Phase I Randomized Placebo-controlled, Double-blind Study of the Safety and Tolerability of Bremelanotide Coadministered With Ethanol in Healthy Male and Female Participants

Purpose This was a Phase I study to evaluate the safety, tolerability, and hemodynamic and pharmacokinetic effects of bremelanotide (BMT) coadministered with ethanol to healthy male and female participants. Methods This was a randomized, placebo-controlled, double-blind, 3-period, 3-way crossover study. Individuals meeting the inclusion/exclusion criteria received BMT or placebo with or without ethanol at the research facility for 7 consecutive days. Participants were randomized to receive 1 of 6 treatment paths; each participant received single intranasal doses of BMT (20 mg) or placebo on days 1, 4, and 7, with or without oral ethanol (0.6 g/kg) while in a fasted state. The intranasal 20-mg dose of BMT has an exposure equivalent to ~1 to 2 times the subcutaneous dose currently being evaluated in Phase III studies. Vital signs, self-rated sedation scores, nursing and medical observations, and spontaneous reporting by participants provided the basis for evaluation of adverse events. A physical examination and a resting 12-lead electrocardiogram were performed at baseline and on study day 7. Blood and urine samples were obtained for clinical safety profile laboratory tests. Findings A total of 24 participants were enrolled (12 men; 12 women) and completed the study. Single doses of 20 mg intranasal BMT, administered with or without 0.6 g/kg ethanol, were found to be safe and generally well tolerated with mean maximum ethanol concentrations exceeding 80 mg/dL in women. No clinically significant pharmacokinetic interactions were found between ethanol and BMT either overall or by sex. No significant drug-related hypotensive or orthostatic hypotensive effects were noted. Treatment with BMT did not result in an increased frequency of treatment-emergent adverse events, and no participants discontinued the study because of adverse events. Physical examination, electrocardiography, and laboratory tests disclosed no clinically significant changes. Implications Female sexual dysfunction is a multifactorial condition with anatomic, physiologic, medical, psychological, and social components. BMT is a synthetic peptide analogue of the naturally occurring hormone α-melanocyte–stimulating hormone and a melanocortin receptor agonist that is being developed for the treatment of hypoactive sexual desire disorder. Its mechanism of action involves activation of endogenous melanocortin hormone pathways involved in the sexual desire and arousal response. The results of this Phase I study found that BMT and ethanol can be safely coadministered and are generally well tolerated with no reports of drug-related serious adverse events. Phase III trials of subcutaneous BMT for the treatment of hypoactive sexual desire disorder in premenopausal women are in progress. ClinicalTrials.gov identifiers NCT02338960 and NCT02333071.