FDA Panel Rejects Vioxx-Like Pain Drug

April 12, 2007 -- A federal advisory panel on Thursday rejected Merck's bid to market a new osteoarthritis medication similar to Vioxx, a drug the company pulled from the U.S. market in 2004 because it put patients at risk for heart attacks and strokes.

The decision, delivered in a 20 to 1 vote, makes it highly unlikely that the FDA will approve the drug, called Arcoxia.

Arcoxia is in the class of nonsteroidal anti-inflammatory drugs (NSAIDs) known as Cox-2 inhibitors, which includes Vioxx and Bextra -- both removed from U.S. pharmacies -- as well as Celebrex, which is still on the market. Cox-2 drugs have a lower risk for stomach ulcers and gastrointestinal bleeding than other NSAIDs such as aspirin and ibuprofen.

Arcoxia has been sold for the last five years in Europe and in dozens of countries around the world. The drug represented Merck's first attempt to return to the once-lucrative Cox-2 pain drug market in the U.S.

The company had hoped to convince experts that the drug was a better pain drug than related drugs -- and also that it was safer.

"Patients with osteoarthritis want and deserve additional treatment options," said Scott Korn, MD, Merck's executive director of regulatory affairs.

But experts and some FDA officials criticized Merck for using poorly designed scientific studies in an attempt to put Arcoxia in the best possible light.

Panel member David Felson, MD, noted that more than roughly 20 nonsteroidal anti-inflammatory drugs are already on the market.

"A new drug has to have some reason why you would put it in the top six of your rotation or it's not going to have much of an effect," said Felson, a professor of medicine at the Boston University School of Medicine.

After hearing Merck's results, Felson said he'd concluded that "20 is enough."

Robert Shibuya, an FDA medical officer, told experts that studies in nearly 4,000 patients left "little doubt" that Arcoxia is an effective pain reliever. But in question was the drug's potential, like similar drugs, to increase risk for cardiovascular problems like heart attacks and stroke in millions of potential users.

Heart Risks

FDA Safety Officer David Graham, MD, presented an analysis estimating that for every 1 million patients, between 6,800 and 30,000 additional heart attacks would occur per year if the patients were treated with Arcoxia instead of a widely available older NSAID, naproxen (brand names include Aleve and Naprosyn).

"What you're talking about is a potential public health disaster," said Graham, who played a key role in publicizing safety problems with other Cox-2 drugs in 2004. "And then we'll have a repeat of what we had with [Vioxx]."

In a statement released after the vote, a Merck official said the company was disappointed in the panel's recommendation. Peter Kim, PhD, president of Merck Research Laboratories, said, "We are committed to continuing to work with the FDA to discuss the application in an effort to gain U.S. regulatory approval for Arcoxia."