Efficacy, cycle control, and safety of two triphasic oral contraceptives: Cyclessa (desogestrel/ethinyl estradiol) and ortho-Novum 7/7/7 (norethindrone/ethinyl estradiol): a randomized clinical trial

Abstract

The contraceptive efficacy, cycle control, and safety of a new low-dose, triphasic desogestrel/ethinyl estradiol oral contraceptive (CTR 77, Cyclessa(TM)) was compared to that of a marketed, triphasic norethindrone/ethinyl estradiol oral contraceptive (Ortho-Novum(R) 7/7/7). Two identical multicenter, open-label, randomized, parallel group, comparative Phase III 6-cycle trials were designed to each enroll 4200 healthy women. The combined comparative data for Cyclessa versus Ortho-Novum 7/7/7 for both studies are reported here. Cyclessa and Ortho-Novum 7/7/7 had comparable contraceptive efficacy. Despite a lower ethinyl estradiol dose (25 microg/day vs. 35 microg/day), the Cyclessa group had significantly improved cycle control in comparison to the Ortho-Novum 7/7/7 group for presence of a withdrawal bleed (p = 0.001), lack of early withdrawal bleed (p = 0.01), and breakthrough bleeding/spotting (p = 0.001). For each of the months of the study, the incidence of breakthrough bleeding/spotting was lower in the Cyclessa group than the Ortho-Novum 7/7/7 group (breakthrough bleeding, p = 0.006; breakthrough spotting, p = 0.001). The incidence of other adverse events was similar among treatment groups, an observation that supports the safety of both formulations. There was significantly less weight gain (p = 0.0002) and less increase in the body mass index (BMI) (p = 0.0002) in the Cyclessa group. The contraceptive efficacy and safety of Cyclessa is comparable to Ortho-Novum 7/7/7. Cyclessa provides significantly improved cycle control with no weight gain.