Safety and Efficacy of Combined Oral Contraceptive Ethinyl Estradiol/Drospirenone (YAZ) in Chinese Women: A Single-Arm, Open-Label, Multicenter, Post-Authorization Study.

Introduction: The study was conducted to assess the safety and efficacy of a combined oral contraceptive, YAZ, containing 3 mg drospirenone/20 μg ethinyl estradiol administered in a 24/4 regimen.

Methods: This was a single-arm, open-label, interventional, post-authorization safety surveillance study of YAZ across 6 treatment cycles. Primary objective was assessing its safety profile in Chinese women. Secondary objectives included assessing contraceptive efficacy, cycle control, and bleeding patterns among subjects with and without preceding abortion, along with efficacy in moderate acne vulgaris. Subgroup analyses included assessing efficacy in the dysmenorrhea group using a visual analog scale. All variables were analyzed by descriptive statistical methods.

Results: Of 1921 women treated with YAZ (mean age: 29.9 ± 5.5 years), 12.9% reported adverse drug reactions. Most frequently reported adverse events were nausea (2.6%), breast pain (2.3%), and breast swelling (1.3%). Unintended pregnancy rate (adjusted Pearl Index) was 0.3 (n = 2 pregnancies, 95% confidence interval 0.1-1.2). Incidence of overall withdrawal bleeding (cycle 2-cycle 5) was 93.3%-95.2%, of which 87.8%-95.1% in post-abortion subjects and 94.0%-95.3% in subjects without preceding abortion. Intra-cyclic bleeding (cycle 2-cycle 6) decreased in the overall population (from 14.9 to 5.5%), post-abortion subgroup (32.4% to 6.9%), and in subjects without preceding abortion (12.4% to 5.3%). Incidence of onset of withdrawal bleeding < 7 days among abnormal uterine bleeding patients at baseline was 85.2% and 87.2% at cycles 2 and 5, respectively, and incidence of intra-cyclic bleeding was 23.5% and 8.0% at cycles 1 and 6, respectively. Mean percent change in total acne lesion count from baseline to cycle 6 was - 79.9% ,and mean change in pain severity due to dysmenorrhea was - 31.2 mm at cycle 6 when compared with baseline.

Conclusion: The 24/4 YAZ regimen showed good safety profile, contraceptive reliability, good cycle control along with subgroup of patients. Improvements in dysmenorrhea and acne were also observed. No events of venous thromboembolism/arterial thromboembolism were reported.

Trial Registration: ClinicalTrials.gov identifier, NCT02710708; Center for Drug Evaluation (CDE), China Food and Drug Administration (CFDA) number: CTR20160203.