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Calculated Odds: ; Pfizer Finds Heart Attack Risk With Celebrex; Continue to Sell Drug

Posted on: Monday, 20 December 2004, 21:00 CST

NEW YORK - Pfizer Inc. said it found an increased risk of heart attacks for patients taking high dosages of its top-selling painkiller Celebrex, the same problem that led to the withdrawal of its one-time competitor Vioxx.

The company said it has no plans to remove Celebrex from the market, but the disclosure on Friday sent Pfizer's shares tumbling because of fears that it could cripple sales of what had been the most-prescribed drug for treating arthritis.

The drug industry has already been under fire for numerous high profile debacles: Merck & Co.'s withdrawal of Vioxx, the failure of Chiron Corp. to deliver half the country's flu vaccines, and disclosures that drug companies had stifled negative clinical trial data from studies examining anti-depressant use in children.

"We thought Celebrex was safe and the problem was just with Vioxx," said Dr. Richard Hayes, a New York cardiologist who is now recommending that his patients switch from Celebrex to nonprescription medicines such as Advil to treat pain. "The problem is more complex than we thought."

Market reacts to announcement

Shares of Pfizer, a member of the Dow index and the world's largest pharmaceutical maker, plunged $3.30, or 11.39 percent, to $25.68 in late afternoon trading on the New York Stock Exchange. The decline wiped out more than $25 billion of Pfizer's market value.

Both Celebrex and Vioxx are a type of drug called cox-2 inhibitors, which have become popular because of their effectiveness in treating the pain of arthritis and other ailments.

Vioxx was pulled from the market in September because it doubled patients' risk of heart attack and strokes. Both Pfizer and Merck spent heavily to advertise their products.

Cancer studies' results vary

News of the increased heart risk for patients using Celebrex came in one of two long-term cancer prevention trials.

The National Cancer Institute, which was conducting the study for Pfizer, suspended the use of Celebrex after discovering that patients taking 400mg to 800mg of the drug daily had a 2.5 times greater risk of experiencing major heart problems than those who were not.

The study was intended to show whether Celebrex could prevent precancerous growths called polyps in patients that had already had at least one such growth.

A separate cancer study found no increased heart risk with patients taking 400mg of Celebrex per day.

Dr. Joseph Feczko, president of worldwide development for Pfizer, noted that the results in the trial finding increased risk of heart attacks were not consistent with either the other cancer prevention trial or with a "large body of data" that the company had collected.

Given recent heavy criticism about the timeliness of Merck's disclosures about Vioxx, Pfizer seemed to feel compelled to rush out the news of the National Cancer Institute findings.

Pfizer chairman Henry McKinnell said in a statement the company wanted to "rapidly communicate new information to regulators, physicians and patients around the world."

Sales, studies to continue

But the early morning press release from the company did not include the news that Celebrex sales would continue; that came hours later after senior executives huddled to consider their options.

Feczko said in an intervew later in the day that sales of Celebrex will continue because "it has not shown in totality that it increases the risk of heart attacks."

He said Pfizer still hadn't seen the data from the study so he couldn't speculate on how the two trials could have such different outcomes.

He added that the company was still planning to go ahead with a previously announced study to see if Celebrex could actually help patients at high risk of heart attacks.

Sales expected to fall by 50 percent

For the first nine months of the year, worldwide sales of Celebrex more than doubled from a year earlier to $2.3 billion, accounting for 6 percent of Pfizer's total sales of $37.6 billion during that period.

Barbara Ryan, a managing director at Deutsche Bank said she expects Celebrex's sales to fall by 50 percent next year and has dropped her Pfizer 2005 earnings estimate to $2.10 a share from $2.35 a share.

"In this environment people are hysterical," said Ryan, who said all the headlines would scare people even though the drug's problem manifested itself at high doses.

Dr. Marie Griffin, an epidemiologist and drug safety expert at Vanderbilt University, said that while the Celebrex findings suggest that all cox-2 drugs have similar risks, the safety concerns may only apply to patients taking Celebrex at high doses.

She noted that the halted study was testing a 400 to 800 milligram dose. The highest recommended dose for Celebrex to treat rheumatoid patients is 400 milligrams a day while the dose for osteoarthritis patients is 200 milligrams a day.

Other drugs come into question

Griffin and two other Vanderbilt epidemiologists also raised fresh concerns about Bextra, in a letter to be published Thursday in the New England Journal of Medicine. Doctors should not prescribe the drug "except in extraordinary circumstances," they recommend.

Still, some doctors are concerned about the drug at lower doses because different patients metabolize drugs at different rates.

"You can't say as a result of this study that doses under 400 milligrams are absolutely safe," said Dr. Eric Matteson, a professor of medicine in the division of rheumatology at the Mayo Clinic in Rochester, Minn.

Matteson said his office has been besieged with calls and that he plans to review his patients' records and take some of them off the drug. Some have specifically asked to be given something else.

The withdrawal of Vioxx has been a financial and public relations disaster for Merck.

Its legal liabilities are estimated at up to $18 billion, and its shares have dropped by nearly one-third since the recall announcement in late September.

Vioxx had been a blockbuster drug for Merck, it's No. 2 earner with annual global sales of $2.5 billion, amounting to 11 percent of the company's $22.49 billion in revenue last year.

Earlier this month, the Food and Drug Administration said it was adding a warning to the labels of another Pfizer drug, Bextra, noting a risk of potential heart problems associated with the use of Bextra in people who have recently had heart bypass surgery. Bextra is also a cox-2 inhibitor type of drug.

Also on Friday, Eli Lilly & Co. said it is warning doctors to stop using its attention deficit disorder drug Strattera in patients with jaundice or laboratory evidence of liver injury.

Lilly said it was putting a boldface warning in the prescribing information that it gives doctors about the drug after two patients on the medication developed liver problems. Lilly shares fell $1.51, or 2.6 percent, to $55.89 in afternoon trading on the New York Stock Exchange.

Meanwhile, AstraZeneca PLC announced that trials of its new lung cancer drug found it didn't help patients live longer. Its shares fell $3.30, or 8.21 percent, to $36.91 on the New York Stock Exchange.

Source: Charleston Gazette, The

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