Ospemifene's effect on vasomotor symptoms: a post hoc analysis of phase 2 and 3 clinical data

To examine the effect of ospemifene 60 mg/d on vasomotor symptoms in postmenopausal women using clinical safety and efficacy data from five phase 2 and 3 studies.

The incidence of hot flush treatment-emergent adverse events (TEAEs) was compiled from five randomized, placebo-controlled clinical studies; baseline parameters associated with hot flush incidence were also identified. Ospemifene's effects on the frequency and severity of hot flushes were evaluated in a previously unpublished, 6-week, placebo-controlled study.

Analysis of pooled hot flush TEAE data for 2,166 women showed an incidence of hot flush of 8.5% for ospemifene and 3.2% for placebo (P < 0.0001). Hot flushes were most frequent during the first 4 weeks of ospemifene treatment and decreased in frequency thereafter. Logistic regression analysis revealed that hormone therapy within 6 months before study start (P = 0.0234), longer study treatment duration (P = 0.0234), and more hot flush days per month at baseline (P = 0.0313) were associated with more hot flushes. Ospemifene 60 mg/d did not worsen the frequency and severity of existing hot flushes in a 6-week, placebo-controlled trial of 198 postmenopausal women who were experiencing moderate to very severe hot flushes.

In randomized trials, hot flush TEAEs were more frequent with ospemifene 60 mg/d than with placebo, particularly among women with prior history of hormone therapy use. The majority of hot flushes, however, waned after 4 weeks of ospemifene treatment. Ospemifene did not worsen existing hot flushes in women experiencing moderate to very severe hot flushes.