Open-label study of ultra low-dose mifepristone for the treatment of uterine leiomyomata.

Objective: To assess the effect of ultra low-dose mifepristone on uterine size, pain, bleeding and quality of life among women with symptomatic leiomyomata.

Study Design: Open-label cohort study of 2.5mg mifepristone orally among adult women with at least moderately severe symptoms related to leiomyomata and total uterine volume of greater than 160 cm(3), or at least one myoma of greater than 2.5 cm diameter. Assessments of leiomyomata and uterine size (ultrasound), pain (McGill Pain Questionnaire), bleeding (daily log duration), quality of life (Uterine Fibroid Symptom and Quality of Life) and health status (SF-36) were conducted at baseline, three months and six months. Endometrial sampling was done at baseline and six months.

Results: Seventeen (74%) participants completed the entire six-month trial. Each of the measures showed significant improvement at six months compared to baseline (p<0.001). Uterine volume decreased by 11% and anemia, bleeding, pain, health status and fibroid-related quality of life improved during the course of the trial. Endometrial sampling showed cystic glandular dilatation, but no evidence of endometrial hyperplasia or cellular atypia.

Conclusion: Treatment of women with symptomatic leiomyomata with ultra low-dose mifepristone for six months is associated with modest reduction in uterine size, appreciable improvements in symptoms and quality of life and no evidence of endometrial hyperplasia.