[推荐]EASL2019 PS-074 一流的口服ccc_R08使不稳定cccDNA

StephenW

PS-074
A first-in-class orally available HBV cccDNA destabilizer ccc_R08 achieved sustainable HBsAg
and HBV DNA suppression in the HBV circle mouse model through elimination of cccDNA-like
molecules in the mouse liver
Li Wang1, Qihui Zhu1, Jing Zeng1, Zhipeng Yan1, Andrew Feng1, John Young2, Lu Gao1
1Roche Innovation Centre Shanghai, Shanghai, China; 2Roche Innovation Centre Basel, Basel,
Switzerland
Email: [email protected]
Background and aims: The persistence of covalently closed circular DNA (cccDNA) in the nuclei of
infected hepatocytes is a major barrier for achieving cure with existing therapies in chronic hepatitis B
(CHB) patients. Therapeutic agents that can reduce the level of pre-existing cccDNA are needed to
achieve the goal of cccDNA eradication. Here we report the discovery of a novel small molecule,
ccc_R08, which reduces pre-existing cccDNA both in vitro and in vivo.
Method: Primary human hepatocytes (PHH) were used for HBV infection experiments and evaluation
of antiviral activities. The HBVcircle mouse model was used to study in vivo efficacy. Compound
treatment was initiated after viral persistence established. The levels of HBV DNA, pgRNA, HBsAg,
HBeAg were measured by quantitative polymerase chain reaction (qPCR), HBsAg chemiluminescent
immunoassay (CLIA), and HBeAg CLIA kits, respectively. cccDNA from infected hepatocytes and
mouse liver was measured with Southern Blot or qPCR after Hirt DNA extraction.
Results: We observed potent and dose-dependent inhibition of HBV DNA, HBsAg, and HBeAg upon
ccc_R08 treatment initiated two days after HBV infection in PHH. More importantly, the pre-existing
level of cccDNA was reduced significantly by ccc_R08 in HBV infected PHH. ccc_R08 did not show
any significant cytotoxicity in PHH or in multiple proliferating cell lines at up to 100 μM. No significant
effect on mitochondrial DNA was observed, indicating a specific effect on cccDNA. In vivo efficacy was
evaluated in the HBVcircle mouse model, in which HBV replication was driven by cccDNA-like
molecules. ccc_R08 was orally dosed twice daily for two weeks. Notably, the levels of serum HBV
DNA, pgRNA, HBsAg, HBeAg were significantly reduced, and sustained during the off-treatment
follow-up period. Moreover, at the end of follow-up, levels of cccDNA molecules in the liver of ccc_R08
treated mice were reduced to below lower limit of quantification (LLOQ). As a control, entecavir did not
impact cccDNA level in this model. In summary, these results demonstrate that ccc_R08 can reduce
pre-existing cccDNA.
Conclusion: We have reported results that a novel small molecule ccc_R08 can substantially reduce
cccDNA levels in HBV infected hepatocytes and in HBVcircle mouse model. These data encourage
exploration of this type of molecule in the clinic to evaluate its potential for curing CHB infection.

StephenW

PS-074
一流的口服HBV cccDNA去稳定剂ccc_R08实现了可持续的HBsAg
HBV环小鼠模型中的HBV DNA抑制通过消除cccDNA样
小鼠肝脏中的分子
李旺1，朱启辉1，景曾1，严志鹏1，冯安德1，John Young2，陆高1
1Roche创新中心，上海，中国;巴塞尔巴塞尔2Roche创新中心
瑞士
电子邮件：[email protected]
背景和目的：共价闭合环状DNA（cccDNA）在细胞核中的持久性
感染的肝细胞是用慢性乙型肝炎中现有疗法治愈的主要障碍
（CHB）患者。需要能够降低预先存在的cccDNA水平的治疗剂
实现cccDNA根除的目标。在这里，我们报告了一种新型小分子的发现，
ccc_R08，可在体外和体内减少预先存在的cccDNA。
方法：原代人肝细胞（PHH）用于HBV感染实验和评估
抗病毒活动。 HBVcircle小鼠模型用于研究体内功效。复合
在建立病毒持续性后开始治疗。 HBV DNA，pgRNA，HBsAg水平，
通过定量聚合酶链反应（qPCR），HBsAg化学发光测量HBeAg
免疫测定（CLIA）和HBeAg CLIA试剂盒。来自感染的肝细胞和肝细胞的cccDNA
在Hirt DNA提取后，用Southern印迹或qPCR测量小鼠肝脏。
结果：我们观察到HBV DNA，HBsAg和HBeAg的有效和剂量依赖性抑制
在PHH中HBV感染后两天开始ccc_R08治疗。更重要的是，预先存在
在HBV感染的PHH中，ccc_R08显着降低了cccDNA的水平。 ccc_R08没有显示
在高达100μM的PHH或多种增殖细胞系中的任何显着细胞毒性。没有意义
观察到对线粒体DNA的影响，表明对cccDNA的特异性影响。体内疗效为
在HBVcircle小鼠模型中评估，其中HBV复制由cccDNA样驱动
分子。 ccc_R08每天口服两次，持续两周。值得注意的是，血清HBV水平
在治疗期间，DNA，pgRNA，HBsAg，HBeAg显着降低并持续存在
随访期。此外，在随访结束时，ccc_R08肝脏中cccDNA分子的水平
处理的小鼠降低至低于定量下限（LLOQ）。作为对照，恩替卡韦没有
影响该模型中的cccDNA水平。总之，这些结果表明ccc_R08可以减少
预先存在的cccDNA。
结论：我们已经报道了一种新的小分子ccc_R08可以大大减少的结果
HBV感染的肝细胞和HBVcircle小鼠模型中的cccDNA水平。这些数据鼓励
在临床上探索这种类型的分子，以评估其治疗CHB感

StephenW

这张海报被禁运(embargoes)，现已发布.

newchinabok

cccdna能否被耗尽，要试验才能回答