability of ICT01+IL-2 combination to trigger profound γ9δ2 T-cell activation and expansion, suggesting that the clinical combination of ICT01 with a lymphoproliferative cytokine (e.g., IL-2) may be a novel therapeutic approach for cancer patients.Ethics ApprovalPseudonymized samples isolated from healthy volunteers: whole blood by ImCheck Therapeutics under the agreement n° 7173 between ImCheck Therapeutic SAS and EFS PACA (Etablissement Français du Sang Provence-Alpes-cote d’Azur)ReferencesGentles AJ, Newman AM, Liu CL, et al. The prognostic landscape of genes and infiltrating immune cells across human cancers. Nature Medicine 2015;21(8):938–945.Tosolini M, Pont F, Poupot M, et al. Assessment of tumor-infiltrating TCRVγ9Vδ2 γδ lymphocyte abundance by deconvolution of human cancers microarrays. OncoImmunology 2017;6(3):e1284723.Nada MH, Wang H, Workalemahu G, Tanaka Y, Morita CT. Enhancing adoptive cancer immunotherapy with Vγ2Vδ2 T cells through pulse zoledronate stimulation. Journal for ImmunoTherapy of Cancer 2017;5(1):9.Sicard H, Ingoure S, Luciani B, et al. In Vivo Immunomanipulation of Vγ9Vδ2 T cells with a synthetic phosphoantigen in a preclinical nonhuman primate model. The Journal of Immunology 2005;175(8):5471–5480.Ali Z, Shao L, Halliday L, et al. Prolonged (E)-4-Hydroxy-3-Methyl-But-2-Enyl pyrophosphate-driven antimicrobial and cytotoxic responses of pulmonary and systemic Vγ2Vδ2 T cells in macaques. The Journal of Immunology 2007;179(12):8287–8296.

scholarly journals PAX8 lineage-driven T cell engaging antibody for the treatment of high-grade serous ovarian cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emily Lee ◽  
Sarah Szvetecz ◽  
Ryan Polli ◽  
Angelo Grauel ◽  
Jayson Chen ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Standard Of Care ◽  
Tumor Growth Inhibition ◽  
High Grade ◽  
Ovarian Cancers ◽  
Late Stage Diagnosis ◽  
Anti Tumor Activity

AbstractHigh-grade serous ovarian cancers (HGSOC) represent the most common subtype of ovarian malignancies. Due to the frequency of late-stage diagnosis and high rates of recurrence following standard of care treatments, novel therapies are needed to promote durable responses. We investigated the anti-tumor activity of CD3 T cell engaging bispecific antibodies (TCBs) directed against the PAX8 lineage-driven HGSOC tumor antigen LYPD1 and demonstrated that anti-LYPD1 TCBs induce T cell activation and promote in vivo tumor growth inhibition in LYPD1-expressing HGSOC. To selectively target LYPD1-expressing tumor cells with high expression while sparing cells with low expression, we coupled bivalent low-affinity anti-LYPD1 antigen-binding fragments (Fabs) with the anti-CD3 scFv. In contrast to the monovalent anti-LYPD1 high-affinity TCB (VHP354), the bivalent low-affinity anti-LYPD1 TCB (QZC131) demonstrated antigen density-dependent selectivity and showed tolerability in cynomolgus monkeys at the maximum dose tested of 3 mg/kg. Collectively, these data demonstrate that bivalent TCBs directed against LYPD1 have compelling efficacy and safety profiles to support its use as a treatment for high-grade serous ovarian cancers.

scholarly journals Bifunctional iRGD-anti-CD3 enhances antitumor potency of T cells by facilitating tumor infiltration and T-cell activation

2021 ◽  
Vol 9 (5) ◽  
pp. e001925
Author(s):  
Shujuan Zhou ◽  
Fanyan Meng ◽  
Shiyao Du ◽  
Hanqing Qian ◽  
Naiqing Ding ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Confocal Microscope ◽  
Mechanistic Studies ◽  
Tumor Spheroids ◽  
Antitumor Effects ◽  
Transport Pathway

