Inotersen is an orphan drug from the substance class of RNA interference (RNAi) therapeutics.
Inotersen is an antisense oligonucleotide (ASO) that is used to treat the hereditary form of transthyretin amyloidosis (hATTR).
Antisense oligonucleotides are single-stranded RNA molecules that specifically bind directly to the target RNA and inactivate it. They therefore differ in structure and mechanism of action from the double-stranded siRNA therapeutics (patisiran and vutrisran), which inactivate the mRNA by means of a mechanism naturally present in the cell, but have the same effect of inactivating the defective mRNA and thereby inhibiting the protein biosynthesis of defective TTR and its deposition as amyloid in the tissue of various organs.
Inotersen was first approved in Europe and Canada in 2018, then also in the USA.