Abstract 5186: Human stem cell humanized mouse model forin vivoevaluation of bispecific antibody efficacy and drug-induced cytokine release

BackgroundThe pleiotropic TNF-alpha:TNFR axis plays a central role in the immune system. While the cellular expression of TNFR1 is broad, TNFR2 expression is mainly restricted to immune cells. The therapeutic potential of targeting TNFR2 for cancer treatment has been previously indicated and to gain further insight, we characterized a wide panel antibodies, generated from the n-CoDeR F.I.R.S.T™ target and antibody discovery platform. We identified parallel human and mouse TNFR2 specific, complete ligand (TNF-alpha) blocking antibodies and could show potent anti-tumor activity in several immune-competent models, both as single agent and in combination with anti-PD1 using a BI-1808 murine surrogate. The mechanism-of-action was shown to be FcgR dependent and likely mediated through a combination of intra-tumor T reg depletion, CD8+ T cell expansion and modulation of tumor-associated myeloid cells. These findings were confirmed using BI-1808 in a humanized mouse model.MethodsTo address safety of the human lead-candidate BI-1808 two toxicological studies were performed in cynomolgus monkeys. The first study was a dose-range-finding study and the second a GLP study where three doses (2, 20 and 200 mg/kg) were given weekly for four consecutive weeks followed by a recovery period of eight weeks. In addition, cytokine release was further studied in T cell stimulation assays and in a humanized mouse model. Moreover, the BI-1808 murine surrogate was used to study the relationship between dose, receptor occupancy (RO) and efficacy in immune competent mouse cancer experimental models.ResultsFour weekly administrations of BI-1808 to cynomolgus monkeys were well tolerated at all doses, with no associated clinical signs, and no histopathological changes. Non-adverse and reversible increases in neutrophil counts and decreases in T cells were observed at all dose levels. No drug-related adverse events were observed and consequently the NOAEL for BI-1808 was determined to be 200 mg/kg. Pharmacokinetic studies demonstrated an expected half-life of two weeks at receptor saturation. There were no indications of cytokine release in any of the systems tested. Finally, we could show that to achieve max therapeutic effect, sustained RO was needed for approximately two weeks, covering the time it takes to generate a full adaptive Immune response.ConclusionsThere is a clear association between RO and therapeutic effect and BI-1808 is well tolerated at doses associated with high and sustained RO. Collectively, these studies were used to determine the starting dose in upcoming phase I/II study in solid cancer aiming for first-patient in during December 2020.Ethics ApprovalThe study on cynomolgous monkeys was conducted by Citox/Charles River Laboratories in compliance with animal health regulations, in particular: Council Directive No. 2010/63/EU of 22 September 2010 and French decree No. 2013-118 of 01 February 2013 on the protection of animals used for scientific purposes. Studies in mice were approved by the Swedish Animal Experiment Ethics Board, ethical permit/ethical license numbers 5.2.18-17196/2018 and 5.8.18-03333/2020

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A Novel Chimeric Antigen Receptor Against Prostate Stem Cell Antigen Mediates Tumor Destruction in a Humanized Mouse Model of Pancreatic Cancer

Human Gene Therapy ◽

10.1089/hum.2013.209 ◽

2014 ◽

Vol 25 (12) ◽

pp. 1003-1012 ◽

Cited By ~ 78

Author(s):

Daniel Abate-Daga ◽

Kiran H. Lagisetty ◽

Eric Tran ◽

Zhili Zheng ◽

Luca Gattinoni ◽

...

Keyword(s):

Pancreatic Cancer ◽

Stem Cell ◽

Mouse Model ◽

Chimeric Antigen Receptor ◽

Antigen Receptor ◽

Prostate Stem Cell Antigen ◽

Humanized Mouse ◽

Humanized Mouse Model ◽

Cell Antigen ◽

Tumor Destruction

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A donor-dependent in vivo model for single agent and drug combination cytokine release syndrome safety evaluation.

Journal of Clinical Oncology ◽

10.1200/jco.2019.37.15_suppl.2612 ◽

2019 ◽

Vol 37 (15_suppl) ◽

pp. 2612-2612

Author(s):

James G. Keck ◽

Mingshan Cheng ◽

Michael Brehm ◽

Dale Greiner ◽

Lenny J. Shultz ◽

...

Keyword(s):

Mouse Model ◽

Single Agent ◽

Cytokine Release ◽

Cytokine Release Syndrome ◽

Humanized Mouse ◽

Humanized Mouse Model ◽

Human Pbmc ◽

Cytokine Levels

2612 Background: Although antibodies and CART cells therapies have been successfully used for cancer therapy, they can have lethal adverse effects such as cytokine release syndrome (CRS). The animal models and in vitro human PBMC assays presently in use can’t reliably predict the CRS in patients. A predictive marker for identifying patients at risk for developing CRS upfront would improve the safety of immune-oncology drug development. Methods: We have developed a rapid, sensitive and reproducible in vivo humanized mouse model for quantitating CRS. The NSG mouse and its derivatives are engrafted with human PBMCs. On day 6 we induced cytokines release with pembrolizumab, avelumab, atezolizumab, ipilimumab, anti-CD28, ATG and OKT3 in single dose; as well as combination treatments involving pembrolizumab, lenalidomide, ATG and anti-CD28. Furthermore, we compared our method versus the in vitro PBMC assay. The cytokine levels were also compared to the dose response. Results: There are about 10-15% CD45+ human cells on day 5 of engraftment; and among of them, there were approximately 70% CD3 T cells and 25% CD56 NK cells. All tested cytokines, human IFN-γ, IL-2, IL-4, IL-6, IL-10 and TNF were upregulated after 2 and 6 hours of OKT3, ATG, anti-CD28, pembrolizumab, avelumab and atezolizumab drug treatment. Mouse’s rectal temperatures dropped from 37-38 °C to about 36 °C at 6 hours’ time point in the treated groups. There is various cytokines release levels, low to high response in different donors with anti-CD28 treatment. All donors showed high response to OKT3. The cytokine release levels were consistent with a dose response or variable PBMC engraftment. The cytokine levels were also higher in some drug combination studies such as pembrolizumab combined with lenalidomide or ATG; anti-CD28 combined with ATG. Our in vivo method was able to determine CRS missed in the in vitro testing method. Conclusions: We have developed a rapid, sensitive and reproducible novel in vivo PBMC humanized mouse model that is able to differentiate human PBMC donors based on individual safety response to single agent and combination therapeutics of immune checkpoint inhibitors and possibly CAR-T therapy. This assay could be employed in future drug development.

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