scholarly journals 856 INBRX-106: a novel hexavalent anti-OX40 agonist for the treatment of solid tumors

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A897-A897
Author(s):  
Emily Rowell ◽  
Heather Kinkead ◽  
Elisabeth Torretti ◽  
Bryan Becklund ◽  
Florian Sulzmaier ◽  
...  
Keyword(s):  
T Cell ◽  
Dose Response ◽  
Response Curve ◽  
Single Agent ◽  
Cell Assays ◽  
Human Igg1 ◽  
Anti Tumor Activity ◽  
T Cell Assays

BackgroundOX40 is a co-stimulatory receptor enriched on immune cells in the tumor microenvironment. OX40 agonism promotes anti-tumor responses, both singly and in combination with checkpoint inhibitors. The cognate OX40 ligand, OX40L, is a trimeric protein that activates robust signaling through clustering. INBRX-106 is a novel hexavalent OX40 agonist that has been rationally designed to optimize target clustering and provide superior agonism to previously explored bivalent entities, leading to more potent anti-tumor activity.MethodsINBRX-106 is a homodimer, each half comprising three identical humanized, camelid single-domain antibody binding domains targeting OX40 linked end-to-end, and fused to an effector-enabled human IgG1 constant domain (Fc). Due to lack of rodent cross-reactivity, a valency, affinity and activity-matched murine surrogate, Hex-C04, was generated for the purpose of preclinical modeling. Hex-C04 contains an mIgG2a effector enabled Fc, the mouse isotype most analogous to the activity of human IgG1. The activity and potency of INBRX-106 and Hex-C04 were evaluated in functional in vitro T-cell assays, and the anti-tumor efficacy of Hex-C04 was evaluated alone or in combination with PD-1 blockade across a number of syngeneic tumor models.ResultsINBRX-106 binds specifically to OX40 with a sub nanomolar apparent affinity, without blocking the binding of its ligand OX40L. In vitro, cross-linking by INBRX-106 rapidly induces loss of OX40 surface expression in addition to driving receptor signaling. In primary T-cell assays, INBRX-106 is more potent than a bivalent comparator antibody, inducing greater upregulation of activation markers, cytokine production and proliferation. This costimulatory activity exhibits a bell-shaped dose-response curve, with maximal activity occurring at receptor occupancies of 30–100%. In vivo, tumor growth control by Hex-C04 also follows a bell-shaped dose response curve. Rapid loss of OX40 is observed in vivo as well, with both the degree and duration of OX40 loss dependent on Cmax and exposure. Hex-C04 demonstrated strong single-agent activity across a variety of preclinical tumor models including models that do not respond to a PD-1/PD-L1 checkpoint inhibitor, and this activity was improved in combination with a PD-1 blocking antibody.ConclusionsPreclinically, INBRX-106 significantly outperforms bivalent antibodies in co-stimulatory capacity and anti-tumor activity. On the weight of this data, Inhibrx Inc. has initiated a first-in-human Phase 1 trial of INBRX-106 as a single agent or in combination with Keytruda® (pembrolizumab). The complex relationship between dose, OX40 target modulation and activity indicate the importance of integrating preclinical data sets with emerging clinical data to make informed decisions regarding INBRX-106 dose and schedule.Trial RegistrationNCT04198766Ethics ApprovalThe care and use of all animals were reviewed and approved by the IACUC committees of Explora BioLabs and Molecular Diagnostic Services and conducted in accordance with AAALAC regulations.

scholarly journals Cd2 Sets Quantitative Thresholds in T Cell Activation

1999 ◽  
Vol 190 (10) ◽  
pp. 1383-1392 ◽  
Author(s):  
Martin F. Bachmann ◽  
Marijke Barner ◽  
Manfred Kopf
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Dose Response ◽  
Response Curve ◽  
Cell Activation ◽  
Dose Response Curve ◽  
Lymphocyte Function

