C/EBP-beta PEPTIDES FOR THE TREATMENT OF LIVER INJURY AND FIBROSIS

描述（由申请人提供）：肝星状细胞（HSC）的活化是所有原因的慢性肝病中肝纤维化发展的原因，值得注意的是，通过细胞凋亡清除HSC可使肝损伤恢复和肝纤维化逆转。肝纤维化专家完全同意抑制或逆转HS激活（治疗靶点）对于肝纤维化的治疗至关重要。尽管我们在临床前研究中明确记录了持续的肝损伤，但肝纤维化的消退以及肝纤维化的缺乏进展都被认为是慢性肝病和肝纤维化患者的重要临床目标。最后，阻断肝纤维化的进展将减少这些患者中原发性肝癌的发展，因为大多数肝细胞癌发生在缺血性肝脏中。我们研究和开发Ac-KAVD-CHO相关类肽的基础如下：i）不可磷酸化的C/EBP <$-Ala 217转基因防止内源性C/EBP <$的磷酸化，并激活半胱天冬酶8，导致HSC在其激活后的凋亡，防止肝纤维化的进展和诱导肝纤维化的消退; ii）这些作用既不需要反式激活也不需要亮氨酸拉链结构域;和iii]含有C/EBP的RSK磷酸受体结构域的细胞渗透性四肽足以复制这些作用。我们使用模拟合成创建了一个库，以改善人类使用的潜在陷阱; ii]在 逐步方式测定以选择最安全和最有效的肽（包括活化的原代人HSC中的细胞凋亡测定;无细胞半胱天冬酶8活化测定;急性肝损伤/纤维化模型;高度分化的原代人肝细胞培养物和小鼠中的毒理学测定）。我们已经开发出有效的抗纤维化化合物，在临床试验期间具有预期的降低的免疫原性和改善的稳定性和生物利用度。所提出的化合物在肝纤维化的临床前模型中的培养物和体内显著抑制人和小鼠肝星状细胞的活化并减少肝损伤。在初步毒理学研究中，这些化合物对高度分化的肝细胞和小鼠没有毒性，至少在100倍的治疗剂量下。本STTR拟完成的目的是：小鼠模型中的慢性肝纤维化试验;药代动力学;体外ADMET研究：代谢稳定性; CYP-450抑制;和探索性毒理学;剂量递增研究和重复给药范围探索毒性研究。目前尚无治疗或预防肝纤维化的药物。完成这些任务的拟议化合物将使我们能够进行2期STTR和肝纤维化患者的临床开发。

DESCRIPTION (provided by applicant): Activation of hepatic stellate cells (HSC) is responsible for the development of liver fibrosis in chronic liver diseases of all causes and remarkably, HSC clearance by apoptosis may allow recovery from liver injury and reversal of liver fibrosis. There is full agreement among liver fibrosis experts that inhibiting o reversing HS activation (the therapeutic target) is critical for the treatment of liver fibrosis. Both regressio of liver fibrosis as well as lack of progression of liver fibrosis, in spite of continued liver injury as we clearly documented in our pre-clinical studies, are considered important clinical targets for patients with chronic liver disease and liver fibrosis. Finally, blocking the progression of liver fibrosis would decrease development of primary liver cancer in these patients since the majority of hepatocellular carcinomas arise in cirrhotic livers. The basis for our Research and Development of the Ac-KAVD-CHO related peptoids are the following: i] that the nonphosphorylatable C/EBP¿-Ala217 transgene prevents phosphorylation of endogenous C/EBP¿, and activates caspase 8 resulting in apoptosis of HSC upon their activation, preventing progression and inducing regression liver fibrosis; ii] that neither the transactivation nor the leucine zipper domains are required for these effects; and iii] that a cell permeant tetrapeptide containing the RSK phosphoacceptor domain of C/EBP¿ is sufficient to replicate these effects . We created a library using analog synthesis to improve potential pitfalls for human use; ii] use in a step-wise manner assays to select the safest and most efficient peptides (including apoptosis assays in activated primary human HSC; cell-free caspase 8 activation assays; acute liver injury/fibrogenesis models; toxicology assays in highly differentiated, primary human hepatocyte cultures and mice). We have developed effective antifibrotic compounds with expected decreased immunogenicity and improved stability and bioavailability during clinical trials. The proposed compounds markedly inhibit activation of human and mouse hepatic stellate cells in culture and in vivo in preclinical models of liver fibrosis and decreased liver injury. These compounds were not toxic in the preliminary toxicology studies, including toxicogenomics, to highly differentiated hepatocytes and mice at least at 100-fold the therapeutic dose. The aims that are proposed for completion by this STTR are: Chronic liver fibrogenesis assays in mouse models; Pharmacokinetics; In Vitro ADMET Studies :Metabolic stability; CYP-450 Inhibition; and Exploratory Toxicology; Dose Escalation Study and Repeat-Dose Range-finding Toxicity Study. There is no medication for the treatment or prevention of liver fibrosis. Completion of these tasks for the proposed compounds will allow us proceeding with a Phase-2 STTR and clinical development in patients with liver fibrosis.