Rapirosiran

**Semantic type:** Pharmacologic Substance

**Definition:** A N-acetylgalactosamine (GalNAc)-conjugated small-interfering RNA (siRNA) directed against liver-expressed 17-beta-hydroxysteroid dehydrogenase 13 (HSD17B13) mRNA, that may potentially be used in the treatment of steatohepatitis including metabolic dysfunction-associated steatohepatitis (MASH). Upon subcutaneous administration of rapirosiran, the GalNAc moiety targets and binds with high affinity to asialoglycoprotein receptors (ASGPRs) expressed on hepatocytes. Once inside the cells, the siRNAs bind to and silence HSD17B13 mRNA, and inhibit both the translation and expression of the HSD17B13 protein. This may reduce inflammation in the liver and slow the progression from steatosis to steatohepatitis. Loss-of-function variants in the HSD17B13 gene have been associated with a reduced risk of progression from steatosis to steatohepatitis, liver injury and chronic liver disease.

**Synonyms:** - AD 288996 - AD-288996 - AD288996 - ALN 288996 - ALN-288996 - ALN-HSD - ALN288996 - Anti-HSD17B13 siRNA ALN-HSD - GalNAc-conjugated siRNA ALN-HSD - RAPIROSIRAN