An advisory panel of the United States Food and Drug Administration (FDA) has rejected pharmaceutical giant Merck's bid to market Arcoxia, a new osteoarthritis medication following concerns that it may carry cardiovascular risks.
Osteoarthritis is a joint disease that mostly affects cartilage. Cartilage is the slippery tissue that covers the ends of bones in a joint.
While healthy cartilage allows bones to glide over each other and helps absorb shock of movement, in osteoarthritis, the top layer of cartilage breaks down and wears away.
This allows bones under the cartilage to rub together. The rubbing causes pain, swelling, and loss of motion of the joint.
Merck's Arcoxia is in the class of non-steroidal anti-inflammatory drugs (NSAIDs) known as COX-2 inhibitors.
It had to pull yet another CoX-2 inhibitor Vioxx from the US market in 2004, also following evidence that it increased the patients' risk of heart attacks and strokes.
G.D.Searle and Company too withdrew a COX-2 inhibitor, Bextra because of similar concerns.
These newly developed drugs for treatment of inflammation selectively block an enzyme called COX-2. Blocking this enzyme impedes the production of the chemical messengers (prostaglandins) that cause the pain and swelling resulting from arthritis inflammation.
And they are supposed to be gentler on the stomach, making it easier for patients than traditional pain relievers. But then one has to contend with serious side-effects.
The FDA advisory panel on Thursday rejected by a 20-to-1 margin the Merck's new formulation, Arcoxia.
"We got what appears to be a very clear vote advising us against approval," said Robert Meyer, director of FDA's office of drug evaluation.
Dr. David Graham, a leading critic of the now withdrawn Vioxx, told the panel that Arcoxia might increase substantially the risk of stroke and heart attack and was no more effective for pain relief than other medicines in the same class. "What you're talking about is a potential public health disaster," he said.
COX-2 drugs have never been shown to be better pain relievers than older NSAIDs like ibuprofen. But doctors eagerly prescribed them in part because they tend to cause fewer ulcers and less gastrointestinal bleeding.
There is nothing special about this drug that would warrant giving it to patients and putting them at risk of cardiovascular death, said Dr.David Felson, a professor of medicine at the Boston University School of Medicine and a member of the advisory panel.
Arcoxia has been sold for the past five years in Europe and in dozens of other countries around the world. The drug represented Merck's first bid to return to the once-lucrative COX-2 pain drug market in the United States.
The company had hoped to convince experts that the drug was a safer and more effective pain reliever than related drugs.
Patients with osteoarthritis want and deserve additional treatment options, said Scott Korn, Merck's executive director of regulatory affairs.
But experts and some FDA officials criticized Merck for using what they called poorly designed scientific studies in an attempt to put Arcoxia in the best possible light.
Bruce Psaty, director of the cardiovascular health research unit at the University of Washington, says manufacturers can "rig" trials by comparing their drug to one known to be relatively weak. "It makes their drug look good or comparable but doesn't provide much in useful public health information," he says.
More than 20 NSAIDs were already on the U.S. market, it has been pointed out.
The idea should not be that we need new drugs. The idea should be that we need better drugs, said Martha Solanche, a consumer representative on the advisory panel.