scholarly journals 847 Pharmacokinetics and pharmacodynamics of GS-3583 in cynomolgus monkeys

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A888-A888
Author(s):  
Michelle Kuhne ◽  
Hamlet Chu ◽  
Christopher Clarke ◽  
Brian Carr ◽  
Manuel Baca ◽  
...  
Keyword(s):  
T Cell ◽  
Tyrosine Kinase ◽  
Clinical Signs ◽  
Fold Increase ◽  
Relative Increase ◽  
Repeat Dose ◽  
Cynomolgus Monkeys ◽  
Cell Responses ◽  
Anti Tumor Activity ◽  
Dose Dependent

BackgroundThe ligand for the receptor tyrosine kinase FMS-like tyrosine kinase 3 (FLT3) plays an importantrole in hematopoiesis. FLT3 signaling is required for the differentiation andexpansion of dendritic cells. In the context of cancer immunity, the conventional dendritic cellsubtype 1 (cDC1) are required for the generation of tumor-specific T cell responses in mousepreclinical models. In human tumors cDC1 are often underrepresented in thetumor microenvironment, supporting the hypothesis that therapeutically increasing their number via FLT3 pathway stimulation has the potential to promote T cell-mediated anti-tumor activity.MethodsGS-3583 is a fusion protein composed of the extracellular domain of human FLT3 ligand(FLT3L) combined with a modified fragment crystallizable (Fc) region of human IgG4. GS-3583was designed to induce cDC1 expansion and subsequently promote tumor-reactive T cell priming, activation and recruitment into the tumor microenvironment. The pharmacokinetics (PK) and pharmacodynamics (PD) of GS-3583 has been characterized in a 4-week repeat dose GLP study in cynomolgus monkeys at doses ranging from 0.3 to 10mg/kg GS-3583 was given as an intravenous injection.ResultsImmunophenotyping analysis of peripheral blood cells from GS-3583 treated monkeys demonstrated a non-dose-dependent expansion of cDC1 and cDC2 populations. The peak expansion for cDC1 and cDC2 occurred at Day 8 to Day 15. At peak, there was a 160-fold relative increase in cDC1 and 150-fold increase in cDC2 at the highest dose tested. There were dose-dependent increases in the exposure (AUC and Cmax) of GS-3583. GS-3583 was well-tolerated with no mortality or adverse clinical signs.ConclusionsThe administration of GS-3583 leads to increases in cDC1 and cDC2 populations. It was well tolerated at the maximal dose tested with no adverse clinical signs. Further clinical development of GS-3583 is warranted.

scholarly journals 846 Pre-clinical validation of a FLT3L-fusion protein for dendritic cell expansion and anti-tumor efficacy

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A887-A887
Author(s):  
Michelle Kuhne ◽  
Hamlet Chu ◽  
Sarah Ng ◽  
Christopher Clarke ◽  
Brian Carr ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Fusion Protein ◽  
Tyrosine Kinase ◽  
Single Agent ◽  
Tumor Growth Inhibition ◽  
Cell Responses ◽  
Dose Dependent ◽  
Cell Death Protein

