Study of the Contraceptive Efficacy and Safety of a NOMAC-E2 Combined Oral Contraceptive (COC)(P06448)

The purpose of this study was to assess the contraceptive efficacy of a nomegestrol acetate + 17ß-estradiol (NOMAC-E2) combined oral contraceptive (COC) in healthy, sexually-active American women at risk for pregnancy. Vaginal bleeding patterns of women taking NOMAC-E2 were assessed and compared to those of women taking a norethisterone acetate + ethinyl estradiol (NETA-EE) COC. The safety of NOMAC-E2 was also assessed. Participants were randomized to receive either NOMAC-E2 or NETA-EE in a 3:1 ratio. As of Amendment 1 (which increased the sample size of the NOMAC-E2 group), the randomization ratio was adapted accordingly for participants randomized after the sample size increase.