Biologic therapies involve the utilization of proteins, DNA, antibodies, or other substances derived or synthesized from living tissue for therapeutic effects. There are several biologic therapies in clinical development for the prevention and treatment of atherosclerosis. The most advanced in human trials are apolipoprotein mimetics, which include apolipoprotein A-1 Milano and phospholipid complexes. Infusions of these apolipoprotein mimetics have been demonstrated to reduce atherosclerotic development in both animal models and humans. Autoimmunization to create neutralizing antibodies to cholesteryl ester transfer protein is also in human trials. Gene therapies to reduce low-density lipoproteins and increase high-density lipoproteins are on the horizon, but the ability to safely prolong gene expression in humans will require the development of novel vectors.