Doctors debate worth of lipid-lowering agent that combines 2 medications
SUNDAY, March 30 (HealthDay News) -- A divided cardiology community is trying once again to make sense of a trial showing that a drug can lower levels of "bad" LDL cholesterol and yet give no apparent benefit to people at high risk of heart attack and other cardiovascular problems.
The drug, Vytorin, combines a well-known statin -- simvastatin -- with ezetimibe, which also lowers LDL cholesterol, but in a different way. A controversy erupted earlier this year when Merck/Schering-Plough, which markets the drug in the United States, released results of a European trial that showed the combined medication did not reduce buildup of potentially artery-blocking plaque deposits any more than simvastatin alone.
Those results and their implications are being discussed this weekend at the American College of Cardiology annual meeting, in Chicago. The New England Journal of Medicine, which will publish two papers and two editorials on the drug in its April 3 issue, is releasing the papers early to coincide with the meeting.
One paper by European researchers goes over the trial results again and comes to the same conclusion: Vytorin did not reduce plaque buildup any more than statin treatment alone in the study group -- people with an inherited condition that causes them to have an unusually high level of blood cholesterol and a resulting higher risk of cardiovascular problems early in life.
Then the interpretation of those results begins.
Dr. B. Greg Brown, a professor of medicine at the University of Washington School of Medicine in Seattle, who co-authored one of the editorials, said the results might not apply to the general population because "this population [in the study] had been treated for many years because they had a very high cholesterol level. That might affect their response to the new treatment."
The basic question remains unanswered, Brown said. "The drug [Vytorin] does lower LDL cholesterol very effectively. The question is, does it help reduce the risk of heart attack or stroke or things like them? Is it cosmetic or is there a risk reduction as well?"
Those questions have yet to be answered, Brown said. But, he added, "my sense is that this was the wrong population to study." Other studies now under way might provide an answer, but not until 2011 or 2012, he said.
Meanwhile, Brown said, "I agree with the statements made by the American Heart Association and the American College of Cardiology, to use ezetimibe if it is needed to get people down to a target level of LDL cholesterol."
Dr. Harlan M. Krumholz, a professor of medicine at Yale University School of Medicine and co-author of another of the journal papers, disagreed with Brown's view.
"For myself, I would not take the medication, and if I recommended it to anyone, it would be for the highest-risk patient who couldn't tolerate statins," Krumholz said.
The paper he co-authored compared use of Vytorin in the United States and Canada. The proportion of cholesterol-lowering drug prescriptions represented by Vytorin rose from 0.2 percent to 3.4 percent in Canada from 2002 to 2006. In the United States, the increase was from 0.1 percent to 15.2 percent of all such prescriptions.
"That is a pretty remarkable difference," Krumholz said. "If we had adopted the drug at the same speed as in Canada, we would have saved $1.5 to $2 billion in health-care costs. What did we get for that? Did it produce benefits for patients? We can't say we're sure of that."
It's also possible that the new cholesterol-lowering agent might turn out to be harmful, Krumholz said. He recalled the history of torcetrapib, a drug developed by Pfizer that increased blood levels of HDL cholesterol, the "good" kind that prevents plaque formation. Pfizer stopped tests of the drug in 2006 because of a trial showing higher mortality among those taking it.
"It was a new drug, the first in its class," Krumholz said. "The laboratory results looked great, and it ended up hurting people."
It's not clear whether the same will be true of Vytorin, he said. "The evidence we have on hand makes a benefit less likely," Krumholz said. "We have a $5-billion-a-year market without outcomes data."
His journal paper noted that use of statins remained constant in Canada but has declined in the United States as use of Vytorin rose.
"We did not push statins to the maximum," Krumholz said. "That is definitely the wrong thing to do."
The various kinds of cholesterol and what can be done about them are described by the American Heart Association.
SOURCES: B. Greg Brown, M.D., professor, medicine, University of Washington School of Medicine, Seattle; Harlan Krumholz, M.D., professor, medicine, Yale University School of Medicine; March 30, 2008, presentation, American College of Cardiology annual meeting, Chicago; April 3, 2008, New England Journal of Medicine
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