Evaluation of the efficacy and safety of dienogest in the treatment of painful symptoms in patients with adenomyosis: a randomized, double-blind, multicenter, placebo-controlled study.

OBJECTIVE: To evaluate the efficacy and safety of dienogest (DNG), a progestational 19-norsteroid, in patients with symptomatic adenomyosis.

DESIGN: Phase III, randomized, double-blind, multicenter, placebo-controlled study.

SETTING: Clinical study sites in Japan.

PATIENT(S): Sixty-seven patients with adenomyosis.

INTERVENTION(S): Patients were randomly assigned to receive DNG (2 mg/d, orally) or placebo for 16 weeks. In cases of complicated anemia, patients were treated for anemia before randomization.

MAIN OUTCOME MEASURE(S): The primary end point was the change from baseline to after treatment pain score, using zero- to three-point verbal rating scales that defined pain severity according to limited ability to work and need for analgesics. The visual analogue scale was used as another pain parameter.

RESULT(S): Decreases from baseline in the pain score and the visual analogue scale at the end of treatment were significantly more in the DNG group than in the placebo group (P<.001). During the treatment period, almost all of the patients treated with DNG experienced irregular uterine bleeding and one patient had mild anemia. No severe cases of anemia were observed.

CONCLUSION(S): These results suggest that DNG is effective and well tolerated in the treatment for painful symptoms associated with adenomyosis not complicated by severe uterine enlargement or severe anemia.

CLINICAL TRIAL REGISTRATION NUMBER: JapicCTI-142642(en).