It has been proposed that CD2, which is highly expressed on T cells, serves to enhance T cell–antigen presenting cell (APC) adhesion and costimulate T cell activation. Here we analyzed the role of CD2 using CD2-deficient mice crossed with transgenic mice expressing a T cell receptor specific for lymphocytic choriomeningitis virus (LCMV)-derived peptide p33. We found that absence of CD2 on T cells shifted the p33-specific dose–response curve in vitro by a factor of 3–10. In comparison, stimulation of T cells in the absence of lymphocyte function–associated antigen (LFA)-1–intercellular adhesion molecule (ICAM)-1 interaction shifted the dose–response curve by a factor of 10, whereas absence of both CD2–CD48 and LFA-1–ICAM-1 interactions shifted the response by a factor of ∼100. This indicates that CD2 and LFA-1 facilitate T cell activation additively. T cell activation at low antigen density was blocked at its very first steps, as T cell APC conjugate formation, TCR triggering, and Ca2+ fluxes were affected by the absence of CD2. In vivo, LCMV-specific, CD2-deficient T cells proliferated normally upon infection with live virus but responded in a reduced fashion upon cross-priming. Thus, CD2 sets quantitative thresholds and fine-tunes T cell activation both in vitro and in vivo.

scholarly journals Predicting the in vivo developmental toxicity of benzo[a]pyrene (BaP) in rats by an in vitro–in silico approach

2021 ◽  
Author(s):  
Danlei Wang ◽  
Maartje H. Rietdijk ◽  
Lenny Kamelia ◽  
Peter J. Boogaard ◽  
Ivonne M. C. M. Rietjens
Keyword(s):  
Dose Response ◽  
In Silico ◽  
Response Curve ◽  
Developmental Toxicity ◽  
Toxicity Testing ◽  
Maximal Effect ◽  
Blood Concentrations ◽  
Reverse Dosimetry

AbstractDevelopmental toxicity testing is an animal-intensive endpoints in toxicity testing and calls for animal-free alternatives. Previous studies showed the applicability of an in vitro–in silico approach for predicting developmental toxicity of a range of compounds, based on data from the mouse embryonic stem cell test (EST) combined with physiologically based kinetic (PBK) modelling facilitated reverse dosimetry. In the current study, the use of this approach for predicting developmental toxicity of polycyclic aromatic hydrocarbons (PAHs) was evaluated, using benzo[a]pyrene (BaP) as a model compound. A rat PBK model of BaP was developed to simulate the kinetics of its main metabolite 3-hydroxybenzo[a]pyrene (3-OHBaP), shown previously to be responsible for the developmental toxicity of BaP. Comparison to in vivo kinetic data showed that the model adequately predicted BaP and 3-OHBaP blood concentrations in the rat. Using this PBK model and reverse dosimetry, a concentration–response curve for 3-OHBaP obtained in the EST was translated into an in vivo dose–response curve for developmental toxicity of BaP in rats upon single or repeated dose exposure. The predicted half maximal effect doses (ED50) amounted to 67 and 45 mg/kg bw being comparable to the ED50 derived from the in vivo dose–response data reported for BaP in the literature, of 29 mg/kg bw. The present study provides a proof of principle of applying this in vitro–in silico approach for evaluating developmental toxicity of BaP and may provide a promising strategy for predicting the developmental toxicity of related PAHs, without the need for extensive animal testing.

scholarly journals 13-Methyltetradecanoic Acid Exhibits Anti-Tumor Activity on T-Cell Lymphomas In Vitro and In Vivo by Down-Regulating p-AKT and Activating Caspase-3

PLoS ONE ◽  
2013 ◽  
Vol 8 (6) ◽  
pp. e65308 ◽  
Author(s):  
Qingqing Cai ◽  
Huiqiang Huang ◽  
Dong Qian ◽  
Kailin Chen ◽  
Junhua Luo ◽  
...  
Keyword(s):  
T Cell ◽  
Caspase 3 ◽  
T Cell Lymphomas ◽  
Anti Tumor Activity

Targeting the PI3K/mTOR Pathway in Lymphoma with PQR309 and PQR620: Single Agent Activity and Synergism with the BCL2 Inhibitor Venetoclax

