Therapy of heavy menstrual bleeding in Korea: Subanalysis and results from a multinational clinical trial in the Asian region investigating the levonorgestrel-releasing intrauterine system versus conventional therapy

OBJECTIVE: To compare real-life clinical outcomes with the levonorgestrel-releasing intrauterine system (LNG-IUS) and conventional medical therapies (CMTs), including combined oral contraceptives and oral progestins in the treatment of idiopathic heavy menstrual bleeding (HMB) in South Korea. METHODS: This prospective, observational cohort study recruited a total of 647 women aged 18 to 45 years, diagnosed with HMB from 8 countries in Asia, including 209 women from South Korea (LNG-IUS, 169; CMTs, 40), who were followed up to one year. The primary outcome was cumulative continuation rate (still treated with LNG-IUS and CMTs) at 12 months. Secondary outcomes included bleeding pattern, assessment of the treatment efficacy by treating physician and safety profile. RESULTS: The continuation rate at 12 months was significantly higher with the LNG-IUS than CMTs (85.1% vs. 48.5%, respectively; P<0.0001). The 51.5% of CMTs patients discontinued treatment and 18.8% of LNG-IUS patients discontinued treatment. The most common reasons for discontinuation for CMTs were switching to another treatment and personal reasons. When compared to CMTs, the LNG-IUS offered better reduction in subjectively assessed menstrual blood loss and the number of bleeding days, tolerability and with better efficacy in HMB, as assessed by physician's final evaluation. CONCLUSION: This study provides novel information on the real-life treatment patterns of HMB in South Korea. The efficacy of CMTs was inferior compared to the LNG-IUS in the clinical outcomes measured in this study. Due to the better compliance with LNG-IUS, the cumulative continuation rate is higher than CMTs. We conclude that the LNG-IUS should be used as the first-line treatment for HMB in Korean women, in line with international guidelines.