An Evidence-Based Review of Elagolix for the Treatment of Pain Secondary to Endometriosis.

Purpose of Review: This is a review of elagolix use for pain related to endometriosis. It summarizes the background and recent data available about the pathogenesis of endometriosis and pain that is secondary to this syndrome. It then reviews the evidence to support the use of elagolix and the indications for use. Recent Findings: Endometriosis occurs in 10% of reproductive-age women and is a common source of chronic pelvic pain, infertility, and co-morbid disorders. It usually presents with some combination of dysmenorrhea, dyspareunia, chronic pelvic pain, and infertility. Treatment options may be surgical or hormonal. Traditional treatment is divided into medical and surgical. The latter, though effective, is reserved for surgical emergencies and patients failing medical management. Medical management with NSAIDs is usually limited in efficacy. It is generally based on hormonal suppression leading to atrophy of endometrial lesions. Elagolix (Orlissa) is a GnRH antagonist that suppressed the entire hypophysis-gonadal axis. Reduced levels of estrogen and progesterone lead to involution of the endometrial lesions and improvement in symptoms. Clinical trials showed that elagolix is effective in treating dysmenorrhea and non-menstrual pain that is secondary to endometriosis. It is well tolerated and has a relatively safe usage profile. Studies up to 12 months long showed continued efficacy and reduction in dysmenorrhea of up to 75%, with 50%-60% reduction in non-menstrual pain. Elagolix was found effective when compared to both placebo and alternative treatments. Summary: Endometriosis is a common syndrome that causes significant pain, morbidity, and disability, as well as financial loss. Elagolix is an effective drug in treating the symptoms of endometriosis and is a relatively safe option. Phase 4 studies will be required to evaluate the safety and efficacy of long term chronic use.