Department of Obstetrics & Gynecology - January 2017
SHERYL KINGSBERG, PHD
Chief of Behavioral Medicine in the Department of Obstetrics and Gynecology, University Hospitals Cleveland Medical Center; Professor of Reproductive Biology and Psychiatry, Case Western Reserve University School of Medicine
Nearly 10 percent of women, close to 6 million in the United States, are affected by Hypoactive Sexual Drive Disorder (HSDD), defined by distressing persistent or recurrent lack of interest in sexual activity. That 10 percent is likely a conservative estimate, however, as HSDD is not widely recognized. Many women believe they must simply live with these symptoms, and that a declining sexual drive is a natural part of aging. Others have no idea how common the condition is and are embarrassed to admit their distressing loss of desire for fear they are alone. Even those who want to ask for help don’t know where to turn or are too embarrassed to address these issues with a healthcare professional.
Although HSDD has been a recognized medical condition for decades, it was only last year that the first FDA approved pharmacologic treatment, flibanserin (brand name Addyi), was approved for use in premenopausal women. It is a daily medication that has been shown to be effective for up to 60 percent of women in clinical trials, according to Sheryl Kingsberg, PhD, Chief of Behavioral Medicine in the Department of Obstetrics and Gynecology, University Hospitals Cleveland Medical Center, and Professor of Reproductive Biology and Psychiatry at the Case Western Reserve University School of Medicine. Flibanserin is non-hormonal, and it is hypothesized that it corrects an imbalance of the neurotransmitters associated with sexual desire, including dopamine, norepinephrine and serotonin.
Greater recognition and additional treatment options for HSDD could significantly impact the lives of millions of women both in the United States and around the world. To that end, Dr. Kingsberg led a phase 3 double blind nationwide study investigating a second option for HSDD, bremelanotide. The largest clinical trial of bremelanotide to date, the “Reconnect” study enrolled over 3,000 premenopausal women across 160 sites in the U.S. and Canada in 2015.
Like flibanserin, bremelanotide affects the brain’s neurochemical receptors, in this case specific receptors for a chemical called melanocortin. Also like flibanserin, bremelanotide targets specific brain areas and associated neurotransmitters related to sexual cues and desire.
Unlike flibanserin, which is taken orally every day, bremelanotide is taken as needed, using an autoinjector pen. It starts working within 30 minutes after injection into the skin of the abdomen or thigh, and departs the system within 10-12 hours, replacing a daily medication.
Previous studies of bremelanotide, including a phase 2 multi-site double blind trial with 394 premenopausal women at 67 sites have demonstrated significant efficacy with minor side effects. The results of that phase 2 trial were published in Women’s Health in 2016. The results of this latest trial are expected in late 2016.
While the Reconnect study looks specifically at premenopausal women, testing in post-menopausal women will likely follow. Currently, post-menopausal women have no approved pharmacologic options to treat HSDD and represent an underserved population.
“We’ve been encouraged by the findings with bremelanotide so far,” Dr. Kingsberg noted, “and are eager to see the results of this latest study. If the outcomes are successful, the company plans to file a New Drug Application with the FDA mid-2017. If approved, bremelanotide will become another viable treatment choice for the millions of women who suffer from HSDD.”
She concluded, “Not every woman needs a pharmacologic treatment for HSDD. For those that do, more options are needed. We are hopeful that we are close to finding a new treatment that will really improve quality of life for the women who need it.”
Bremelanotide is produced by Palatin Technologies, Inc. The company also funds the clinical trials.