Abstract：
Antibody-drug conjugates (ADCs) tend to be less stable than their parent antibodies, which is often attributed to the hydrophobic nature of their drug payloads. This study investigated how the payload charge affects ADC stability by comparing two interchain cysteine ADCs that had matched drug-to-antibody ratios and identical linkers but differently charged auristatin payloads, vcMMAE (neutral) and vcMMAF (negative). Both ADCs exhibited higher aggregation than their parent antibody under shaking stress and thermal stress conditions. However, conjugation with vcMMAF increased the aggregation rates to a greater extent than conjugation with uncharged but more hydrophobic vcMMAE. Consistent with the payload logD values, ADC-vcMMAE showed the greatest increase in hydrophobicity but minor changes in charge compared with the parent antibody, as indicated by hydrophobic interaction chromatography and capillary electrophoresis data. In contrast, ADC-vcMMAF showed a decrease in net charge and isoelectric point along with an increase in charge heterogeneity. This charge alteration likely contributed to a reduced electrostatic repulsion and increased surface activity in ADC-vcMMAF, thus affecting its aggregation propensity. These findings suggest that not only the hydrophobicity of the payload, but also its charge should be considered as a critical factor affecting the stability of ADCs.
摘要：
抗体-药物缀合物（ADC）往往不如其亲本抗体稳定，这通常归因于其药物有效载荷的疏水性。这项研究通过比较两个链间半胱氨酸ADC，研究了有效载荷电荷如何影响ADC稳定性，这两个链间半胱氨酸ADC具有匹配的药物与抗体比率和相同的接头，但带不同电荷的奥瑞他汀有效载荷。vcMMAE（中性）和vcMMAF（阴性）。在振荡胁迫和热胁迫条件下，两种ADC均表现出比其亲本抗体更高的聚集。然而,与vcMMAF缀合比与不带电荷但更疏水的vcMMAE缀合更大程度地增加聚集速率。与有效负载logD值一致，与亲本抗体相比，ADC-vcMMAE显示出最大的疏水性增加，但电荷变化较小，如疏水性相互作用色谱和毛细管电泳数据所示。相比之下,ADC-vcMMAF显示净电荷和等电点的降低以及电荷异质性的增加。这种电荷变化可能有助于减少静电排斥和增加的表面活性在ADC-vcMMAF。从而影响其聚集倾向。这些发现表明，不仅有效载荷的疏水性，但其电荷也应被视为影响ADC稳定性的关键因素。
