Hot flush frequency and severity at baseline as predictors of time to transient and stable treatment success: pooled analysis of two CE/BZA studies.

Objective: To evaluate the impact of baseline hot flush frequency and severity on time to symptom improvement during treatment with conjugated estrogens/bazedoxifene (CE/BZA).

Methods: Data were pooled through week 12 from two randomized placebo-controlled trials (SMART-1 and SMART-2) of nonhysterectomized postmenopausal women with hot flushes treated with CE 0.45 mg/BZA 20 mg or CE 0.625 mg/BZA 20 mg. Time to transient and stable improvement (≥ 50% reduction in hot flush frequency/severity) was estimated using nonparametric models.

Results: Transient improvement in hot flush frequency occurred earlier in women treated with CE 0.45 mg/BZA 20 mg with less frequent versus more frequent baseline hot flushes per day: median time to transient improvement was 2, 7, and 11 days for women with < 3, 3 to < 8, and ≥ 8 hot flushes per day at baseline, respectively (P = 0.0009). Transient improvement in severity occurred earlier for women with less severe versus more severe baseline hot flushes: median time to transient improvement was 2, 6, and 16 days for women with mild, moderate, and severe hot flushes at baseline, respectively (P < 0.0001). Stable improvement typically occurred 2 to 3 days after the transient event and was less influenced by baseline status. A similar pattern was observed with CE 0.625 mg/BZA 20 mg treatment, though improvement occurred a few days earlier than with CE 0.45 mg/BZA 20 mg.

Conclusion: Women with more frequent/severe hot flushes take longer to achieve transient improvements with CE/BZA and should be encouraged to continue treatment, as it may take longer than a few weeks to achieve significant improvement.