ABSTRACT: OBJECTIVE:To evaluate the long-term safety and efficacy of bremelanotide as treatment for hypoactive sexual desire disorder in premenopausal women. METHODS:Women who completed the 24-week double-blind core phase of RECONNECT, composed of two parallel phase 3 trials (301 and 302) examining the safety and efficacy of bremelanotide compared with placebo in premenopausal women with hypoactive sexual desire disorder, could enroll in the 52-week open-label extension, provided they had not experienced serious adverse events during the core phase. Efficacy was assessed using the coprimary endpoints from the core phase, and all adverse events were collected during the open-label extension. All statistical analyses were descriptive. RESULTS:The study 301 open-label extension began on July 17, 2015, and concluded on July 13, 2017; the study 302 open-label extension began on October 5, 2015, and concluded on June 29, 2017. Of the 856 eligible patients who completed the core phase, 684 elected to participate in the open-label extension, and 272 completed it. The most common treatment-emergent adverse events considered related to study drug were nausea (40.4%), flushing (20.6%), and headache (12.0%), and the only severe treatment-emergent adverse event experienced by more than one participant in both studies was nausea during the open-label extension. The change in Female Sexual Function Index-desire domain score and Female Sexual Distress Scale-Desire/Arousal/Orgasm item 13 from baseline to end of the open-label extension ranged from 1.25 to 1.30 and -1.4 to -1.7, respectively, for patients who received bremelanotide during the core phase, and 0.70-0.77 and -0.9, respectively, for patients who received placebo during the core phase. CONCLUSION:During the 52-week open-label extension of RECONNECT, no new safety signals were observed, and premenopausal women treated with bremelanotide exhibited sustained improvements in hypoactive sexual desire disorder symptoms. CLINICAL TRIAL REGISTRATION:ClinicalTrials.gov, NCT02333071 (study 301) and NCT02338960 (study 302). FUNDING SOURCE:Palatin Technologies, Inc., and AMAG Pharmaceuticals, Inc.