A Study to Assess the Efficacy and Safety of OBE2109 in Subjects With Endometriosis

The study is a prospective, dose-finding, randomized, parallel group, double-blind,
placebo-controlled phase 2b study investigating the efficacy and safety of OBE2109 in the
treatment of 330 women with moderate-to-severe endometriosis associated pain.

Subject will be randomized to one of 6 treatment groups in a 1:1:1:1:1:1 ratio (1 placebo
group, 5 dose groups with different dosage/regimen).

Eligible subjects will be offered the opportunity to continue treatment with OBE2109 in an
extension phase. Subjects who do not continue in the extension will enter the treatment-free
follow-up phase of the study.

Key Inclusion Criteria:

- The subject must have had her most recent surgical and - if available - histological,
diagnosis of pelvic endometriosis up to 10 years before screening.

- The subject has moderate to severe endometriosis-associated pain during the screening
period.

- The subject has regular menstrual cycles.

- The subject has a BMI ≥ 18 kg/m2 at the screening visit.

Key Exclusion Criteria:

- The subject is pregnant or breast feeding or is planning a pregnancy within the
duration of the treatment period of the study.

- The subject had an interventional surgery for endometriosis performed within a period
of 60 days before screening.

- The subject did not respond to prior treatment with gonadotropin releasing hormone
(GnRH) agonists or GnRH antagonists for endometriosis.

- The subject has a history of, or known osteoporosis or other metabolic bone disease.

- The subject has chronic pelvic pain that is not caused by endometriosis and requires
chronic analgesic / therapy, or that would interfere with the assessment of
endometriosis related pain.