BackgroundThe ligand for the receptor tyrosine kinase FMS-like tyrosine kinase 3 (FLT3) plays an importantrole in hematopoiesis. FLT3 signaling is required for the differentiation andexpansion of dendritic cells. In the context of cancer immunity, the conventional dendritic cellsubtype 1 (cDC1) are required for the generation of tumor-specific T cell responses in mousepreclinical models. In human tumors cDC1 are often underrepresented in thetumor microenvironment, supporting the hypothesis that therapeutically increasing their number via FLT3 pathway stimulation has the potential to promote T cell-mediated anti-tumor efficacy.MethodsGS-3583 is a fusion protein composed of the extracellular domain (ECD) of human FLT3 ligand(FLT3L) combined with a modified fragment crystallizable (Fc) region of human IgG4. GS-3583was designed to induce cDC1 expansion and subsequently promote tumor-reactive T cell priming, activation and recruitment into the tumor microenvironment. To evaluate the therapeutic efficacy of FLT3 stimulation in vivo, a mouse surrogate mGS-3583was designed using the ECD of mouse FLT3L fused to an engineered mouse IgG2a Fc withattenuated binding to mouse FcgRs.Results mGS-3583 bound to recombinant mouse FLT3 with an estimated affinity of 15 nM, and to mouse FLT3-expressing cells with an EC50 of 0.15 nM. In vivo, mGS-3583 showed single agent dose-dependent tumor growth inhibition (TGI) in tumors that correlated with peripheral and intratumoral cDC1 expansion. In tumors with no initial immune infiltration, mGS-3583 led to an influx of T cells into the tumors. In addition to single agent efficacy, mGS-3583 combined effectively with programmed cell death protein (ligand)-1 (PD(L)-1) pathway blockade.ConclusionsIn vivo expansion of dendritic cells can convert uninflamed (cold) tumors to immunologically active (hot) tumors and initiate productive anti-tumor immune responses. These findings support the development GS-3583 as a promising candidate for cancer immunotherapy.

Activity of CBT-501, a novel humanized anti-PD-1 antibody, in a humanized genetically engineered mouse model of colon carcinoma.

2017 ◽  
Vol 35 (7_suppl) ◽  
pp. 108-108
Author(s):  
Qing Zhou ◽  
Weihong Nian ◽  
Ziyong Sun ◽  
Junzhuan Qiu ◽  
Zhun Wang ◽  
...  
Keyword(s):  
T Cell ◽  
Mouse Model ◽  
Genetically Engineered ◽  
T Cell Response ◽  
Asia Pacific ◽  
Cell Subpopulation ◽  
Repeat Dose ◽  
Genetically Engineered Mouse Model ◽  
Anti Tumor Activity ◽  
Dose Dependent

108 Background: CBT-501 (Genolimzumab, GB-226) is a novel humanized mAb (IgG4k) against human Programmed Death-1 (PD-1). CBT-501 demonstrated highly specific binding to PD-1 of human (KD= 505 pM) and cynomolgus (KD= 7.2 nM). It did not completely block the binding of nivolumab or pembrolizumab, suggesting a novel epitope. CBT-501 efficiently inhibited the binding of PD-L1/L2 to PD-1 through a competitive action for both human and monkey. It enhanced human T-cell activation in the Mix Lymphocyte Reaction (MLR), as shown by increased release of IL-2 and INF-γ. The Fc-fragment bound to FcRn dose-dependently without any effector function. The PK/PD studies in cynomolgus showed a linear dose exposure, with a T1/2of 115-142 h for single and repeat dosing. The PD-1 receptor occupancy after a single dose was dose-dependent reaching 100% at peak, maintained after multiple dosing and continued for 6 wk after last dose. Single and repeat dose toxicology studies in cynomolgus showed weight gain of the thyroid and mild expansion of the thyroid follicles at the highest dose of 100 mg/kg which were reversible. No abnormal drug-related toxicity was found. In rhesus vaccinated with adenovirus-mediated Simian Immunodeficiency Virus, biweekly IV CBT-501 promoted the antigen-specific T-cell response, as shown by ELISPOT and intracellular staining of IL-2, INF-γ and TNF-α in PBMC and T-cell subpopulation. Due to lack of immunoselectivity to mouse PD-1, investigation of the in vivo anti-tumor activity in rodent model is challenging. Methods: Crown Bioscience has developed humanized genetically engineered mouse model expressing human PD-1 extracellular domain with a fully functional murine immune system. Subcutaneous colon adenocarcinoma MC38 syngeneic tumor draft was established in mice. Results: CBT-501 injected IP q2w×3wk demonstrated significant anti-tumor activity. The tumor growth reduction was dose dependent with comparable or improved activity over nivolumab, and with the highest inhibition rate at 83%. Conclusions: Based on the strong nonclinical data and differentiation, and an acceptable safety profile, a first in human Phase 1 trial is planned in the Asia-Pacific region.

