This doesn’t sound sexy, but trust me, it is: On Thursday, a group of specialists in reproductive and urological health are to gather in a bland meeting room outside Washington, D.C., to consider the safety and effectiveness of an experimental drug currently known only by its prosaic chemical name: flibanserin.
Flibanserin might well be the pharmaceutical industry’s holy grail: a drug that would make women whose sex drives have driven off somewhere want and enjoy sex again.
The drug’s sponsor, North Carolina-based Sprout Pharmaceuticals, is hoping the Food and Drug Administration will approve flibanserin for marketing in the United States as the first-ever nonhormonal treatment for “hypoactive sexual desire disorder,” or HSDD, in premenopausal women.
It’s not the first time flibanserin has come before the FDA or its panel of independent experts. In 2010, when the German pharmaceutical company Boehringer Ingelheim asked the agency to consider approval, an advisory panel voted 10-1 to recommend against its approval, citing scant evidence of the drug’s effectiveness. The FDA denied its blessing and ordered Boehringer Ingelheim – and Sprout Pharmaceuticals, who took on the role of the drug’s sponsor – to conduct further trials to demonstrate the drug’s safety.
Some have called flibanserin “pink Viagra” – a drug that could do for women’s sex lives (or at least younger women’s sex lives) what medications for erectile dysfunction have done for men’s.
Experts in female sexuality scoff at the notion that a 100-milligram pill, taken daily at bedtime, will turn women’s sexual desires on with the ease of flipping a light switch. But hypoactive sexual desire is a complaint that afflicts some 4.8 million premenopausal women, according to Sprout Pharmaceuticals. And it is a complaint for which their physicians have had essentially nothing to offer.
The FDA staff, in a report on flibanserin posted to the agency’s website Wednesday in advance of Thursday’s meeting, calls the treatment of HSDD “clearly an area of unmet medical need.” The drug works on the brain’s hydroxytryptamine receptors, which are thought to malfunction in major depression as well as hypoactive sexual desire disorder, and to increase levels of serotonin in the brain.
In the coming months, the FDA will weigh such factors as the drug’s safety if used by large numbers of women, its effectiveness as shown in clinical trials, and whether other treatments exist for the complaint flibanserin aims to treat. And it will weigh heavily the recommendation it receives from its advisory panel on bone, reproductive and urological drugs.
In clinical trials conducted by Sprout Pharmaceuticals, women whose age averaged 36 and took the medication for five months reported they had increased sexual desire, reduced distress and an increase in “sexually satisfying events” compared with women taking a placebo. Flibanserin offers “meaningful and quantifiable benefits to HSDD patients,” a representative from Sprout will tell the FDA’s advisory committee Thursday.
At what cost, however, is a source of concern.
On Wednesday, the National Women’s Health Network, a nonprofit activist group, called on the FDA to deny approval of flibanserin, citing “significant known and unknown adverse reactions, drug-drug interactions and side effects” that outweigh the drug’s benefits.
Chief among flibanserin’s safety concerns are clinical trial evidence that some women taking it are at higher risk of low blood pressure and fainting while on the drug. The FDA is concerned that the risk is heightened when flibanserin is taken in conjunction with alcohol.
Given the prevalence of alcohol use in the United States, the FDA asked members of its advisory panel to consider whether “avoiding alcohol indefinitely while using flibanserin” is a realistic – or necessary – requirement to make of women taking the drug.
Cindy Pearson, executive director of the National Women’s Health Network, suggested Wednesday that inattention to women’s health may have slowed progress toward finding a drug to address some women’s distressing sexual problems. But, she added, “based on our review of the data about flibanserin, it’s clear the problem with this drug is not gender bias at the FDA but rather the drug itself.”
If flibanserin receives the FDA’s go-ahead, the range of women for whom Sprout Pharmaceuticals would be allowed to market the drug would be circumscribed. The medication would not be “indicated” – or judged by the FDA to be safe and effective – for women whose sexual desire has ebbed due to menopausal changes, for women who have lost sexual interest after giving birth, or for women whose low libido is attributable to physical disease or relationship troubles.
