Flibanserin: From Bench to Bedside

Introduction The process of approval for flibanserin (trade name Addyi) has been associated with controversy since before its approval on August 18, 2015. This argument centered on challenges to the validity of the diagnosis of hypoactive sexual desire disorder in women and the safety and efficacy of the drug. Aim To explore the process of Food and Drug Administration (FDA) approval for flibanserin and delve further into the research, concerns, and various roadblocks to its approval. Methods A literature review was undertaken using the terms flibanserin and hypoactive sexual desire disorder and relevant commentary from supporters and critics regarding the medication and difficulties leading up to approval. Main Outcome Measures Review of the process of FDA approval of a medication to treat hypoactive sexual desire disorder and research published exploring the efficacy and safety of flibanserin. Results Before flibanserin, there were no drugs approved to treat hypoactive sexual desire disorder, which has a reported estimated incidence of 10% of women. For studying the effectiveness of flibanserin, the FDA required satisfying sexual events as the primary end point, although this end point does not measure level of desire or the associated distress. The satisfying sexual event measurement was significant across all three flibanserin trials in premenopausal women, as was an increase in desire according to the Female Sexual Function Index desire domain and a decrease in distress as recorded with the Female Sexual Distress Scale–Revised, Item 13. Safety concerns centered on the incidence of sedation, syncope, hypotension, and the interaction of flibanserin with alcohol and CYP3A4 inhibitors. Additional targeted challenge studies were mandated by the FDA. Conclusion The process of approval of flibanserin was lengthy. This was due in part to it being the first drug in its class and one with no clear guidance on study design from the FDA or roadmap for development and approval. Dooley EM, Miller MK, Clayton AH. Flibanserin: From Bench to Bedside. Sex Med Rev 2017;5:461–469.