scholarly journals An Adenovirus-Based Influenza Tablet Vaccine Induces Dose-Dependent T-Cell Responses

2015 ◽  
Vol 2 (suppl_1) ◽  
Author(s):  
Wendy Peters ◽  
Jennifer Brandl ◽  
Leesun Kim ◽  
Sean Tucker
Keyword(s):  
T Cell ◽  
T Cell Responses ◽  
Cell Responses ◽  
Dose Dependent

scholarly journals 702 TJ-CD4B (ABL111), a Claudin18.2-targeted 4-1BB tumor engager induces potent tumor-dependent immune response without dose-limiting toxicity in preclinical studies

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A730-A730
Author(s):  
Wenqing Jiang ◽  
Zhengyi Wang ◽  
Zhen Sheng ◽  
Jaeho Jung ◽  
Taylor Guo
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Gene Expression Analysis ◽  
Cell Activation ◽  
Clinical Development ◽  
Cynomolgus Monkeys ◽  
Anti Tumor Activity

Background4-1BB (CD137) is a co-stimulatory receptor that stimulates the function of multiple immune cells. Its ability to induce potent anti-tumor activity makes 4-1BB an attractive target for immuno-oncology. However, clinical development of a monospecific 4-1BB agonistic antibody has been hampered by dose-limiting hepatic toxicities. To minimize systemic toxicities, we have developed a novel Claudin18.2 (CLDN18.2) x 4-1BB bispecific antibody, TJ-CD4B (ABL111) that stimulates 4-1BB pathway only when it engages with Claudin 18.2, a tumor-associated antigen specifically expressed in gastrointestinal cancers. TJ-CD4B (ABL111) is now being evaluated in patients with advanced solid tumors in a first-in-human trial (NCT04900818).MethodsTJ-CD4B (ABL111) was evaluated in vivo using the human 4-1BB knock-in mice bearing CLDN18.2 expressing MC38 tumor cells. Pharmacodynamic effects upon treatment were characterized in tumor tissue and blood. Immunophenotyping of the tumor microenvironment (TME) and peripheral blood was performed by flow cytometry. Soluble biomarkers were measured using Luminex-based multiplex assay. In-depth gene expression analysis was performed on primary human CD8+ T cells that were co-cultured with CLDN18.2 expressing cells in the presence of anti-CD3 using NanoString nCounter®. Pharmacokinetic (PK) and toxicity study were performed in cynomolgus monkeys.ResultsTJ-CD4B (ABL111) elicited complete tumor regression in 13 out of 18 MC38 tumor bearing mice given at a dose above 2 mg/kg. Dose-dependent anti-tumor activity was associated with enhanced T cell activation in TME and expansion of memory T cells in the peripheral blood. Increased CD8+ T cells number and proliferation were observed in both tumor nest and surrounding stroma while the level of soluble 4-1BB in the serum was also elevated in response to the treatment. In vitro gene expression analysis by Nanostring revealed TJ-CD4B(ABL111) effectively activated immune pathways characterized by IFN?-signaling and T cell inflammation. Preclinically, TJ-CD4B was well tolerated at the repeated doses up to 100 mg/kg/wk in cynomolgus monkeys without the adverse influence on the liver function which is generally affected by 4-1BB activation. Besides, no cytokine release or immune activation was observed in the periphery.ConclusionsTJ-CD4B (ABL111) is a novel CLDN18.2 dependent 4-1BB bispecific agonist antibody that induced T cell activation and memory response in tumor with CLDN18.2 expression, leading to a strong anti-tumor activity in vivo. TJ-CD4B did not induce systemic immune response nor hepatic toxicity due to the CLDN18.2 dependent 4-1BB stimulation. These data warrant the current clinical development in phase I trial to validate the safety properties and tumor specific responses.

scholarly journals Codelivery of IL-7 Augments Multigenic HCV DNA Vaccine-induced Antibody as well as Broad T Cell Responses in Cynomolgus Monkeys

