Efficacy and safety of the contraceptive vaginal ring (NuvaRing) compared with a combined oral contraceptive in Chinese women: a 1-year randomised trial

Abstract

Objectives: The aim of the study was to assess the efficacy and tolerability of the monthly vaginal ring (NuvaRing; 15 μg ethinylestradiol [EE] and 120 μg etonogestrel per day) compared with a monophasic (21/7) combined oral contraceptive (COC) containing 30 μg EE and 3 mg drospirenone in healthy Chinese women aged 18–40 years.

Methods: This was a phase III, open-label, randomised multicentre trial conducted in China. Participants received NuvaRing or COC for 13 cycles (3 weeks of ring/pill treatment followed by a 1-week ring-free/pill-free period). Contraceptive efficacy was assessed by in-treatment pregnancies and expressed by the Pearl Index (PI; number of pregnancies/100 woman-years of use). Cycle control was assessed by unscheduled (breakthrough) and absence of scheduled (withdrawal) bleeding events. Safety and tolerability were assessed throughout the study.

Results: Participants were randomised either to the NuvaRing (n = 732) or to the COC (n = 214); 588 (82.4%) and 182 (78.4%) participants, respectively, completed the study. There were 10 in-treatment pregnancies in the NuvaRing group (PI 1.92; 95% confidence interval [CI] 0.92, 3.53) and five in the COC group (PI 3.12; 95% CI 1.01, 7.29). Breakthrough bleeding/spotting ranged from 18.6% (Cycle 1) to 4.2% (Cycle 11) for NuvaRing and from 21.6% (Cycle 1) to 7.9% (Cycle 11) for COC. Absence of withdrawal bleeding ranged from 8.6% (Cycle 1) to 3.0% (Cycle 11) for NuvaRing and from 14.6% (Cycle 1) to 6.4% (Cycle 5) for COC. For NuvaRing and COC, respectively, 26.6% and 25.0% of participants had treatment-related adverse events, and 7.0% and 9.1% discontinued the study as a result.

Conclusions: Once-monthly NuvaRing is efficacious and safe for use in Chinese women.

Chinese abstract

目的：本研究的目的是评估18-40岁的中国健康妇女应用月使用型的阴道环（NuvaRing;每天释放15μg炔雌醇和120μg依托孕烯）的有效性和耐受性与含30μg炔雌醇和3mg屈螺酮的单相（21/7）复方口服避孕药（COC）的比较。

方法：这是一项在中国进行的III期、开放标签、随机多中心的临床试验。受试者接受阴道避孕环NuvaRing或复方口服避孕药13个周期（1个周期包括3周环/药治疗+1周无环/药）。避孕有效性通过治疗期间的妊娠情况进行评估, 使用珀儿指数（PI;100名妇女的年妊娠量）表示。周期控制通过不定期的（突破性）出血事件和缺乏计划的（撤退性）出血事件进行评估。并在整个研究中对安全性和耐受性进行了评估。

结果：受试者被随机分到阴道避孕环组（n = 732）或复方口服避孕药组（n = 214）, 分别有588名（82.4%）及182名（78.4%）受试者完成了该研究。阴道避孕环组治疗期间有10例妊娠（PI 1.92;95%置信区间[CI] 0.92, 3.53）, 复方口服避孕药组治疗期间有5例妊娠（PI 3.12;95%置信区间[CI] 1.01, 7.29）。阴道避孕环组突破性出血/点滴出血的发生率为18.6%（第1周期）到4.2%（第11周期）, 而复方口服避孕药组突破性出血/点滴出血的发生率为21.6%（第1周期）到7.9%（第11周期）。阴道避孕环组无撤退性出血的发生率为8.6%（第1周期）到3.0%（第11周期）, 而复方口服避孕药组无撤退性出血的发生率为14.6%（第1周期）到6.4%（第5周期）。阴道避孕环组和复方口服避孕药组与治疗相关的不良事件发生率分别为26.6%和25%, 并因此有7.0%和9.1%的受试者终止该研究。

结论：每月1次的阴道避孕环（NuvaRing）用于中国女性是安全有效的。

Keywords:

• Compliance
• contraceptive pill
• efficacy
• NuvaRing
• tolerability

Acknowledgements

The authors thank Kristen Lewis of Merck & Co., Inc., Kenilworth, NJ, USA, for editorial assistance with the preparation of this manuscript for journal submission.

Disclosure statement

Y.Q., C.Y., C.M.S. and G.W. report that they are current employees of Merck & Co., Inc. and hold stock or stock options in the company. T.K. reports that he has received personal fees from Merck & Co., Inc. during the conduct of the study. M.M.-P. reports that she is a former employee of Merck & Co., Inc. G.F., M.R., W.D., P.S., Q.C. and S.W. report that they served as investigators on the study and received study funding from Merck & Co., Inc. All authors are responsible for the work described in this manuscript. All authors were involved in at least one of the following: conception, design, acquisition, analysis, statistical analysis or interpretation of data and drafting the manuscript and/or revising it for important intellectual content. All authors provided final approval of the version to be published.

Funding information

Funding for this study was provided by Merck & Co., Inc., Kenilworth, NJ, USA.