The Food and Drug Administration has approved elagolix (Orilissa) for oral treatment of moderate to severe pain associated with endometriosis, announced AbbVie and Neurocrine Biosciences; this approval makes it the first such treatment in more than a decade. It is expected to be available in the United States in early August.
Elagolix is a gonadotropin-releasing hormone (GnRH) antagonist and the first and only one developed specifically for managing this kind of pain.
The approval is based on two 6-month, randomized, double-blind, placebo-controlled phase 3 trials that compared a total of 952 adult women treated with either elagolix with 734 treated with placebo. All of the women experienced moderate to severe endometriosis pain; their ages ranged from 18 to 49 years.
Of the women in the treatment group, 475 were treated with a 150-mg daily dose, and 477 were treated with a 200-mg twice-daily dose. Both treatment groups showed significantly greater mean reductions in pain – both daily menstrual and nonmenstrual pelvic pain – at 6 months. Furthermore, women in the 200-mg twice-daily group also showed statistically significant greater reductions in pain with sex at 3 months, compared with placebo. Altogether, these represent the three most common kinds of endometriosis pain.
The most concerning adverse event associated with elagolix is dose-dependent decreases in bone mineral density; this effect limits treatment to either 150 mg daily for up to 24 months or 200 mg twice daily for up to 6 months. Bone mineral density loss might not be completely reversible, even with treatment cessation. Common adverse events (occurring in at least 5%) included hot flush/night sweats, headache, and nausea. Elagolix is not recommended for women who are or may be pregnant, have osteoporosis, have severe liver disease, or take strong OATP1B1 inhibitors.
Full prescribing information, as well as further details on the approval, can be found on the AbbVie website.