Bondza Sina, Stenberg Jonas, Nestor Marika, Andersson Karl, Björkelund Hanna
Section of Biomedical Radiation Sciences, Department of Radiology, Oncology and Radiation Science, Rudbeck Laboratory, Uppsala University , SE-751 85 Uppsala, Sweden.
Mol Pharm. 2014 Nov 3;11(11):4154-63. doi: 10.1021/mp500379d. Epub 2014 Oct 9.
Antibody-drug conjugates (ADC) have shown promising effects in cancer therapy by combining the target specificity of an antibody with the toxicity of a chemotherapeutic drug. As the number of therapeutic antibodies is significantly larger than those used as ADCs, there is unused potential for more effective therapies. However, the conjugation of an additional molecule to an antibody may affect the interaction with its target, altering association rate, dissociation rate, or both. Any changes of the binding kinetics can have subsequent effects on the efficacy of the ADCs, thus the kinetics are important to monitor during ADC development and production. This paper describes a method for the analysis of conjugation effects on antibody binding to its antigen, using the instrument LigandTracer and a fluorescent monovalent anti-IgG binder denoted FIBA, which did not affect the interaction. All measurements were done in real time using living cells which naturally expressed the antigens. With this method the binding profiles of different conjugations of the therapeutic anti-EGFR antibody cetuximab and the anti-CD44v6 antibody fragment AbD15171 were evaluated and compared. Even comparatively small modifications of cetuximab altered the interaction with the epidermal growth factor receptor (EGFR). In contrast, no impact on the AbD15171-CD44v6 interaction was observed upon conjugation. This illustrates the importance to study the binding profile for each ADC combination, as it is difficult to draw any general conclusion about conjugation effects. The modification of interaction kinetics through conjugation opens up new possibilities when optimizing an antibody or an ADC, since the conjugations can be used to create a binding profile more apt for a specific clinical need.
抗体药物偶联物（ADC）通过将抗体的靶向特异性与化疗药物的毒性相结合，在癌症治疗中显示出了良好的效果。由于治疗性抗体的数量远多于用作ADC的抗体，因此存在实现更有效治疗的未开发潜力。然而，在抗体上偶联额外的分子可能会影响其与靶点的相互作用，改变结合速率、解离速率或两者。结合动力学的任何变化都可能对ADC的疗效产生后续影响，因此在ADC的研发和生产过程中监测动力学非常重要。本文描述了一种使用LigandTracer仪器和一种不影响相互作用的荧光单价抗IgG结合剂FIBA来分析偶联对抗体与其抗原结合影响的方法。所有测量均在天然表达抗原的活细胞上实时进行。通过该方法，评估并比较了治疗性抗表皮生长因子受体（EGFR）抗体西妥昔单抗和抗CD44v6抗体片段AbD15171不同偶联物的结合情况。即使是西妥昔单抗相对较小的修饰也改变了其与表皮生长因子受体（EGFR）的相互作用。相比之下，偶联后未观察到对AbD15171与CD44v6相互作用的影响。这说明了研究每种ADC组合结合情况的重要性，因为很难对偶联效应得出任何一般性结论。通过偶联改变相互作用动力学为优化抗体或ADC开辟了新的可能性，因为偶联可用于创建更适合特定临床需求的结合情况。
