Elagolix, an oral GnRH antagonist for endometriosis-associated pain: a randomized controlled study

Elagolix, an oral GnRH antagonist for endometriosis-associated pain: a randomized controlled study

J Endometr Pelvic Pain Disord 2013; 5(3): 105 - 115




Bruce Carr, Linda Giudice, W. Paul Dmowski, Chris O’Brien, Ping Jiang, Joshua Burke, Roland Jimenez, Steven Hass, Mahesh Fuldeore, Kristof Chwalisz


Objective: The aim of this study was to estimate the efficacy of elagolix, an oral gonadotropin-releasing hormone (GnRH) antagonist, for the treatment of endometriosis-associated pelvic pain.

Methods: This was a phase II, randomized, placebo-controlled parallel group study conducted at 37 US centers, consisting of an 8-week double-blind period followed by a 16-week open-label period. Patients were 137 women aged 18 to 49, with laparoscopically confirmed endometriosis and moderate to severe nonmenstrual pelvic pain and dysmenorrhea, who were administered elagolix 150 mg daily or placebo. The primary outcomes of the study were the daily assessment of dysmenorrhea, nonmenstrual pelvic pain and dyspareunia using a modified Biberoglu-Behrman scale.

Results: During the double-blind period, there were significantly greater mean reductions from baseline to week 8 in dysmenorrhea (-1.13 ± 0.11 vs. -0.37 ± 0.11, p<0.0001), nonmenstrual pelvic pain (-0.47 ± 0.07 vs. -0.19 ± 0.07, p = 0.0066), and dyspareunia scores (-0.61 ± 0.10 vs. -0.23 ± 0.10, p = 0.0070) in the elagolix group compared with placebo. Continued improvements were observed during the open-label treatment regardless of initial treatment allocation. Elagolix treatment was also associated with significant improvements in quality-of-life measures during the double-blind and open-label periods. The most common adverse events occurring with elagolix were nausea, headache and hot flush, each in 9.9% of patients.

Conclusion: Elagolix effectively reduced endometriosis-associated pelvic pain over a 24-week period and was well-tolerated.

Article History


Financial Support: This study was designed and funded by Neurocrine Biosciences. Elagolix is being developed by AbbVie and Neurocrine Biosciences. Neurocrine Biosciences, AbbVie and all authors participated in data analysis and interpretation. AbbVie provided funding for writing support. All authors contributed to the development of the content. The authors and AbbVie reviewed and approved the manuscript; the authors maintained control over the final content.
Conflicts of Interest: B.C. has received grant support from Neurocrine Biosciences and has been a consultant for AbbVie (formerly Abbott), and also received research grants from Syneract and Evofem. L.G. was a consultant to Neurocrine Biosciences and AbbVie; currently nothing to disclose. W.P.D. has been a consultant for Neurocrine Biosciences and AbbVie. J.B., R.J. and C.O.B. are Neurocrine Biosciences employees and own Neurocrine Biosciences stock. K.C., S.H., M.F. and P.J. are AbbVie employees and own AbbVie stock.

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  • University of Texas Southwestern Medical Center, Dallas, Texas - USA
  • University of California San Francisco, San Francisco, California - USA
  • Institute for the Studies and Treatment of Endometriosis, Oakbrook, Illinois - USA
  • Neurocrine Biosciences, San Diego, California - USA
  • AbbVie, North Chicago, Illinois - USA

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