2010 ◽  
Vol 10 (6) ◽  
pp. 198 ◽  
Author(s):  
Su-Hyung Park ◽  
Mi-Young Song ◽  
Hyo Jung Nam ◽  
Se Jin Im ◽  
Young-Chul Sung
Keyword(s):  
T Cell ◽  
Dna Vaccine ◽  
T Cell Responses ◽  
Cynomolgus Monkeys ◽  
Cell Responses

scholarly journals Safety Profile of a Virus-Like Particle-Based Vaccine Targeting Self-Protein Interleukin-5 in Horses

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 213 ◽  
Author(s):  
Sigridur Jonsdottir ◽  
Victoria Fettelschoss ◽  
Florian Olomski ◽  
Stephanie C. Talker ◽  
Jelena Mirkovitch ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Mononuclear Cells ◽  
Clinical Signs ◽  
T Cell Response ◽  
Type I ◽  
Cell Responses ◽  
Virus Like Particle ◽  
Ifn Γ

Background: Insect bite hypersensitivity (IBH) is an eosinophilic allergic dermatitis of horses caused by type I/IVb reactions against mainly Culicoides bites. The vaccination of IBH-affected horses with equine IL-5 coupled to the Cucumber mosaic virus-like particle (eIL-5-CuMVTT) induces IL-5-specific auto-antibodies, resulting in a significant reduction in eosinophil levels in blood and clinical signs. Objective: the preclinical and clinical safety of the eIL-5-CuMVTT vaccine. Methods: The B cell responses were assessed by longitudinal measurement of IL-5- and CuMVTT-specific IgG in the serum and plasma of vaccinated and unvaccinated horses. Further, peripheral blood mononuclear cells (PBMCs) from the same horses were re-stimulated in vitro for the proliferation and IFN-γ production of specific T cells. In addition, we evaluated longitudinal kidney and liver parameters and the general blood status. An endogenous protein challenge was performed in murine IL-5-vaccinated mice. Results: The vaccine was well tolerated as assessed by serum and cellular biomarkers and also induced reversible and neutralizing antibody titers in horses and mice. Endogenous IL-5 stimulation was unable to re-induce anti-IL-5 production. The CD4+ T cells of vaccinated horses produced significantly more IFN-γ and showed a stronger proliferation following stimulation with CuMVTT as compared to the unvaccinated controls. Re-stimulation using E. coli-derived proteins induced low levels of IFNγ+CD4+ cells in vaccinated horses; however, no IFN-γ and proliferation were induced following the HEK-eIL-5 re-stimulation. Conclusions: Vaccination using eIL-5-CuMVTT induces a strong B-cell as well as CuMVTT-specific T cell response without the induction of IL-5-specific T cell responses. Hence, B-cell unresponsiveness against self-IL-5 can be bypassed by inducing CuMVTT carrier-specific T cells, making the vaccine a safe therapeutic option for IBH-affected horses.

Dissecting The Potential Role Of Prevnar As An Anti-Myeloma Vaccine

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1980-1980
Author(s):  
Kimberly Noonan ◽  
Lakshmi Rudraraju ◽  
Anna Ferguson ◽  
Amy Sidorski ◽  
Andrea Casildo ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Clinical Response ◽  
Plasma Cells ◽  
T Cell Responses ◽  
Fold Increase ◽  
T Cell Response ◽  
Cell Phenotype ◽  
Cell Responses

