A spate of recent activity at the FDA seems to indicate that the bar for approval of bona fide cognitive enhancers will be quite high, at least if one considers the balance between risk and benefit. The latest in a series of advisory committee recommendations came on Thursday when the weight loss drug lorcaserin was voted down 9-to-5 [These advisory committee recommendations are different than FDA rulings, but they are influential and it is rare for the FDA to go against the advice that it receives from these expert panels.] The safety issue was quite modest, and given the seriousness of obesity as a health issue in the USA, the setback is all that much more surprising. Writing about the vote in the New York Times, Andrew Pollack points out that,
“the F.D.A. is very safety conscious in this area since the drugs will be taken by millions of people”.
Perhaps the biggest sticking point was that the drug met only one of two FDA benchmarks for weight-loss drugs and it did so by only a small margin. In July, again citing safety concerns, the same committee voted against approval of another weight loss drug, Qnexa, even though that drug produced a much greater weight loss than lorcaserin. A different committee voted unanimously against approval of flibanserin, a drug that was being developed for hypoactive sexual desire disorder in women, once again citing the thin benefit even though side effects were modest.
What is most relevant to the development of cognitive enhancers is that both in the case of weight loss and hypoactive sexual desire disorder the FDA has put out guidance for industry to provide clarity about the kinds of evidence it would find compelling, thereby hastening the efficiency of drug development. The FDA has not issued any guidance on cognitive enhancement, and this makes the regulatory environment even more challenging for the pharmaceutical industry.
There may be relevant compounds in the pipeline, and new targets that pop up on a regular basis, but without some encouragement from the regulatory authorities, the likelihood of a new cognitive enhancer being approved for use seems further off than ever.
Link to New York Times article on lorcaserin