NCT03271489

Long-Term Safety Study of Elagolix in Combination With Estradiol/Norethindrone Acetate for the Management of Heavy Menstrual Bleeding Associated With Uterine Fibroids in Premenopausal Women

A Phase 3b Study to Evaluate the Long-Term Safety of Elagolix in Combination With Estradiol/Norethindrone Acetate for the Management of Heavy Menstrual Bleeding Associated With Uterine Fibroids in Premenopausal Women

• Status: Completed
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 478 (actual)
• Sponsor: AbbVie · Industry
• Sex: Female
• Age: 18 Years – 50 Years
• Healthy volunteers: Not accepted

Summary

This randomized multicenter phase 3b study seeks to evaluate the safety of elagolix in combination with estradiol/norethindrone acetate for the management of heavy menstrual bleeding associated with uterine fibroids in premenopausal women. This study was double-blind (DB) during the first 12 months and open-label (OL) for the next 36 months.

Detailed description

478 participants were randomly assigned at a ratio of 2:1 to the following treatment groups: 1. Elagolix 300 mg twice daily (BID) plus estradiol 1.0 mg/norethindrone acetate 0.5 mg (E2/NETA) once daily (QD) for 48 months, followed by 12 months PTFU 2. Placebo for 12 months, followed by elagolix 300 mg BID plus E2/NETA QD for 36 months, followed by 12 months PTFU This study was double-blinded during the first 12 months and open-label for the next 36 months. Participants entered up to 12 months of PTFU after completing treatment Month 48 (or at any time a participant prematurely discontinued treatment).

Conditions

• Heavy Menstrual Bleeding
• Uterine Fibroids

Interventions

Type	Name	Description
DRUG	Elagolix	Film-coated 300 mg tablets
DRUG	Estradiol /norethindrone acetate (E2/NETA)	Estradiol 1 mg/norethindrone acetate 0.5 mg capsules
OTHER	E2/NETA Placebo	Placebo capsules
OTHER	Elagolix Placebo	Film-coated placebo tablets

Timeline

• Start date: 2017-09-13
• Primary completion: 2024-06-28
• Completion: 2024-06-28
• First posted: 2017-09-05
• Last updated: 2025-07-22
• Results posted: 2025-07-22

Locations

157 sites across 2 countries: United States, Puerto Rico

Regulatory

• FDA-regulated drug study