Rational design of a fully active, long-acting PEGylated factor VIII for hemophilia A treatment
Rational design of a fully active, long-acting PEGylated factor VIII for hemophilia A treatment
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DOI：
10.1182/blood-2009-11-254755
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发表时间：
2010-07-15
期刊：
影响因子：
20.3
通讯作者：
Murphy, John E.
中科院分区：
文献类型：
--
作者：
Mei, Baisong;Pan, Clark;Murphy, John E.
长效因子 VIII (FVIII) 作为血友病 A 的替代疗法将显着改善血友病 A 患者的治疗选择。为了开发具有延长循环半衰期但不降低活性的 FVIII，我们设计了 23 个 FVIII 变体，其中引入了表面暴露的半胱氨酸，并与聚乙二醇 (PEG) 聚合物进行了特异性缀合。通过对变体表达水平、聚乙二醇化产量和功能测定的筛选，鉴定出几种保留完全体外凝血活性和冯维勒布兰德因子 (VWF) 结合的缀合物。聚乙二醇化 FVIII 变体在血友病小鼠和兔子中表现出改善的药代动力学。此外，VWF 敲除小鼠的药代动力学研究表明，较大分子量的 PEG 可以替代 VWF，以保护 PEG 化的 FVIII 免于体内清除。在血友病小鼠的出血模型中，聚乙二醇化的 FVIII 不仅表现出与改进的药代动力学一致的延长功效，而且在停止急性出血方面也表现出与未修饰的 rFVIII 相当的功效。总之，位点特异性聚乙二醇化 FVIII 有潜力成为一种长效预防性治疗，同时对 A 型血友病患者的按需治疗完全有效。 (Blood. 2010; 116(2): 270-279)
A long-acting factor VIII (FVIII) as a replacement therapy for hemophilia A would significantly improve treatment options for patients with hemophilia A. To develop a FVIII with an extended circulating half-life, but without a reduction in activity, we have engineered 23 FVIII variants with introduced surface-exposed cysteines to which a polyethylene glycol (PEG) polymer was specifically conjugated. Screening of variant expression level, PEGylation yield, and functional assay identified several conjugates retaining full in vitro coagulation activity and von Willebrand factor (VWF) binding. PEGylated FVIII variants exhibited improved pharmacokinetics in hemophilic mice and rabbits. In addition, pharmacokinetic studies in VWF knockout mice indicated that larger molecular weight PEG may substitute for VWF in protecting PEGylated FVIII from clearance in vivo. In bleeding models of hemophilic mice, PEGylated FVIII not only exhibited prolonged efficacy that is consistent with the improved pharmacokinetics but also showed efficacy in stopping acute bleeds comparable with that of unmodified rFVIII. In summary site-specifically PEGylated FVIII has the potential to be a long-acting prophylactic treatment while being fully efficacious for on-demand treatment for patients with hemophilia A. (Blood. 2010; 116(2): 270-279)