This randomized withdrawal study is an international phase 3 double-blind, placebo-controlled study that will enroll eligible patients with uterine fibroids who have completed the 24-week treatment period in a parent study (MVT-601-3001 or MVT-601-3002) and the 28-week treatment period of the open-label extension study (MVT-601-3003). When including treatment during the parent study and the extension study, patients completing this randomized withdrawal study will have received up to a total of 104 weeks of treatment with relugolix.~Approximately 360 women with heavy menstrual bleeding associated with uterine fibroids completing the extension study with a response to treatment will be eligible to participate in this study. A responder is defined as a patient who demonstrates a menstrual blood loss of < 80 mL and at least a 50% reduction from parent study baseline menstrual blood loss volume on the alkaline hematin analysis of the feminine products returned at Week 48 in the extension study.~Screening procedures will be done on the same day as the Week 52 visit for the extension study. This visit will be referred to as the Week 52/Baseline visit. When the Week 52/Baseline procedures in the extension study have been completed, the investigator will assess patient eligibility for participation in this study. The eligibility assessment will be based on data available at the Week 52/Baseline visit.~Patients will be asked to provide feminine products for alkaline hematin analysis at each visit until the analysis confirms the return of heavy menstrual bleeding. The patients will then be offered retreatment with open-label relugolix with E2/NETA with the onset of the next menses. They will resume collection of feminine products for alkaline hematin analysis until two consecutive analyses confirm resolution of heavy menstrual bleeding (menstrual blood loss of < 80 mL). Safety will be assessed throughout the study by monitoring adverse events, vital signs, physical examinations, clinical laboratory tests, and assessments of bone mineral density.
The objectives of this randomized withdrawal study are to evaluate the long-term efficacy and safety of the combination of relugolix, estradiol (E2) and norethindrone acetate (NETA), once daily, for up to 104 weeks in patients with uterine fibroids who have completed a total of 52 weeks of treatment, including a 24-week treatment period in a parent study (study MVT-601-3001 or MVT-601-3002) and a 28-week treatment period in the open-label extension study (MVT-601-3003), and who meet the definition of responder, defined as a patient who demonstrates a menstrual blood loss of < 80 mL and at least a 50% reduction from parent study baseline menstrual blood loss volume on the alkaline hematin analysis of the feminine products returned at Week 48 in the extension study.