More testing urged for 'female Viagra'

GAITHERSBURG, Md. -- A hormone patch intended to improve the sex lives of women should not be approved now by the US Food and Drug Administration, an advisory committee of scientists recommended yesterday in a unanimous vote.

Citing concerns about possible cardiovascular and breast cancer risks, the panel recommended that Intrinsa, a testosterone patch popularly dubbed a ''female Viagra," go through more clinical trials, including longer-term studies that involve more women, to ensure it is safe for multiyear use.

Throughout a daylong hearing, members of the advisory committee and FDA drug reviewers made reference to the Women's Health Initiative, an influential study that in 2002 showed that hormone replacement therapy with estrogen, a menopause treatment taken by millions of women, caused an increased long-term risk of cardiovascular disease, stroke, and breast cancer.

Given the known connections between heart disease and another hormone, ''I don't want to expose millions of women to heart attack and stroke . . . for one more episode of sex per month," said Dr. Steven Nissen, a cardiology specialist on the panel.

In studies presented to the panel by Intrinsa's maker, Procter and Gamble, women taking the patch experienced an average of one more sexual episode per month than those who were given a patch without the hormone, and they reported less distress and more sexual desire. Dr. Jan L. Shifren, director of the menopause program at Massachusetts General Hospital, said surveys showed that women taking Intrinsa went from seldom feeling desire to sometimes feeling it, and from often being distressed about sex to sometimes feeling distressed.

The committee voted, 14-3, that the drug imparted a ''clinically meaningful benefit" above placebo, showing that they believed the drug was generally effective.

Intrinsa is the first drug to be considered for female sexual dysfunction, and the FDA put it on its ''fast track" review process because no other therapies had been approved for female sexual dysfunction. Estimates vary, but a widely cited and controversial 1999 study concluded that 43 percent of American women suffer from the disorder.

The company sought approval of the patch, which is worn on the abdomen, for a fraction of that group -- women who had had their ovaries removed, who were also taking estrogen therapy, and felt distressed by the fact that after surgery they lacked sexual desire. Testosterone is produced by the ovaries, and the hormone is thought to have a role in creating sexual desire.

Doctors on the committee had deep concerns about the long-term safety of the patch in that small group -- and within a larger population of women who might seek to use the drug ''off label" if it was approved by the FDA and then widely advertised to consumers -- as has occurred with Viagra, the male erectile dysfunction drug. The committee recommended studies of larger groups of women over longer periods of time, with better efforts to test the patch in underrepresented African-American and elderly women.

Some panel members suggested studies for risk factors of diseases that take years to develop. If the FDA recommended that the company undertake such studies, they could take years to complete.

Procter and Gamble presented long-term data on only 127 women who had been wearing the patch for 18 months. ''It is not uncommon to have unanswered questions at approval," Joan M. Meyer, the company's senior director of new drug development, told the committee.

But members of consumer and medical groups who testified at the hearing cautioned that it is a crucial time for the FDA to monitor drug safety carefully, after serious side effects were discovered with other drugs only after the medications were approved. Among those cases were an increased risk of heart attacks found among patients taking Merck's painkiller Vioxx, and a small risk of suicidal thoughts or behavior in children taking antidepressants. Vioxx was withdrawn by Merck, and the FDA has ordered warning labels placed on antidepressants.

In their presentations on Intrinsa, FDA reviewers struck a cautionary note. Dr. Lisa Soule, a medical officer in the division of reproductive and urologic drugs, listed a number of long-term safety concerns.

Lorraine J. Tulman, the panel's consumer representative, raised questions about the fundamental basis of the drug: ''What is the mechanism, for testosterone to produce the effect of improving a woman's sex life?"

Top administrators at the FDA expect to reach a decision on Intrinsa by the end of the month, said Kathleen Quinn, an FDA spokeswoman. She said the agency usually follows the recommendations of its advisory commitees.

Carolyn Johnson can be reached at cjohnson@globe.com.