Mifepristone is Safe and Effective for Treating Patients With Adenomyosis

Mifepristone has shown promise as a viable treatment option for patients with adenomyosis due to its effectiveness and tolerability, according to study results published in JAMA Network Open.

The study authors conducted a multicenter, placebo-controlled, double-blind, randomized clinical trial in 10 hospitals in China to determine whether mifepristone is effective and safe for adenomyosis treatment.

The investigators enrolled patients with adenomyosis pain symptoms between May 2018 and April 2019. Analyses were conducted between October 2019 and February 2020. Participants were randomized 1:1 to receive mifepristone 10 mg or placebo orally once daily for 12 weeks. The primary study outcome was reduction in pain intensity caused by adenomyosis-associated dysmenorrhea, which was evaluated using the visual analog scale (VAS) after 12 weeks of treatment. Secondary outcomes included changes in menstrual blood loss, hemoglobin levels in patients with anemia, platelet count, and uterine volume after 12 weeks of treatment. The safety of the treatment was evaluated based on any adverse events, vital signs, gynecological examinations, and laboratory evaluations.

A total of 126 patients were included in the study analysis. After 12 weeks of treatment, the mean (SD) changes in VAS scores from baseline were -6.63 (1.92) points in the mifepristone group and -0.95 (1.75) points in the placebo group with a -5.68 between-group difference (95% CI, -6.37 to -4.99; P <.001). The total efficacy rates for dysmenorrhea in mifepristone group were 91.8% compared with 23.1% in the placebo group (P <.001). Complete remission rates for dysmenorrhea in mifepristone group were 88.5% compared with 6.2% in the placebo group (P <.001).

The mifepristone group showed improvements in all secondary outcomes. A total of 30.51% of patients in the mifepristone group experienced adverse events compared with 21.88% in the placebo group. No serious adverse events were reported and all were reported to be mild or moderate.

Study limitations include the inclusion of only patients from China; the nonperformance of endometrial biopsies due to ethical principles; and the trial’s 12-weeks treatment period.

The study authors concluded, “In this placebo-controlled randomized clinical trial of mifepristone vs placebo for the treatment of adenomyosis, 12 weeks of mifepristone treatment at a dose of 10 mg per day led to a significant remission for patient symptoms with acceptable tolerability. Therefore, mifepristone was effective and safe for the treatment of adenomyosis.”