Ultra-low-dose estradiol and dydrogesterone for treatment of vasomotor symptoms in Europe and China.

OBJECTIVE: Among postmenopausal women, oral, ultra-low-dose continuous combined estradiol (E0.5 mg) plus dydrogesterone (D2.5 mg) reduces vasomotor symptoms (VMS). METHODS: This study was a post hoc analysis of data from two phase 3, double-blind studies. Postmenopausal women were randomized 2:1:2 to receive E0.5 mg/D2.5 mg, E1 mg/D5 mg (not included in this analysis) or placebo for 13 weeks (European study), or randomized 1:1 to receive E0.5 mg/D2.5 mg or placebo for 12 weeks (Chinese study). Endpoints assessed in ethnicity subgroups (European and Chinese) included changes from baseline in number of hot flushes, number of moderate-to-severe hot flushes and Menopause Rating Scale (MRS) score. RESULTS: Overall, 579 women were included in the analysis (E0.5 mg/D2.5 mg, n = 288; placebo, n = 291). European and Chinese women receiving E0.5 mg/D2.5 mg experienced greater reductions from baseline in mean daily number of hot flushes and mean daily number of moderate-to-severe hot flushes at week 4, week 8 and end of treatment versus those receiving placebo. Significant improvements in the 'hot flushes, sweating' MRS item score were reported in both European and Chinese women. CONCLUSION: Oral, ultra-low-dose continuous combined 0.5 mg 17β-estradiol and 2.5 mg dydrogesterone improved VMS compared with placebo in European and Chinese postmenopausal women, with a positive impact on health-related quality of life.