Elagolix (ORILISSA™), an orally bioavailable, second-generation, non-peptide 
gonadotropin-releasing hormone (GnRH) receptor antagonist, is being developed 
AbbVie and Neurocrine Biosciences for the treatment of reproductive 
hormone-dependent disorders in women. In July 2018, the US FDA approved elagolix 
tablets for the management of moderate to severe pain associated with 
endometriosis. This approval was based on positive results in two replicate 
phase III trials; additional phase III trials in the USA, Canada and Puerto Rico 
are currently evaluating elagolix as both monotherapy and in combination with 
low-dose hormone add-back therapy in the same indication. Elagolix with and 
without low-dose hormone add-back therapy is also undergoing phase III clinical 
development for heavy menstrual bleeding associated with uterine fibroids in the 
aforementioned locations. This article summarizes the milestones in the 
development of elagolix leading to its first approval for the management of 
moderate to severe pain associated with endometriosis.