HEALTH JOURNAL
By TARA PARKER-POPE
Equal Time: FDA Panel to Review Drug
That Would Increase Women's Sex Drive
November 23, 2004; Page D1
A Food & Drug Administration hearing next week will have a dramatic impact on the sex lives of American women.
An FDA panel is set to review clinical trial data for Intrinsa, a testosterone patch that can boost a woman's sex drive. If approved, Intrinsa would be the first prescription drug for treating sexual dysfunction in women.
But there's a lot more riding on the decision than the future of one drug. Several other drugs to treat desire and arousal problems in women are being studied, and whether they ever come to market may hinge on how the FDA views Intrinsa.
But the Dec. 2 hearing comes at an inopportune time for marketers of female sex drugs. The FDA is under growing scrutiny about drug safety after Merck's recent withdrawal of the arthritis drug Vioxx after it was linked with heart damage. In addition, regulators and physicians remain skittish about prescription hormones after a major study showed higher heart-attack risk among older women taking menopause hormones. Although women have taken testosterone in various forms since the 1930s, there's very little reliable data on long-term safety.
Backers of sex drugs say at least five million women suffer from low-desire problems that have ruined their sex lives. Given that the FDA has approved three drugs for men -- Viagra, Cialis and Levitra -- proponents say it's time for a woman's sexual health to receive equal attention. "There's certainly a plethora of information to suggest sexual problems are common," says James A. Simon, clinical professor of gynecology at George Washington University School of Medicine in Washington, D.C., who has worked with firms studying female sex drugs. "But there are people who don't believe women have sexual dysfunction, and people who don't believe hormones are good for anything."
Intrinsa isn't a female version of Viagra. While Viagra and similar drugs increase blood flow to the genital area, making sex physically possible for men, testosterone therapies such as Intrinsa essentially start at the top, affecting a woman's brain and her desire for sex. Although testosterone typically is viewed as a male hormone, women also produce it, and the hormone plays a key role in sexual desire.
Patch marketer Procter & Gamble has taken a conservative approach in seeking approval for Intrinsa only for women who have undergone surgical removal of their ovaries, a procedure that reduces half of a woman's testosterone supply. About 10 million U.S. women don't have their ovaries, and about 300,000 women a year undergo the procedure. About 20% of them suffer from a low-desire disorder as a result.
P&G also is studying the patch in naturally menopausal women who have lost interest in sex because of waning testosterone levels as they age. It's estimated that about 10% of naturally menopausal women are upset by a noticeable loss in sexual desire. Proper diagnosis of these women may be more tricky, because low desire also can be caused by depression or relationship problems. In addition, not every lab test that measures testosterone is reliable, notes Sheryl A. Kingsberg, associate professor at Case Western Reserve School of Medicine. "Physicians need a little bit of training on how to appropriately assess patients," Dr. Kingsberg says.
Doctors have been giving women testosterone injections, pills or creams to boost sex drive for years, but the use never has been approved by the FDA. An estrogen-testosterone pill, Estratest from Solvay Pharmaceuticals, has been marketed as a menopause therapy since the 1980s.
BOOSTING LIBIDO
Here's a look at some of the testosterone products being developed to improve sexual desire in women.
Product/Drug Company Status/Anticipated Availability
Intrinsa patch (Procter & Gamble) December FDA hearing; expected launch 2005
MDTS spray (Vivus) Final studies next year; may be available 2006
Libigel gel (BioSante) In late-phase studies; may be available late 2006, early 2007
Androsorb cream (Novavax) Midphase studies expected next year
Estratest pill (Solvay) Approved for menopause treatment; early sexual-dysfunction studies under way
Although there's very little long-term safety data on the use of testosterone in women, some studies suggest it actually might lower breast-cancer risk among women taking estrogen. In September, the medical journal Menopause published a study of 500 Australian women who were taking testosterone and other menopause hormones. After six years, the breast-cancer rate among the testosterone users was 20% to 40% lower than breast-cancer rates reported in other major studies of menopause hormones. That said, the drug has been studied only in women who also are taking estrogen therapy. Additional studies of the patch in menopausal women who don't use other hormones are planned.
Some women who use testosterone develop acne or increased hair growth, but in P&G's studies, most of the complaints were mild, such as a stray facial hair. Fewer than 1% of women dropped out because of side effects.
The most common side effect of Intrinsa is a minor skin reaction at the site of the patch. As a result, other drug makers are developing new ways to deliver testosterone into a woman's body. BioSante is studying Libigel, a gel applied to the arm, while Vivus is studying a patented spray delivery system. None of the drugs is expected to be available before 2006.
Another drug under study is alprostadil, a hormone that can boost a woman's arousal by increasing blood flow to a woman's genitals, making it similar to drugs such as Viagra. Alprostadil already is approved for men in the drug Muse. Pfizer also is studying lasofoxifene, a selective estrogen receptor modulator or SERM. The drug is in the same category as the breast-cancer drug Tamoxifen and the osteoporosis drug Evista, but unlike other SERMs, one side effect of lasofoxifene appears to be an increase in sexual desire. Estratest, although already marketed as a menopause hormone, is being studied for its effect on sexual function.
The biggest hurdle for sex drugs may be that they only improve sex for about half the people who try them. "No single hormone determines sexual function," notes Susan R. Davis, professor of women's health at Monash University in Melbourne and a principle investigator for the Vivus spray. "It won't change anything for a woman who doesn't like the look of her partner or if she's desperately unhappy, depressed or worried about money."
