PT-141 (Bremelanotide): mechanism of action
Bremelanotide is a cyclic heptapeptide melanocortin receptor agonist studied in premenopausal women with hypoactive sexual desire disorder. This page summarises the receptor pharmacology and the clinical research record.
Bremelanotide is a synthetic cyclic heptapeptide melanocortin receptor agonist. It is also referred to in the literature and in trial records as PT-141 and by the abbreviation BMT. As a peptide, it is handled in laboratory work as a lyophilised solid and is characterised by its amino acid sequence, molecular formula and molecular weight rather than by any small-molecule identifier. The evidence block for this page does not supply those sequence, formula or molecular weight values, so they are not restated here.
The work on this compound centres on the melanocortin receptor family, a group of G-protein-coupled receptors that bind melanocortin peptides and are the pharmacological target class through which bremelanotide is understood to act.
Research Studies
Bremelanotide and subcutaneous administration in premenopausal women with hypoactive sexual desire disorder
Two Phase 3 trials were run to evaluate the efficacy and safety of bremelanotide in premenopausal women with hypoactive sexual desire disorder (HSDD), with or without decreased arousal. Both were randomised, double-blind, placebo-controlled, parallel-group trials with an optional open-label extension, and in both the compound was administered subcutaneously on an as-needed basis [1][2].
The two records describe the same design and the same population, and differ in their registry identifiers. They are presented together in the table below because the evidence block does not distinguish them by any other parameter.
| Registry identifier | Phase | Design | Route | Population |
|---|---|---|---|---|
| NCT02338960 [1] | Phase 3 | Randomised, double-blind, placebo-controlled, parallel-group, optional open-label extension | Subcutaneous, as needed | Premenopausal women with HSDD, with or without decreased arousal |
| NCT02333071 [2] | Phase 3 | Randomised, double-blind, placebo-controlled, parallel-group, optional open-label extension | Subcutaneous, as needed | Premenopausal women with HSDD, with or without decreased arousal |
Bremelanotide and fixed subcutaneous dose levels in premenopausal women with FSAD and/or HSDD
A separate trial was designed to evaluate the efficacy and safety of three fixed dose levels of bremelanotide, administered subcutaneously on an as-needed basis under conditions of home use. The population was premenopausal women with female sexual arousal disorder (FSAD), hypoactive sexual desire disorder (HSDD), or mixed FSAD/HSDD [3].
This study is distinct from the Phase 3 programme above in two respects that the evidence block makes explicit: it tested three fixed dose levels rather than a single as-needed regimen, and it enrolled a population defined by FSAD, HSDD or a mixed presentation rather than HSDD alone [3].
Bremelanotide and intranasal administration in women with female sexual arousal disorder
An earlier eight-week at-home study was designed to explore efficacy endpoints and evaluate the safety of intranasal bremelanotide in women with female sexual arousal disorder. Efficacy in that study was assessed against a parallel placebo group [4].
This is the only record in the evidence block that describes an intranasal route of administration. The other three records describe subcutaneous administration [1][2][3]. The route difference is summarised below.
| Registry identifier | Route | Duration / setting | Population | Comparator |
|---|---|---|---|---|
| NCT00425256 [4] | Intranasal | 8 weeks, at home | Women with FSAD | Parallel placebo group |
| NCT01382719 [3] | Subcutaneous, as needed | Home use | Premenopausal women with FSAD, HSDD, or mixed FSAD/HSDD | Three fixed dose levels evaluated |
| NCT02338960 [1] | Subcutaneous, as needed | Phase 3, optional open-label extension | Premenopausal women with HSDD, with or without decreased arousal | Placebo |
| NCT02333071 [2] | Subcutaneous, as needed | Phase 3, optional open-label extension | Premenopausal women with HSDD, with or without decreased arousal | Placebo |
Bremelanotide and the melanocortin receptor family
The receptor family at the centre of this work is the melanocortin receptor family. Bremelanotide is described in this page's framing as a melanocortin receptor agonist, and the trial programme above constitutes the clinical research record in which the compound has been studied. The evidence block does not specify which melanocortin receptor subtypes are engaged, nor does it provide binding affinities, selectivity ratios or functional potency values. Those parameters are therefore not stated here.
Bremelanotide and the premenopausal population
Every study in the evidence block enrolled premenopausal women. Two Phase 3 trials enrolled premenopausal women with HSDD, with or without decreased arousal [1][2]. One trial enrolled premenopausal women with FSAD, HSDD, or mixed FSAD/HSDD [3]. One earlier study enrolled women with FSAD [4].
No study in the evidence block reports outcomes in men, in postmenopausal women, or in any paediatric population. Any statement about effects outside the premenopausal female population would not be supported by the material available here.
Bremelanotide and the placebo-controlled design
Three of the four records in the evidence block describe a placebo comparison. The two Phase 3 trials were placebo-controlled and parallel-group [1][2]. The eight-week intranasal study assessed efficacy against a parallel placebo group [4]. The fixed-dose study evaluated three fixed dose levels under home-use conditions and is described as designed to evaluate efficacy and safety, without the evidence block specifying a placebo arm [3].
Bremelanotide and as-needed subcutaneous dosing schedules
Three records describe as-needed subcutaneous administration. The two Phase 3 trials used as-needed subcutaneous dosing in premenopausal women with HSDD [1][2]. The fixed-dose study used as-needed subcutaneous dosing under home-use conditions in premenopausal women with FSAD, HSDD, or mixed FSAD/HSDD [3]. The evidence block does not give the absolute dose amounts, the dosing intervals, or the maximum frequency of administration for any of these schedules.
Bremelanotide and the open-label extension design
Both Phase 3 trials included an optional open-label extension in addition to the randomised, double-blind, placebo-controlled, parallel-group core phase [1][2]. The evidence block does not report the duration of the extension, the number of participants who entered it, or any outcome data from it.
Bremelanotide and the limits of the available evidence
The evidence block for this page consists of four clinical trial registry records. It contains no preclinical data, no in vitro receptor pharmacology data, no animal model data, and no published efficacy or safety results. Where this page describes a mechanism, it does so at the level of the receptor family named in the framing, not at the level of a measured signalling event.
Because the evidence block provides no sequence, formula, molecular weight, binding data, dose values or outcome statistics, none of those are reported here. Any figure not present in the evidence block has been left out rather than estimated.
If you are reading this for personal health reasons
The material described on this page is sold for laboratory research use only. We do not provide dosing information, medical guidance, or advice on the use of any compound in a person. Anyone considering a compound for themselves should speak to a licensed clinician.
Sources
- [1] Study to Evaluate the Efficacy/Safety of Bremelanotide in Premenopausal Women With Hypoactive Sexual Desire Disorder — https://clinicaltrials.gov/study/NCT02338960
- [2] Study to Evaluate the Efficacy/Safety of Bremelanotide in Premenopausal Women With Hypoactive Sexual Desire Disorder — https://clinicaltrials.gov/study/NCT02333071
- [3] Bremelanotide in Premenopausal Women With Female Sexual Arousal Disorder and/or Hypoactive Sexual Desire Disorder — https://clinicaltrials.gov/study/NCT01382719
- [4] Evaluate the Safety and Efficacy of Bremelanotide in Women With Female Sexual Arousal Disorder (FSAD) — https://clinicaltrials.gov/study/NCT00425256