Effects of ospemifene on bone parameters including clinical biomarkers in postmenopausal women

Objective: Ospemifene is an estrogen-receptor agonist/antagonist (also known as a selective estrogen-receptor modulator) that is FDA approved for the treatment of moderate-to-severe dyspareunia, a symptom of vulvovaginal atrophy, due to menopause. Preclinical and clinical data suggest that ospemifene may also have an effect on bone health in postmenopausal women. Methods: Relevant articles, including cellular and preclinical studies and clinical trials written in English pertaining to ospemifene and bone health, were identified from a database search of PubMed (from its inception to June 2015) and summarized in this comprehensive review. Results: In vitro data suggest that ospemifene may mediate a positive effect on bone through osteoblasts. Ospemifene effectively reduced bone loss and resorption in ovariectomized rats, with activity comparable to estradiol and raloxifene. Clinical data from three phase 1 or 2 clinical trials (2 placebo-and 1 raloxifene-controlled) found ospemifene 60 mg/d to have a positive effect on the biochemical markers for bone turnover in healthy, postmenopausal women with significant improvements relative to placebo and comparable to raloxifene. Conclusions: Ospemifene 60 mg/d may have a protective effect on the bone health of women being treated for dyspareunia. The initial clinical data for ospemifene follows a trend similar to raloxifene and bazedoxifene, suggesting that ospemifene may have bone-protective effects in postmenopausal women. However, additional rigorous clinical trials are necessary to confirm any positive effects ospemifene may have on vertebral fractures and bone mineral density in healthy and osteoporotic women.