Cholesterol Drug Fails to Slow Progression of Coronary Disease, Cleveland Clinic Study Reports

NEW ORLEANS, March 26, 2007 /PRNewswire/ -- Cleveland Clinic researchers today report that the drug torcetrapib, despite raising high density lipoprotein cholesterol (HDL) or the "good" cholesterol by more than 60%, did not slow the progression of plaque buildup in the coronary arteries as measured using an ultrasound probe.

Steven Nissen, M.D., Chairman of Cardiovascular Medicine at Cleveland Clinic and lead investigator of this clinical trial, will present the study on Monday, March 26 at 8:30 a.m. at the of Cardiology's (ACC) 56th Annual Scientific Session. Dr. Nissen is also President of the ACC. The study will be simultaneously published in the New England Journal of Medicine.

All development of this drug was terminated on Dec. 2, 2006 after the safety board monitoring a separate large clinical outcomes trial reported that torcetrapib increased the risk of death and other adverse cardiovascular outcomes.

"We found that the torcetrabip/atorvastatin combination markedly increased good cholesterol levels and lowered bad cholesterol in patients. Unfortunately this drug also substantially raised blood pressure and failed to slow the buildup of plaque," Dr. Nissen said. "It is yet to be determined of this failure represents a problem unique to torcetrapib or predicts a lack of efficacy for the entire class of similar drugs. These findings further demonstrate the great difficulty in developing therapies to disrupt the atherosclerotic disease process."

The development of drugs to raise HDL has been a key research priority because, despite lowering LDL (low-density lipoprotein, or "bad") cholesterol with statin drugs, many patients continue to experience heart attacks, stroke or sudden cardiac death.

A total of 1,188 coronary artery disease patients were enrolled in the "Investigation of Lipid Level management using coronary UltraSound To assess Reduction of Atherosclerosis by CETP Inhibition and HDL Elevation" (ILLUSTRATE) trial. All patients had a clinical indication for cardiac catheterization, had a baseline intravascular ultrasound (IVUS) and received 10-80 gm of atorvastatin adjusted during a two- to 10-week period until LDL levels reached national guidelines.

Patients were then randomized to receive either 60 mg of torcetrapib or a matching placebo for two years. At the end of the treatment period, a second IVUS was performed, examining the same coronary arteries. Researchers measured the change in plaque volume in the artery, comparing the baseline to the follow-up ultrasound. They also measured patients' blood cholesterol levels and biomarkers of inflammation at several points during the trial.

Patients in the torcetrapib/atorvastatin group experienced a 61 percent relative increase in HDL cholesterol levels and a 20 percent relative decrease in LDL levels, as compared with patients in the atorvastatin-only group. Despite those results, there was no statistical difference between the two groups in plaque volume changes. Plaque volume increased by 0.19 percent in the atorvastatin-only patients and 0.12 percent in the combination group, p = 0.72. Torectrapib was also associated with a substantial increase in blood pressure, averaging 4.6 mm.

IVUS is a technique in which a tiny ultrasound probe is inserted into the coronary arteries, providing a precise and reproducible method for determining the change in plaque, or atheroma, burden during treatment.

Cleveland Clinic, located in Cleveland, Ohio, is a not-for-profit multispecialty academic medical center that integrates clinical and hospital care with research and education. Cleveland Clinic was founded in 1921 by four renowned physicians with a vision of providing outstanding patient care based upon the principles of cooperation, compassion and innovation. U.S. News & World Report consistently names Cleveland Clinic as one of the nation's best hospitals in its annual "America's Best Hospitals" survey. Approximately 1,800 full-time salaried physicians and researchers at Cleveland Clinic and Cleveland Clinic Florida represent more than 100 medical specialties and subspecialties. In 2005, there were 2.9 million outpatient visits to Cleveland Clinic. Patients came for treatment from every state and from more than 80 countries. There were nearly 54,000 hospital admissions to Cleveland Clinic in 2005.

The of Cardiology (http://www.acc.org) represents the majority of board certified cardiovascular physicians in the United States. Its mission is to advocate for quality cardiovascular care through education, research, promotion, development and application of standards and guidelines- and to influence health care policy. ACC.07 and the ACC inaugural i2 Summit, the first-ever meeting for interventional cardiologists, will bring together more than 30,000 cardiologists and cardiovascular specialists to share the newest discoveries in the treatment and prevention, while helping the ACC achieve its mission to address and improve issues in cardiovascular medicine.

Posted: March 2007

View comments

Hide
(web4)