GAITHERSBURG - A federal advisory panel yesterday threw cold water on Procter & Gamble's multimillion-dollar bid to market a skin patch designed to restore the sex drive of millions of women who have lost their ovaries to surgery.
Although the Intrinsa testosterone patch offered a modest boost to the libido in the company's clinical trials, the 17-member FDA Advisory Committee for Reproductive Health Drugs voted unanimously to recommend that the agency deny approval until the company demonstrates that Intrinsa is safe for long-term use.
Although its recommendations aren't binding, the agency generally follows the committee's advice.
"We don't want to expose several million American women to [increased risk of] cardiac disease and stroke for one more sexual experience per month," said Dr. Steven Nissen, a cardiologist from the Cleveland Clinic who was on the panel.
Critics of Procter & Gamble's proposed testosterone therapy testified against approval, challenging the adequacy of the company's safety studies. They expressed surprise and elation when the committee agreed.
"I think today is a memorable day for [drug] safety," said Leonore Tiefer, a sex therapist and associate professor of psychiatry at New York University. "People are really concerned about women's health and hormones. ... This is a victory for democracy and transparency."
The FDA is already under criticism for its handling of Vioxx, an arthritis pain medication that was pulled from the market Sept. 30 because of findings linking its long-term use to heart attacks.
Committee members also expressed concern about lessons learned from estrogen replacement therapies, which were recommended for years to reduce hot flashes, bone loss and other symptoms of menopause. After decades of use, those treatments have been linked to an elevated risk of cancer and cardiovascular disease.
Procter & Gamble has been testing Intrinsa for more than two years and had hoped to get FDA approval to begin marketing it during the second half of 2005.
"In the clinical trials we were looking [for] serious adverse events. We didn't see any reason for concern," said Procter & Gamble spokeswoman Mary Johnson. The safety data from the trials spanned 18 months of use by several hundred women.
After the meeting, the company said in a statement that it would work closely with the agency "to agree on a practical approach to provide additional safety data." The drug-maker said it would continue collecting that safety data from the women for three more years.
Intrinsa was developed for the treatment of a narrow group of women - those who have lost their ovaries to surgery, are receiving estrogen therapy and have experienced personal "distress" as a result of their lowered sex drive.
The clear, circular patch, applied to the abdomen twice a week, would have been the first treatment approved by the FDA for female sexual dysfunction.
It has generated enormous public interest and, had it been approved, was expected to open the gates to a variety of similar products, including a testosterone skin spray now being tested by drug-maker Vivus.
Although the drug was strictly targeted, doctors said they anticipated many requests from women with intact ovaries who simply want to kick-start their sex lives. That would be an "off-label" use, but under FDA rules, once a drug is approved, there is no mechanism to prevent doctors from prescribing it for other purposes.
"I've already had calls from women about it," said S. Michael Plaut, a certified sex therapist and associate professor of psychiatry at the University of Maryland School of Medicine.
He said women tell him, "My libido was low, and I heard about the testosterone patch. Can I get some of that and maybe it will fix things?"
Internet "pharmacies," the same ones that cram e-mail inboxes with ads for black-market or counterfeit Viagra - were already gearing up for Intrinsa's arrival. Web sites have been buzzing with references to it as "the passion patch" and "the new female Viagra."
The FDA panel members expressed concern that Procter & Gamble's drug trials failed to anticipate such off-label demand and should have included women with intact ovaries, as well as those experiencing natural menopause.
Despite the concerns, there was considerable testimony yesterday about the need for a treatment to restore the libido of women who have lost their ovaries. Roslyn Washington told the panel her hysterectomy 10 years ago "robbed me of my sexual desire," so she "jumped at the chance to be a volunteer for the clinical trials."
The drug worked for her and she urged approval, saying "a healthy and satisfactory sex life is important to women's physical and emotional well-being."
Representatives of professional associations of sex therapists, endocrinologists and reproductive health specialists all testified to the need for alternative therapies.
But there was also considerable skepticism on the panel about how much help Intrinsa actually supplied.
Compared with a placebo, the patch offered patients in the clinical trials only one additional satisfying sexual experience per month. It provided a 5-point advantage on a 100-point scale of sexual desire, and a 6- or 7-point decline on a similar scale of personal distress.
Daniel Davis, an FDA medical officer who helped review the results, said the patch did help some women but did not bring them to levels of desire and satisfaction that are normal in the larger population.
There was also a large "placebo effect," meaning a positive response among women whose patches contained no testosterone. Slightly more than half of those with the real drug said they felt a "meaningful benefit" from the treatment, compared with just under a third of those on the placebo.