Ospemifene Significantly Improves Female Sexual Dysfunction As Measured By the Female Sexual Function Index (FSFI): Results of a Randomized Placebo Controlled Trial

Background:Ospemifene is a tissue selective, non-steroidal estrogen receptor agonist/antagonist that was recently approved for the treatment of dyspareunia, a symptom of vulvar and vaginal atrophy (VVA), due to menopause.  Postmenopausal dyspareunia has been reported to be associated with female sexual dysfunction (FSD).  The Female Sexual Function Index (FSFI), a 19-item questionnaire, is a widely used patient self-reported outcome tool that scores 6 domains (arousal, desire, orgasm, lubrication, satisfaction, and pain).  Clinical trial data were analyzed to determine the effect of ospemifene 60 mg on FSD as assessed by the FSFI.

Methods:A multicenter phase 3 trial used a randomized, double-blind, parallel-group design to compare the efficacy, safety, and tolerability of oral ospemifene 60 mg versus placebo. A total of 919 women (ospemifene, n=463; placebo, n=456), aged 40 to 80 years, were assigned to one of 2 VVA symptom strata, based on self-reported most bothersome symptom (MBS) of dyspareunia or dryness, to receive a once-daily dose of ospemifene 60 mg or placebo for 12 weeks. Data from each stratum were independently analyzed. A vaginal lubricant was provided for use as needed. Co-primary endpoints were change from Baseline to Week 12 (LOCF) in: % superficial cells and % parabasal cells in the Maturation Index (MI), vaginal pH, and MBS. A secondary efficacy endpoint measured mean changes from Baseline to Weeks 4 and 12 (LOCF) for FSFI total score and for each of the 6 domains based on patient-assessed sexual function in the FSFI questionnaire. This abstract reports the sexual function assessment results.

Results: Statistically significant (p<0.05) improvements for ospemifene 60 mg vs placebo were seen for every FSFI domain score (desire, arousal, lubrication, orgasm, satisfaction, and pain) and the total score at Week 12 (LOCF).   At Week 4, every domain was significantly improved except for orgasm (p=0.0820) and satisfaction (p=0.3206).

Conclusion:  In a randomized, placebo-controlled clinical trial, ospemifene 60 mg was shown to significantly improve FSD in the total FSFI score. Significant improvement was also seen in 4 of the domains at Week 4 and in all 6 domains at Week 12 of treatment.  Consistency of effect was observed in all of the domains, which distinguishes ospemifene from other agents that treat dyspareunia. Confirmation of this data and assessment as to whether these effects are related solely to the improvement in dyspareunia remains to be elucidated.