Antibodies that block interaction of immune checkpoint receptors with its ligands have revolutionized the treatment of several cancers. Despite the success of this approach, the high cost has been restricted the use of this class of drugs. In this context, the development of biosimilar can be an important strategy for reducing prices and expanding access after patent has been dropped. Here, we evaluated the use of HEK293 cells for transient expression of an immune checkpoint-blocking antibody as a first step for biosimilar development. Antibody light and heavy chain genes were cloned into pCI-neo vector and transiently expressed in HEK293 cells. The culture supernatant was then subjected to protein A affinity chromatography, which allowed to obtain the antibody with high homogeneity. For physicochemical comparability, biosimilar antibody and reference drug were analyzed by SDS-PAGE, isoelectric focusing, circular dichroism and fluorescence spectroscopy. The results indicated that the both antibodies have a high degree of structural similarity. Lastly, the biosimilar antibody binding capacity to target receptor was shown to be similar to reference product in ELISA and flow cytometry assays. These data demonstrate that the HEK293 system can be used as an important tool for candidate selection and early development of biosimilar antibodies.

中文翻译：

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使用HEK293细胞的生物仿制药免疫检查点阻滞剂的初步开发。

阻断免疫检查点受体与其配体相互作用的抗体彻底改变了几种癌症的治疗方法。尽管这种方法取得了成功，但高昂的费用限制了此类药物的使用。在这种情况下，生物仿制药的开发可能是降低专利价格并降低专利获得后的获取的重要战略。在这里，我们评估了HEK293细胞在瞬时表达免疫检查点封闭抗体中的应用，作为生物仿制药开发的第一步。将抗体轻链和重链基因克隆到pCI-neo载体中，并在HEK293细胞中瞬时表达。然后将培养上清液进行蛋白A亲和层析，从而获得具有高均一性的抗体。为了理化可比性，通过SDS-PAGE，等电聚焦，圆二色性和荧光光谱分析生物仿制药抗体和参考药物。结果表明两种抗体具有高度的结构相似性。最后，在ELISA和流式细胞仪分析中，生物仿制药对靶受体的结合能力与参考产品相似。这些数据表明，HEK293系统可以用作候选候选物和生物相似抗体的早期开发的重要工具。在ELISA和流式细胞仪分析中，生物仿制药对靶受体的结合能力与参考产品相似。这些数据表明，HEK293系统可以用作候选候选物和生物相似抗体的早期开发的重要工具。在ELISA和流式细胞仪分析中，生物仿制药对靶受体的结合能力与参考产品相似。这些数据表明，HEK293系统可以用作候选候选物和生物相似抗体的早期开发的重要工具。