Alnylam Pharmaceuticals, Inc., Cambridge, MA 02142, USA.
Division of Biopharmaceutics, Leiden Academic Center for Drug Research, 2300 RA Leiden, the Netherlands.
Mol Ther. 2018 Jan 3;26(1):105-114. doi: 10.1016/j.ymthe.2017.08.019. Epub 2017 Sep 7.
The hepatocyte-specific asialoglycoprotein receptor (ASGPR) is an ideal candidate for targeted drug delivery to the liver due to its high capacity for substrate clearance from circulation together with its well-conserved expression and function across species. The development of GalNAc-siRNA conjugates, in which a synthetic triantennary N-acetylgalactosamine-based ligand is conjugated to chemically modified siRNA, has enabled efficient, ASGPR-mediated delivery to hepatocytes. To investigate the potential impact of variations in receptor expression on the efficiency of GalNAc-siRNA conjugate delivery, we evaluated the pharmacokinetics and pharmacodynamics of GalNAc-siRNA conjugates in multiple pre-clinical models with reduced receptor expression. Despite greater than 50% reduction in ASGPR levels, GalNAc conjugate activity was retained, suggesting that the remaining receptor capacity was sufficient to mediate efficient uptake of potent GalNAc-siRNAs at pharmacologically relevant dose levels. Collectively, our data support a broad application of the GalNAc-siRNA technology for hepatic targeting, including disease states where ASGPR expression may be reduced.
肝细胞特异性的去唾液酸糖蛋白受体(ASGPR)是一种理想的药物靶向递药受体,因为其能够从循环中高效清除底物,并且在不同物种间表达和功能都高度保守。GalNAc-siRNA 偶联物的开发,即将合成的三触角 N-乙酰半乳糖胺基配体与化学修饰的 siRNA 偶联,使得能够高效地通过 ASGPR 介导递送至肝细胞。为了研究受体表达的变化对 GalNAc-siRNA 偶联物递药效率的潜在影响,我们在多个受体表达降低的临床前模型中评估了 GalNAc-siRNA 偶联物的药代动力学和药效动力学。尽管 ASGPR 水平降低了 50%以上,但 GalNAc 偶联物的活性仍然保留,这表明剩余的受体容量足以介导在药理学相关剂量水平下高效摄取有效的 GalNAc-siRNA。总的来说,我们的数据支持 GalNAc-siRNA 技术在肝脏靶向递药中的广泛应用,包括 ASGPR 表达可能降低的疾病状态。