FDA Advisory Panel To Consider Proctor & Gamble Testosterone Patch for Women
An FDA advisory committee on Thursday will meet to consider whether to recommend Proctor & Gamble's Intrinsa testosterone patch, "the first of a wave of new products" -- so-called "female Viagra" therapies -- that are "intended to boost women's sex drive with male hormones," the Philadelphia Inquirer reports (McCullough, Philadelphia Inquirer, 12/1). The patch has been granted "fast-track" consideration by FDA (Nesmith, Cox/Contra Costa Times, 12/1). P&G is seeking approval for the drug as a treatment for sexual dysfunction in women who have had their ovaries removed and gone through "surgical menopause" (Philadelphia Inquirer, 12/1). The patch gradually releases a small amount of testosterone, which replaces the hormones lost from ovary removal (Jarvis, Fort Worth Star-Telegram, 12/1). According to P&G, about 10 million U.S. women have had their ovaries removed, about 20% of whom may have what the company has labeled "hypoactive sexual desire disorder." P&G currently is testing the drug on naturally menopausal women (Agovino, AP/Las Vegas Sun, 12/1).
As many as 43% of women experience some form of sexual dysfunction, often including lack of interest, according to Karen Bradshaw, a professor at the University of Texas Southwestern Medical Center (Fort Worth Star-Telegram, 12/1). P&G is one of about 10 companies developing female sexual dysfunction treatments; none of the other products is expected to reach the market before 2006. Decision Resources predicts that the female sexual dysfunction market could grow to $1 billion in the next decade (AP/Las Vegas Sun, 12/1). P&G spokesperson Mary Johnson said, "Viagra works on the plumbing. Intrinsa works on the largest sex organ in a woman, the brain" (Fort Worth Star-Telegram, 12/1).
P&G conducted two clinical trials of Intrinsa involving a total of 1,095 surgically menopausal women. One study found that women wearing the patch reported a 74% increase in satisfying sexual encounters, at an average of 4.92 over a four-week period, compared with a 35% increase to 3.8 encounters among the placebo group (AP/Las Vegas Sun, 12/1).
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. According to the Inquirer, it is "not clear whether the FDA might approve Intrinsa only in combination with estrogen." Robin Kroll, an OB/GYN who helped conduct the P&G trials, said the patch delivered a "very low dose" that only raised women's testosterone levels from abnormally low to normal (Philadelphia Inquirer, 12/1).
While Johnson said the studies presented "strong clinical safety and efficacy data," some experts said there was still not enough data available on testosterone use to treat female sexual dysfunction (Cox/Contra Costa Times, 12/1). The American College of Obstetricians and Gynecologists, which has reviewed P&G's Intrinsa studies, recently released guidelines that conclude, "[A]t this time, there are too few studies to say that the use of estrogen or androgen improves sex drive in postmenopausal women" (Philadelphia Inquirer, 12/1).
Lenore Tiefer, a New York University psychologist and sex therapist who will speak at the advisory panel hearing, noted that while the drug may increase desire by one more sexual episode a month, women would have to wear the patch for several months before it starts to take effect. "There is a very serious question about the side effects, and they have not been sufficiently studied. This is not like Viagra or some other drug that you'd take and then it washes out of the system. This is a steroid hormone, like estrogen," Tiefer said. She added that the potential benefits of Intrinsa are "insufficient" to "outweigh the negatives: the dangers, the harms, the uncertainties" (Cox/Contra Costa Times, 12/1).
According to the Inquirer, the hormone drug also is "raising concerns about dangerous side effects, corporate-sponsored research and misleading media coverage." Journalist Ray Moynihan wrote in this week's edition of the British Medical Journal that "some media outlets are exaggerating the benefits of the patch, inflating the potential pool of patients, playing down well-established harms and ignoring important conflicts of interest." The Inquirer reports that "drug companies are behind" much of the research that suggests the "vast market" for a female version of Viagra. Tiefer said, "Lots of women have lots of periods in their life when they're not that interested in sex. That's normal. People are anxious and gullible, and the companies will exploit that" (Philadelphia Inquirer, 12/1). She added, "This is a company interested in building another billion-dollar brand" (AP/Las Vegas Sun, 12/1).
Critics also say young women may go on the patch without realizing the potential dangers of testosterone supplements, which can increase the risk of heart disease, liver damage and precancerous changes in the breasts and uterus (Philadelphia Inquirer, 12/1). In addition, the AP/Las Vegas Sun reports that some experts predict that, in the wake of Merck's September withdrawal of its painkiller Vioxx, FDA could delay Intrinsa's approval until more data is available. Andre Guay, director for sexual dysfunction at the Massachusetts-based Lahey Clinic, said, "It is hotly debated whether the lack of long-term data will mean waiting another six to 12 months for approval."
Johnson said P&G plans a marketing campaign to inform doctors and women about the proper use of Intrinsa. "We know this drug isn't for everyone. We don't want people to be disappointed," she said (AP/Las Vegas Sun, 12/1). Johnson on Tuesday confirmed that P&G had sought a recommendation for Intrinsa from the International Society for the Study of Women's Sexual Health, which the company has "support[ed] financially," the Cox/Contra Costa Times reports.
BMJ last week reported that P&G Instrinsa manager Andrew Klemes had written to the society asking for a letter of recommendation for FDA. Johnson said such a request is appropriate in a regulated industry, adding, "This society understands that [female sexual dysfunction] is a common condition, and its members understand there could be a biological cause" (Cox/Contra Costa Times, 12/1).