MTP

Class

MTP inhibitor

Microsomal triglyceride transfer protein (MTP) is an intracellular lipid transfer protein located in the endoplasmic reticulum of liver and intestinal cells. Its normal role is to load triglycerides and cholesterol esters onto apolipoprotein B (apoB) as very-low-density lipoprotein (VLDL) particles are assembled in the liver and chylomicrons are assembled in the intestine. These apoB-containing particles are the vehicles that carry cholesterol and fat through the bloodstream, and their downstream metabolism produces low-density lipoprotein (LDL), the primary target of cholesterol-lowering therapy. Inhibiting MTP blocks this assembly step, reducing the secretion of VLDL from the liver and chylomicrons from the intestine, which in turn lowers circulating LDL cholesterol and triglycerides. This mechanism is particularly relevant in severe, genetically driven forms of high cholesterol where standard LDL-lowering approaches acting on cholesterol uptake or synthesis pathways are insufficient, because MTP inhibition works through an entirely separate route: limiting the production of lipoprotein particles rather than clearing them from circulation. Because the same assembly process occurs in both liver and gut, blocking MTP affects fat handling at both sites, which explains why this class carries distinct considerations around fat accumulation in the liver and absorption of dietary fat.