Elagolix dosage and impact on endometriosis

New research on two different dosages of elagolix show that both doses improved dysmenorrhea and nonmenstrual pelvic pain in women with endometriosis. The findings, published in NEJM, add to data from previous studies of the drug, which showed that it produced partial to nearly full estrogen suppression.

Supported by AbbVie, the studies were both double-blind, randomized, 6-month phase 3 trials evaluating the effects of 150 mg once daily (lower-dose group) and 200 mg twice daily (high-dose group) of elagolix versus placebo in women with surgically diagnosed endometriosis and moderate or severe endometriosis-associated pain. The two primary efficacy end points were the proportion of women with a clinical response to dysmenorrhea and the proportion with a clinical response to nonmenstrual pain at 3 months.

A total of 653 and 632 premenopausal women were randomized to Elaris EM-I and Elaris EM-II, respectively. In both trials, at 3 months, significantly more women who received either dose of elagolix achieved the primary end points than did those who received placebo. In Elaris EM-II, 46.4% of women who received the lower dose and 75.8% of those had received the higher dose had a clinical response to dysmenorrhea, versus 22.7% (P<0.001) in the placebo group. In Elaris EM-I, the percentages of women achieving a response to nommenstrual pelvic pain were 50.4% and 54.5% with the lower and higher doses, respectively, versus 36.5% for placebo. In Elaris EM-II, the corresponding percentages were 49.8% and 57.8% versus 36.5%. The responses to dysmenorrhea and nonmenstrual pelvic pain were sustained at 6 months.

Rates of hot flushes were higher as were levels of serum lipids in the women who took elagolix, irrespective of the dosage. The drug also was associated with decreases from baseline in bone mineral density. There were no adverse endometrial findings.