Cholesterol News: Experimental Heart Drug Fails to Slow Atherosclerosis

Three new studies found that torcetrapib, an experimental heart drug, did not inhibit atherosclerosis, or plaque build-up in coronary arteries.

Two studies' results were presented March 26 at the American College of Cardiology's annual meeting in New Orleans. A third study will appear in the March 29 issue of the New England Journal of Medicine.

"Something very strange is going on with this drug [torcetrapib], where none of these fantastic changes translate into benefit for the arterial walls," said Dr. John J.P. Kastelein of the Academic Medical Center in Amsterdam. Dr. Kastelein led the research team for two of the three studies.

Experts once had high hopes for the drug, which does appear to raise levels of HDL or "good" cholesterol and lowers LDL or "bad" cholesterol. Pfizer, the manufacturer of torcetrapib, stopped a large clinical trial in December 2006. The drug was blamed for raising the risk of death and other serious adverse events.

With the results of these latest studies, the class of drugs which includes torcetrabib may no longer be a viable option for doctors seeking to decrease heart disease risk by raising HDL levels. However, experts don't want to jump to conclusions just yet.

"This needs more extensive research. That's very, very important for us, because raising HDL is the next holy grail," Kastelein said. "We have already attained the first holy grail by reducing LDL. But this drug is a dirty drug. We need more research with compounds that are clean."

According to the American Heart Association, experts have good reason to be concerned about reducing low-density cholesterol, or LDL. LDL is the main carrier of cholesterol in the blood. Excess LDL builds up over time along the walls of the arteries which bring blood to the heart and brain. LDL combines with other substances to create plaque, a thick, hard material which can clog the arteries.

The formation of clots near this plaque can have serious consequences. A heart attack can result if a clot inhibits blood flow to the heart. Similarly, a stroke may occur if a clot inhibits blood flow to the brain.