Hemostatic effects of two desogestrel-containing combined oral contraceptive regimens: a multinational, multicenter, randomized, open-label study.

PURPOSE OF INVESTIGATION: To compare the effects of desogestrel (DSG) 150 mcg/ethinyl estradiol (EE) 20 mcg for 21 days followed by either seven days of EE ten mcg (21/7-active) or no treatment (DSG/EE+no Tx) on hemostatic markers.

MATERIALS AND METHODS: This was a randomized, multicenter, open-label study that enrolled healthy premenopausal women. Non-inferiority of 21/7-active to DSG/EE+no Tx was determined if the upper limit of the two-sided 95% CI of the mean treatment difference in prothrombin fragment 1+2 (F1+2) over 24 weeks between groups was < 130 pmol/L.

RESULTS: 246 subjects (n = 125, 21/7-active; n = 121, DSG/EE+no Tx) comprised the primary analysis. Mean F1+2 levels increased in both 21/7-active and DSG/EE+no Tx regimens (least square [LS] mean changes +45 pmol/L and +56.8 pmol/L, respectively). LS mean treatment difference was -11.8 pmol/L (95% CI: -54.8, 31.2).

CONCLUSION: The effect of adding EE ten mcg to the seven-day hormone-free interval of DSG/EE on F1+2 levels was non-inferior to traditional DSG/EE.