Transthyretin (TTR)

Class

Anti-transthyretin monoclonal antibody

Transthyretin (TTR) is a protein made mainly in the liver that circulates in blood, transporting thyroid hormone and vitamin A-binding protein. Normally, four TTR molecules assemble into a stable tetramer. In some people, this tetramer can dissociate, either because of an inherited mutation or simply with aging, and the resulting misfolded protein units aggregate into amyloid fibrils. These fibrils deposit in tissues such as the heart and peripheral nerves, causing transthyretin amyloidosis, a disease that presents as restrictive cardiomyopathy or progressive polyneuropathy. Existing therapeutic strategies include small molecules that stabilize the tetramer and gene-silencing agents that reduce TTR production in the liver. Anti-TTR monoclonal antibodies represent a distinct approach: rather than preventing new amyloid formation, they are designed to bind amyloid deposits already present in tissue and flag them for clearance by the immune system. This matters because stabilizers and silencers slow disease progression but do little to remove amyloid that has already accumulated, whereas an antibody-mediated clearance mechanism aims to reduce existing tissue burden, potentially offering benefit even in patients with established organ damage.