Swiss Study Slams Merck and FDA on VioxxNov 5, 2004 | Philadelphia Inquirer Swiss researchers are reporting today in an international medical journal that evidence was clear and overwhelming in 2000 that Vioxx doubled the rate of heart attacks and that Merck & Co. Inc. should have withdrawn the drug four years ago.
The analysis, by Peter Juni and colleagues at the University of Berne, looked at results from 18 Vioxx studies, all sponsored by Merck, which showed that 41 patients out of about 11,000 Vioxx users had suffered heart attacks by late 2000, twice the rate of those receiving a placebo or other painkillers.
The study, funded by the Swiss National Science Foundation, analyzed 18 randomized controlled Vioxx trials and 11 related observational studies. The results were published online by the British journal the Lancet. The data were based on data obtained primarily from the U.S. Food and Drug Administration.
When Merck withdrew Vioxx on Sept. 30, after a company-sponsored study found the risk of heart attack and stroke doubled in users after 18 months, Merck said the data were "unexpected."
Merck said in a news release yesterday that it had been "vigilant in monitoring and disclosing the cardiovascular safety of Vioxx" and "we absolutely disagree with any implication to the contrary."
The Swiss researchers concluded that the heart attack risk was as great in patients taking smaller 12.5-milligram and 25-milligram doses as the 50-milligram Vioxx dose. "The increased risk appears not to be dose-dependent," Juni said in telephone interview.
Researchers said the increased rate of heart attacks occurred in patients who took Vioxx for less than six months and in those who took it longer. "We don't have evidence to suggest the length of treatment influences increased risk," Juni said.
In a scathing editorial that accompanied the Swiss academic researchers' analysis, Lancet editor Richard Horton faulted Merck for "astonishing failures" in monitoring the post-marketing safety of its drug. Horton also criticized the FDA for "lethal weaknesses" in regulatory oversight.
The Lancet had commended Merck a few weeks ago for "acting promptly" to withdraw Vioxx, but said today that its praise "was premature."
"With Vioxx, Merck and the FDA acted out of ruthless shortsighted and irresponsible self-interest," the editorial says. "It's hard to see how Merck's chief executive officer, Raymond Gilmartin, can retain the confidence of the public, his company's most important constituency."
The Lancet editorial also criticized the FDA. "Too often, the FDA saw and continues to see the pharmaceutical industry as its customer a vital source of funding for its activities and not as a sector of society in need of strong regulation," it says.
The Swiss researchers said that while the data established "robust evidence" of cardiovascular risk, the data did not indicate a greater risk of stroke or cardiovascular deaths among Vioxx users. "The number of those events was too small to reliably determine the exact risk," Juni said.
In March 2000, when results of Merck's Vigor study showed that Vioxx patients had heart attack rates four or five times higher than the naproxen group, the company said the differences were due to naproxen's heart-protective effect.
However, the Swiss researchers said in the Lancet that Merck's notion was based on "hypothesis" and not on studies to support it. Researchers said the cardio-protective effect of naproxen, "if it exists, was small" and "certainly could not explain the increased heart attacks" in Vioxx users.
In its response, Merck said that data used in the Lancet analysis "are not new and are essentially consistent with the results from the combined analyses of randomized controlled clinical trials that Merck published in 2001."
What's more, Merck said, the Lancet's analysis is "not as comprehensive as our combined analyses because it fails to include several studies, including two large placebo-controlled studies that are publicly available and were summarized in the U.S. prescribing information for Vioxx."
Two things to prove
Prudential Equity Group analyst Tim Anderson said the Lancet's report "plays into the hands of plaintiffs' attorneys" and "has the ability to bolster their case against the company." However, Anderson said lawyers suing Merck must prove two things: that the company was negligent and knew about the Vioxx risks, and that the drug played a role in causing heart attacks or strokes.
Proving causation that Vioxx caused people's heart problems will be "much harder to achieve," Anderson said. "We do not think, at this time, at least, that the company's ultimate liability will sum to fen-phen-like proportions," he said, referring to the $16.6 billion Wyeth has set aside to pay for liability from its recalled diet drugs.
David Risinger, an analyst at Merrill Lynch & Co. Inc., estimates that Merck's legal costs could reach $4 billion to $18 billion, including $2.5 billion to $15.3 billion to cover "serious" cardiovascular claims.
Merck said recently that at least 300 lawsuits have been filed by people who took Vioxx. More than 20 million Americans have used Vioxx since it was introduced in 1999. With annual sales of $2.5 billion, Vioxx accounted for about 11 percent of Merck's revenue last year.
Shares of Merck fell 85 cents, or 3.1 percent, to $27.02 yesterday on the New York Stock Exchange.