Analysis: Celebrex ups heart-attack riskFeb 28, 2006 | UPI
A meta-analysis released Tuesday indicates Pfizer's Celebrex increases the risk of a heart attack by over two-fold and experts are calling for regulatory authorities to respond promptly to the new findings.
"It's an important finding that regulators need to consider in future prescriptions of this drug," Kamran Abbasi, editor of Journal of the Royal Society of Medicine, where the study was published, told United Press International.
Asked if he thought Celebrex should be taken off the market, Abbasi said, "I'm not saying that." But he added, "This is new data suggesting the risk profile of myocardial infarction is somewhat similar to the risk profile of Vioxx and we know what happened with that, so we need to be careful with this drug."
Merck withdrew Vioxx from the market in 2004 after it was linked to an increased risk of heart attacks and strokes.
Richard Beasley, the principal author of the study and a professor at New Zealand's Medical Research Institute, also thought regulatory officials should take a closer look at Celebrex.
"Our evidence shows an increased risk of heart attack in patients taking celecoxib," Beasley said. "Drug regulatory authorities need to urgently re-examine the assessment of the drug in light of these findings."
Beasley noted the myocardial infarction risk with Celebrex seen in his meta-analyses is similar to a 2.24-fold increased risk with Vioxx that was reported in a separate meta-analysis.
"It will be interesting to see if the drug regulators tighten restrictions and whether celecoxib is now withdrawn as occurred with Vioxx," he added.
However, some experts think the findings are consistent with what was already known about COX-2 inhibitors.
"I don't think this is a huge increment in our knowledge but it does continue to support the notion that there is some potential concern with COX-2 inhibitors and cardiovascular events," David Harrington, a professor in the section on cardiology at Wake Forest University School of Medicine, told UPI.
"At this point, I don't see this as sufficient grounds to change what we previously recommended about COX-2 inhibitors," added Harrington, who also serves as a spokesman for the American Heart Association.
Pfizer criticized the meta-analysis design of the study and pointed out that previous studies had not found an increased risk of heart attacks in Celebrex patients.
"It's not a well-designed study," Pfizer spokeswoman Cathy Cantone told UPI. She also noted that Celebrex had been studied in more than 40 randomized, controlled trials involving nearly 45,000 patients. Of the nearly 25,000 people who took Celebrex, the drug was not associated with an increased risk of heart stroke or cardiovascular deaths when compared with those who received nonspecific NSAIDs.
In the study, Beasley's team conducted two meta-analyses of 10 studies involving Celebrex. In the primary meta-analysis, four trials with more than 4,400 patients were reviewed and the researchers found a 2.26-fold increase in myocardial infarction in patients treated with Celebrex compared to those on placebo. There was no significant increase in risk in composite cardiovascular events, cardiovascular deaths or stroke in the Celebrex patients.
The secondary meta-analysis included six studies involving a total of 12,780 patients treated with placebo, diclofenac, ibuprofen, paracetamol or Celebrex. The Celebrex patients had a 1.88-fold increased risk of myocardial infarction.
The study comes on the heels of a Pfizer-funded study released last week that found no increased risk of cardiovascular or cerebrovascular problems in Celebrex patients compared to those who received naproxen or diclofenac.
However, that study, which is called SUCCESS-I and appeared in the March issue of the American Journal of Medicine, was not designed to look at those issues and Pfizer backed away from giving Celebrex the all clear. Instead, the company said it was waiting on the results of the PRECISION trial, which is slated to begin later this year.
There are other COX-2's in the pipeline, including one GlaxoSmithKline is developing and Novartis' Prexige, that could offer some competition in the coming years, but some analysts think Celebrex will likely retain the predominant share of the market if it is not withdrawn.