['endometriosis']
['placebo', 'levonorgestrel', 'anastrozole', 'lupron / leuprolide acetate']

        Inclusion Criteria:

          -  Premenopausal women18 years and above at the time of screening.

          -  Women with endometriosis confirmed by laparoscopy or laparotomy within the last ten
             years but not less than 8 weeks before the screening visit In Japan, diagnosis based
             on imaging (transvaginal ultrasound or MRI) also qualifies for inclusion.

          -  Moderate to severe endometriosis-associated pelvic pain (EAPP) of ≥5 in the last 28
             days before screening visit 1 measured on the numeric rating scale (NRS; i.e. 4-week
             recall period).

          -  At randomization: Adherence to the study procedures during the screening period, at
             least 24 diary entries of ESD item 1 during the last 28 consecutive days before the
             randomization visit, and a sum of the available ESD item 1 ('worst pain' on the daily
             NRS) entries during this period of at least 98 (corresponding to an average score of ≥
             3.5).

          -  Willingness to use only ibuprofen as rescue pain medication for EAPP, if needed
             according to investigator's instruction.

          -  Use of a non-hormonal barrier method (i.e. spermicide-coated condoms) for
             contraception from screening visit until the end of the study. This is not required if
             adequate contraception is achieved by vasectomy of the partner

        Exclusion Criteria:

          -  Pregnancy or lactation (less than three months since delivery, abortion, or lactation
             before start of treatment)

          -  Any diseases or conditions that can compromise the function of the body systems and
             could result in altered absorption, excessive accumulation, impaired metabolism, or
             altered excretion of the study drug

          -  Any diseases or conditions that might interfere with the conduct of the study or the
             interpretation of the results.

          -  Any disease or condition that may worsen under hormonal treatment according to the
             assessment and opinion of the investigator.

          -  Undiagnosed abnormal genital bleeding

          -  Wish for pregnancy during the study

          -  Regular use of pain medication due to other underlying diseases

          -  Non-responsiveness of endometriosis associated pelvic pain (EAPP) to GnRH-a or surgery
             (partial response is not exclusionary).
      