Women are being recruited to participate in a new multicenter study of the safety of testosterone gel for postmenopausal women with low sexual desire. The study design and goals will be presented at The Endocrine Society's 90th Annual Meeting in San Francisco.
The testosterone gel, LibiGel®, has the "potential to be the first drug approved to treat female sexual dysfunction in menopausal women," said Michael Snabes, MD, PhD, medical director for BioSante Pharmaceuticals, Inc. BioSante makes LibiGel and is funding the research.
"Despite several currently approved pharmaceutical products for men with sexual dysfunction, no drug has been approved in the U.S. for female sexual dysfunction," he said.
The company seeks to enroll 2,400 to 3,100 women ages 50 to 80 who have hypoactive sexual desire disorder (HSDD). This condition is the most common type of female sexual dysfunction, affecting 14 to 39 percent of women. HSDD is the persistent or recurrent absence of sexual fantasies, thoughts and desires, causing the woman distress and resulting in lower sexual activity. After menopause, a woman's body produces less testosterone, which may contribute to symptoms of HSDD.
To be eligible to participate in the study, women with HSDD must have gone through menopause, either surgically or naturally, and have at least one risk factor for heart disease or stroke, such as diabetes, high blood pressure or age older than 70.
"Women will randomly be assigned to receive either the testosterone gel, which they will apply daily to the arm, or an identical placebo gel (inactive substance). They will receive the treatment for a minimum of a year at which time BioSante plans to seek FDA approval to market LibiGel. Study subjects will be followed up for another 4 years," Snabes said.
The primary aim of the study is to ensure that the testosterone gel does not increase the risk of cardiovascular events, such as a heart attack or stroke, or the risk of breast cancer.
"The FDA [Food and Drug Administration] has requested this preapproval study," Snabes said, "due to a perceived risk of cardiovascular events and breast cancer with the use of testosterone in women, despite no clear evidence of this."
"This new type of study," he continued, "shows the public that pharmaceutical companies and the FDA are willing to provide an increased level of assurance of drug safety prior to approval."
Other research has found that testosterone effectively treats HSDD, with "few serious adverse events associated with its use," Snabes said. However, there are no long-term studies of testosterone use in women. The Endocrine Society has called for more long-term data.