Early Stage Pharmaceutical Development, Genentech, Inc, South San Francisco, California 94080, United States.
Anal Chem. 2012 Sep 4;84(17):7479-86. doi: 10.1021/ac301568f. Epub 2012 Aug 22.
Antibody drug conjugates enable the targeted delivery of potent chemotherapeutic agents directly to cancerous cells. They are made by the chemical conjugation of cytotoxins to monoclonal antibodies, which can be achieved by first reducing interchain disulfide bonds followed by conjugation of the resulting free thiols with drugs. This process yields a controlled, but heterogeneous, population of conjugated products that contains species with various numbers of drugs linked to different former interchain disulfide cysteine residues on the antibodies. We have developed a mathematical approach using inputs from capillary electrophoresis and hydrophobic interaction chromatography to determine the positional isomer distribution within a population of antibody drug conjugates. The results are confirmed by analyzing isolated samples of specific drug-to-antibody ratio species. The procedure is amenable to rapid determination of positional isomer distributions and features low material requirements. A survey of several antibody drug conjugates based on the same IgG framework and small molecule drug combination has shown a very similar distribution of isomers among all of the molecules using this technique, suggesting a robust conjugation process.
抗体药物偶联物能够将有效化疗药物靶向递送至癌细胞。它们是通过将细胞毒素化学偶联到单克隆抗体上来制备的，这可以通过首先还原链间二硫键，然后将生成的游离巯基与药物偶联来实现。这个过程产生了一种受控的，但不均匀的偶联产物群体，其中包含具有不同数量的药物与抗体上不同的前链间二硫键半胱氨酸残基连接的物种。我们开发了一种数学方法，该方法使用毛细管电泳和疏水相互作用色谱的输入来确定抗体药物偶联物群体中位置异构体的分布。通过分析特定药物与抗体比物种的分离样本来验证结果。该程序适用于快速确定位置异构体分布，并且需要的材料很少。对几种基于相同 IgG 骨架和小分子药物组合的抗体药物偶联物的调查表明，使用该技术所有分子的异构体分布非常相似，表明该偶联过程非常稳健。
