Department of Pharmaceutical Chemistry, University of Kansas, 2093 Constant Avenue, Lawrence, KS 66047, USA.
Department of Pharmaceutical Chemistry, University of Kansas, 2093 Constant Avenue, Lawrence, KS 66047, USA.
Eur J Pharm Biopharm. 2023 Sep;190:121-130. doi: 10.1016/j.ejpb.2023.07.011. Epub 2023 Jul 21.
Fragmentation may compromise the clinical efficacy and safety profile of monoclonal antibodies (mAbs). We recently reported that Fe(III)-containing histidine (His) buffer mediates site-specific mAb fragmentation within the Fc domain when exposed to visible light (Y. Zhang and C. Schöneich, Mol. Pharm. 2023, 20, 650-662). Here, we show that this fragmentation proceeds even more efficiently under near-UV light. Several formulation strategies were applied in an attempt to reduce the photo-induced fragmentation. In solution formulations, the fragmentation can be mitigated by reducing the concentration of His buffer, adding Fe(III)-chelating agents, and replacing His with other amino acids. Fragmentation can be almost completely inhibited by formulating the protein in the lyophilized state. Mechanistically, His plays a critical role in the fragmentation process, likely due to its affinity for Fe(II), driving a photo-redox reaction towards product formation.
片段化可能会影响单克隆抗体 (mAb) 的临床疗效和安全性特征。我们最近报道了含铁的组氨酸 (His) 缓冲液在可见光下会介导 Fc 结构域中单克隆抗体的定点片段化 (Y. Zhang 和 C. Schöneich, Mol. Pharm. 2023, 20, 650-662)。在这里，我们表明，这种片段化在近紫外光下的效率更高。我们应用了几种制剂策略来试图减少光诱导的片段化。在溶液制剂中，通过降低 His 缓冲液的浓度、添加 Fe(III)螯合剂以及用其他氨基酸替代 His，可以减轻片段化。将蛋白质制成冻干状态几乎可以完全抑制片段化。从机制上讲，His 在片段化过程中起着关键作用，可能是因为它对 Fe(II)的亲和力，促使光氧化还原反应向产物形成方向进行。
