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Study compares Lipitor, Zocor

/ Source: The Associated Press

High doses of the cholesterol-lowering drug Lipitor were no better at preventing major heart problems than regular doses of rival Zocor, according to the latest study on efforts to aggressively treat the conditions released Tuesday.

The results present another challenge for Pfizer Inc., which will have to defend Lipitor against generic versions of Merck & Co.'s Zocor when that company loses patent protection next summer. Generic drugs are often 50 percent to 60 percent cheaper than brand name medicines, and health plans and pharmacy-benefit managers are already preparing financial incentives to make Zocor more attractive.

Lipitor outperformed Zocor on several fronts such as lowering cholesterol and preventing nonfatal heart attacks. The findings will continue to give it an advantage in the market even if generic Zocor is less expensive, some doctors said.

"The study certainly isn't ideal for Pfizer," said Jason Napodano, an analyst at Zacks Investment Research. "There were some positives for Pfizer, and they will have to go out and do some education (on them)."

But Pfizer said that the total number of prescriptions in the cholesterol-lowering market grew only 10 percent in third quarter compared with 14 percent in the first half of 2005 when it reported results last month. Uncertainty over the market was one reason the company cut its profit estimates for this year and withdrew guidance beyond that.

Lipitor is Pfizer's best-selling drug, and the company has lost patent protection on key medicines recently. Napodano lowered his Lipitor sales estimate by roughly $500 million this year to $12.01 billion and at least $500 million next year to $12.6 billion.

Pfizer funded and conducted the study, which was presented at an American Heart Association meeting in Dallas. It also appears in Wednesday's Journal of the American Medical Association.

Not a head-to-head comparison

The results can't be considered a direct comparison because different doses of the competing drugs were used. It was meant to be a test of aggressive treatment, not a head-to-head comparison, said Dr. Terje Pedersen, of Ulleval University Hospital in Oslo, Norway, who was lead author of the study.

Many heart specialists recommend aggressively lowering LDL cholesterol levels, the bad kind, to help heart patients avoid future cardiovascular problems. Pfizer set out to see if treating patients who had already suffered a heart attack with the highest dose of Lipitor would lead to fewer major heart problems than those treated with a more moderate dose of Zocor. The study involved 8,888 mostly male Scandinavian patients aged 61 on average who had previous heart attacks.

Researchers didn't find the main difference they sought — fewer "major coronary events" in the Lipitor group during an average follow-up of almost five years. That category lumped together cardiovascular deaths, nonfatal heart attacks and nonfatal cardiac arrest. These events totaled 463 in the Zocor patients and 411 in the Lipitor patients, a difference that was not statistically significant.

Other studies that have shown more aggressive lipid lowering results in fewer cardiovascular problems have also measured the incidence of stroke, which the most recent trial did not. The failure to measure stroke could be one reason the study failed to show a statistically significant difference, doctors said.

The study did show Lipitor reduced nonfatal heart attacks by 17 percent and angiograms and bypass surgery by 23 percent, said Dr. John Tsai, leader of Pfizer's worldwide Lipitor team. Tsai said the study's individual categories show Lipitor's ability to significantly lower cholesterol provides better results for patients.

Robert Seidman, chief pharmacy officer at health insurer Wellpoint Inc., says there will always be a place for Lipitor, but that "there will be an expanded role for generic Zocor."

Wellpoint will waive the copayment for patients on generic Zocor for four to six months. Meanwhile, pharmacy-benefits manager Express Scripts Inc. is recommending that clients take Lipitor off its preferred drug list to encourage use of generic Zocor.

"This study shows they are both excellent drugs, and as advocates of quality affordable medicine we will stress use of generic Zocor," Seidman said.

Some doctors said many patients will be fine using Zocor, but other aren't sure.

"I think the drug that lowers cholesterol the most is the better one," said Dr. Howard Weintraub, co-clinical director of Lipid Treatment and Research at New York University Medical Center.

Weintraub said the hospital received a steep discount on Zocor and removed all but the highest dose of Lipitor off its preferred list. He said many of the doctors prefer using the high dose of Lipitor to the lower doses of Zocor, though, and health insurers will have a tough time pushing the latter because effectiveness is more important to physicians than cost.