By LINDA A. JOHNSON TRENTON, N.J., 09 jan 2009 – The Food and Drug Administration said Thursday patients should not stop taking Vytorin or other cholesterol-lowering drugs, based on its just-completed review of a controversial study that hammered Vytorin sales.
A statement from the regulatory agency said it is sticking to its original position that medicines that reduce bad cholesterol benefit patients at risk of heart attack, stroke, or sudden death.
"What the FDA is saying is exactly the way I'm practicing," said former American Heart Association President Dr. Valentin Fuster, now director of the Mount Sinai Heart Center in New York.
Dr. Timothy Gardner, the current heart association president, said he agreed with the FDA.
"Patients who are taking Vytorin without difficulty should continue until there's any further relevant information," he said.
But for the past year, some experts have instead been saying — based on results of the study of cholesterol drugs sold by Merck & Co. and Schering-Plough Corp. — that reducing cholesterol levels isn't necessarily enough to reduce those risks if there's no evidence the medicines control plaque buildup in arteries.
Vytorin, a pricey combination pill, is sold by a joint venture of Merck, based in Whitehouse Station, N.J., and Schering-Plough, based in Kenilworth, N.J. It contains drugs that lower cholesterol in two different ways: Schering-Plough's Zetia, which reduces the amount of cholesterol absorbed from food, and Merck's former blockbuster Zocor, which lowers the amount of cholesterol produced by the body based on one's genes. Zocor got generic competition in June 2006, and those versions cost about one-third as much as $100-a-month Vytorin.
"The price differential between the two products is so big that this may not make much of a difference" in sales of Vytorin and Zetia, given the recession, said analyst Steve Brozak of WBB Securities.
Last January, initial results of a study called ENHANCE showed Vytorin was no better than Zocor at reducing plaque buildup in neck arteries — indicating Zetia gave no added benefit over Zocor. That led several prominent doctors to urge patients to abandon Vytorin in favor of older cholesterol drugs with a longer track record. Sales of both Vytorin and Zetia began falling almost immediately as a result, with the number of prescriptions filled dropping 39 percent between January and November.
On Thursday, FDA said it had completed its review of the final report on the study. The agency said results showed that after two years of treatment, even though there was no difference in the thickness of carotid artery walls — related to plaque formation — in patient groups that got either Vytorin or Zocor, there was a significant difference in cholesterol levels.
Those in the Vytorin groups saw their level of bad, or LDL cholesterol, fall by 56 percent, versus a 39 percent drop in the Zocor group, FDA wrote.
Fuster, the Mount Sinai doctor, said he never stopped prescribing Vytorin for his patients for several reasons — some cited by FDA.
"There is no evidence from any trial that (significantly) lowering cholesterol does not decrease coronary events," Fuster said, referring to heart attack and stroke.
In addition, the two-year study period is too short for a disease that can take 20 or 30 years to develop, he said, and most patients in this study had been treated to reduce their cholesterol levels, which could have made it difficult to spot a difference between the patient groups.
Finally, there's not enough evidence of whether the ultrasound imaging technique used in the study can predict risk of heart attack or stroke, particularly in a short time, said Fuster, who is currently running an 8,000-patient study comparing eight imaging techniques to see which one provides the most reliable predictions.
In its statement, the FDA wrote that, "Based on currently available data, patients should not stop taking Vytorin or other cholesterol-lowering drugs and should talk to their doctor or other health care professional if they have any questions."
The drugmakers' joint venture issued a brief response repeating that statement.
"We are pleased that the agency has completed its review of the ENHANCE study," the companies said.