Shares of pharmaceutical giant Merck slid markedly on Monday, following a report that the number of people either injured or killed by its now-recalled drug Vioxx may be much higher than previously anticipated.
Merck stock was down 2.05 percent to $31.48 in midday trading following the three-day holiday weekend.
David Graham, a leading researcher for the Food and Drug Administration, said in an interview with the Financial Times that he now estimates Vioxx may have harmed as many as 139,000 users. He had said previously that he thought the number might only be 28,000.
Graham told the newspaper that he planned to publish evidence supporting his claim in the prestigious British medical journal the Lancet. He also accused the FDA of threatening to fire him if he published his findings.
Merck abruptly withdrew Vioxx from the market on Sept. 30 after a study showed long-term users had an increased risk of suffering a heart attack or stroke. Reports have since surfaced that Merck management may have been aware as early as 1999 that Vioxx could cause cardiac problems. The arthritis and pain drug had been on the market since 1999.
The company has since been named as a defendant in almost 500 lawsuits and is currently being investigated by the Justice Department and the Securities and Exchange Commission. If Graham’s estimates are correct, Merck’s liability could be much higher than originally anticipated.
Graham, a longtime FDA employee, has become a harsh critic of both Merck and the agency, charging both with suppressing negative data that indicated Vioxx could cause cardiovascular problems.
In November, the researcher was called to testify about his concerns before a special meeting of the Senate Finance Committee. Graham told the committee that he believed the FDA had failed in its mission of keeping dangerous drugs off the market.