Abstract 7174: Pharmacokinetics and immunogenicity of anti-PD-1 antibody in humanized FcRn mouse models compared to immunocompetent mouse models
Authors: Tu Xiaolong , Feng Xinhe , Wang Weifang , Ding Xunhua , Huang Dong , Bourre Ludo , Chen Xiaobo 
Published: March 2024

Abstract
Introduction: The development and use of therapeutic antibodies in cancer therapy has increased significantly in recent years, led by the success of approved immune checkpoint blockade antibodies targeting PD-1 and PD-L1 axis. However, obtaining more clinically relevant pharmacokinetics (PK), safety and efficacy data for antibodies is still challenging in preclinical phase. Humanized FcRn (hFcRn) transgenic mouse model has a more faithful catabolism compared to WT mice, providing more accurate and predictable PK data of innovative antibody-based therapeutics at discovery stage[1]. In this study, we sought to investigate pharmacokinetics and immunogenicity characteristics of anti-PD-1 antibody in hFcRn transgenic mice and provide guidance for its differentiation of prediction value for drug PK and safety by comparing to WT mice.
Methods: Non-tumor bearing hFcRn mice and wild type C57BL/6 mice were divided into 2 groups, 5 mice were enrolled into each group. Mice were administered anti-PD-1(Nivolumab) at 10 mg/kg single dose after grouping by intravenous (IV) injection. Blood samples at 12 timepoints (15min, 6h, 1, 2, 4, 7, 10, 14, 21, 28, 35, 42 days) post-dosing were collected for PK and Anti-Drug Antibody (ADA) analysis by MSD and ELISA.
Results: Nivolumab clearance in hFcRn mice followed a typical linear profile with rapid distribution phase and slow elimination phase (t1/2 = 350 to 400 h). While the PK profile in C57BL/6 mice displayed non-linear clearance and very short elimination phase (t1/2 = 45 to 50 h). This data demonstrated that hFcRn mice have better correlated half-life with human (Nivolumab single dose by IV with 10mg/kg, t1/2 = 595 h) [2].
ADA analysis revealed that it was produced starting from Day 10 in wild type C57BL/6 mice and the frequency of ADA induced by Nivolumab in wild type mice (2/5) was higher than hFcRn mice (0/5). The variation of Nivolumab level was correlated with ADA production in wild type mice. This suggested hFcRn shows lower immunogenicity than wild type mice for human IgG drug and can potentially improve negative effect of ADA interference on PK evaluation.
Conclusion: The result of this study demonstrated that the PK data in hFcRn mouse model was more predictive of human PK profile compared to wild type C57BL/6 mice. This advances innovation in antibody-based therapeutics and translational applications, with improved PK, safety and efficacy evaluation for preclinical human IgG drug development in cancer therapy.
References: 1. Enhanced half-life of genetically engineered human IgG1 antibodies in a humanized FcRn mouse model: potential application in humorally mediated autoimmune disease. Int Immunol. 18(12):1759-69. 2. Centre for drug evaluation and research. Clinical pharmacology and biopharmaceutics reviews of pembrolizumab: application number:125514Orig1s000. Accessed 04 April 2016.
Citation Format: Xiaolong Tu, Xinhe Feng, Weifang Wang, Xunhua Ding, Dong Huang, Ludo Bourre, Xiaobo Chen. Pharmacokinetics and immunogenicity of anti-PD-1 antibody in humanized FcRn mouse models compared to immunocompetent mouse models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7174.