Drug giant Merck is in trouble again. The Federal Drug Administration of U.S (FDA) has rejected its proposed successor(Arcoxia) to the drug Vioxx, that was pulled out of the market due to safety reasons.
The arthritis drug Arcoxia which belongs to the same class of drugs as Vioxx ,was voted out 20-1 by an advisory panel two weeks back.
Merck pulled Vioxx from the market in September 2004 after research showed that it doubled the risk of heart attacks and strokes. This move triggered an avalanche of lawsuits and a nosedive for Merck's stock prices.
Yet, despite safety concerns in the United States, Arcoxia is still on sale in 63 other countries. Merck officials have confirmed that they intend to keep working to get it on the U.S. market.
These drugs are meant for the treatment of arthritic diseases. Osteoarthritis is a joint disease that mostly affects cartilage, 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.
These newly developed drugs for treatment of inflammation selectively block an enzyme called COX-2. Blocking this enzyme blocks the production of the chemical messengers (prostaglandins) that cause the pain and swelling resulting from arthritis inflammation.
Though they are supposed to be gentler on the stomach, making it easier for patients than traditional pain relievers, one has to contend with serious side effects.
Dr. David Graham, a leading critic of the now withdrawn Vioxx, told the panel that Arcoxia might increase the risk of stroke and heart attack and was no more effective for pain relief than other medicines in the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. Yet 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, says 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, says Scott Korn, Merck's executive director of regulatory affairs.
Yet 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.
Says Martha Solanche, a consumer representative on the advisory panel: "The idea should not be that we need new drugs. The idea should be that we need better drugs."