Background
Hypoactive Sexual Desire Disorder (HSDD) and Female Sexual Interest/Arousal Disorder (FSIAD) affect an estimated 8–10% of premenopausal women. Unlike flibanserin (which acts on serotonin/dopamine), bremelanotide acts as a melanocortin receptor agonist — directly modulating central pathways governing sexual motivation and arousal.
The RECONNECT program (two identical pivotal trials) provided the data for FDA approval of bremelanotide (Vyleesi) in June 2019.
Methods
Two randomized, double-blind, placebo-controlled, parallel-group Phase 3 trials (RECONNECT Study 1 and Study 2) conducted simultaneously with identical protocols. Premenopausal women aged 18–55 with HSDD or FSIAD.
Treatment: bremelanotide 1.75 mg SC self-administered on demand (up to 1 per day, ≥45 min before anticipated sexual activity) vs. placebo for 24 weeks.
Primary endpoints:
- Change from baseline in satisfying sexual events (SSEs) per month
- Female Sexual Function Index – desire domain (FSFI-D)
- Female Sexual Distress Scale – Desire/Arousal/Orgasm (FSDS-DAO) item 13
Key Findings
| Endpoint | Bremelanotide | Placebo | p-value |
|---|---|---|---|
| SSEs/month increase | +0.7 | +0.4 | 0.0036 |
| FSFI desire domain | Significant improvement | — | 0.0017 |
| FSDS-DAO distress | Significant reduction | — | <0.001 |
| Responders (≥1 SSE increase) | 25.5% | 17.4% | — |
Common adverse events: nausea (40.0% vs. 1.3%), flushing (20.1% vs. 0.4%), headache (11.3% vs. 2.2%), transient blood pressure increase.
Clinical Significance
RECONNECT established bremelanotide (PT-141) as an effective on-demand treatment for HSDD/FSIAD — the first melanocortin receptor agonist approved for sexual dysfunction. Unlike daily-dosing flibanserin, bremelanotide’s on-demand use profile offers flexibility.
The statistical effect sizes, while modest in absolute terms, are consistent with FDA benchmarks for PRO endpoints in sexual dysfunction. Patient-reported improvements in distress (the most clinically meaningful endpoint) were robust.
Limitations
- High nausea rate (40%) — the primary reason many women discontinue
- Blood pressure elevation: mean +6 mmHg systolic for ~12 hours; CI for hypertensive patients
- Absolute SSE increase (0.7) is modest; patient selection for responders is important
- Not studied in postmenopausal women or men (though PT-141 is used off-label)