Female libido drug nears approval with FDA panel’s backing

An experimental pill to treat low sexual desire in women moved closer to becoming the first such drug to be sold in the U.S. after regulatory advisers backed its approval.

The benefit of Sprout Pharmaceuticals Inc.’s flibanserin outweighs the risk of fainting caused by the treatment, Food and Drug Administration advisers voted 18-6 on Thursday. The advisers said flibanserin should only be approved with measures such as prescriber certification requirements to minimize the risk, including the drug’s interaction with alcohol that enhances the potential for harm.

“I think we all wish it was a drug that was a better one, but overall very modest benefit outweighs the real risk associated with it,” when combined with a risk-management plan, said Amy Whitaker, a panel member and assistant professor in the University of Chicago’s Department of Obstetrics and Gynecology.

The agency previously rejected the pill, which closely held Sprout proposes to call Addyi, in 2013 for its modest effect. In a report on Tuesday, FDA staff raised concern over possible danger caused by women fainting when they took the drug.

Whitaker’s comments echoed many who voted in favor of the drug because it will be the first, even though they don’t think it will be as helpful as many would like.

Deciding for themselves

Women who spoke at the meeting argued that they could determine for themselves whether the risk was worth the benefit of more sex. Others contended flibanserin has been the subject of an intense lobbying campaign backed by Sprout that painted FDA’s earlier rejection as sexist when, in fact, the drug’s effect isn’t strong.

Some women try estrogen treatments for low sexual desire, though there isn’t an approved drug on the market indicated for the condition. In contrast, after Pfizer Inc.’s blue pill Viagra was approved by the FDA in 1998, drugs to boost men’s sex lives have become ubiquitous. The blockbusters in that category, Viagra and Indianapolis-based Eli Lilly and Co.’s Cialis, generated sales of $3.98 billion last year.

Women in three clinical trials who took flibanserin recorded a median increase of 0.5 to one more satisfying sexual events each month than those who got a placebo. Women began the trials experiencing two to three satisfying sexual events a month.

Extra sex

“My patients would jump at the chance to have one extra sexual experience a month,” said Marianne Brandon, a panel member and sex therapist. “This is a quality-of-life issue. This is a mental health issue.”

Flibanserin acts on neurotransmitters that communicate information throughout the brain and body and can affect mood. The drug lowers the level of serotonin in the brain and boosts the amounts of dopamine and norepinephrine.

Sprout said the pill would be indicated for what’s called female hypoactive sexual desire disorder, defined as low libido that causes stress, in women who haven’t yet gone through menopause.

Palatin Technologies Inc. is studying the drug bremelanotide for female sexual dysfunction. Palatin began enrolling patients in a final-phase clinical trial in December, according to the company’s website.