Pfizer Analysis of Internal Studies Shows Celebrex Is Safe

Pfizer on Friday told FDA officials that an analysis of 41 clinical trials involving its COX-2 inhibitor Celebrex showed no increased risk of cardiovascular problems among participants, the New York Times reports. The analysis involved trials including 44,000 patients but did not take into account data from studies conducted by independent researchers or other pharmaceutical companies, including an NIH study that was stopped in December 2004 after it showed high doses of Celebrex tripled the risk of heart attack and stroke.

Joseph Feczko, Pfizer's president for worldwide development, said that while a few studies have shown an association between Celebrex and the company's other COX-2 inhibitor, Bextra, and an increased risk of heart problems, "the overwhelming preponderance of evidence" indicates the medications are safe. He noted that there is less evidence to support Bextra's safety because Pfizer's clinical trials were short term (Harris/Berenson, New York Times, 2/5). Pfizer's analysis did show patients had an increased risk of heart attack compared with those taking nonsteroidal anti-inflammatory medications, such as naproxen. However, the risk was offset by a decreased risk of stroke.

Feczko said that while he could not explain why Celebrex had different outcomes with heart attacks and strokes, the point was that the cardiovascular risk "is not a class effect." He added, "What we have is different from what we saw with Vioxx," Merck's COX-2 inhibitor that increased patients' risk of heart attack and stroke (Agovino, AP/Pittsburgh Post-Gazette, 2/4).

FDA included Pfizer's analysis with documents the agency released publicly on Friday. On Feb. 16, the agency is scheduled to begin a series of hearings to determine "whether there should be continued marketing of COX-2" inhibitors, according to an FDA summary of the documents (New York Times, 2/5).

The "latest revelation" about problems linked to Celebrex "strengthens the case for reforming" the FDA approval and monitoring systems, a Boston Globe editorial states. The editorial says medications that are "not lifesaving and will be taken for chronic conditions" should undergo more extensive pre-approval testing and pharmaceutical companies should be "required to reveal publicly all studies on new drugs as soon as they are done."

In addition, the editorial states that FDA should better monitor pharmaceutical company ads and that funding for the FDA Office of Drug Safety should be increased to help it act autonomously and without the influence of "FDA decision-makers who give the initial green light to new drugs." The Globe concludes that "[w]ithout changes of this kind, more drugs with harmful side effects will find their way into Americans' medicine cabinets" (Boston Globe, 2/6).