New Drug Shows Promise for Women with Sexual Dysfunction

Women's sexual dysfunction

A study in the July issue of The Journal of Sexual Medicine reports that bremelanotide, originally developed for the treatment of erectile dysfunction, has the potential to positively affect desire and arousal in women with female sexual arousal disorder (FSAD). Additionally, researchers encourage further evaluation of the drug in an at-home study.

Bremelanotide (PT-141), administered nasally, is the first in a new class of therapies called melanocortin agonists and is novel in that it works through the brain's functions, rather than through the body's blood system as do currently available treatments.

Researchers conducted this study on 18 pre-menopausal women between the ages of 22 and 44 years to see what effects would result in women with female sexual arousal disorder after a single dose of the drug. Female sexual disorder (FSD) is defined by the American Foundation for Urologic Disease as: "The persistent or recurrent inability to attain or maintain sufficient sexual excitement, causing personal distress. It may be expressed as a lack of subjective excitement or a lack of genital or other somatic responses." FSAD is one of the female sexual disorder categories.

Each subject was randomly assigned to receive a single dose (20 mg) of bremelanotide or matching placebo during an initial in-clinic session, and then the alternate medication in a second session. During the sessions, each subject viewed 20 minutes of a neutral video, followed by 20 minutes of a sexually explicit video. Vaginal pulse amplitude (VPA) was monitored continuously through a probe beginning 20 minutes before the dosing until 60 minutes afterwards.

The difference between the mean maximum amplitude change in VPA after placebo and bremelanotide treatment was not significant. However, among individuals, data showed a marked variability with percent changes in VPA ranging from negative 11 percent to 49 percent after placebo treatment and from 13 percent to 35 percent after bremelanotide treatment.

In analyzing the at-home experience 24 hours after dosing, the subjects were also asked to fill out a satisfaction survey. Seventy-two percent of the women reported feelings of genital arousal after bremelanotide compared with 39 percent after placebo treatment. Sixty-seven percent of the women reported experiencing sexual desire after bremelanotide with only 22 percent of women responding similarly after placebo treatment. Among those women who attempted sexual intercourse within 24 hours after the dose was administered, significantly more were satisfied with their level of sexual arousal following bremelanotide compared with placebo treatment.

"These preliminary data suggest a synthetic peptide melancortin analog, acting in the brain, may increase self-reported experiences of desire and arousal in women with sexual arousal problems, more likely women 34 and older," states Dr. Julia R. Heiman, Director of the Kinsey Institute for Research in Sex, Gender and Reproduction in Indiana. "While the sample size is small and the effects are modest, these data are interesting in that they suggest an effect of PT-141 not in the lab to sexual stimuli, but where it most matters, in the sexual lives of some women."

According to the study, despite the prevalence of female sexual disorder and its impact on women's quality of life, there is a lack of data on the treatment of it. In fact, few medical treatments have been evaluated for female sexual disorder, thus marking this research an important step in more understanding and eventually having new treatments in women's sexual health.

"Clinical and pre-clinical data, taken collectively, evoke a cautious optimism leading me to strongly encourage the sponsor to continue evaluation of bremelanotide for the treatment of female sexual disorder," states Dr. Michael A. Perelman, Co-Director of the Human Sexuality Program at The NYWeill Cornell Medical Center, in Manhattan. "The potential use of this centrally acting compound to treat female sexual disorder is the most interesting development in sexual medicine research in years. Once concluded, I look forward to reviewing data from the larger at-home trial, currently underway."