Cox-2 Inhibitors have been a major therapeutic class since their introduction in the late 1990s. Led by Pfizer’s Celebrex and Merck’s Vioxx, the pain-relievers are roughly a $6bn market–not as large as the statin market but nothing to sneeze at. These drugs have been aimed primarily at arthritis’ sufferers, in particular at the substantial minority who have had stomach problems from regimes using traditional painkillers like ibuprofen or NSAIDs. But in recent years the growth of the market has slowed due to several setbacks, including a 2001 JAMA report of cardiovascular side-effects, and suggestions that COX-2 inhibitors might impede blood vessel creation (for wound repair), and also suggestions that Celebrex wasn’t as good for gastro-irritation as was promised. Additionally two new Cox-2 inhibitors have had their approval delayed. These are Prexige from Novartis that won’t appear in the US until 2005 although it is already approved in the UK, and Arcoxia, Merck’s new COX-2 inhibitor.
But looked at another way, COX-2 inhibitors have been an example of big pharma’s ability to change patient and physician behavior. Don’t forget that this class of drugs doesn’t offer any superior pain relief than ibuprofen or NSAIDs, and costs seven to ten times as much. The reason for their success is that they reduce associated stomach irritation. Of course that means that people who don’t have that kind of irritation from long-term ibuprofen use shouldn’t need to go on COX-2 inhibitors, at least until they have some other symptom or reach a certain age (often 60 is used). So the PBMs, health plans and other formulary enforcers have a tricky job. They have to battle the weight of the pharma DTC advertising and physician promotion in order to get patients to stay with the OTC or generics.
Well it appears that they are not succeeding. A new report in The American Journal of Managed Care from PBM, Express Scripts, looked at new users of COX-2 in 2000 at a PPO. 65% had no indication of being at risk for gastrointestinal events. Furthermore 68% had not tried an NSAID first. In the study only 18% of the population were over 60–one of the minimum required indicators for going straight to COX-2. In other words, in order to be somewhat conservative about costs in a sub-Medicare populations almost everyone should be first trying NSAIDs or ibuprofen. In fact over 60% are going straight to COX-2 inhibitors.
You can look at this two ways. Perhaps there should be a 60% reduction in COX-2 use. Or perhaps PBMs and formularies are ineffective in the face of the pharmas. Either way what’s happening now is presumably not the right answer. Given that there’ll be new COX-2 drugs on the market soon and PBMs are going to be used by Medicare (Maybe!) to restrict Medicare drug costs, the question of how this gets resolved is key for the future of PBMs’ credibility.