Elagolix shows long-term efficacy

Having had the opportunity to review Dr. Eric Surrey's abstract for this year's annual clinical and scientific meeting of the American College of Obstetricians and Gynecologists, entitled "Long-term Safety and Efficacy of Elagolix Treatment in Women With Endometriosis-associated Pain," I believe use of Elagolix, an oral nonpeptide gonadotropin-releasing hormone (GnRH) antagonist, is a much-needed advancement in the long-term treatment of endometriosis-related pain. The fact that it is an oral medication, thus, not requiring a monthly or 3-month injection as does Lupron Depot (leuprolide acetate), the most popular GnRH agonist in the United States, is advantageous both for the patient and the busy office staff.

Furthermore, the reduction in dysmenorrhea and nonmenstrual pain is rapid at both the 150-mg once daily as well as the 200-mg twice daily dose. This is consistent with Elagolix being a GnRH antagonist, which immediately down-regulates the pituitary and thus, suppresses the release of follicle-stimulating hormones and luteinizing hormonesboth are on acceptable abbrevs list but we could spell out since they're used once//dw. Without gonadotropin stimulation to the ovaries, estrogen production decreases, resulting in diminishment of endometriosis.

While I certainly understand that it is easy to compare data regarding bone loss in the use of an oral antagonist, Elagolix, with historical data with the GnRH agonist and note a lessening of bone loss in the Elagolix patients, it would be interesting to compare bone loss in patients utilizing Elagolix with bone loss in those treated with GnRH-agonist plus add-back therapy. Many practitioners will utilize progesterone supplementation or estrogen/progesterone supplementation when using GnRH-agonist therapy to decrease this risk. Furthermore, it would be interesting, in the future, to evaluate the impact on efficacy and bone loss if progesterone and estrogen/progesterone add-back were utilized in Elagolix therapy.

While I certainly realize and deeply respect Dr. Surrey's vast experience as both a clinical researcher and clinician utilizing a GnRH-agonist regimen, I am curious as to the basis of Dr. Surrey's comments regarding less severe hot flashes in comparison to GnRH-agonist treatment. I am not aware of any head-to-head studies comparing hot flashes between GnRH agonists (in particular, leuprolide acetate) and Elagolix.

Without a side-by-side comparison utilizing a validated scoring system, I find it hard to accept this conclusion.

Nevertheless, after reviewing this study and Dr. Surrey's comments, I look forward to utilizing Elagolix in my practice for long-term treatment of endometriosis-related pain.

Charles Miller, MD, is a minimally invasive gynecologic surgeon in Naperville, Ill., and a past president of the AAGL. He is a consultant and involved in research for AbbVie.