Alnylam Pharmaceuticals is a leader in the study of RNA interference (RNAi) therapeutics. RNAi is a naturally occurring biological pathway within cells for sequence-specific silencing and regulation of gene expression. Alnylam has five drugs on the market: Onpattro and Amvuttra for hATTR amyloidosis, Givlaari for acute hepatic porphyria, Oxlumo for primary hyperoxaluria type 1, and Leqvio for hypercholesterolemia.