Ospemifene, a novel selective estrogen receptor modulator for treating dyspareunia associated with postmenopausal vulvar and vaginal atrophy

OBJECTIVE: The aim of this work was to study the role of ospemifene, a novel selective estrogen receptor modulator, in the treatment of vulvar and vaginal atrophy in postmenopausal women with moderate to severe dyspareunia and physiological vaginal changes. METHODS: This multicenter phase 3 study used a randomized, double-blind, parallel-group design to compare the efficacy, safety, and tolerability of oral ospemifene 60 mg/day versus placebo. A total of 605 women aged 40 to 80 years who self-reported a most bothersome symptom of dyspareunia and had a diagnosis of vulvar and vaginal atrophy were randomized to take a once-daily dose of ospemifene (n = 303) or placebo (n = 302) for 12 weeks. RESULTS: Analysis of the intent-to-treat (n = 605) population found the efficacy of ospemifene to be significantly greater than that of placebo for each of the following coprimary endpoints: percentages of parabasal and superficial cells, vaginal pH, and severity of dyspareunia. With ospemifene, the percentage of parabasal cells and vaginal pH significantly decreased; the percentage of superficial cells significantly increased; and dyspareunia was significantly reduced versus placebo (all P < 0.0001, except for dyspareunia: P = 0.0001). Among the randomized women, 186 (61.4%) in the ospemifene group and 154 (51.0%) in the placebo group reported at least one treatment-emergent adverse event. Hot flushes were the most frequently reported treatment-related adverse event (ospemifene 6.6% vs placebo 3.6%); only one participant discontinued in each group. As determined by the investigators, no serious adverse events related to the study drug were reported. CONCLUSIONS: In this study, once-daily oral ospemifene 60 mg was effective for the treatment of vulvar and vaginal atrophy in postmenopausal women with dyspareunia.