A Phase 3, SingleArm, OpenLabel Study to Evaluate the Safety and Contraceptive Efficacy of Relugolix Combination Therapy in Women with Uterine Fibroids or Endometriosis who are 18 to 50 Years of Age and at Risk for Pregnancy

The purpose of this study is to evaluate if relugolix, given with low-dose estradiol (estrogen) and norethindrone acetate (progesterone) (referred to as relugolix combination therapy) is safe and works in the prevention of pregnancy in women with uterine fibroids or endometriosis. Relugolix combination therapy is approved by the US Food and Drug Administration (FDA) to treat heavy menstrual bleeding in women with uterine fibroids (muscular growths in the wall of the uterus [womb]) and to treat moderate to severe pain associated with endometriosis (a condition in which the layer of tissue inside of the uterus is found in other places such as the tubes or ovaries).This drug has also been shown to prevent women from ovulating (releasing an egg), which is the same way many birth control pills work. This study seeks to understand whether women using this study drug for uterine fibroids or endometriosis can also use it as a contraceptive (a drug to prevent pregnancy).

Inclusion criteria:

- Have a confirmed diagnosis of endometriosis or fibroids
- Are a woman between the ages of 18-50 years of age
- Have periods that come at about the same time every month, when you are not on birth control
- Are sexually active with a male partner who has not had a vasectomy

Exclusion criteria:

- Has a presence or history of a venous thromboembolic event, an arterial thrombotic or thromboembolic event, a transient ischemic attack, angina pectoris, or claudication or is at higher risk for these disorders
- Unable to become pregnant for any reason (including hysterectomy)
- Currently pregnant, breastfeeding, or has breastfed in the past year
- Regular (at least once daily) cigarette smoking
- Use of use contraceptive injections (Depo-Provera) in the past two years
- Other criteria may apply

Conditions:
• Endometriosis
• Uterine Fibroids