Gottlieb warns that a recent FDA advisory panel vote against approval of a new Cox-2 drug may portend a new stance by the FDA that will limit therapeutic options for patients out of a misguided fear of ever more subtle side effects.
Last week's recommendation by a FDA advisory panel against approving the Merck painkiller Arcoxiaalready in use in 63 countries around the worldhas dramatic implications for the future of drug research in this country. In effect, the agency is establishing new rules for approving drugs to treat some conditions for which other therapies exist, and you can bet drug companies are frantically re-examining their current R&D efforts.
The goal was once to continuously expand the pharmacopeia of available drugs, as long as each drug was safe. But, apparently, not any more. In voting 20-1 to reject Arcoxia, FDA's advisers said that for certain ailments, we have enough medicines. This will ultimately deny patients needed choices and it reflects a dangerous way of looking at drug development, safety, and, more importantly, the practice of medicine. Science is leading us toward matching specific drugs to specific patients, a therapeutic process that requires more drug variety, not less. The FDA may now be moving in the opposite direction.
Asked about Arcoxia, one of FDA's senior officials said "simply having another drug on the market . . . didn't seem to be sufficient reason" for approval. But the fact remains that all drugs that are tweaks on other medicines have different profiles. Sometimes small changes can dramatically impact how a new drug performs. But more often the therapeutic differences are subtler, mattering only for subsets of patients who only respond well to one particular version of a molecule. This is why doctors sometimes cycle a patient through multiple drugs in a "class" of medicines before finding one that works well for that person.
Merck did a poor job explaining to the FDA that fine genetic differences lead some people to respond differently to similar drugs. Merck also ignored the FDA's advice on how to show these differential benefits. The company didn't even offer a few patient testimonials to explain why Arcoxia could benefit a subset of those who don't find relief with existing medicines.
But this is no reason to be indifferent about Arcoxia's approval, because there are larger issues at stake here than whether Merck gets another drug to market. While the NSAIDS are well understood, when it comes to many other drugs it is going to be hard to specify before approval which subpopulation of patients might benefit. Benefits to subpopulations typically require non-predefined analysis of large data setsthe kind of analysis that often comes after a drug is approved, not before. Requiring a new drug to show superiority for some people to existing treatments will ultimately lead to fewer therapeutic options.