NEW YORK (AFP) - Pfizer dismissed a report on the safety of its pain reliever Bextra, but the new controversy weighed on the stock price of the US pharmaceutical giant.
Fresh questions about the drug came after a clinical study Tuesday linked Bextra to a higher incidence of heart attacks and strokes in patients who had recently undergone coronary bypass surgery.
But Pfizer said a New York Times article "draws unsubstantiated conclusions about the cardiovascular safety" of Bextra, which comes from the same class of COX-2 inhibitors as Vioxx, a former blockbuster drug withdrawn by Merck in September.
Pfizer said the report on Bextra was "based on information that has not been published in a medical journal or subject to independent scientific review."
Pfizer said an analysis published earlier this year in the American Journal of Therapeutics found no increased risk of cardiac problems associated with short-and intermediate-term treatment with Bextra.
"Pfizer has shared Bextra clinical results in a timely manner with regulatory authorities both in the United States and worldwide," said Joseph Feczko, Pfizer's president of worldwide development.
Pfizer, a Dow component, was down 1.43 percent to 27.59 in late-day trading.
Along with Pfizer's Celebrex, the company's painkillers are part a class of drugs called COX-2 inhibitors, which have come under close scrutiny in recent weeks since Merck withdrew its COX-2 inhibitor Vioxx from the market, after a clinical study showed long-term users had a notably higher risks of cardiac problems.
Tuesday's study further fanned fears that Pfizer might be forced to either relabel Bextra, warning of possible cardiac risks, or remove it from the market altogether.
Although the company has conducted a number of studies that have shown Celebrex to be safe, it has done fewer cardiovascular safety studies on Bextra.
"We think that Bextra's withdrawal is already being reflected in the stock," analyst Barbara Ryan at Deutsche Bank said, adding that it was difficult to predict whether Pfizer would actually take it off the market.
A Pfizer spokeswoman said that the company was planning a large-scale clinical trial for Bextra specifically to determine if the drug posed any cardiac risks to users.
Bextra had sales of about 700 million dollars in 2003, according to Pfizer.
At Tuesday's American Heart Association scientific meetings in New Orleans, clinical studies showed Bextra users who had recently had cardiac surgery were twice as likely to suffer a heart attack or stroke.
11/10/2004 - 21:17 GMT - AFP