Development of a Novel MRI Contrast Agent for Early Detection of Alcoholic Steatohepatitis

摘要 慢性肝病是全世界发病率和死亡率的主要原因[1-4]。肝纤维化可以 发展为任何类型的慢性肝病(CLD)的患者，包括酒精性肝病(ALD)、肝炎 乙肝、非酒精性脂肪性肝病(NAFLD)和自身免疫性肝炎。主要的临床 肝硬变的后果是肝功能衰竭和肝细胞癌，这两者都会增加风险。 对死亡的恐惧。酒精性肝病(ALD)是全球肝病和与肝脏相关的死亡的主要原因， 尤其是在发达国家。目前的金标准诊断方法，肝活检是有创的，并且 许多限制，包括抽样误差和高观察者间变异性，即使对于晚期 肝纤维化分期。作为替代方案研究的几种技术中，没有一种能够提供所需的灵敏度 对肝纤维化的早期发现和分期具有特异性。因此，一种创新的、安全的磁共振造影剂是 需要克服几个主要限制，包括对早期纤维化和 异质组织中的检测。我们的团队已经开创了一种新型的基于Gd的造影剂 它利用蛋白质支架结合Gd3+原子。我们已经证明了ProCA32.胶原蛋白，一种靶向的胶原蛋白1 蛋白质磁共振造影剂，对I型胶原蛋白有很强的亲和力，其表达水平和空间分布模式 取决于纤维化的分期。ProCA32.胶原蛋白在两个1.4%处都具有高的每粒子松弛活性(R1和R2 和7.0T，这使得能够稳健地检测早期酒精性肝纤维化和非酒精性肝纤维化 通过双重对比模式建立脂肪性肝炎动物模型。毒性谱和体内毒性的初步研究 我们的化合物在使用非GLP级材料的动物身上的稳定性提供了信心 该化合物将在人体临床试验中显示出良好的敏感性和特异性，用于肝纤维化的早期检测。 在这项建议的第一阶段，我们寻求及时支持进行IND启用的CMC研究，以生成 GLP/cGMP级ProCA32.胶原蛋白。在第二阶段，我们将进行毒性和安全概况研究，使用 GLP/cGMP级产品完成IND临床试验所需的研究。

Abstract Chronic liver disease (CLD) is a major cause of morbidity and mortality worldwide[1-4]. Hepatic fibrosis can develop in patients with any type of chronic liver disease (CLD), including alcoholic liver disease (ALD), hepatitis C, hepatitis B, nonalcoholic fatty liver disease (NAFLD) and autoimmune hepatitis. The major clinical consequences of cirrhosis are liver failure and hepatocellular carcinoma (HCC), both of which increase the risk of death. Alcoholic liver disease (ALD) is a leading cause of liver disease and liver-related deaths globally, particularly in developed nations. The current gold standard diagnostic method, liver biopsy is invasive and has many limitations including sampling error and high inter-observer variability even for the diagnosis of advanced stages of liver fibrosis. None of several technologies investigated as alternatives offers the desired sensitivity and specificity for the early detection and staging of fibrosis. Thus, an innovative, safe MRI contrast agent is required to overcome several major limitations including low sensitivity and specificity for early stage fibrosis and detection in heterogeneous tissue. Our team has pioneered a new class of gadolinium based contrast agents which utilize a protein scaffold to bind Gd3+ atoms. We have shown that ProCA32.collagen, a collagen 1 targeted protein MRI contrast agent, exhibits strong affinity to collagen I, whose expression level and spatial pattern depend on the stage of fibrosis. ProCA32.collagen possesses high relaxivities per particle (r1 and r2) at both 1.4 and 7.0 T, which enables the robust detection of early-stage alcohol-induced liver fibrosis and nonalcoholic steatohepatitis in animal models via dual contrast modes. Our preliminary studies on toxicity profiles and in vivo stability of our compound in animals using non-GLP grade materials have provided confidence that the compound will exhibit good sensitivity and specificity for early detection of liver fibrosis in human clinical trials. In Phase I of this proposal, we seek timely support for conducting IND enabled CMC studies for generating GLP/cGMP grade ProCA32.collagen. In Phase II, we will conduct toxicity and safety profile studies using GLP/cGMP grade products to complete IND required studies for clinical trials.