Pfizer provides safety update on Celebrex

As readers may recall, Celebrex has attracted a lot of attention in recent months. First, after the recall of Vioxx, Pfizer was successful in positioning it as an alternative to Vioxx and it received widespread praise from investors who were delighted with as much as $1 billion in sales in just three months after Vioxx was recalled on September 30, 2004. Then it received a lot of negative attention for adverse cardiovascular side effects of Celebrex. Early this year, FDA warned Pfizer for misleading Celebrex ads.

In its annual financial review this morning, Pfizer provided an update on where Celebrex stands right now. The company also announced that it will sponsor more research to assess the safety profile of Celebrex in arthritis patients. The following is the statement released by Pfizer:

"In December 2004, three controlled prevention studies involving Celebrex were halted. These three studies provide preliminary but inconsistent information. More specifically, on December 16, 2004, Pfizer learned of new information concerning two of these studies—large, well-controlled cancer-prevention studies involving patients who took high doses of Celebrex. One study, sponsored by the National Cancer Institute and involving patients taking 400 mg/day and 800mg/day of Celebrex, showed an increase in overall cardiovascular events, such as heart attack, stroke, and death, compared to placebo.

The second study, sponsored by Pfizer and involving patients taking 400 mg/day of Celebrex, did not show an increased overall cardiovascular risk over placebo.

A third large, well-controlled Alzheimer's prevention study sponsored and conducted by the National Institute on Aging, a part of the National Institutes of Health, reported preliminary information on December 20, 2004. This third study had enrolled more than 2,400 patients over the previous 3½ years to determine if Celebrex 400 mg/day or Aleve (naproxen sodium) 440 mg/day were effective treatments to prevent the development of Alzheimer's disease in people at risk of developing this serious disease.

Preliminary safety results from the study indicated in part "an apparent increase in cardiovascular and cerebrovascular events among the participants taking naproxen sodium when compared with those on placebo." No increased cardiovascular risk was seen in patients taking Celebrex relative to placebo. We believe these three studies require considerable additional analysis before any conclusions can be reached. (Related article: Pfizer refuses to recall Celebrex)

The results from the National Cancer Institute study noted above differ from the other two studies halted at about the same time and from the body of data that we and others have accumulated over time. Within this accumulated body of data, there were certain studies in which there was an increased percentage of specific cardiovascular events for patients taking Celebrex versus patients taking placebo or other drugs; in other studies, there was a decreased percentage of specific cardiovascular events.

The investigators of those studies determined at the time that the differences were not meaningful and did not establish an increased or decreased cardiovascular risk for Celebrex. All of this information was shared with appropriate regulatory authorities and will be further evaluated in the context of the ongoing regulatory review.

We will be sponsoring a major clinical study to further assess the cardiovascular profile of Celebrex in arthritis patients at high risk for cardiovascular disease."

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