How safe is vioxx as arthritis pain relief drug?
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. Such polyps can turn cancerous. The trial was stopped after Merck discovered study participants had double the risk of a heart attack compared to other participants taking dummy pills.
Medical experts advised patients to stop taking Vioxx and consult their doctor about alternatives.
"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 -- about 11 percent of the company's $22.49 billion in revenue that year. 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, said in a statement.
The Food and Drug Administration said there were early signs of potential problems with Vioxx. A Merck study led to warnings about heart risks being placed on the drug's label in 2001, and the FDA has been monitoring problems reported to it since then.
"This is not a total surprise," said Dr. Steven Galson, acting director of the federal Food and Drug Administration's Center for Drug Evaluation and Research.
Officials don't know yet how the drug may be causing the increased risk.
Merck, the world's third-biggest drug-maker, announced the news before the stock market opened. In midday trading on the New York Stock Exchange, Merck shares plunged $12.02, or more than 26 percent, to $33.05.
Shah said for Merck, the withdrawal of Vioxx comes "at a time when they really need to get ready for expiration" of its patent for Zocor, a drug for high cholesterol that is the company'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's announcement stands to benefit rival Pfizer Inc., the world's biggest drug-maker. The two companies have been battling for market share, with Pfizer's Celebrex arthritis drug dominating the market with about $5 billion in U.S. sales alone last year. Pfizer shares were up 30 cents to $30.48 in early trading on the NYSE.
"I think Celebrex sales are going to significantly increase," Shah said.
Vioxx and a successor drug called Arcoxia, approved in some other countries and awaiting Food and Drug Administration approval here, are part of a class of anti-inflammatory drugs heavily touted by the pharmaceutical industry as being more effective and having less side effects, particularly on the gastrointestinal system, than older drugs.
Pfizer's Celebrex and its successor drug, Bextra, which already is on the market in the United States, also are in that class, called cox-2 inhibitors.
Vioxx's removal will be a blow to hopes that it and other cox-2 inhibitors could be used to prevent cancer in people at high risk of developing it. A landmark study in 2002 showed that small, daily doses of aspirin could prevent colon cancer, and studies hinted that cox-2 inhibitors might do the same, possibly without aspirin's side effects.
All cox-2 inhibitors can raise blood pressure, but Vioxx appears to be the only one that's been linked to higher risk of heart attacks and strokes, said Galson said.
Merck said the Vioxx recall will slash about 50 cents to 60 cents a share from its earnings for the rest of this year. That includes foregone sales, write-offs of inventory held by Merck, customer returns of product previously sold and other costs of the pullback. Merck expects foregone fourth quarter sales of Vioxx of $700 million to $750 million alone.
Merck, which is based in Whitehouse Station, N.J., had previously been expecting 2004 earnings per share of $3.11 to $3.17.
Merck is scheduled to release financial results for the third quarter, which ends today, on Oct. 21.