Marketed as Vyleesi, also known as bremelanotide, the medication is a shot that comes in a push pen device that can be self-administered as needed for premenopausal women who experience marked distress as a result of low sexual desire.
"There are women who, for no known reason, have reduced sexual desire that causes marked distress, and who can benefit from safe and effective pharmacologic treatment," said Hylton Joffe, director of the FDA Center for Drug Evaluation and Research's Division of Bone, Reproductive and Urologic Products. "Today's approval provides women with another treatment option for this condition. As part of the FDA's commitment to protect and advance the health of women, we'll continue to support the development of safe and effective treatments for female sexual dysfunction."
Julie Krop, chief medical officer for AMAG Pharmaceuticals Inc., which makes the drug, recommends using it about 45 minutes before the "anticipation" of intimacy. She said the drug is a synthetic hormone that activates key brain receptors involved in sexual responses by reducing inhibition and increasing what's known as neural excitation.
"It's not just about low sexual desire, but about how it impacts patients' relationships and quality of life," Krop said in an interview. "These women are really suffering."
The drug is intended to be a treatment for hypoactive sexual desire disorder, or HSDD, which the medical community recognizes can be a serious issue. The FDA acknowledged that it's not clear how the drug works.
And there's disagreement about whether drugs are the right approach - low sexual desire can be a result of numerous psychological, physiological or external factors including stress - and how widespread the condition really is.
Vyleesi activates certain receptors, but the mechanism by which it improves sexual desire and related distress is unknown. Patients inject Vyleesi under the skin of the abdomen or thigh at least 45 minutes before anticipated sexual activity. Patients should not use more than one dose within 24 hours or more than eight doses per month.
One study estimated that as many as 1 out of 10 women may have low sexual desire, and the FDA several years ago convened a meeting to better understand the impact of female sexual dysfunction.
Critics have pointed out that nearly all of the doctors on the recent panel that defined HSDD were consultants or advisory board members for Sprout Pharmaceuticals, the drugmaker that introduced the world to the first women's libido drug, Addyi, also known as flibanserin, in 2015.
On Vyleesi, which was approved Friday, several women's health advocates said more information needed to be known before approval. They noted that the FDA had not convened an advisory panel to scrutinize the drug.
"It is unfortunate that the FDA decided to approve this drug despite the skimpy peer-reviewed data and complete lack of long-use safety information," said Diana Zuckerman, president of the National Center for Health Research. "The good news is that it doesn't need to be taken every day, the way Addyi does. The bad news is that the public can't have confidence in the safety of the drug because we don't have access to long-term safety information about it."
Cynthia Pearson, executive director of the National Women's Health Network, said the group was "disappointed" by the approval and said that women "simply do not have enough information to make an informed decision about whether the drug is safe and effective."
Earlier this year, Sprout caused a stir with a campaign that told women they have a "right to desire." "Why aren't we talking about it?" the ads asked. Women's groups that focus on access to birth control and abortion took issue with the idea of invoking civil rights language for what they essentially called a sales pitch.
AMAG, which is based in Waltham, Massachusetts, has done its own disease awareness outreach about HSDD this year through its Instagram and Facebook "unblush" campaign that told women that "HSDD is nothing to blush about."
Addyi never really took off, partly because it is a daily pill that takes a while to work, and the product carries a "black box" label that warned of serious side effects such as dizziness and low blood pressure when the drug was taken with alcohol. The FDA softened the warning this April to advise women that while complications may still exist with alcohol, they needn't avoid it entirely. In May, Sprout released the results of three safety studies that appeared to bolster the idea that the link to side effects was not as clear as previously thought.
The effectiveness and safety of Vyleesi were studied in two 24-week, randomized, double-blind, placebo-controlled trials in more than 1,200 premenopausal women with HSDD. Most patients used Vyleesi two or three times per month and no more than once a week. In these trials, about 25% of patients treated with Vyleesi had an increase in their sexual desire score compared to about 17 percent of those who took placebo.
About 35% of the patients treated with Vyleesi had a decrease of one or more in their distress score compared to about 31% of those who took placebo, the FDA said. Side effects during the trial included headaches, flushing and nausea.
Initial consumer uptake of Vyleesi is expected to be slow, according to industry analysts. But some expect revenue to increase significantly over time, hitting as much as $150 million by 2030, according to Barclay's.