Mol Pharm. 2018 Oct 1;15(10):4529-4537. doi: 10.1021/acs.molpharmaceut.8b00536. Epub 2018 Aug 29.
A critical part of the clinical development path for a therapeutic antibody involves evaluating the physical and chemical stability of candidate molecules throughout the manufacturing process. In particular, the risks of chemical liabilities that can impact antigen binding, such as deamidation, oxidation, and isomerization in the antibody CDR sequences, need to be controlled through formulation development or eliminated by replacing the amino acid motif displaying the chemical instability. Commonly, the antibody CDR sequence contains multiple sequence motifs (potential hotspots) for chemical instability. However, only a subset of these motifs results in actual chemical modification, and thus, experimental assessment of the extent of instability is necessary to identify positions for potential sequence engineering. Ideally, this information should be available prior to antibody humanization at the stage of parental rodent antibody identification. Early knowledge of liabilities allows for ranking of clones or the mitigation of liabilities by concurrent engineering with the antibody humanization process instead of time-consuming sequential activities. However, concurrent engineering of chemical liabilities and humanization requires translatability of the chemical modifications from the rodent parental antibody to the humanized. We experimentally compared the stability of all sequence motifs by mass spectrometric peptide mapping between the rodent parental antibody and the final humanized antibody and observed a linear correlation. These results have enabled a streamlined developability assessment process for therapeutic antibodies from lead discovery to clinical development.
治疗性抗体临床开发路径的一个关键部分涉及在整个制造过程中评估候选分子的物理和化学稳定性。特别是，需要通过制剂开发来控制可能影响抗原结合的化学不良影响（如抗体 CDR 序列中的脱酰胺、氧化和异构化）的风险，或者通过替换显示化学不稳定性的氨基酸模体来消除这些风险。通常，抗体 CDR 序列包含多个化学不稳定的序列模体（潜在热点）。然而，这些模体中只有一部分导致实际的化学修饰，因此，需要进行实验评估不稳定性的程度，以确定潜在序列工程的位置。理想情况下，在抗体人源化阶段之前的亲本啮齿动物抗体鉴定阶段就应该获得这些信息。在早期了解不良影响后，可以对克隆进行排序，或者通过与抗体人源化过程同时进行工程处理来减轻不良影响，而不是耗时的顺序活动。然而，化学不良影响和人源化的并行工程需要将化学修饰从啮齿动物亲本抗体转化为可转化的人源化抗体。我们通过对啮齿动物亲本抗体和最终人源化抗体的质谱肽图进行实验比较，发现所有序列模体之间都存在线性相关性，从而比较了它们的稳定性。这些结果使我们能够从先导发现到临床开发，对治疗性抗体的可开发性评估过程进行简化。
