Safety and efficacy of a triphasic oral contraceptive containing desogestrel: results of three multicenter trials.

This report combines the data obtained in three multicenter efficacy studies with a new triphasic oral contraceptive combination containing desogestrel (DSG) and ethinyl estradiol (EE). The studies were conducted at 40 investigational sites in the United States (38 centers) and Canada (2 centers) in support of the FDA approval of the product. In total, 1,095 subjects were exposed to the study medication for 11,231 cycles, corresponding to approximately 864 woman-years of use. Of these subjects, 414 completed at least 13 cycles of treatment. Contraceptive efficacy was high; six pregnancies occurred during the in-treatment period (two due to method failure and four due to user failure), corresponding to Pearl Indices of 0.23 and 0.46, respectively. The incidence of irregular bleeding was low, and the acceptability was excellent as evidenced by the low incidence of drug-related drop-outs. No drug-related serious adverse experiences were reported, and the incidence of other drug-related adverse experiences was generally low and decreased with continued use. No effects were seen on blood pressure, body mass index, laboratory parameters, cervical cytology and breast nodularity. These studies demonstrate that triphasic DSG/EE is an effective and acceptable triphasic oral contraceptive preparation with excellent cycle control and no significant physiologic effects.