The Battle Over Female Viagra Ensues

Will there ever be a drug for female sexual dysfunction?

Female hands holding a bunch of blue pills
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"Hopefully, 2014 will be the year of the woman," says Irwin Goldstein, hardly masking his frustration by the U.S. Food and Drug Administration's recent rejection of a treatment for female sexual dysfunction.

As editor-in-chief of the Journal of Sexual Medicine and director of sexual medicine at Alvarado Hospital in San Diego, Goldstein has played a pivotal role in advancing various treatments to promote sexual health. He was a key player in Pfizer's development of Viagra and lead author of a landmark study on its use to treat erectile dysfunction. But while Goldstein's seen substantial progress in men's sexual health over the last several decades, women have had no such luck, he says. By his count, there are more than 20 FDA-approved drugs for sexual dysfunction in men. But for women? Except for a drug to treat dyspareunia, or painful sex, there's nothing to help a woman achieve desire, let alone an orgasm.

[Read: Vaginas and Vulvas 101.]

And yet, roughly one-third of women complain of low libido, a condition technically termed hypoactive sexual desire disorder, and struggle with emotional and relationship distress as a result. Of the pharmaceutical efforts underway to address HSDD, a drug called flibanserin has shown great promise, say sexual health experts, citing clinical benefits and only minor side effects in more than 11,000 subjects. But such improvements were considered only modest by the FDA, which rejected the drug on those grounds and is now facing an appeal by flibanserin's manufacturer, Raleigh, N.C.-based Sprout Pharmaceuticals.

"The basis of our dispute is that what the [FDA] characterizes as a modest effect in their risk/benefit analysis, we see as a meaningful effect – as the women in the trials themselves reported," Sprout president and chief operating officer Cindy Whitehead wrote in an e-mail to U.S. News.

For its part, the FDA does not comment on drugs under review, since the information belongs to the manufacturer or sponsor developing the drug, according to FDA spokeswoman Andrea Fischer. "The FDA is only able to provide information on approved drug product applications," Fischer wrote in an e-mail.

The problem pertains, in part, to FDA's reliance on "satisfying sexual events" as a benchmark for evaluation, says Sheryl Kingsberg, chief of behavioral medicine at University Hospitals Case Medical Center in Cleveland. "Many women will have desire and not act on it, and, in contrast, many women will have sexual events without necessarily having desire, so to use it as the primary endpoint was never really the best choice," she says. Both sexual desire and satisfying sexual events were the "primary endpoints" – FDA-speak for its metrics – with emotional distress as a secondary measurement.

In Sprout's appeal process, which starts next week, Whitehead says that the company plans "to focus on the hallmark characteristics of the condition – increasing sexual desire and decreasing the distress associated with its loss – to properly assess effect."

While Kingsberg concedes that measuring desire can be trickier to tackle than erectile dysfunction – "You either get an erection, or you don't" – she blames a double standard in society's "willingness to allow women to take any risk for improving their sexual health."

[Read: Sexy Tips From a Septuagenarian.]

In the case of flibanserin, these risks include being dizzy or sleepy – "the seven dwarfs of side effects," she says, as if to stress the benign nature of such symptoms. By contrast, drugs for erectile dysfunction carry a risk of death, she says, and adds that a drug approved last month to treat Peyronie's disease, a curvature of the penis, can actually rupture the penis.

"This is absolutely unfair to women," Goldstein says. "The modest benefit of this drug is exactly parallel to numerous modest-benefit drugs that have been approved for men." Furthermore, flibanserin "has been studied in more people than almost any drug submitted to the FDA ... 11 freaking thousand people." Alternatively, the drug for Peyronie's was tested in less than 2,000 patients, he says.