This is the long-term extension of a phase III, efficacy and safety open-label (protocol PGL09-026) with PGL4001 10mg tablets once daily for three months, blinded towards the administration of progestin or placebo tablets after end of PGL4001 treatment.

This extension study consists of three periods of 3 months open-label PGL4001 treatment, each followed by ten days of double-blind treatment with progestin or placebo and then a period without treatment.

Inclusion Criteria:

• Subject completed visit 6 of PGL09-026 study, 10 to 18 days after menstruation following end of treatment with PGL4001, and did not take medications forbidden by the protocol.

Exclusion Criteria:

• Subject has a large uterine polyp (> 2cm).
• Subject has one or more ovarian cysts ≥ 4cm diagnosed by ultrasound during PGL09-026 study.
• Subject has abnormal hepatic function at re-test.
• Subject has clinically significant abnormal findings at visit A or any other medical condition(s) or laboratory findings that, in the opinion of the investigator, might jeopardize the subject's safety or interfere with study evaluations.
• Subject has a positive pregnancy test or is planning a pregnancy during the course of the study.