This study was designed to assess the long-term safety and tolerability of a new flexible extended regimen of EE, 20 μg/DRSP 3 mg, which allows management of intracyclic bleeding compared to conventional 28-day and fixed extended regimens.

In this Phase III, multicentre, open-label study, women were randomized to EE/DRSP in the following regimens: flexibleMIB, conventional 28-day or fixed extended during a 1-year comparative phase. After that, women entered a 1-year safety extension phase in which the majority received the flexibleMIB regimen. Researchers conducted a separate analysis of specific safety parameters at two study centers.

Researchers analyzed the results in 1067 and 783 women in the comparative and safety extension phases. Overall, 56.3% of women experienced ≥one adverse event (AE) in the safety extension phase. Serious AEs occurred in 3.0%, 1.4%, and 3.3% of women receiving the flexibleMIB, conventional, and fixed extended regimens. No unexpected endometrial, hormonal, lipid, hemostatic, or metabolic findings occurred with any of the three regimens.

The study concluded that EE/DRSP in a flexible extended regimen with intracyclic bleeding management is well-tolerated.