Pharmaceutical giant Merck & Co. is pulling its blockbuster arthritis drug Vioxx from the market worldwide because new data from a clinical trial found an increased risk of heart attack and stroke.
Whitehouse Station-based Merck said Thursday that data from the trial showed the increased risk of heart attack and other cardiovascular complications began 18 months after patients started taking Vioxx.
The data comes from a three-year study aimed at showing that Vioxx at a 25 milligram dose prevents recurrence of polyps in the colon and rectum. The trial was stopped after Merck discovered the higher heart risk compared to patients taking dummy pills.
"It's a disaster for Merck, coming at the worst time," said independent health care analyst Hemant Shah of HKS & Co. in Warren, N.J.
Vioxx is one of Merck's most important drugs, with $2.5 billion in sales in 2003. But sales dipped 18 percent in the second quarter of this year to $653 million, partly due to increasing concerns about the drug's safety.
"We're taking this action because we believe it best serves the interest of patients," Ray V. Gilmartin, Merck's chairman, president and chief executive officer, said in a prepared statement.
"Although we believe it would have been possible to continue to market Vioxx with labeling that would incorporate these new data, given the availability of alternative therapies and the questions raised by the data, we concluded that a voluntary withdrawal is the responsible course to take," he said.
The analyst Shah said the withdrawal of Vioxx comes "at a time when they really need to get ready for expiration" of its patent for Zocor, a high cholesterol drug which is Merck's top-selling drug. Zocor loses patent protection early in 2006 and sales are expected to plunge when generic competition begins. In an effort to replace those revenues, Merck recently launched a drug with partner Schering-Plough Corp., Vytorin that combines Zocor and Schering-Plough's Zetia to attack cholesterol levels in two complementary ways.
"This makes it almost inevitable for the company to find a merger partner for them to continue to grow," Shah said.
Merck, the world's third-biggest drug maker, announced the news before the stock market opened. In pre-market activity on the New York Stock Exchange, Merck shares plunged 14.1 percent, or $6.35, to $38.72.
Merck is scheduled to release financial results for the third quarter, which ends Thursday, on Oct. 21.