Delpacibart is a humanized IgG1 kappa monoclonal antibody designed to specifically target Transferrin Receptor 1 (TFRC, also known as CD71). Its primary application is not as a standalone therapeutic but as a targeting component for the construction of Antibody Oligonucleotide Conjugates (AOCs), such as Delpacibart etedesiran. This approach leverages the antibody's ability to deliver conjugated oligonucleotide payloads across biological barriers, particularly the blood-brain barrier (BBB), by hijacking the natural TFRC-mediated endocytic pathway. It represents a novel strategy in precision medicine for treating diseases of the central nervous system (CNS) and other tissues with high TFRC expression.