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3017-3017
Author(s):  
Chiara Tarantelli ◽  
Eugenio Gaudio ◽  
Petra Hillmann ◽  
Filippo Spriano ◽  
Ivo Kwee ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Cell Lines ◽  
Mtor Inhibitor ◽  
Cell Lymphoma ◽  
Single Agent ◽  
Apoptosis Induction ◽  
In Vivo Experiments

Abstract Background. The PI3K/AKT/mTOR pathway is an important therapeutic target in lymphomas. PQR309 is a dual PI3K/mTOR inhibitor that has shown in vitroanti-lymphoma activity (Tarantelli et al, ASH2015) and is in phase 2 trial (NCT02249429, , NCT02723877, NCT02669511). PQR620 is a novel mTORC1/2 inhibitor that has shown preclinical activity in solid tumor models (Beaufils et al, AACR 2016). Here, we present the in vitro and in vivo anti-lymphoma activity of PQR620 as single agent and also the in vivo results of PQR620 or PQR309 containing combinations with the BCL2 inhibitor venetoclax. Materials and Methods. The drug concentration causing 50% inhibition of cell proliferation (IC50) was obtained in lymphoma cell lines [diffuse large B cell lymphoma (DLBCL), no.=26; mantle cell lymphoma (MCL), no.=8; anaplastic large T-cell lymphoma, no.=5; others, no=5] exposed to increasing doses of PQR620 for 72h using a Tecan D300e Digital Dispenser on 384well plates. For in vivo experiments, NOD-Scid (NOD.CB17-Prkdcscid/J) mice were subcutaneously inoculated with 10 x106 (RIVA) or with 5 x106(SU-DHL-6) cells. Results. PQR620 had a median IC50 of 250 nM (95%CI, 200-269 nM) when tested on 44 lymphoma cell lines. Activity was higher in B cell (no.=36) than in T cell tumors (no.=8) (median IC50s: 250 nM vs 450 nM; P=0.002). At 72h, anti-tumor activityof PQR620 was mostly cytostatic and apoptosis induction was seen only in 6/44 cell lines (13%), Sensitivity to PQR620 or apoptosis induction did not differ between DLBCL and MCL, and they were not affected by the DLBCL cell of origin, by TP53 status or by the presence of MYC or BCL2 translocations. The activity of PQR620 as single agent underwent in vivo evaluation in two DLBCL models, the germinal center B cell type DLBCL (GCB-DLBCL) SU-DHL-6 and the acivated B cell-like DLBCL (ABC-DLBCL) RIVA. Treatments with PQR620 (100mg/kg dose per day, Qdx7/w) started with 100-150 mm3 tumors and were carried for 14 (SU-DHL-6) or 21 days (RIVA). In both models, PQR620 determined a 2-fold decrease of the tumor volumes in comparison with control, with significant differences in both SU-DHL-6 (D7, D9, D11, D14; P < 0.005) and RIVA (D14, D16, D19, D21; P < 0.005). Based on the previously reported synergy between the dual PI3K/mTOR inhibitor PQR309 and venetoclax (Tarantelli et al, ASH 2015), we evaluated the combination of the PQR620 or PQR309 with the BCL2 inhibitor venetoclax (100 mg/kg, Qdx7/w) in the SU-DHL-6 model. Both the venetoclax combination with the dual PI3K/mTOR inhibitor and the venetoclax combination with mTORC1/2 inhibitor were superior to the compounds given as single agents, leading to the eradication of the xenografts. The combination of PQR620 with venetoclax showed highly significant differences either versus control or single agents during all days of the experiment (D4, D7, D9, D11, D14; P < 0.001). Similarly, the combination of PQR309 with venetoclax showed highly significant differences versus venetoclax (D7, D9, D11, D14; P < 0.001) and PQR309 (D7, D9, D11; P < 0.005) alone. Conclusions. The novel mTORC1/2 inhibitor PQR620 had in vitro and in vivo anti-lymphoma activity as single agent. In vivo experiments showed that both PQR620 and the dual PI3K/mTOR inhibitor PQR309 can strongly benefit from the combination with the BCL2 inhibitor venetoclax. Disclosures Hillmann: PIQUR Therapeutics AG: Employment. Fabbro:PIQUR Therapeutics AG: Employment. Cmiljanovic:PIQUR Therapeutics AG: Employment, Membership on an entity's Board of Directors or advisory committees.