By TARA PARKER-POPE
Equal Time: FDA Panel to Review Drug
That Would Increase Women's Sex Drive
November 23, 2004; Page D1
A Food & Drug Administration hearing next week will have a dramatic impact on the sex lives of American women.
An FDA panel is set to review clinical trial data for Intrinsa, a testosterone patch that can boost a woman's sex drive. If approved, Intrinsa would be the first prescription drug for treating sexual dysfunction in women.
But there's a lot more riding on the decision than the future of one drug. Several other drugs to treat desire and arousal problems in women are being studied, and whether they ever come to market may hinge on how the FDA views Intrinsa.
But the Dec. 2 hearing comes at an inopportune time for marketers of female sex drugs. The FDA is under growing scrutiny about drug safety after Merck's recent withdrawal of the arthritis drug Vioxx after it was linked with heart damage. In addition, regulators and physicians remain skittish about prescription hormones after a major study showed higher heart-attack risk among older women taking menopause hormones. Although women have taken testosterone in various forms since the 1930s, there's very little reliable data on long-term safety.
Backers of sex drugs say at least five million women suffer from low-desire problems that have ruined their sex lives. Given that the FDA has approved three drugs for men -- Viagra, Cialis and Levitra -- proponents say it's time for a woman's sexual health to receive equal attention. "There's certainly a plethora of information to suggest sexual problems are common," says James A. Simon, clinical professor of gynecology at George Washington University School of Medicine in Washington, D.C., who has worked with firms studying female sex drugs. "But there are people who don't believe women have sexual dysfunction, and people who don't believe hormones are good for anything."
Intrinsa isn't a female version of Viagra. While Viagra and similar drugs increase blood flow to the genital area, making sex physically possible for men, testosterone therapies such as Intrinsa essentially start at the top, affecting a woman's brain and her desire for sex. Although testosterone typically is viewed as a male hormone, women also produce it, and the hormone plays a key role in sexual desire.
Patch marketer Procter & Gamble has taken a conservative approach in seeking approval for Intrinsa only for women who have undergone surgical removal of their ovaries, a procedure that reduces half of a woman's testosterone supply. About 10 million U.S. women don't have their ovaries, and about 300,000 women a year undergo the procedure. About 20% of them suffer from a low-desire disorder as a result.
P&G also is studying the patch in naturally menopausal women who have lost interest in sex because of waning testosterone levels as they age. It's estimated that about 10% of naturally menopausal women are upset by a noticeable loss in sexual desire. Proper diagnosis of these women may be more tricky, because low desire also can be caused by depression or relationship problems. In addition, not every lab test that measures testosterone is reliable, notes Sheryl A. Kingsberg, associate professor at Case Western Reserve School of Medicine. "Physicians need a little bit of training on how to appropriately assess patients," Dr. Kingsberg says.
Doctors have been giving women testosterone injections, pills or creams to boost sex drive for years, but the use never has been approved by the FDA. An estrogen-testosterone pill, Estratest from Solvay Pharmaceuticals, has been marketed as a menopause therapy since the 1980s.
BOOSTING LIBIDO
Here's a look at some of the testosterone products being developed to improve sexual desire in women.
Product/Drug Company Status/Anticipated Availability
Intrinsa patch (Procter & Gamble) December FDA hearing; expected launch 2005
MDTS spray (Vivus) Final studies next year; may be available 2006
Libigel gel (BioSante) In late-phase studies; may be available late 2006, early 2007
Androsorb cream (Novavax) Midphase studies expected next year
Estratest pill (Solvay) Approved for menopause treatment; early sexual-dysfunction studies under way
Although there's very little long-term safety data on the use of testosterone in women, some studies suggest it actually might lower breast-cancer risk among women taking estrogen. In September, the medical journal Menopause published a study of 500 Australian women who were taking testosterone and other menopause hormones. After six years, the breast-cancer rate among the testosterone users was 20% to 40% lower than breast-cancer rates reported in other major studies of menopause hormones. That said, the drug has been studied only in women who also are taking estrogen therapy. Additional studies of the patch in menopausal women who don't use other hormones are planned.
Some women who use testosterone develop acne or increased hair growth, but in P&G's studies, most of the complaints were mild, such as a stray facial hair. Fewer than 1% of women dropped out because of side effects.
The most common side effect of Intrinsa is a minor skin reaction at the site of the patch. As a result, other drug makers are developing new ways to deliver testosterone into a woman's body. BioSante is studying Libigel, a gel applied to the arm, while Vivus is studying a patented spray delivery system. None of the drugs is expected to be available before 2006.
Another drug under study is alprostadil, a hormone that can boost a woman's arousal by increasing blood flow to a woman's genitals, making it similar to drugs such as Viagra. Alprostadil already is approved for men in the drug Muse. Pfizer also is studying lasofoxifene, a selective estrogen receptor modulator or SERM. The drug is in the same category as the breast-cancer drug Tamoxifen and the osteoporosis drug Evista, but unlike other SERMs, one side effect of lasofoxifene appears to be an increase in sexual desire. Estratest, although already marketed as a menopause hormone, is being studied for its effect on sexual function.
The biggest hurdle for sex drugs may be that they only improve sex for about half the people who try them. "No single hormone determines sexual function," notes Susan R. Davis, professor of women's health at Monash University in Melbourne and a principle investigator for the Vivus spray. "It won't change anything for a woman who doesn't like the look of her partner or if she's desperately unhappy, depressed or worried about money."
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