A dose-ranging study to determine the efficacy and safety of 1, 2, and 4 mg of dienogest daily for endometriosis

Objectives: To compare the efficacy and safety of dienogest at doses of 1, 2, and 4 mg/day orally in the treatment of endometriosis. Methods: An open-label, randomized, multicenter, 24-week comparative trial in women with histologically confirmed endometriosis. Efficacy was assessed by second-look laparoscopy and patient-reported symptoms. Statistical tests included chi(2) and Wilcoxon signed rank tests. Results: Dienogest reduced mean revised American Fertility Society scores from 11.4 to 3.6 (n=29; P<0.001) in the 2-mg group and from 9.7 to 3.9 (n=35; P<0.001) in the 4-mg group. Dienogest at 2 and 4 mg/day was associated with symptom improvements in substantial proportions of women. Both dienogest doses were generally well tolerated, with low rates of treatment discontinuation due to adverse events. The 1-mg dose arm was discontinued owing to insufficient bleeding control. Conclusion: Dienogest at 2 mg once a day is recommended as the optimal dose in future studies of endometriosis. (C) 2009 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.