Elagolix, a novel gonadotropin-releasing hormone receptor antagonist, won FDA approval Tuesday for treating moderate to severe endometriosis pain and will be sold under the name Orilissa, .
It's the first new treatment for the condition to be approved in more than 10 years, AbbVie said.
Two similar phase III trials supported the approval. In them, about 55%-58% of patients taking 200 mg twice daily showed "clinically meaningful reduction in non-menstrual pelvic pain and decreased or stable use of analgesics" after 3 months, and about 50% taking 150 mg once daily did so as well. This compared to about 37% of the trials' placebo groups meeting the same endpoint.
The drug's label will indicate that treatment should ordinarily be limited to 2 years at a dose of 150 mg/day or 6 months at 200 mg twice daily, owing to dose-dependent decreases in bone mineral density (BMD) with elagolix over time. As a GnRH receptor antagonist, elagolix reduces estrogen secretion, which in turn diminishes bone density. AbbVie is telling potential patients that "your BMD may improve after stopping Orilissa but may not recover completely."
Elagolix is also contraindicated for women who are pregnant or are trying to conceive. AbbVie noted that elagolix may alter patients' menstrual cycles such that they may not be aware of becoming pregnant.
Other adverse effects seen in the phase III trials included increases in blood lipids and greater rates of mild-moderate hot flushes.
AbbVie said it expects elagolix to be available in pharmacies next month, with a price of about $10,000 per year, . The company is also pursuing an indication of reducing menstrual bleeding in patients with uterine fibroids.