NEW YORK – Pfizer Inc. said it found an increased risk of heart attacks and strokes for patients taking high dosages of its top-selling arthritis 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.
Acting FDA Commissioner Lester Crawford said the government is advising physicians to consider prescribing drugs other than Celebrex to their patients.
“We’re leaving open all regulatory decisions as we move forward. But we do not have a decision on the fate of the product,” said Crawford, during a press briefing. “We do have great concern about this product (Celebrex) and the class of products,”
But doctors have already been besieged with phone calls from worried patients and say they will curtail writing prescriptions for the drug. Shares of Pfizer, a member of the Dow index and the world’s largest pharmaceutical maker, plunged $3.23, or 11.15 percent, to $25.75 in late afternoon trading on the New York Stock Exchange. The decline wiped out almost $25 billion of Pfizer’s market value.
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.
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.
National Institutes of Health director Dr. Elias Zerhouni said that he ordered a full review of the more than 40 agency-supported studies involving cox-2 inhibitors.
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, said patients in the clinical trial taking 800 milligrams of Celebrex had a 3.4 times greater risk of cardiovascular events compared to a placebo. For patients in the trial taking 400 milligrams of Celebrex the risk was 2.5 times greater. The average duration of treatment in the trial was 33 months.
In the 2,000-patient study, 15 individuals taking 400 milligrams, 20 patients taking 800 milligrams and six patients on placebo suffered either a cardiac-related death, heart attack or stroke.
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 done by Pfizer found no increased heart risk with patients taking 400 milligrams 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.
Feczko said in an interview 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 National Cancer Institute 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.
Finding patients to participate in such a study will be a challenge because doctors are now saying patients at high risk of heart attacks should avoid taking Celebrex.
Dr. Garret A. FitzGerald, who has been critical of cox-2 inhibitors, said he doesn’t believe Pfizer should take Celebrex off market but has to work hard to find the appropriate patient population for the drug. Cox-2s were developed to be gentler on the stomach than older pain relievers called nonsteroidal anti-inflammatory drugs, such as naproxen, that are associated with gastrointestinal problems. But unlike Vioxx, Celebrex was never statistically proven to decrease the risk of ulcers. It also doesn’t reduce pain better than older drugs.
“The challenge for Pfizer now is to show why this drug should be chosen,” said FitzGerald, a cardiologist at the University of Pennsylvania.
FitzGerald said Pfizer’s huge marketing push behind the drug accounted for its dramatic use. Last year, Pfizer spent $87.6 million to advertise Celebrex. It recently launched a new campaign for the drug and placed full-page ads in newspapers touting Celebrex’s safety in the wake of the Vioxx recall.
FitzGerald said he believed the news has implications for cox-2 inhibitors such as those under development at Merck and Novartis.
“The trial concludes the controversy about whether there is a class effect of these drugs. Now there is clear evidence of it,” said FitzGerald. “You would need to believe the earth is flat if you thought this was just a coincidence.”
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.
Moody’s Investors Service revised its outlook on Pfizer to negative from stable because it believes Celebrex use may decline as the controversy about the drug class increases. Moreover, it said the likelihood that the drug could be pulled from the market may have risen and Pfizer’s litigation may increase.
Moody’s points out that this is happening when Pfizer is facing high exposure to patent expirations, with 30 percent to 35 percent of its revenues coming off patent through 2007. The combination means Pfizer may not be able to maintain its triple A rating, Moody’s said.
Dr. Marie Griffin, an epidemiologist and drug safety expert at Vanderbilt University, said concerns may only apply to patients taking Celebrex at high doses.
Talk to us
> Give us your news tips.
> Send us a letter to the editor.
> More Herald contact information.
