Ethinylestradiol 20 μg/drospirenone 3 mg in a flexible extended regimen for the management of endometriosis-associated pelvic pain: A randomized controlled trial

Fertility and Sterility | September 13, 2017

Harada T, et al. - A randomized controlled trial is performed to research the effectiveness and safety of ethinylestradiol 20 μg/drospirenone 3 mg in a flexible extended regimen (FlexibleMIB) compared with placebo to treat endometriosis-associated pelvic pain (EAPP). The outcome of this study suggests that the FlexibleMIB improved EAPP and was well tolerated and they recommending that it may be a new option for managing endometriosis.


  • For this research, they designed a phase 3, randomized, double-blind, placebo-controlled, parallel-group study, consisting of a 24-week double-blind treatment phase followed by a 28-week open-label extension phase with an unblinded reference arm.
  • This study was conducted at 32 centers.
  • A total of 312 patients with endometriosis were enrolled in this study.
  • All the participants were randomized to FlexibleMIB, placebo, or dienogest.
  • The FlexibleMIB and placebo arms received 1 tablet per day continuously for 4 months, with a 4-day tablet-free interval either after 120 days or after ≥ 3 consecutive days of spotting and/or bleeding on days 25-120.
  • After 24 weeks, placebo recipients were changed to FlexibleMIB. Patients randomized to dienogest received 2 mg/d for 52 weeks in an unblinded reference arm.


  • Compared with placebo, FlexibleMIB significantly decreased the most severe EAPP (mean difference in visual analog scale score: -26.3 mm).
  • FlexibleMIB also improved other endometriosis-associated pain and gynecologic findings and decreased the size of endometriomas.

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