according to results from two small randomized controlled trials.
The data suggest that injections of kisspeptin can boost sexual desire in men and women and can increase penile rigidity in men.
Together, these two studies provide proof of concept for the development of kisspeptin-based therapeutics for men and women with distressing hypoactive sexual desire disorder (HSDD), study investigator Alexander Comninos, MD, PhD, Imperial College London, said in a news release.
One study was published online Feb. 3, 2022, in JAMA Network Open. The other was published in October 2022.
Unmet need
HSDD affects up to 10% of women and 8% of men worldwide and leads to psychological and social harm, the news release noted.
“There is a real unmet need to find new, safer, and more effective therapies for this distressing condition for both women and men seeking treatment,” Dr. Comninos said.
Kisspeptin is a naturally occurring reproductive hormone that serves as a crucial activator of the reproductive system. Emerging evidence from animal models shows that kisspeptin signaling has key roles in modulating reproductive behavior, including sexual motivation and erections.
In a double-blind, placebo-controlled, crossover study, the researchers enrolled 32 healthy heterosexual men (mean age, 37.9 years) who had HSDD.
At the first study visit, the men were given an infusion of kisspeptin-54 (1 nmol/kg per hour) or placebo (saline) over 75 minutes. The participants then crossed over to the other treatment at a second study visit at least 7 days later.
The active treatment significantly increased circulating kisspeptin levels. A steady state was reached after 30-75 minutes of infusion, the researchers reported.
Similar data in men, women
While the men viewed sexual videos, kisspeptin significantly modulated brain activity on fMRI in key structures of the sexual-processing network, compared with placebo (P = .003).
In addition, the treatment led to significant increases in penile tumescence in response to sexual stimuli (by up to 56% more than placebo; P = .02) and behavioral measures of sexual desire – most notably increased happiness about sex (P = .02).
Given the significant stimulatory effect of kisspeptin administration on penile rigidity, coupled with its demonstrated proerectile effect in rodents, future studies should examine the use of kisspeptin for patients with erectile dysfunction, the researchers wrote.
The second study included 32 women with HSDD and had the same design. Its results also showed that kisspeptin restored sexual and attraction brain processing without adverse effects.
“It is highly encouraging to see the same boosting effect in both women and men, although the precise brain pathways were slightly different, as might be expected,” coinvestigator Waljit Dhillo, PhD, Imperial College London, said in the news release.
“Collectively, the results suggest that kisspeptin may offer a safe and much-needed treatment for HSDD that affects millions of people around the world; and we look forward to taking this forward in future larger studies and in other patient groups,” Dr. Dhillo added.
The study was funded by the National Institute for Health and Care Research Imperial Biomedical Research Centre and the Medical Research Council, part of UK Research and Innovation. Dr. Comninos reported no relevant financial relationships. Dr. Dhillo reported receiving consulting fees from Myovant Sciences and KaNDy Therapeutics outside the submitted work.
A version of this article first appeared on Medscape.com.