New generation of long acting nucleos(t)ides and immune stimulant for treatment of chronic hepatitis B

减轻慢性乙肝(CHB)感染的负担和预防 乙肝病毒相关的终末期肝病和癌症的发展。对现有疗法的改进 有望帮助实现这一目标。具体地说，一次两个月可注射核素(T)ide的使用 类似物与免疫调节的抗病毒化合物相结合，而不是终生服用的每日药片，有 有很强的潜力帮助实现慢性乙肝的功能性治愈。为此，我们建议将水溶性 抗病毒药物，一线药物替诺福韦(TFV)和恩替卡韦(ETV)，以及免疫调节药物甲硝唑 (TiZ)制成疏水性亲脂结晶性前药。我们将把它们配制成适合于 肌肉注射。纳米晶体的物理化学性质的有效优化有望 改善他们的药代动力学(PK)和药效学(PD)曲线。这一优化将增强 肝巨噬细胞和肝细胞摄取前药纳米晶以确保缓慢释放和 乙肝病毒复制部位的持续治疗药物浓度。 长效TFV、ETV和TIZ的治疗有望减少给药频率，限制毒性， 并促进持续的病毒抑制和治疗。对乙肝病毒的功能性治愈有望实现 通过多因素机制，包括抑制病毒聚合酶，防止cccDNA的形成，以及 TIZ通过刺激宿主天然免疫清除HBV微染色体。因此，总体上， 本提案的目的是开发临床可翻译、长效、可注射的抗病毒药物。 纳米制剂，以增加依从性和加强药物输送到持续的乙肝病毒感染部位， 从而有利于持续的病毒抑制和有限的治愈。为此，提出了三个具体目标： 目的1：研制长效抗乙肝病毒前药纳米制剂并评价其疗效。在这里，我们将 应用原核苷酸(ProTide)和改进的HepDirect前药技术将现有药物转化为 适合制成纳米混悬剂的疏水前药，以实现长期治疗活性 肝细胞内药物浓度。这有望改善药物在受感染的肝细胞中的生物分布。 而不会影响药物的效力和安全性。前药制剂将在#年进行体外筛选。 人巨噬细胞作为潜在的药库，感染的肝细胞作为最终靶点。抗乙肝病毒 前药纳米晶的活性将在体外和体内使用感染乙肝病毒的人源化小鼠进行检测。目标 2：开发长效TiZ纳米制剂并评价TiZ抑制乙肝病毒的机制 在受感染的肝细胞中复制。目的3：评价所选长效TIZ的协同效应 和NUC制剂，并评价这种组合从肝细胞中清除HBVccDNA的能力 并显著降低乙肝病毒表面抗原浓度。

There is a global aim to reduce the burden of chronic hepatitis B (CHB) infection and prevent the development of HBV-associated end-stage liver disease and cancer. The improvement of existing therapeutics is expected to help achieve this goal. Specifically, the usage of once two-month injectable nucleos(t)ide analogs in combination with immunomodulating antiviral compounds instead of life-long daily pills has the strong potential to help to achieve a functional cure for CHB. To this end, we propose to transform water-soluble antiviral drugs, first-line drugs tenofovir (TFV) and entecavir (ETV), and immunomodulating drug tizoxanide (TIZ) into hydrophobic lipophilic crystalline prodrugs. We will formulate them as nanosuspensions suitable for intramuscular injection. The efficient optimization of physicochemical properties of nanocrystals is expected to improve their pharmacokinetics (PK) and pharmacodynamics (PD) profiles. This optimization will enhance uptake of the prodrug nanocrystals by liver macrophages and hepatocytes to ensure a slow release and sustained therapeutic drug concentrations at the site of hepatitis B viral replication. The treatment with long-acting TFV, ETV, and TIZ is expected to decrease dosing frequency, limit toxicity, and facilitate sustained viral suppression and treatment. A functional cure for HBV is expected to be achieved via multifactorial mechanisms, including inhibition of viral polymerase, prevention of cccDNA formation, and the clearance of HBV micro-chromosomes via stimulation of host innate immunity by TIZ. Thus, the overall objective of this proposal is to develop clinically translatable, long-acting, injectable, antiviral drug nanoformulations to increase adherence and enhance drug delivery to sites of persistent HBV infection, thereby facilitating sustained viral suppression and finite cure. To this end, three specific aims are proposed: Aim 1: Develop long-acting anti-HBV prodrug nanoformulations and evaluate the drug efficacy. Here, we will apply pronucleotide (ProTide) and a modified HepDirect prodrug technology to transform existing drugs into hydrophobic prodrugs suitable for formulation as nanosuspensions to achieve prolonged therapeutic active drug concentrations in hepatocyte. This is expected to improve drug biodistribution to infected hepatocytes without compromising drug potency and safety profile. The prodrug formulations will be screened in vitro in human macrophages as a potential drug depot and in infected hepatocytes as final targets. The anti-HBV activity of prodrug nanocrystals will be examined in vitro and in vivo using HBV-infected humanized mice. Aim 2: To develop long-acting TIZ nanoformulation and evaluate the mechanisms by which TIZ suppresses HBV replication in infected hepatocytes. Aim 3: To evaluate the synergistic efficacy of the selected long-acting TIZ and NUC formulations and evaluate the ability of this combination to eliminate HBV cccDNA from hepatocytes and significantly reduce the concentration of HBsAg.