Abstract Background Prevnar, is a multi-valent conjugate vaccine given to children and adults over 50 for the prevention of Streptococcus pneumonia, otis media and pneumococcal pneumonia. The conjugate in Prevnar is a CRM-197 protein molecule which is a nontoxic recombinant Diphtheria toxin. Prevnar serves as an excellent tool in monitoring overall immune response changes in myeloma patients’ pre and post treatment. Humoral B-cell responses can be measured by antibody responses to the pneumococcal antigens, while T cell responses to CRM-197. Clinical Study We previously conducted a study to determine the efficacy of lenalidomide to augment vaccine specific responses in patients with myeloma. Two cohorts of patients were studied. In cohort A (N=10), the first Prevnar vaccine was given two weeks prior to starting lenalidomide and the second vaccine on day 14 of cycle 2 of lenalidomide. In cohort B (N=7), both Prevnar vaccines were given on lenalidomide (day 14 of cycle 2 and 4). As we previously reported patients in cohort B had an overall better B and T cell response to Prevnar compared to cohort A. These responses were due to an overall change in B and T cell phenotype attained with lenalidomide therapy. Results Prospectively, patients in cohort B also had an unexpected overall increase in disease response and in response duration. In Cohort A only 10% of patients responded to therapy while 60% of patients in Cohort B had a clinical response. The patients with a measurable clinical response had a 5-fold increase in the percentage of tumor specific bone marrow (BM) T cells after two vaccinations with Prevnar whereas the non-responding patients had no increase in tumor specific BM T cells. Parelleling the anti-tumor response, responders showed a 15 fold increase in CRM-197 specific BM T cells after the second vaccination. Patients with no clinical response showed minimal CRM-197 T cell immunity. CRM-197 is a specific inhibitor of HB-EGF; syndecan-1 (CD138) is an HB-EGF co-receptor as well as a marker for myeloma plasma cells. We hypothesized that HB-EGF specific responses produced by vaccination with the Prevnar vaccine, and CRM-197 specifically, may have contributed to the overall increased clinical responses in our clinical trial. Responding patients had a 5-fold increase in HB-EGF specific BM T cells after vaccine 2 while clinical non-responders had no increase in HB-EGF specific BM T cells. T cells specificity for purified HB-EGF correlated with both CRM-197 and tumor specific responses. Finally the myeloma cell lines U266, H929, KMS-11 and KMS-12 co-stained for CD138 and HB-EGF with 47% of CD138+ myeloma cells co-expressing HB-EGF. Conclusions We hypothesize that the CRM-197 moiety of the Prevnar vaccine can prime T cell responses against HB-EGF on plasma cells. This immune response, in turn, weakens the tumor stromal interactions in the tumor microenvironment and potentially enhances the anti-tumor efficacy of immunomodulatory drugs such as lenalidomide. Therefore, Prevnar may possibly serve as a candidate anti-myeloma vaccine. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Differential Regulation of Antigen-Specific CD8+ T Cell Responses by IL-12p40 in a Dose-Dependent Manner

2008 ◽  
Vol 180 (11) ◽  
pp. 7167-7174 ◽  
Author(s):  
Doo-Jin Kim ◽  
Je-In Youn ◽  
Sang-Hwan Seo ◽  
Hyun-Tak Jin ◽  
Young-Chul Sung
Keyword(s):  
T Cell ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Differential Regulation ◽  
Dependent Manner ◽  
Cell Responses ◽  
Dose Dependent

Proliferation of CD8+ T-Cells Specific for CMV and EBV in Response to TCR Mediated Recognition of Cognate Antigen Is Inhibited by Imatinib in a Dose-Dependent Manner.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1342-1342
Author(s):  
Ruth Seggewiss ◽  
Karin Lore ◽  
Elisabeth Greiner ◽  
Magnus K. Magnusson ◽  
David A. Price ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Tyrosine Kinase ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
T Cell Proliferation ◽  
Cell Transplant ◽  
Dose Dependent

