Effects of ospemifene and raloxifene on biochemical markers of bone turnover in postmenopausal women.

Ospemifene is a novel selective estrogen receptor modulator (SERM) that is initially being developed for the treatment of vaginal atrophy in postmenopausal women. However, it also shows promise in the prevention and treatment of osteoporosis. As a part of a phase II trial, we compared the effects of ospemifene and raloxifene on bone turnover in postmenopausal women. The study was conducted as a randomized, double-blind study in which 118 healthy postmenopausal women received 30 (n = 29), 60 (n = 30), or 90 mg (n = 30) ospemifene or 60 mg (n = 29) raloxifene for 3 months. Bone resorption was assessed by measuring the urinary outputs of N- and C-terminal cross-linking telopeptides of type I collagen (NTX and CTX, respectively). Bone formation was assessed by measuring bone-specific alkaline phosphatase (bone ALP), osteocalcin (OC), procollagen type I N propeptide (PINP), and procollagen type I C propeptide (PICP) in serum. All markers were studied before and at 3 months and 2-4 weeks after cessation of the medication. Urine NTX outputs decreased in all study groups, and the only statistically significant difference in NTX was observed between raloxifene and 30 mg ospemifene, which was reduced more in the raloxifene group. The output of CTX decreased most clearly in 60- and 90-mg ospemifene groups, but no significant differences between study groups emerged. A significant difference was found between the 90-mg ospemifene group and raloxifene in PINP in favor of ospemifene. No other differences in bone formation markers emerged between ospemifene and raloxifene. The study confirms the bone-restoring activity of ospemifene, which is comparable to that of raloxifene.

Effects of ospemifene, a novel SERM, on hormones, genital tract, climacteric symptoms, and quality of life in postmenopausal women: a double-blind, randomized trial.

OBJECTIVE: Ospemifene, a novel selective estrogen receptor modulator, shows a potential for prevention and treatment of osteoporosis in postmenopausal women. We studied the effects of ospemifene on hormone levels, genital tract organs, climacteric symptoms, and quality of life. DESIGN: A double-blinded study in which 160 postmenopausal women were randomly allocated to receive either ospemifene at three different daily doses (30, 60, or 90 mg) or placebo for 3 months. RESULTS: No significant differences were observed among the study groups in clinical characteristics or parameters reflecting estrogen action at baseline. Ospemifene reduced follicle-stimulating hormone and insulin-like growth factor I levels, whereas estradiol failed to change at all, and luteinizing hormone was reduced only in the 90-mg group of ospemifene. In the vast majority of participants, the endometrium remained atrophic after 3 months of treatment with ospemifene. Although the rate of proliferative endometrium slightly increased in all groups, including placebo, no hyperplasia or bleeding occurred in any participant. Ospemifene had no effect on the appearance of proliferation marker Ki-67 in the endometrium as compared with placebo, and endometrial thickness increased by mean 0.4 to 0.6 mm (P < 0.01, P < 0.05 and P < 0.05 for 30, 60 and 90 mg ospemifene, respectively). Uterine volume slightly increased (8.4%-14.7%) in the ospemifene groups (P > 0.05), perhaps as a result of increased uterine blood flow. The most conspicuous finding was the significant estrogenic effect on vaginal epithelium, as evidenced by an increase in intermediate and superficial cells in repeat Pap smears. Ospemifene was not observed to aggravate climacteric symptoms or cause adverse events, nor did it suppress climacteric symptoms. CONCLUSIONS: Ospemifene at daily doses of 30 to 90 mg did not stimulate endometrium or aggravate hot flashes but clearly had a rather strong estrogenic effect on the vaginal epithelium during a 3-month treatment period. Such effects would be advantageous if ospemifene were found to be effective in the long-term prevention of osteoporosis.

Effects of ospemifene, a novel SERM, on vascular markers and function in healthy, postmenopausal women.

OBJECTIVE: Ospemifene, a novel selective estrogen receptor modulator (SERM), shows promise for bone preservation in postmenopausal women. This study examined the effects of ospemifene on different vascular surrogate markers. DESIGN: A double-blinded study was conducted in 160 healthy, postmenopausal women who used, in a randomized order, ospemifene (at daily doses of 30, 60, or 90 mg) or placebo for 3 months. RESULTS: Although ospemifene caused falls from basal levels in total cholesterol, low-density lipoprotein cholesterol, oxidized low-density lipoprotein cholesterol, and a rise in high-density lipoprotein cholesterol, the only statistically significant difference between ospemifene and placebo was an increase of triglyceride levels (11.3%) in the 90-mg group. Ospemifene caused no significant effect on endothelial markers or homocysteine. Of the markers reflecting coagulation and fibrinolysis, plasma fibrinogen was significantly reduced in the 60- and 90-mg groups of ospemifene (8.7% and 8.5%, respectively) when compared with the placebo group. No changes were seen in generation of thrombin or degradation of crosslinked fibrin D-dimer. The uterine or carotid arteries and 24-h ambulatory blood pressure were not affected by ospemifene. Ospemifene caused no changes in basal insulin or in a 2-h glucose tolerance test, suggesting unaltered insulin sensitivity. CONCLUSIONS: Neutral effects of short-term use of ospemifene on vascular surrogate markers imply no effect for ospemifene on the risk for cardiovascular disorders in healthy, postmenopausal women.