Ribofuranose-based GalNAc-conjugated siRNA enhances the liver-targeted delivery and elicits robust RNAi-mediated gene silencing

. When compared in detail with inclisiran, an approved siRNA drug that incorporates a triantennary GalNAc construct (designated L96) for targeted liver delivery, inc-G5, which contains ribofuranose ring within its GalNAc cluster, exhibits superior efficacy. Additionally, pharmacokinetic (PK) analysis in rats revealed that G5-conjugated siRNAs preferentially accumulate in the liver, have an extended elimination half-life, and exhibit the highest liver-to-kidney ratio, which indicated excellent liver delivery specificity. Moreover, the synthesis of G5 can be readily scaled up to the kilogram level, thereby providing robust support for the production of oligonucleotide drugs. These results underscore the critical application of ribofuranose integration in GalNAc-siRNA drugs, establishing G5 as a promising liver-targeted delivery moiety for siRNAs to achieve sustained gene silencing with improved hepatic specificity and therapeutic durability.