Procter & Gamble Withdraws FDA Application for Female Testosterone Patch
Proctor & Gamble has withdrawn an FDA application for its Intrinsa testosterone patch for female sexual dysfunction -- pre-empting "what many observers saw as a likely rejection" -- and announced plans to submit a new application to FDA that will include larger clinical trials, the Wall Street Journal reports (Ellison, Wall Street Journal, 12/22).
An FDA advisory panel on Dec. 2 unanimously recommended FDA not approve Intrinsa because of long-term safety concerns related to hormone replacement therapy; FDA generally follows the advice of its panels. The agency had granted "fast-track" consideration for Intrinsa, which would have been the first of the so-called "female Viagra" therapies that are intended to increase women's sexual desire by using male hormones.
P&G was seeking approval for the drug as a treatment for what it calls "hypoactive sexual desire disorder" in women who have had their ovaries removed and experienced "surgical menopause." The patch gradually releases a small amount of testosterone, which replaces the hormones lost from ovary removal. P&G is one of about 10 companies developing female sexual dysfunction treatments; none of the other products is expected to reach the market -- which some analysts say could grow to $1 billion -- before 2006.
P&G conducted two clinical trials of Intrinsa involving a total of 1,095 surgically menopausal women. While the trial subjects noted only mild side effects, past studies have shown testosterone supplements for women can result in deepened voices, facial hair and balding. Review documents released by FDA earlier this month stated that the clinical trials for Intrinsa may have found a statistically significant benefit for Intrinsa, but it was unclear whether the results were "clinically meaningful."
FDA also said that the panel should review the potential long-term risk of using estrogen and testosterone together. Previous studies have found that hormone replacement therapies with estrogen can lead to increased risks of breast cancer and cardiovascular disease.
FDA noted that the studies included a "very small number of subjects who have been treated beyond a year" and that such short-term studies "may not provide adequate estimates of the risks of hormonal therapy." The advisory panel also noted that the studies did not take into account the potential for widespread "off-label" use of Intrinsa by younger women and women who have not had their ovaries removed or are naturally menopausal.
The panel recommended P&G conduct larger studies that include more African-American and elderly women. The company said at the time that it would continue to collect safety data from women using Intrinsa for three more years (California Healthline, 12/3).
P&G said that it plans to submit a new application that will include results from a near-completed Phase III trial of Intrinsa involving women who are naturally menopausal. P&G has not yet set a time frame for its new FDA submission, but spokesperson Melissa Johnson said the company is hoping to meet with FDA early next year. "We're just starting fresh," Johnson said (Ellison, Wall Street Journal, 12/22).