BackgroundPoor infiltration and limited activation of transferred T cells are fundamental factors impeding the development of adoptive cell immunotherapy in solid tumors. A tumor-penetrating peptide iRGD has been widely used to deliver drugs deep into tumor tissues. CD3-targeting bispecific antibodies represent a promising immunotherapy which recruits and activates T cells.MethodsT-cell penetration was demonstrated in tumor spheroids using confocal microscope, and in xenografted tumors by histology and in vivo real-time fluorescence imaging. Activation and cytotoxicity of T cells were assessed by flow cytometry and confocal microscope. Bioluminescence imaging was used to evaluate in vivo antitumor effects, and transmission electron microscopy was used for mechanistic studies.ResultsWe generated a novel bifunctional agent iRGD-anti-CD3 which could immobilize iRGD on the surface of T cells through CD3 engaging. We found that iRGD-anti-CD3 modification not only facilitated T-cell infiltration in 3D tumor spheroids and xenografted tumor nodules but also induced T-cell activation and cytotoxicity against target cancer cells. T cells modified with iRGD-anti-CD3 significantly inhibited tumor growth and prolonged survival in several xenograft mouse models, which was further enhanced by the combination of programmed cell death protein 1 (PD-1) blockade. Mechanistic studies revealed that iRGD-anti-CD3 initiated a transport pathway called vesiculovacuolar organelles in the endothelial cytoplasm to promote T-cell extravasation.ConclusionAltogether, we show that iRGD-anti-CD3 modification is an innovative and bifunctional strategy to overcome major bottlenecks in adoptive cell therapy. Moreover, we demonstrate that combination with PD-1 blockade can further improve antitumor efficacy of iRGD-anti-CD3-modified T cells.

NFATc3 regulates the transcription of genes involved in T-cell activation and angiogenesis

Blood ◽  
2011 ◽  
Vol 118 (3) ◽  
pp. 795-803 ◽  
Author(s):  
Katia Urso ◽  
Arantzazu Alfranca ◽  
Sara Martínez-Martínez ◽  
Amelia Escolano ◽  
Inmaculada Ortega ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Target Genes ◽  
Gene Knockout ◽  
Activated T Cells ◽  
Knock Down ◽  
And Function

Abstract The nuclear factor of activated T cells (NFAT) family of transcription factors plays important roles in many biologic processes, including the development and function of the immune and vascular systems. Cells usually express more than one NFAT member, raising the question of whether NFATs play overlapping roles or if each member has selective functions. Using mRNA knock-down, we show that NFATc3 is specifically required for IL2 and cyclooxygenase-2 (COX2) gene expression in transformed and primary T cells and for T-cell proliferation. We also show that NFATc3 regulates COX2 in endothelial cells, where it is required for COX2, dependent migration and angiogenesis in vivo. These results indicate that individual NFAT members mediate specific functions through the differential regulation of the transcription of target genes. These effects, observed on short-term suppression by mRNA knock-down, are likely to have been masked by compensatory effects in gene-knockout studies.

scholarly journals Response of the Splenic Dendritic Cell Population to Malaria Infection

2004 ◽  
Vol 72 (7) ◽  
pp. 4233-4239 ◽  
Author(s):  
Andrew L. Leisewitz ◽  
Kirk A. Rockett ◽  
Bonginkosi Gumede ◽  
Margaret Jones ◽  
Britta Urban ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Dendritic Cell ◽  
Cell Population ◽  
T Cell Activation ◽  
Malaria Infection ◽  
Cell Activation ◽  
Splenic Dendritic Cell ◽  
Dendritic Cell Population

ABSTRACT Dendritic cells, particularly those residing in the spleen, are thought to orchestrate acquired immunity to malaria, but it is not known how the splenic dendritic cell population responds to malaria infection and how this response compares with the responses of other antigen-presenting cells. We investigated this question for Plasmodium chabaudi AS infection in C57BL/6 mice. We found that dendritic cells, defined here by the CD11c marker, migrated from the marginal zone of the spleen into the CD4+ T-cell area within 5 days after parasites entered the bloodstream. This contrasted with the results observed for the macrophage and B-cell populations, which expanded greatly but did not show any comparable migration. Over the same time period dendritic cells showed upregulation of CD40, CD54, and CD86 costimulatory molecules that are required for successful T-cell activation. In dendritic cells, the peak intracellular gamma interferon expression (as shown by fluorescence-activated cell sorting) was on day 5, 2 days earlier than the peak expression in B-cells or macrophages. These findings show that splenic dendritic cells are actively engaged in the earliest phase of malarial infection in vivo and are likely to be critical in shaping the subsequent immune response.

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