Glycogen Storage Disease IB

2023年10月27日，由刘如谦博士联合创办的下一代基因编辑公司Prime Medicine公布其一项基于非病毒递送技术平台的体内基因先导编辑（prime editing）新的临床前数据。该数据证明，其开发的肝脏靶向先导编辑器（Prime Editors）能够有效、精确地纠正非人灵长类动物（NHP）和小鼠模型中最普遍的糖原贮积病1b（GSD1b）致病突变之一。Prime Medicine在本次欧洲基因和细胞治疗学会（ESGCT）2023大会上公布首批Prime Editing数据，其主要报告了在非人灵长类动物体内成功进行的LNP递送Prime Editing组件RNA，进行肝脏突变位点高效修复的临床前数据。该类Prime Editors由靶向相应突变的先导编辑器指导RNA（pegRNA）、包装在Prime Medicine所开发的通用LNP配方中的切口指导RNA（nick-guide RNA，ngRNA）和信使RNA（mRNA）组成，该LNP带有靶向肝细胞的的配体。通过高通量筛选和后续优化，Prime Medicine的科学家识别出能够精确纠正肝细胞p.L348fs和p.G339C突变的pegRNAs。先导编辑器可精确编辑NHP肝细胞所携带的突变。来源：参考资料[1]目前技术成熟的精准编辑系统碱基编辑（base editing）和先导编辑（Prime editing）的mRNA形式尺寸都较Cas9大很多。参考刘如谦团队2021年发表在Cell上的相关文章，其mRNA的长度可达6600nt[2]。这是目前LNP-mRNA递送的最大尺寸并成功体内作用的精准基因编辑工具，其对纳米颗粒进行了靶向配体的改造，大大提升了肝靶向能力。来源：参考资料[2]数据显示，在静脉输注先导编辑器后，高达83%的肝细胞（高达50%全肝脏）的p.L348fs突变获精确编辑，此数值充分高于所预期认为逆转疾病表型所需的阈值，且在NHP中未观察到安全性问题。先导编辑器的脱靶编辑分析来源：参考资料[1]这些发现为Prime Medicine的脂质纳米颗粒（LNP）肝脏靶向递送方法提供了重要的概念验证，并支持该公司针对GSD1b与其他肝脏靶向的先导编辑器项目作进一步开发。参考资料[1]Prime editing precisely corrects prevalent pathogenicmutations causing Glycogen Storage Disease Type 1b (GSD1b). Retrieved October27, 2023 from https://investors.primemedicine.com/static-files/25727159-d40e-4b79-9f54-bf6d63aef11c[2]Chen PJ, Hussmann JA, Yan J, Knipping F, Ravisankar P, Chen PF, Chen C, Nelson JW, Newby GA, Sahin M, Osborn MJ, Weissman JS, Adamson B, Liu DR. Enhanced prime editing systems by manipulating cellular determinants of editing outcomes. Cell. 2021 Oct 28;184(22):5635-5652.e29. doi: 10.1016/j.cell.2021.09.018.

The prime editors were targeted to and designed to edit hepatocytes, which make up roughly 60% of the cells in the liver. Prime Medicine’s prime editors have corrected a gene mutation in primates that causes a rare liver disease, a step toward taking the tech to humans. In an Oct. 27 presentation at the annual European Society of Cell & Gene Therapy Congress in Brussels, the company showed that a single dose of its therapy could repair the gene associated with glycogen storage disease 1b in up to 83% of target cells in the livers of primates. An estimated 10% correction is required for therapeutic benefit in humans, according to the company. “[We] are highly encouraged by the efficient and precise corrections we have observed across in vitro evaluations, in vivo rodent studies and now, NHP studies,” Jeremy Duffield, M.D., Ph.D., Chief Scientific Officer at Prime Medicine, said in a press release. “Importantly, we continue to observe minimal to no detectable off-target edits with our Prime Editors, providing further confidence in the precision of this technology.” A primer on prime editing: The tech is another way to edit genes, but with more functionality than CRISPR. If CRISPR is like scissors that snip out mutated gene sequences, prime editors are like a keyboard’s search-and-replace functionality, using what’s known as Prime Editing guide RNAs, or pegRNAs, to find a mutated sequence and alter it, thereby correcting the pathology that stems from it. Each of the primates in the new study received a single dose of prime editors delivered in Prime Medicine’s universal lipid nanoparticle. The therapy was designed to repair the p.L348 mutation in the gene SLC37A4, one of the causes of glycogen storage disease 1b. Roughly half of the primates had never received gene therapy before, while the other half had previously been treated with a universal lipid nanoparticle to target a different gene. In an email to Fierce Biotech Research, the company said they could not comment on the previously edited gene, though they noted that if the prior therapy had any impact on the new one, it would have decreased editing efficacy.   The prime editors were targeted to and designed to edit hepatocytes, which make up 60% of the cells in the liver. In the primate with the best response, the editors corrected the mutation in an estimated 50% of all liver cells and 83% of hepatocytes, Prime’s presentation showed. In the other animals, editing was between 20% and 40% of all liver cells. The researchers found few off-target edits in the cells, and while they noted some transient moderate changes to liver function tests and minimal cytokine abnormalities, there were no lasting or serious side effects. The animals that had previously received a different gene therapy tolerated the drug no differently than those who were being treated for the first time. In an email to FBR, the team said that although they will have to see clinical data before they can determine the clinical benefit in humans, “high-level prime editing in NHP is likely to support that we can achieve high-level editing in humans,” they wrote. They declined to comment on a timeline for clinical testing. Prime is studying the use of prime editors in other conditions, too. The company reported in May 2023 that they had corrected a mutation that leads to chronic granulomatous disease in human stem cells that were engrafted into mice, with an efficacy rate of 90%.

