FDA asks for more trials of Sprout’s drug for low female libido

The U.S. Food and Drug Administration has denied an appeal by Sprout Pharmaceuticals to approve its experimental drug for low female sexual desire but offered a potential pathway to approval, the company said on Tuesday.

The FDA has asked for three additional studies, two to test the drug’s interaction with other drugs, and a third to simulate driving since nearly 10 percent of women in clinical trials became sleepy while taking the drug, flibanserin.

Privately held Sprout said it welcomed the FDA’s guidance and views it as “a significant step” toward approving flibanserin, a once-a-day treatment for hypoactive sexual desire disorder (HSDD).

The FDA rejected flibanserin last year saying its effects were “modest” and did not outweigh side effects such as dizziness, nausea and fatigue. Sprout appealed the decision, and women’s groups have been pressing the FDA to approve the product, claiming gender bias in the drug approval process.

The FDA has approved 24 drugs to treat male sexual dysfunction, and none for women.

On January 28 representatives from eight women’s advocacy groups, including the National Organization for Women, the Center for Health and Gender Equity, Jewish Women International and the National Council of Women’s Organizations met with Dr. Janet Woodcock, head of the FDA’s pharmaceuticals division.

They expressed their concern that the requirements for approval for flibanserin exceeded those required for male erectile dysfunction drugs and that the risk versus benefit assessment seems “inconsistent” with that applied to male drugs.

“We see this not only as an important unmet women’s health issue, but an inflection point for the agency to ensure that similar standards are applied for drug approvals in conditions uniquely affecting women,” the group wrote in a January 30 follow-up letter to Woodcock.

A number of members of Congress have been part of the lobbying effort. In January, Democratic lawmakers Debbie Wasserman Schultz, Chellie Pingree, Nita Lowey and Louise Slaughter - wrote to FDA Commissioner Margaret Hamburg urging the agency to give “careful review” to the flibanserin data and apply “the same standards of consideration given to the approved drugs for men in your risk/benefit evaluation.”

Female sexual dysfunction has been identified by the FDA as one of several therapeutic areas that it plans to focus on as part of its patient-focused drug development program, which aims to gather patients’ perspectives on their condition and potential treatments.

Following the FDA’s original rejection of the drug, Sprout’s president, Cindy Whitehead, said that the effect the FDA considers modest, “we see as meaningful.”

“It is true that flibanserin does not cause hypersexuality, but by that definition, modest would be what we’re aiming for,” she said.

Sprout said it expects to resubmit its application by the third quarter.

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By Toni Clarke