Abstract We and others have shown that the tyrosine kinase inhibitor imatinib (STI571, Gleevec®) inhibits T-cell proliferation and activation at concentrations achieved in vivo. At 10μM, imatinib inhibited T-cell receptor (TCR)-mediated proliferation of purified peripheral blood T-cells almost completely. Up-regulation of the activation markers CD25 and CD69 at 24h in response to TCR cross-linking was suppressed by imatinib at a mean IC50 of 5.4μM and 7.3μM, respectively and IL-2 production was also severely impaired. However, these assays may not fully reflect the response to clinical relevant antigens. Therefore, we chose to investigate the antigen-triggered proliferation of memory CD8+ T-cells specific for immunodominant CMV and EBV HLA-A2 peptide epitopes. We used HLA-peptide tetramers to identify healthy blood donors with detectable CMV- or EBV-specific CD8+ T-cell populations. Purified T-cells from these donors were then stimulated with the CMV peptide pp65495–503 or the EBV peptide BMFLI259–267. Antigen-induced proliferation was measured by dilution of the vital dye CFSE over a period of 4 or 8 days. The magnitude of the virusspecific CD8+ T-cell population ranged from 0.5 % to 7.1% of CD8+ T-cells for CMV and from 0.05% to 0.35% of CD8+ T-cells for EBV. Antigen-specific CD8+ T-cells from all 10 donors studied proliferated in response to the CMV peptide. In 8 from 10 donors, imatinib reduced CMV peptide induced proliferation. With increasing imatinib concentrations (range: 5 – 10μM), we observed dose dependent reduction of both the number of cells undergoing cell division and the average number of divisions completed per cell. Comparable inhibition of specific T-cell proliferation in response to the EBV-derived peptide was observed in two donors. Immunoblots demonstrated that imatinib substantially reduced tyrosine phosphorylation of ZAP70 and LAT in response to TCR-mediated activation in Jurkat T-cells. Sequence comparisons of all 90 tyrosine kinase genes in the human genome for homology in the ATP binding pocket identified Lck, which is required for ZAP70 activation, as a likely target for imatinib. Our results indicate that imatinib may interfere with clinically important T-cell effector functions. As concentrations sufficient for half-maximal inhibition of TCR signalling are achieved in vivo, imatinib could increase the risk of opportunistic infections and impact on GVH and GVL reactions post-transplantation especially when used in conjuction with other immunosuppressive agents. Therefore, close monitoring of patients on imatinib for CMV reactivation or EBV-induced lymphoproliferative diseases, especially in stem cell transplant recipients, appears warranted.

Human mesenchymal stem cells alter antigen-presenting cell maturation and induce T-cell unresponsiveness

Blood ◽  
2005 ◽  
Vol 105 (5) ◽  
pp. 2214-2219 ◽  
Author(s):  
Shaul Beyth ◽  
Zipora Borovsky ◽  
Dror Mevorach ◽  
Meir Liebergall ◽  
Zulma Gazit ◽  
...  
Keyword(s):  
Stem Cells ◽  
T Cells ◽  
Mesenchymal Stem Cells ◽  
T Cell ◽  
Human Mesenchymal Stem Cells ◽  
Cell Responses ◽  
Dependent Inhibition ◽  
Dose Dependent Inhibition ◽  
Antigen Presenting ◽  
Dose Dependent

AbstractInfusion of either embryonic or mesenchymal stem cells prolongs the survival of organ transplants derived from stem cell donors and prevents graft-versus-host-disease (GVHD). An in-depth mechanistic understanding of this tolerization phenomenon could lead to novel cell-based therapies for transplantation. Here we demonstrate that while human mesenchymal stem cells (hMSCs) can promote superantigen-induced activation of purified T cells, addition of antigen-presenting cells (APCs; either monocytes or dendritic cells) to the cultures inhibits the T-cell responses. This contact- and dose-dependent inhibition is accompanied by secretion of large quantities of interleukin (IL)–10 and aberrant APC maturation, which can be partially overridden by the addition of factors that promote APC maturation (ie, lipopolysaccharide [LPS] or anti-CD40 monoclonal antibody [mAb]). Thus, our data support an immunoregulatory mechanism wherein hMSCs inhibit T cells indirectly by contact-dependent induction of regulatory APCs with T-cell–suppressive properties. Our data may reveal a physiologic phenomenon whereby the development of a distinct APC population is regulated by the tissue's cellular microenvironment.

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