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

Abstract 

Objectives

To compare the efficacy and safety of dienogest at doses of 1, 2, and 4mg/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 χ² 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 4mg/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 2mg once a day is recommended as the optimal dose in future studies of endometriosis.

Keywords: Dienogest, Endometriosis, Dose finding, Pelvic pain, Progestins