Trial halted on drug shown to increase HDL cholesterol

Torcetrapib is out, but the pursuit continues for a means to raise good cholesterol without causing harm.

By Victoria Stagg Elliott, AMNews staff. Jan. 15, 2007.

The abrupt shutdown of a large study of a medication that raises high density lipoprotein is being viewed as a significant letdown. Experts agree, though, that this recent action is by no means the end of the story when it comes to interest in this heart disease risk reduction strategy.

"Ultimately, the HDL approach will work, but this is a huge setback," said Steven Nissen, MD, president of the American College of Cardiology, who has been involved in the research. "We have to go back and figure out what happened and what we can learn from it."

On Dec. 2, 2006, Pfizer Inc. ended its 15,000-subject study assessing the safety and efficacy of torcetrapib, a cholesteryl ester transfer protein inhibitor, along with all other research related to this drug. The action was taken because the project's independent data safety monitoring board detected an increased rate of cardiovascular events and deaths among participants who took it.

It was definitely a shock; positive results from smaller trials were published as recently as a month earlier. According to a pair of papers published in the Nov. 7, 2006, Journal of the American College of Cardiology, torcetrapib -- either alone or in combination with atorvastatin -- raised HDL by as much as 54%. It was also well tolerated, although some patients did experience a small rise in blood pressure.

"This was somewhat of a spectacular failure," said Christie Ballantyne, MD, director of the Center for Cardiovascular Disease Prevention at Methodist DeBakey Heart Center and the atherosclerosis clinical research laboratory at Baylor College of Medicine in Houston. He was one of the drug's researchers.