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.