Effect of a combination of epigenetic agents on the malignant phenotype in models of T-cell lymphoma.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13569-e13569
Author(s):  
Enrica Marchi ◽  
Matko Kalac ◽  
Danielle Bongero ◽  
Christine McIntosh ◽  
Laura K Fogli ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cell ◽  
Cell Lines ◽  
Molecular Level ◽  
Cell Lymphoma ◽  
Single Agent ◽  
T Cell Lymphoma ◽  
Cytotoxicity Assays

e13569 Background: CHOP and CHOP-like chemotherapy are the most used regimens for the treatment of peripheral T-cell lymphomas (PTCLs) despite sub-optimal results. Histone deacetylase inhibitors (HDACIs) have shown class activity in PTCLs. The interaction between the HDACIs (depsipeptide (R), belinostat (B), vorinostat (V) and panobinostat (P)) and a DNMT inhibitor (decitabine (D) was investigated in vitro, in vivo and at the molecular level in T-cell lymphoma and leukemia cell lines (H9, HH, P12, PF-382). Methods: For cytotoxicity assays, luminescence cell viability assay was used (CellTiter-Glo). Drug:drug interactions were analyzed with relative risk ratios (RRR) based on the GraphPad software (RRR<1 defining synergism). Apoptosis was assessed by Yo-Pro-1 and propidium iodine followed by FACSCalibur acquisition. Gene expression profiling was analyzed using Illumina Human HT-12 v4 Expression BeadChip microarrays and Gene Spring Software for the analysis. Results: The IC50s for B, R, V, P, D and 5-Azacytidine alone were assessed at 24, 48 and 72 hours. In cytotoxicity assays the combination of D plus B, R, V or P at 72 hours showed synergism in all the cell lines (RRRs 0.0007-0.9). All the cell lines were treated with D, B or R for 72 hours and all the combinations showed significantly more apoptosis than the single drug exposures and controls (RRR < 1). In vivo, HH SCID beige mice were treated i.p. for 3 cycles with the vehicle solution, D or B or their combination at increasing dose. The combination cohort showed statistically significant tumor growth inhibition compared to all the other cohorts. Gene expression analysis revealed differentially expressed genes and modulated pathways for each of the single agent treatment and the combination. The effects of the two drugs were largely different (only 39 genes modified in common). Most of the effects induced by the single agent were maintained in the combination group. Interestingly, 944 genes were modulated uniquely by the combination treatment. Conclusions: The combination of a DNMTI and HDACIs is strongly synergistic in vitro, in vivo and at the molecular level in model of T-cell lymphoma and these data will constitute the basis for a phase I-II clinical trials.

Adenosine preconditions against endothelin-induced constriction of coronary arterioles

2000 ◽  
Vol 279 (6) ◽  
pp. H2593-H2597 ◽  
Author(s):  
Daphne Merkus ◽  
David W. Stepp ◽  
Deron W. Jones ◽  
Yasuhiro Nishikawa ◽  
William M. Chilian
Keyword(s):  
Ischemic Preconditioning ◽  
Dose Response ◽  
Response Curve ◽  
Protective Function ◽  
Vasodilatory Effect ◽  
Arteriolar Diameter ◽  
Myocardial Hypoperfusion ◽  
Coronary Arterioles

