Case Report: An EGFR-Targeted 4-1BB-agonistic Trimerbody Does Not Induce Hepatotoxicity in Transgenic Mice With Liver Expression of Human EGFR.

Marta Compte,Luis Alvarez-Vallina,Gema Perez-Chacon,Paul M P Van Bergen En Henegouwen,Laura Sanz,Patricia González-García,Aránzazu Sánchez,Isabel Fabregat,Antonio Tapia-Galisteo,Jorge Martínez-Torrecuadrada,Seandean L Harwood,Juan M Zapata

doi:10.3389/fimmu.2020.614363

Abstract

Agonistic monoclonal antibodies (mAbs) targeting the co-stimulatory receptor 4-1BB are among the most effective immunotherapeutic agents across pre-clinical cancer models. However, clinical development of full-length 4-1BB agonistic mAbs, has been hampered by dose-limiting liver toxicity. We have previously developed an EGFR-targeted 4-1BB-agonistic trimerbody (1D8N/CEGa1) that induces potent anti-tumor immunity without systemic toxicity, in immunocompetent mice bearing murine colorectal carcinoma cells expressing human EGFR. Here, we study the impact of human EGFR expression on mouse liver in the toxicity profile of 1D8N/CEGa1. Systemic administration of IgG-based anti-4-1BB agonist resulted in nonspecific immune stimulation and hepatotoxicity in a liver-specific human EGFR-transgenic immunocompetent mouse, whereas in 1D8N/CEGa1-treated mice no such immune-related adverse effects were observed. Collectively, these data support the role of FcγR interactions in the major off-tumor toxicities associated with IgG-based 4-1BB agonists and further validate the safety profile of EGFR-targeted Fc-less 4-1BB-agonistic trimerbodies in systemic cancer immunotherapy protocols.

Highlights

The success of immune checkpoint blockade using PD-1/PDL1 and/or CTLA-4 inhibitors has validated the concept of immunomodulating monoclonal antibodies as a powerful therapeutic strategy, but responses are still limited to a minor fraction of cancer patients [1]
The 1D8N/CEGa1 trimerbody did not induce the systemic cytokine production and hepatotoxicity associated with IgG-based 4-1BB agonists [10]. To further investigate this aspect and given that the anti-EGFR EGa1 VHH single-domain antibody was isolated from a phage-displayed llama VHH library immunized with EGFRpositive human cells [14, 15], we studied here the impact of human EGFR expression on the liver in the 1D8N/CEGa1 toxicity profile in a liver-specific human EGFR:hFc chimera (huEGFR)-transgenic immunocompetent mouse [16]
To investigate the binding of 1D8N/CEGa1 to hu-EGFR or mouse EGFR: hFc (moEGFR), 30 nM of huEGFR or moEGFR in fusion with a human Fc region were immobilized onto AHC biosensors (Fortebio) coated with anti-human Fc antibodies for 20 min, in 20 mM HEPES, 150 mM NaCl pH 7.4 buffer (HBS)

Summary

Introduction

The success of immune checkpoint blockade using PD-1/PDL1 and/or CTLA-4 inhibitors has validated the concept of immunomodulating monoclonal antibodies (mAbs) as a powerful therapeutic strategy, but responses are still limited to a minor fraction of cancer patients [1]. The anti-tumor effect of the bispecific trimerbody was dependent on human EGFR expression [13], but the potential toxicity profile was dictated by the endogenous mouse EGFR.

Results

Conclusion