Efficacy, safety and sustainability of treatment continuation and results of an oral contraceptive containing 30 mcg ethinyl estradiol and 2 mg chlormadinone acetate, in long-term usage (up to 45 cycles) — an open-label, prospective, noncontrolled, office-based Phase III study

Abstract

Background This open-label, noncontrolled study assessed the long-term efficacy and tolerability of the monophasic combined low-dose oral contraceptive (OC) ethinyl estradiol (EE) 30 mcg+chlormadinone acetate (CMA) 2 mg (Belara®). Study Design In total, 781 women who had already taken EE 30 mcg+CMA 2 mg for 24 cycles in a previous Phase III study were assessed for up to 45 cycles. Results Over 23,033 cycles, the Pearl Index was 0.16 (95% confidence interval, 0.04–0.42). Approximately 86% of women had regular withdrawal bleeding in each cycle, while incidence of intracyclic bleedings (1.6–6.4%) and proportion of women with amenorrhea (4%) were low. The incidence of acne decreased from 13.8% to 5.7%, while rates of hirsutism, alopecia and seborrhea remained low (≤4%) throughout this study. The most frequent adverse events were consistent with OC treatment, and no unexpected events occurred. No changes in mean blood pressure and pulse rate were observed during the study, and there were no clinically relevant changes in liver or hematological parameters, hemostasis or carbohydrate metabolism. The incidence of pathological findings in gynecological examination was low and decreased over time. Conclusion EE 30 mcg+CMA 2 mg was an effective and well-tolerated OC, with beneficial effects on cycle stability, intracyclic bleeding, amenorrhea and signs of androgenization that were maintained during long-term treatment for up to 5 years. There was no evidence of an increased risk of thromboembolic events, atherogenic disease or cervical cancer, suggesting that 30 EE mcg+CMA 2 mg is highly suitable for long-term use.