Role of the Melanocortin-4 Receptor in Hypoactive Sexual Desire Disorder

What Was Tested

The trial (phase 4) is built around PT-141 (Bremelanotide).

A randomised, double-blind, placebo-controlled, two-way crossover physiological study.

Designed to evaluate the effects of melanocortin-4 receptor (MC4R) activation on brain activity patterns and behavioural psychometric measures of sexual arousal during visual erotic stimuli in approximately 40 right-handed, heterosexual, premenopausal women aged 18 years and over with Hypoactive Sexual Desire Disorder (HSDD) for at least a 6 month duration.

It had two arms (groups): Intervention (experimental) and Placebo (placebo comparator).

The registry classes the interventions as drug.

More on the Plan

The investigators aim to recruit approximately 40 women to allow for subject and technical drop-out, aiming for a minimum of 30 women in the final study who complete the full protocol successfully.

The investigators will collaborate with the Sexual Medicine clinic to identify potential participants, as well as advertise via print (including local and regional newspapers, transport network), radio and online advertisements.

Additionally, the investigators will liaise with the local Clinical Research Network (CRN) to contact potentially eligible patients via their General Practitioner (GP) surgery (via letter or text message).

Potential participants who contact them via advertisements will initially be electronically sent a participant information sheet and self-report questionnaire, to be returned via email.

Who Took Part

40 actual participants took part.

It was open to women only aged from 18 years with no upper age limit.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: Heterosexual premenopausal females ≥ 18 years of age with normal menstrual cycles ≤ 35 days. Right hand dominant. Body mass index (BMI) 18-35kg/m2. Currently in a relationship with a male partner and the relationship has been stable for at least 6 months before screening. Male sexual partner classified as "not impotent" on the Massachusetts Male Aging Study (MMAS) single-question assessment of erectile dysfunction.

The full record lists 15 inclusion and 32 exclusion criteria; among the exclusions: cardiovascular disease; current diagnosis of uncontrolled hypertension defined as:; treatment for hypertension that has been changed at least once in the 4 weeks prior to screening.

How the Study Was Run

It was run as a randomized, crossover and quadruple-blind study.

Because people in this PT-141 (Bremelanotide) study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

In the crossover set-up each of the participants took both PT-141 (Bremelanotide) and the comparison in turn, acting as their own control.

As a double-blind PT-141 (Bremelanotide) study, the assignments were hidden from both participants and investigators until the end.

Those kept unaware of assignments: participant, care provider, investigator and outcomes assessor.

It started in 2019-10-07 with completion listed for 2020-10-06.

It ran at 1 site in United Kingdom.

Its stated primary purpose is treatment.

What Was Measured

Researchers chose this as the main measure: Changes in Blood Oxygen Level Dependent (BOLD) Signal Change on Functional MRI (time frame: Baseline and 15 minutes).

What This Means in Plain Language

Put simply, this is a phase 4, randomized trial of PT-141 (Bremelanotide) in 40 people.

The trial is marked completed; results are posted on the registry, and this page does not restate them.

More context: the PT-141 (Bremelanotide) compound page, all human trials.