The US Food and Drug Administration has granted Orphan Drug Designation to revusiran for the treatment of transthyretin (TTR)-mediated amyloidosis (ATTR amyloidosis). Revusiran is a RNAi therapeutic targeting wild-type and all mutant forms of TTR developed by Alnylam Pharmaceuticals, a therapeutic company based in Cambridge, MA. ATTR amyloidosis is a rare genetic disease caused by mutations in the TTR gene. TTR gene encodes a protein responsible for transporting retinol (vitamin A) and thyroxine hormone in the body. Mutations in the TTR gene result in misfolding of the protein and the formation of amyloid fibrils in organs such as the peripheral nerves and heart, leading to neuropathy and/or cardiomyopathy. Currently, there is no effective treatment option for this progressive and debilitating disease. Revusiran is in phase III trial designed to investigate the efficacy and safety in patients with Familial Amyloidotic Cardiomyopathy, one of the predominant clinical manifestations of ATTR amyloidosis.