Myocardial hypoperfusion is accompanied by concomitant increases in adenosine and endothelin-1 (ET-1) production, but the vasodilatory effect of adenosine prevails over that of ET-1. Therefore, we hypothesized that adenosine-induced or ischemic preconditioning reduces the vasoconstrictive effect of ET-1. Coronary arteriolar diameter in vivo was measured using fluorescence microangiography in anesthetized open-thorax dogs. ET-1 (5 ng · kg−1 · min−1administered intracoronary, n = 10) induced progressive constriction over 45 min [25 ± 6% (SE)]. The constriction was blocked by preconditioning with adenosine (25 μg · kg−1 · min−1administered intracoronary) for 20 min and 10 min of washout ( n = 10) or attenuated by ischemic preconditioning (four 5-min periods of ischemia, 9 ± 5% at 45 min). To investigate the receptor involved in this process, coronary arterioles (50–150 μm) were isolated and pressurized at 60 mmHg in vitro. The ET-1 dose-response curve (1 pM–5 nM) was rightward shifted after preconditioning with adenosine (1 μM) for 20 min and 10 min of washout ( n = 11). Blockade of A2 receptors [8-(3-chlorostyryl)caffeine, 1 μM, n = 9] but not A1 receptors (8-cyclopentyl-1,3-dipropylxanthine, 100 nM, n = 7) prevented this shift. These results suggest that adenosine confers a vascular preconditioning effect, mediated via the A2 receptor, against endothelin-induced constriction. This effect may offer a new protective function of adenosine in preventing excessive coronary constriction.

scholarly journals ITK inhibition induced in vitro and in vivo anti-tumor activity through downregulating TCR signaling pathway in malignant T cell lymphoma

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yalu Liu ◽  
Xiaogan Wang ◽  
Lijuan Deng ◽  
Lingyan Ping ◽  
Yunfei Shi ◽  
...  
Keyword(s):  
T Cell ◽  
Signaling Pathway ◽  
Cell Lymphoma ◽  
T Cell Lymphoma ◽  
Tcr Signaling ◽  
Anti Tumor Activity

Investigation of a novel irreversible pan-HER inhibitor combined with chemotherapy in bladder cancer models.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 4545-4545
Author(s):  
Petros Grivas ◽  
Kathleen C. Day ◽  
Stephanie Daignault ◽  
Nazia Shakir ◽  
Alyssa Paul ◽  
...  
Keyword(s):  
Weight Loss ◽  
Bladder Cancer ◽  
Biomarker Discovery ◽  
Single Agent ◽  
Phase Iii ◽  
G1 Arrest ◽  
Cancer Models ◽  
Anti Tumor Activity

4545 Background: Human Epidermal Receptors (HER) play an important role in bladder cancer (BCa) progression and may mediate chemotherapy resistance. Dacomitinib (Dac) is a novel, potent, irreversible pan-HER inhibitor with activity in several solid tumors, currently in phase III trials in NSCLC. We showed that Dac has single agent anti-tumor activity in human BCa models in vitro and in vivo, inducing apoptosis and G1 arrest. We hypothesized that Dac has additive effects with Gemcitabine (G) and Cisplatin (C) in BCa xenografts. Methods: UM-UC-6 (UC6) or UM-UC-9 (UC9) xenografts were established in age-matched NOD/SCID mice. A week after injection, mice had small tumors, were randomized and treated with i. G 50mg/kg + C 2mg/kg via 3 weekly intra-peritoneal injections (IPI) + daily p.o. buffer for 3 weeks; ii. Dac 6mg/kg p.o. daily for 3 weeks + 3 weekly IPI (saline); iii. GC (same dose/schedule) + Dac starting 1 day after GC (based on cell cycle effect and kinetics); iv. no treatment (control). Mice were monitored daily, weighed weekly, sacrificed at 4 weeks and tumors were weighed. 3 tumors/group were stained for EGFR, HER2, Ki67, E-cadherin, ALDH, p-EGFR, p-ERK, p-Akt. 3rd GC dose in UC6 model was given at 50% due to weight loss; all GC doses were given at 50% in UC9 model. Mann-Whitney test with multiple comparison adjustments was used for analysis. Results: Dac- and GC+Dac-treated mice had no significant weight loss. UC6 tumor weights were significantly lower in Dac and GC+Dac vs control (p<0.0001) or GC (p<0.0001), corresponding to decreased p-ERK %cell expression and staining intensity. GC and control had similar tumor weights (p=0.19). 5 Dac and 3 GC+Dac UC6-injected mice had no tumor at 4 weeks. UC9 tumor weights were significantly lower in Dac (p=0.002, 6x reduction) or GC (p=0.0006; 7x reduction) vs control. GC+Dac had significantly lower tumor weights vs GC (p=0.005), Dac (p=0.06) or control (p<0.0001; 17x reduction). Conclusions: Dac had dramatic singe-agent activity in UC6 xenograft that was GC-resistant. Dac+GC was superior to GC in UC9 xenograft, supporting clinical evaluation. Further investigation of Dac anti-tumor activity and predictive biomarker discovery in additional bladder cancer models is pursued.

