Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zurich, Switzerland.
UCB Pharma, BioTech Sciences-Formulation Development, Chemin du Forriest, 1420 Braine-l'Alleud, Belgium.
Eur J Pharm Biopharm. 2020 Jun;151:53-60. doi: 10.1016/j.ejpb.2020.03.011. Epub 2020 Mar 18.
Native protein-protein interactions can play an important role in determining the tendency of monoclonal antibodies (mAbs) to aggregate under storage conditions. In this context, phase separation of mAb solutions induced by the addition of neutral polymers such as poly(ethylene glycol) (PEG) represents a simple method to assess the tendency of proteins to self-associate in the native state. Here, we investigated their relationships between PEG-induced phase separation, protein-protein interactions and long-term aggregation rate of several formulations of four mAbs at 100 mg/mL and 5 °C over 12 weeks of storage. We observed that the location of the phase boundary correlated well with the osmotic second virial coefficient B determined in absence of the polymer, indicating that for our solutions PEG primarily leads to depletion forces between protein molecules, which are additive to protein-protein interactions. However, limited correlation between aggregation rate at 5 °C and phase behavior was observed across different mAbs, pH values and ionic strengths, indicating that colloidal stability is not the only determinant of aggregation even at such low temperature and high protein concentration. Our results contribute to the growing realization that aggregation propensity in the context of antibody developability is a complex feature, which depends on a variety of biophysical properties rather than one single parameter.
天然的蛋白质-蛋白质相互作用在决定单克隆抗体 (mAb) 在储存条件下的聚集倾向方面起着重要作用。在这种情况下，添加中性聚合物（如聚乙二醇 (PEG)）引起的 mAb 溶液相分离代表了一种评估蛋白质在天然状态下自组装倾向的简单方法。在这里，我们研究了在 5°C 下储存 12 周时，PEG 诱导的相分离、蛋白质-蛋白质相互作用以及四种 mAb 四种制剂的长期聚集率之间的关系，浓度为 100mg/mL。我们观察到相界位置与在不存在聚合物的情况下确定的渗透压第二维里系数 B 很好地相关，表明对于我们的溶液，PEG 主要导致蛋白质分子之间的耗尽力，这与蛋白质-蛋白质相互作用相加。然而，在不同的 mAb、pH 值和离子强度下，观察到聚集率与相行为之间的相关性有限，这表明即使在如此低的温度和高蛋白质浓度下，胶体稳定性也不是聚集的唯一决定因素。我们的研究结果有助于越来越多地认识到，在抗体开发性的背景下，聚集倾向是一个复杂的特征，它取决于多种生物物理性质，而不是一个单一的参数。
