Randomized Trial Assessing Quinagolide Vaginal Ring for Endometriosis-related Pain

Inclusion Criteria: * Pre-menopausal females aged ≥18 years at time of signing informed consent(s) with regular menstrual cycles. * Body mass index (BMI) of 18-42 kg/m2 (both inclusive) at screening. * Initial confirmation of endometriosis by laparoscopy or laparotomy within the last 10 years before the run-in visit or visualization of persistent endometrioma by repeat ultrasound. * Transvaginal ultrasound documenting a uterus with no clinically significant abnormalities and presence of at least one ovary with no clinically significant abnormalities (with the exception of endometrioma) at the run-in visit. * Eligible participants experienced moderate to severe endometriosis-related pain, which was defined as at the run-in visit, the participant having an NRS score of ≥5 for the worst endometriosis related pain during the past menstrual cycle and at randomization, the participant having a mean daily NRS score of ≥4 for the worst endometriosis related pain during each run-in menstrual cycle. Exclusion Criteria: * History of no relief of endometriosis related pain after any medical therapy or surgery. However, history of partial pain relief, discontinuation due to side effects are not exclusionary. * Known bone diseases (e.g. osteoporosis, Paget's disease and osteomalacia) affecting bone resorption or bone formation markers. * Any significant abnormal findings of heart examinations before randomization. * History of mental illness including occurrence of acute psychosis, bipo…