Serum protein interactions are evaluated during the drug development process since they determine the free drug concentration in blood and thereby can influence the drug's pharmacokinetic and pharmacodynamic properties. While the impact of serum proteins on the disposition of small molecules is well understood, it is not yet well characterized for a new modality, RNA interference therapeutics. When administered systemically, small interfering RNAs (siRNAs) conjugated to the N-acetylgalactosamine (GalNAc) ligand bind to proteins present in circulation. However, it is not known if these protein interactions may impact the GalNAc-conjugated siRNA uptake into hepatocytes mediated through the asialoglycoprotein receptor (ASGPR) and thereby influence the activity of GalNAc-conjugated siRNAs. In this study, we assess the impact of serum proteins on the uptake and activity of GalNAc-conjugated siRNAs in primary human hepatocytes. We found that a significant portion of the GalNAc-conjugated siRNAs is bound to serum proteins. However, ASGPR-mediated uptake and activity of GalNAc-conjugated siRNAs were minimally impacted by the presence of serum relative to their uptake and activity in the absence of serum. Therefore, in contrast to small molecules, serum proteins are expected to have minimal impact on pharmacokinetic and pharmacodynamic properties of GalNAc-conjugated siRNAs.

中文翻译：

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血清蛋白对 GalNAc 偶联 siRNA 摄取和 RNAi 活性的影响

在药物开发过程中评估血清蛋白相互作用，因为它们决定了血液中的游离药物浓度，从而影响药物的药代动力学和药效学特性。虽然血清蛋白对小分子分布的影响已广为人知，但对于一种新的 RNA 干扰疗法来说，它还没有得到很好的表征。当全身给药时，与N-乙酰半乳糖胺 (GalNAc) 配体缀合的小干扰 RNA (siRNA) 与循环中存在的蛋白质结合。然而，尚不清楚这些蛋白质相互作用是否会影响通过去唾液酸糖蛋白受体 ( ASGPR ) 介导的 GalNAc 偶联 siRNA 摄取到肝细胞中。)，从而影响 GalNAc 偶联 siRNA 的活性。在这项研究中，我们评估了血清蛋白对人原代肝细胞中 GalNAc 偶联 siRNA 的摄取和活性的影响。我们发现很大一部分 GalNAc 缀合的 siRNA 与血清蛋白结合。然而，相对于它们在没有血清的情况下的摄取和活性， ASGPR介导的 GalNAc 缀合的 siRNA 的摄取和活性受血清存在的影响最小。因此，与小分子相比，预计血清蛋白对 GalNAc 偶联 siRNA 的药代动力学和药效学特性的影响最小。