The Food and Drug Administration has approved the novel selective estrogen receptor modulator ospemifene (Osphena) to treat moderate to severe dyspareunia due to vulvar and vaginal atrophy.
"Dyspareunia is among the problems most frequently reported by postmenopausal women," Dr. Victoria Kusiak, deputy director of the Office of Drug Evaluation III in the FDA’s Center for Drug Evaluation and Research, said in a statement. "Osphena provides an additional treatment option for women seeking relief."
The once-daily pill acts like an estrogen on vaginal tissues, thickening them in the face of declining estrogen levels during menopause, according to the FDA. That may help alleviate pain during intercourse that occurs as a result of the thinned and fragile tissues.
According to ospemifene maker Shionogi Inc. of Florham Park, N.J., 32 million postmenopausal women in the United States experience symptoms of vulvar and vaginal atrophy (VVA). The company claims that only 7% or so are being treated with a prescription medication.
"While more than half of all women in the U.S. will experience symptoms of VVA at some time in their postmenopausal life, the vast majority of women with VVA are not being treated with a prescription medication because women and their health care professionals are not proactively discussing the condition, and its associated symptoms," Dr. David J. Portman, director of the Columbus (Ohio) Center for Women’s Health Research, said in a statement issued by Shionogi.
Most dyspareunia is addressed with over-the-counter moisturizers or creams, or with prescription tablets, creams, or rings, which are inserted vaginally.
Physicians and patients often seek alternatives because of concerns that those prescription estrogen-based treatments may also have effects on breast and endometrial tissue.
Ospemifene, however, will come with a boxed warning about the potential to act on endometrial tissue, which could lead to bleeding, precancerous, or cancerous conditions. The FDA said that ospemifene "should be prescribed for the shortest duration consistent with treatment goals and risks for the individual woman."
Even so, a 180-patient study presented at the American College of Obstetricians and Gynecologists annual meeting in June 2012 showed that ospemifene had minimal effects on the endometrial lining, compared with placebo.
The drug’s label also will contain a warning about increased rates of thrombotic and hemorrhagic strokes (pegging the incidence at 0.72 and 1.45 per 1,000 women, respectively). The label also will state the rate of deep vein thrombosis in ospemifene users (1.45 per 1,000 women). The FDA said that these elevated risks are lower than with therapies that contain only estrogen.
In three studies of 1,889 postmenopausal women with symptoms of vulvar and vaginal atrophy, women were randomly assigned to receive ospemifene or placebo. The first two studies showed a statistically significant improvement of dyspareunia in women treated with ospemifene after 12 weeks, compared with women treated with placebo. The third study showed that ospemifene was a safe drug for treating dyspareunia. Results from one of the first two trials were presented at the annual meeting of the North American Menopause Society in 2011.
The FDA reports that other common side effects reported during trials of ospemifene included hot flush/flashes, vaginal discharge, muscle spasms, genital discharge, and excessive sweating.
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