Efficacy and safety of a combined oral contraceptive containing estradiol valerate/dienogest: results from a clinical study conducted in North America.

Background: This study investigated the efficacy and safety of a combined oral contraceptive (COC) containing estradiol valerate/dienogest (E2V/DNG). Methods: This was a multicenter, noncomparative, 13-cycle (extended to 28 cycles) study conducted in the United States and Canada. Contraceptive efficacy was calculated as a Pearl Index for 13 cycles, based on all on-treatment pregnancies; bleeding patterns were calculated based on bleeding and spotting information recorded daily in diary cards. Safety events during a 16-month extension study were added to the 1-year data. Results: In total, 499 women, aged 18-35 years, were enrolled, and 490 of them were included in the full analysis set for contraceptive efficacy. Five pregnancies occurred in the first year (unadjusted Pearl Index=1.64). In cycles 1-12, an average 23.5% of women had absent scheduled (withdrawal) bleeding. Among women with scheduled (withdrawal) bleeding, bleeding started after a median of 2 days after intake of the last DNG-containing pill. For safety, data included from 147 women followed over an additional 16 months were added to the original 13-cycle data set. Treatment-related adverse events (AEs) occurred in 51.8% of women; 14.9% discontinued because of AEs over the entire 28-month study period. Conclusion: A COC with E2V and DNG was shown to provide effective contraception in women aged 18-35 years in North America.