Predicting the future of human gene therapy for cardiovascular diseases: what will the management of coronary artery disease be like in 2005 and 2010?

Gene therapy is the use of gene delivery as a means to achieve high levels of the therapeutic gene product (ie, “drug” delivery) to treat acquired cardiovascular diseases. Human gene therapy for cardiovascular disease is expected to provide important advances in therapeutic angiogenesis, myocardial protection, myocardial regeneration and repair, restenosis, prevention of bypass graft failure, and risk-factor management. The data from ongoing phase 2 and future phase 3 studies will provide evidence to show whether therapeutic angiogenesis is effective, and these studies will identify the types of patients who may benefit. An important therapeutic target is the cell cycle. Data from the Project in Ex-Vivo Vein Graft Engineering via Transfection (PREVENT) I and II studies suggest that a synthetic DNA decoy can sequester the E2F family of transcription factors and arrest cells at the gap period (G1) checkpoint. This mechanism prevents intimal hyperplasia, which is associated with atherosclerosis and coronary graft failure. Administration of a myocardial protective gene (eg, heme oxygenase) via a recombinant adeno-associated virus vector reduces infarct size in animal models of ischemia and reperfusion. Other studies have shown that fractionated bone marrow stem cells promote myocardial repair and regeneration in myocardial infarction. If applied in humans, it will be possible to use a single administration of gene therapy to provide long-term prophylaxis against secondary coronary events and to promote myocardial repair in patients who have experienced an infarct, as well as in those at high risk of myocardial injury. In the future, new technology using stable gene integration may lead to the development of more effective and lifelong therapy for diabetes, familial homozygous hypercholesterolemia, and other acquired diseases.