▎药明康德内容团队编辑Prime Medicine今天宣布其最新临床前数据证明所开发的肝脏靶向先导编辑器（Prime Editors）能够在非人灵长类动物（NHP）和小鼠模型中高效精确地纠正造成1b型糖原贮积病（GSD1b）的致病突变。数据显示，在静脉输注先导编辑器后，高达83%的肝细胞（高达50%全肝脏）的p.L348fs突变获精确编辑，此数值充分高于所预期认为逆转疾病表型所需的阈值，且在NHP中未观察到安全性问题。这些发现为Prime Medicine的脂质纳米颗粒（LNP）肝脏靶向递送方法提供了重要的概念验证，并支持该公司针对GSD1b与其他肝脏靶向的先导编辑器项目作进一步开发。GSD1b是一种罕见、严重的进行性疾病，由于编码葡萄糖-6-磷酸转运蛋白（G6PT）的基因SLC37A4突变所致，会导致糖原代谢受损。已知P.L348fs和P.G339C突变是该疾病最普遍的致病突变，在约46-52%的GSD1b患者群体中发现。根据科学文献和Prime Medicine研究，纠正不到10%肝细胞中的SLC37A4基因突变可能足以逆转这种疾病的许多表现。▲Prime Medicine所开发的先导编辑器包覆于肝脏靶向的通用型脂质纳米颗粒内（图片来源：参考资料[2]）为了解决GSD1b的潜在遗传原因，Prime Medicine正在开发一款先导编辑器，可通过单次静脉输注递送到肝脏，以精确纠正致病突变，恢复G6PT蛋白表达和葡萄糖稳态。此先导编辑器由靶向相应突变的先导编辑器指导RNA（pegRNA）、包装在Prime Medicine所开发的通用LNP配方中的切口指导RNA（nick-guide RNA，ngRNA）和信使RNA（mRNA）组成，该LNP带有靶向肝细胞的的配体。通过高通量筛选和后续优化，Prime Medicine的科学家识别出能够精确纠正肝细胞p.L348fs和p.G339C突变的pegRNAs。研究的关键结果表明：第14天，NHP中p.L348的全肝精确编辑高达50%，没有显著在靶标上的非预期编辑。据估计，高达83%的关键靶细胞（肝细胞）通过单次LNP给药精确编辑了两个等位基因。▲先导编辑器可精确编辑NHP肝细胞所携带的突变（图片来源：参考资料[2]）GSD1b人源化小鼠模型中的p.L348fs突变全肝精确校正率高达56%，在评估的所有剂量水平上，在靶标上的非预期编辑率低于0.2%。在人源化小鼠模型中，高达44%的先导编辑导致G6PT蛋白表达水平恢复高达46%，校正程度与G6PT蛋白恢复程度直接相关。▲先导编辑器可精确编辑小鼠肝细胞所携带的突变（图片来源：参考资料[2]）在非初治动物中重新给予通用LNP的耐受性与初治动物相似。没有发现输注反应、体重变化，观察到短暂的、中度肝功能变化，这些变化在第7天消失。此外还观察到轻微的暂时性细胞因子异常。▲先导编辑器的脱靶编辑分析（图片来源：参考资料[2]）经过全面的脱靶筛选分析后，在源自实验动物的诱导多能干细胞（iPSC）中没有观察到可检测到的脱靶编辑，这与迄今为止在Prime Medicine对其每个项目进行的广泛脱靶分析中观察到的结果一致。大家都在看作为药明康德旗下专注于细胞和基因疗法的CTDMO，药明生基致力于加速和变革基因和细胞治疗及其他高端治疗的开发、测试、生产和商业化。药明生基能够助力全球客户将更多创新疗法早日推向市场，造福病患。如您有相关业务需求，欢迎点击下方图片填写具体信息。▲如您有任何业务需求，请长按扫描上方二维码，或点击文末“阅读原文/Read more”，即可访问业务对接平台，填写业务需求信息▲欲了解更多前沿技术在生物医药产业中的应用，请长按扫描上方二维码，即可访问“药明直播间”，观看相关话题的直播讨论与精彩回放参考资料：[1] prime medicine presents first-ever prime editing data in non-human primates demonstrating highly efficient ability of prime editors to precisely correct disease-causing mutation of gsd1b. Retrieved October 27, 2023 from https://investors.primemedicine.com/news-releases/news-release-details/prime-medicine-presents-first-ever-prime-editing-data-non-human[2] Prime editing precisely corrects prevalent pathogenic mutations causing Glycogen Storage Disease Type 1b (GSD1b). Retrieved October 27, 2023 from https://investors.primemedicine.com/static-files/25727159-d40e-4b79-9f54-bf6d63aef11c免责声明：药明康德内容团队专注介绍全球生物医药健康研究进展。本文仅作信息交流之目的，文中观点不代表药明康德立场，亦不代表药明康德支持或反对文中观点。本文也不是治疗方案推荐。如需获得治疗方案指导，请前往正规医院就诊。版权说明：本文来自药明康德内容团队，欢迎个人转发至朋友圈，谢绝媒体或机构未经授权以任何形式转载至其他平台。转载授权请在「药明康德」微信公众号回复“转载”，获取转载须知。分享，点赞，在看，聚焦全球生物医药健康创新