ETUDE DE L'ACTION DU FACTEUR HYPOTHALAMIQUE LRF (LH-RELEASING FACTOR) CHEZ LE RAT IN VIVO & IN VITRO

1967 ◽  
Vol 55 (3) ◽  
pp. 481-496 ◽  
Author(s):  
Marian Jutisz ◽  
Annette Bérault ◽  
Marie-Anne Novella ◽  
Geneviève Ribot
Keyword(s):  
Dose Response ◽  
Crude Extract ◽  
Response Curve ◽  
Assay Method ◽  
Hypothalamic Extract ◽  
Rat Pituitary ◽  
Pituitary Glands ◽  
Releasing Effect

ABSTRACT A highly purified ovine LH-releasing factor (LRF) was obtained by a modification of the method previously described. After the fractionation of a crude hypothalamic extract on a Sephadex G-25 column, the LRF fraction was desalted and partially purified by chromatography on a Dowex 50 × 12 column and on an Amberlite CG 4B column. The last step of this method, chromatography on a CMC column, gave a purification of about 1600 times with respect to the crude extract. The action of this highly purified LRF preparation was studied on rat pituitary glands in vivo and in vitro. The method used in vivo was the evaluation of the LH-releasing effect of LRF in chronically ovariectomized, steroid-blocked rats (Ramirez & McCann 1963 b). A procedure was developed which allows a 4-fold concentration of the plasma LH from these rats, so that it can be assayed by a 4-point assay method. In the in vitro method, the pituitary glands of ovariectomized steroidblocked rats (Schally & Bowers 1964 a) were incubated in a Krebs-Ringer buffer with or without LRF, and the LH released into the medium was assayed using the O.A. A.D. method of Parlow. A dose-response curve was established between the log doses of LRF and the amount of LH released. This method can be used as a sensitive and specific assay for LRF. It was shown that a dose of 1.22 μg of LRF releases approximately 5 μg of LH per mg of pituitary tissue. This is about double of the amount of this hormone originally present in the pituitary glands of these rats (2.7 μg/mg). This leads us to the conclusion that the excess of this hormone was probably synthetized during the process of incubation. The amount of steroids injected as a blocking agents, appears to be very important for both in vivo and in vitro tests.

scholarly journals Correspondence of In Vitro and In Vivo Fluconazole Dose-Response Curves for Cryptococcus neoformans

2005 ◽  
Vol 49 (8) ◽  
pp. 3297-3301 ◽  
Author(s):  
Robert A. Larsen ◽  
Madeline Bauer ◽  
Ann M. Thomas ◽  
Alejandro Sanchez ◽  
Diane Citron ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Dose Response ◽  
Response Curve ◽  
Drug Susceptibility Testing ◽  
Response Curves ◽  
In Vitro Susceptibility ◽  
Drug Concentrations ◽  
Wide Range

ABSTRACT We conducted in vitro experiments to evaluate the susceptibility of a clinical isolate of Cryptococcus neoformans to a wide range of concentrations of fluconazole. In vitro susceptibility was tested using broth macrodilution methods modified to provide a numeric count of viable organisms. The association between the quantitative in vitro response and fluconazole drug concentrations was estimated using local nonparametric regression. Regression analysis was used to assess the correspondence between the in vitro fluconazole concentration-response curve and the murine dose-response curve observed in our previously reported murine model. The regression model was then used to predict the murine response. There was a strong correspondence between in vitro measures of response to fluconazole alone and the previously reported biologic effects seen in the mouse. In vitro antifungal drug susceptibility testing can reliably predict the murine response to fluconazole.

Sign in / Sign up

Export Citation Format

Share Document