Lerodalcibep (LIB003) is a potent, high-affinity inhibitor of proprotein convertase subtilisin/kexin type 9 (PCSK9). It is a recombinant fusion protein comprising a small PCSK9-binding protein fused to human serum albumin (HSA) to significantly extend its circulatory half-life. Lerodalcibep binds to circulating PCSK9 and blocks its interaction with low-density lipoprotein receptors (LDLR) on the hepatocyte surface, preventing lysosomal degradation of the receptors. This mechanism increases the density of LDLR on the liver surface, leading to the highly efficient clearance of LDL-cholesterol (LDL-C) from the blood.