N-acetylgalactosamine delivery systems for RNA therapeutics: a patent perspective

INTRODUCTION: SiRNA molecules with a feature of good gene-silencing are critical for drug discovery and development based on RNA interference. GalNAc-RNA therapeutics is a rapid growing area in RNA therapeutics. AREAS COVERED: This article provides patent landscape and modification feature of GalNAc-RNA therapeutics. The US-granted patents from January 2004 to April 2023 were retrieved and analyzed. EXPERT OPINION: Globally, our study is the first one to holistically depict a map of modifications and therapeutic applications for GalNAc-RNA therapeutics by patent data analysis. The results showed there were 8 major modifications and 5 new emerged modifications for GalNAc-RNA therapeutic agents. Especially, the study provides recent new emerged modifications in sugar, base, and internucleotide linkage of GalNAc-RNA therapeutic agents, e.g. morpholino-type ring, 5-methylcytosine, and phosphorodithioates. In addition, our study systematically demonstrated major therapeutic applications for GalNAc-RNA therapeutics, including liver or gallbladder disorders, anticancer, antihyperlipidemics, and disorders of the nervous system etc.