Bleeding profile of a flexible extended regimen of ethinylestradiol/drospirenone in US women: an open-label, three-arm, active-controlled, multicenter study
Contraception, 07/16/2012  Clinical Article

Jensen JT et al. – A flexibleMIB dosing regimen of EE 20 mcg/drospirenone 3 mg is associated with good contraceptive efficacy and fewer bleeding/spotting days than the conventional 24/4 regimen.

• This was a 1–year, open–label, active–controlled, Phase 3 study conducted in the USA. Healthy women (18–45 years) received an ethinylestradiol (EE) 20 mcg/drospirenone 3 mg OC in two flexible extended regimens or in a conventional 24/4 (i.e., 28–day) regimen.
• The primary regimen [management of intracyclic bleeding (flexibleMIB) regimen] was an extended dosing regimen that required subjects to initiate 4–day tablet–free intervals after 3 days of breakthrough bleeding/spotting.
• An alternative extended regimen [active period control (flexibleAPC) regimen] allowed subjects to initiate a 4–day tablet–free interval irrespective of the occurrence of bleeding.
• Bleeding profiles were compared between treatments.
• Efficacy and safety outcomes were also assessed.

• The full analysis set comprised 1864 women (flexibleMIB, N=1406; flexibleAPC, N=232; conventional 24/4, N=226).
• Over 1 year, subjects in the flexibleMIB group experienced significantly fewer (mean±SD, 40±30) bleeding/spotting days than those in the conventional 24/4 group (52±35).
• The corresponding value in the flexibleAPC group was 47±33 days.
• The pregnancy rate in the flexibleMIB group was 1.65 per 100 woman–years (95% confidence interval, 0.96–2.65).
• All three regimens were well tolerated.