A Study to Evaluate the Safety and Efficacy of Elagolix for the Management of Heavy Menstrual Bleeding Associated With Uterine Fibroids in Premenopausal Women

Inclusion Criteria:

• Participant at the time of screening has a diagnosis of uterine fibroids documented bya pelvic ultrasound [transabdominal ultrasound (TAU) and transvaginal ultrasound (TVU)].
• Participant has HMB associated with uterine fibroids as evidenced by menstrual bloodloss (MBL) > 80 mL during 1 menses in screening as measured by the alkaline hematinmethod.
• Participant has negative urine and/or serum pregnancy test in Washout (if applicable)and/or Screening and just prior to first dose.
• Participant has an adequate endometrial biopsy performed during Screening, the resultsof which show no clinical significant endometrial pathology.

Exclusion Criteria:

• Participant has screening pelvic ultrasound or saline infusion sonohysterography (SIS)or magnetic resonance imaging (MRI; if SIS is unevaluable), results that show aclinically significant gynecological disorder.
• Participant has history of osteoporosis, osteopenia, or other metabolic bone disease.
• Participant has clinically significant abnormalities in clinical chemistry,hematology, or urinalysis.
• Participant has a history of major depression or post-traumatic stress disorder (PTSD)episode within 2 years of screening, OR a history of other major psychiatric disorderat any time (e.g., schizophrenia, bipolar disorder).
• Participant is using any systemic corticosteroids for over 14 days within 3 monthsprior to Screening or is likely to require treatment with systemic corticosteroidsduring the course of the study. Over the counter and prescription topical, inhaled,intranasal or intra-articular injectable (for occasional use) corticosteroids areallowed.