Optimized lactoferrin for treatment of intracerebral hemorrhage

 描述(由申请人提供)：脑出血(ICH)是所有中风亚型中死亡率最高的主要公共卫生问题。ICH是导致长期残疾的主要原因之一。由于目前还没有FDA批准的治疗脑出血的方法，因此寻找治疗这种毁灭性疾病的新方法具有极其重要的意义。乳铁蛋白(LTF)是一种广为人知的内源性糖蛋白，具有抗微生物和免疫调节功能，部分是通过有效地隔离游离铁来实现的。在我们正在进行的研究中，使用不同的体外细胞培养系统(模拟脑出血的发病机制)和临床相关的脑出血啮齿动物模型，我们发现乳铁蛋白(LTF)具有独特的多效性。这使得这种内源性蛋白质作为治疗脑出血的候选药物非常有吸引力。由于LTF从循环中迅速排出(T1/2~45min)，我们开发了一种新型的基于重组人乳铁蛋白(RhLTF)和新生儿Fc受体(PRC14)的融合蛋白。这种新型分子的半衰期确实比天然LTf有显著延长(5.8倍)。我们成功地完成了第一阶段的目标，定义了PRC14的最佳治疗剂量，并在脑出血的小鼠模型中显示了非凡的治疗窗口(24小时)。这个第二阶段的主要目标是：(I)根据GMP标准(目标1)，验证PRC14作为一种潜在的治疗药物在稳定的CHO(DG44)细胞中表达的安全性，以及(Ii)使用模拟脑出血后临床风险因素和已知不良结局决定因素的动物模型，进一步表征PRC14在治疗脑出血中的疗效。PRC14的进一步商业化将需要一个强大的、可扩展的程序，在该程序中，最终材料保持活性并满足动物临床前安全性和毒理学的遵从性要求。我们将实现这一目标，在GMP协议下在稳定的CHO细胞中生产PRC14，并根据GLP协议进行测试：(I)药代动力学；(Ii)单剂量安全性研究(毒性)；以及(Iii)重复剂量，7天安全性研究(毒性)。从以下渠道获得的PRC14 放大生产(25g)将用于评估早期水肿和长期神经缺陷：(I)老年雌性和雄性小鼠，(Ii)自发性高血压大鼠(SHR)，和(Iii)猪 允许较大血肿大小的型号。该设计应为今后的临床研究提供坚实的基础。

 DESCRIPTION (provided by applicant): Intracerebral hemorrhage (ICH) is a major public health problem with the highest mortality rate of all stroke subtypes. ICH is one of the leading causes of long-term disability. Since there are no available FDA- approved therapies for ICH, it is of vast importance to search for new approaches in treatment for this devastating medical condition. Lactoferrin (LTF) is a well-known endogenous glycoprotein with anti-microbial and immunoregulatory functions, in part through its effective sequestration of free iron. In our ongoing research, using different in vitro cell-culture systems (to model ICH pathogenesis) and clinically relevant rodent models of ICH, we discovered that lactoferrin (LTF) has unique pleiotropic activities. This makes this endogenous protein highly attractive as a therapeutic candidate for the treatment of ICH. Because LTF is rapidly removed from the circulation (T1/2 ~45 min), we developed a novel fusion protein based on recombinant human lactoferrin (rhLTF) and Fc domain of IgG for neonatal Fc receptor (PRC14). This novel molecule has indeed a significantly extended half- life (5.8 fold) over native LTF. We successfully accomplished the objectives of Phase I by defining the optimal therapeutic dose of PRC14 and showing extraordinary therapeutic window (24h) in a mouse model of ICH. The primary objective of this Phase II is: (i) to validate the safety of PRC14 as a potential therapeutic expressed in stable CHO (DG44) cells according to GMP standards (Aim 1), and (ii) to further characterize the therapeutic utility of PRC14 in treatment for ICH, using animal models that simulate clinical risk factors and known determinants of poor outcome after ICH (Aim 2). Further commercialization of PRC14 will require a robust, scalable procedure where the final material retains activity and meets compliance requirements for pre-clinical safety and toxicology in animals. We will accomplish this goal with PRC14 being produced in stable CHO cells under GMP protocols and tested according to GLP protocols for: (i) pharmacokinetics; (ii) single dose safety studies (toxicity); and (iii) repeat dose, 7-day safety studies (toxicity) in rats. The PRC14 obtained from scale-up production (25g) will be used to assess early edema and long-term neurological deficit: (i) in aged female and male mice, (ii) in spontaneously hypertensive rats (SHR), and (iii) in a pig model allowing for larger hematoma size. This design should provide the strong foundation for future clinical studies.