Greg Critser can feel good about this: Thursday the FDA rejected Merck's application to sell its new pain pill, Arcoxia, a Cox-2 inhibitor that Merck saw as the new Vioxx. The FDA panel's decision was unequivocal (vote was 20 to 1) , and the criticisms of the drug by FDA safety officers, who testified before the panel, were unusually harsh. The New York Times reports that one officer, Dr. David Graham, told the panel that if Arcoxia is approved for sale, “what you’re talking about is a potential public health disaster."
People with arthritis feel pain because of acids released by damaged cells. An enzyme system in the stomach, called COX, manages these and other acids. The Cox-1 system protects the stomach lining by producing acids that maintain cellular structure. The Cox-2 system produces acids that start the chain of reactions that leads to the pain response.
Traditional drugs for arthritis pain, including aspirin, inhibit both Cox systems--leading to a reduction of pain and inflammation, but also a damaged stomach lining. For people with arthritis who took anti-inflamatories regularly, this often led to gastrointestional bleeding, congestion, and ulcers.
Thus, when Cox-2 inhibitors--drugs that stopped the Cox-2 system without affecting Cox-1--like Vioxx were first marketed in the '90s, they were trumped as superaspirins that would take away the pain without hurting the gut.
So why do we even have that nasty Cox-2 enzyme system? Ohhh yea, it has lots of important functions, like preventing tiny bumps inside of arteries from exploding into blockages. But more problematic for heart health is that the Cox-1 system is also responsible for increases in blood clots, which often lead to heart attack; that is, it's good to inhibit it. So patients who switched from aspirin (6¢ per pill) to Cox-2 inhibitors ($3 per pill) were at a much higher risk of heart attack and stroke.
Between 1999 and 2003, Merck sold 92.8 million prescriptions of Vioxx. For .03% of cases, patients died from a heart attack, which doesn't sound like much--until you realize that's 27,785 people. This risk isn't for a life-saving cancer drug; Vioxx is a pain pill, whose huge customer base is exactly why ensuring its safety is so important.
The sales potential, of course, is also the reason Merck's fighting so hard to get back into the pain market. Arcoxia is a Cox-2 inhibitor and almost identical to Vioxx, and thus contributes to heart attacks for the same reasons as Vioxx. According to the FDA safety experts, Arcoxia alleviates pain no better than Aleve, yet causes three times as many heart attacks, strokes and deaths. Yea...I'd say that's a no-brainer decision.
As Martha Solonche, another member of the FDA safety panel, said: "The idea should not be that we need new drugs. The idea should be that we need better drugs.”