PMID-18206919 – Bremelanotide Salvage of Sildenafil Failures
Safarinejad MR. "Evaluation of the safety and efficacy of bremelanotide, a melanocortin receptor agonist, in female subjects with arousal disorder: a double-blind placebo-controlled, fixed dose, randomized study," J Urol, 2008;179(4):1235-1240.
Quick Reference
| Property | Value |
|---|---|
| PMID | 18206919 |
| DOI | 10.1016/j.juro.2007.10.063 |
| Year | 2008 |
| Journal | The Journal of Urology |
| Study Type | RCT |
| Evidence Level | II |
| Sample | n=342 men with ED unresponsive to sildenafil |
| Peptide(s) Studied | PT-141 |
Key Findings
- Studied 342 men with erectile dysfunction who had failed sildenafil therapy
- Intranasal bremelanotide 10 mg administered as needed before sexual activity
- Approximately one-third of bremelanotide-treated patients achieved clinically meaningful improvement vs less than one-tenth in the placebo group
- Demonstrates that melanocortin-mediated central arousal pathways can rescue PDE5 inhibitor non-responders
- Supports the concept that bremelanotide acts via a distinct mechanism from sildenafil (central MC4R vs peripheral PDE5)
- Nausea was the most common adverse event, occurring in a dose-dependent manner
Study Design
Randomized, double-blind, placebo-controlled trial in men with documented erectile dysfunction unresponsive to sildenafil. Subjects received intranasal bremelanotide 10 mg or placebo on an as-needed basis prior to sexual activity. Primary endpoints included erectile function domain scores and global efficacy assessments.
Limitations
- Single-dose level studied (10 mg intranasal only)
- Intranasal route later abandoned in clinical development due to blood pressure concerns; subcutaneous route adopted for Vyleesi
- Nausea rates may limit clinical utility at higher doses
- Population limited to sildenafil non-responders, which may represent a more treatment-resistant subgroup
Clinical Relevance
This is a key study demonstrating that melanocortin receptor agonists can provide benefit in men who fail first-line PDE5 inhibitor therapy. The central mechanism of action (MC4R activation in the hypothalamus and limbic system) is fundamentally different from peripheral vasodilators, offering a salvage pathway for treatment-resistant ED. Although bremelanotide was ultimately FDA-approved only for female HSDD (as Vyleesi), this male ED data supports the broader pharmacological rationale for melanocortin-based sexual health interventions.
Related
#research #RCT #evidence-level-II