This study is looking at how well and how safe a medicine called OG-6219 works for women aged 18 to 49 who have bad pain from a condition called endometriosis. Endometriosis is when tissue like the lining inside the uterus grows outside of it, causing pain. The study will last about 16 weeks, during which you will take OG-6219 or a placebo (a pill that looks like the medicine but has no medicine in it). You will need to visit the study site for check-ups. A few people in the study will have extra tests to see how the medicine moves in the body.

• The study lasts for approximately 16 weeks with follow-up visits.
• You must agree to use two forms of non-hormonal birth control during the study.
• You cannot join if you have certain medical conditions or are taking specific medications.