AbbVie has announced positive results from two replicate Phase 3 clinical trials of Elagolix in premenopausal women with endometriosis. The two Phase 3 trials (M12-665 and M12-671) evaluated the efficacy and safety of Elagolix.

The first trial (M12-665) was a 24-week, randomized, double-blind, placebo-controlled study that included 872 women, aged 18 to 49, with moderate to severe endometriosis-associated pain. Results at month 3 showed that 46% of patients receiving 150mg once daily and 76% of those receiving 200mg twice daily of Elagolix were classified as dysmenorrhea (DYS) responders compared to 20% in the placebo treated group.

Significant improvements were also seen in non-menstrual pelvic pain (NMPP) for those treated with Elagolix; 50% of those treated with 150mg once daily and 55% treated with 200mg twice daily were classified as NMPP responders compared to 36% of those treated with placebo. 

Related Articles

The second Phase 3 trial (M12-671) used the same design as the first though it was conducted across 226 sites and 13 countries. The results from M12-671 were similar to those of M12-665. Together, these two Phase 3 pivotal studies evaluated the safety and efficacy of Elagolix in nearly 1,700 women with moderate-to-severe endometriosis associated pain.

The most frequently reported adverse events (AEs) assessed over six months were hot flush, headache, and nausea. Discontinuations due to AEs were 6.4% and 4.4% for 150mg once daily in study 1 and study 2, respectively and 9% and 10% for 200mg twice daily in study 1 and study 2, respectively. For the placebo group, discontinuation due to AEs was 5.9% and 6.1%, respectively.

Elagolix, a gonadotropin-releasing hormone (GnRH) receptor antagonist, is an orally administered, short-acting molecule that blocks endogenous GnRH signaling by binding competitively to GnRH receptors in the pituitary gland. Administration results in rapid, reversible, dose-dependent inhibition of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion, leading to reduced ovarian production of the sex hormones, estradiol and progesterone, while on therapy.  

AbbVie plans to submit a New Drug Application to the U.S. Food and Drug Administration (FDA) for endometriosis in 2017. Elagolix Phase 3 trials for the management of uterine fibroids are ongoing.

For more information visit