This study is an international phase 3 open-label, single-arm, long-term efficacy and safety extension study that will enroll eligible participants who have completed their participation in one of the phase 3 randomized, double-blind, placebo-controlled parent studies, MVT-601-3001 (LIBERTY 1 - NCT03049735) or MVT-601-3002 (LIBERTY 2 - NCT 03103087). All participants will receive relugolix 40 mg orally once daily co-administered with low-dose E2 (1.0 mg) and NETA (0.5 mg) for 28 weeks.~Approximately 600 women with heavy menstrual bleeding associated with uterine fibroids will be enrolled, after having completed a 24-week treatment period in one of the parent studies. The objectives of the study are to evaluate long-term efficacy and safety through up to 52 weeks of treatment (including treatment during the parent study) of relugolix co-administered with low-dose E2/NETA.~Screening and baseline procedures will be done at the same visit for this extension study (referred to as the Week 24/Baseline Visit), which coincides with the Week 24 Visit from the parent study, and will be defined as the date of completion of the last Week 24 procedure in the parent study. Participants will have received their last dose of study drug in the parent study on the day prior to the Week 24/Baseline Visit and will receive their first dose of study drug for this extension study in the clinic after the participant is determined to be eligible for this extension study and has provided informed consent to participate. The administration of the first dose of study drug for MVT-601-3003 will define enrollment into this study. Study participants will then take the open-label study treatment orally once daily for 28 weeks.
The purpose of this study is to determine the long-term efficacy and safety of relugolix 40 milligrams (mg) once daily co-administered with low-dose estradiol (E2) and norethindrone acetate (NETA) for 28 weeks on heavy menstrual bleeding associated with uterine fibroids in participants who previously completed a 24-week treatment period in one of the parent studies (MVT-601-3001 or MVT-601-3002).