Rajan Sharmila, Sonoda Junichiro, Tully Timothy, Williams Ambrose J, Yang Feng, Macchi Frank, Hudson Terry, Chen Mark Z, Liu Shannon, Valle Nicole, Cowan Kyra, Gelzleichter Thomas
Preclinical and Translational Pharmacokinetics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
Molecular Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
J Pharmacol Toxicol Methods. 2018 Nov-Dec;94(Pt 1):19-25. doi: 10.1016/j.vascn.2018.04.002. Epub 2018 Apr 13.
bFKB1 is a humanized bispecific IgG1 antibody, created by conjoining an anti-Fibroblast Growth Factor Receptor 1 (FGFR1) half-antibody to an anti-Klothoβ (KLB) half-antibody, using the knobs-into-holes strategy. bFKB1 acts as a highly selective agonist for the FGFR1/KLB receptor complex and is intended to ameliorate obesity-associated metabolic defects by mimicking the activity of the hormone FGF21. An important aspect of the biologics product manufacturing process is to establish meaningful product specifications regarding the tolerable levels of impurities that copurify with the drug product. The aim of the current study was to determine acceptable levels of product-related impurities for bFKB1.
To determine the tolerable levels of these impurities, we dosed obese mice with bFKB1 enriched with various levels of either HMW impurities or anti-FGFR1-related impurities, and measured biomarkers for KLB-independent FGFR1 signaling.
Here, we show that product-related impurities of bFKB1, in particular, high molecular weight (HMW) impurities and anti-FGFR1-related impurities, when purposefully enriched, stimulate FGFR1 in a KLB-independent manner. By taking this approach, the tolerable levels of product-related impurities were successfully determined.
Our study demonstrates a general pharmacology-guided approach to setting a product specification for a bispecific antibody whose homomultimer-related impurities could lead to undesired biological effects.
bFKB1是一种人源化双特异性IgG1抗体，通过采用“旋钮入孔”策略，将抗成纤维细胞生长因子受体1（FGFR1）半抗体与抗β-klotho（KLB）半抗体连接而成。bFKB1作为FGFR1/KLB受体复合物的高选择性激动剂，旨在通过模拟激素FGF21的活性来改善肥胖相关的代谢缺陷。生物制品生产过程的一个重要方面是确定与药品共纯化的杂质可耐受水平的有意义的产品规格。本研究的目的是确定bFKB1与产品相关杂质的可接受水平。
为了确定这些杂质的可耐受水平，我们给肥胖小鼠注射富含不同水平高分子量（HMW）杂质或抗FGFR1相关杂质的bFKB1，并测量KLB非依赖性FGFR1信号传导的生物标志物。
在此，我们表明，bFKB1与产品相关的杂质，特别是高分子量（HMW）杂质和抗FGFR1相关杂质，在有意富集时，以KLB非依赖性方式刺激FGFR1。通过这种方法，成功确定了与产品相关杂质的可耐受水平。
我们的研究展示了一种通用的药理学指导方法，用于为双特异性抗体制定产品规格，该双特异性抗体的同源多聚体相关杂质可能导致不良生物学效应。
