RLX0120

The safety and efficacy of raloxifene, a selective estrogen receptor modulator (SERM), has been studied extensively in large, global clinical trials. However, the effect of raloxifene on bone mineral density (BMD) and on biochemical markers of bone turnover in Japanese postmenopausal women with osteoporosis has not been rigorously evaluated. This study was designed to assess the safety and efficacy of raloxifene in Japanese postmenopausal women with osteoporosis following 1 year of therapy. Participants in this multicenter trial were randomly assigned to receive placebo, raloxifene 60 mg/day (RLX60), or raloxifene 120 mg/day (RLX120). Lumbar spine BMD was measured at baseline, 24, 40, and 52 weeks, and biochemical markers of bone turnover were assessed at baseline, 12, 24, and 52 weeks. Serum lipids were assessed at baseline, 12, 24, 40, and 52 weeks, and breast examinations and transvaginal ultrasound of the endometrium were performed at enrollment and 52 weeks. Compared with baseline, women taking RLX60 had significant increases in lumbar spine (L2-L4) BMD at 24 weeks (+3.3%, p<0.001) through 52 weeks (+3.5%, p<0.001) of therapy, and similar results were observed in the RLX120 group. Markers of bone turnover and total cholesterol and LDL-C were significantly reduced, and no significant treatment-group difference was observed for patients reporting at least one adverse event following randomization. In addition, there were no reported venous thromboembolic events (VTE) in any treatment group. The results of this study demonstrate that raloxifene is associated with early increases in lumbar spine BMD, has favorable effects on biochemical markers of bone turnover and lipid profile, and is well tolerated in postmenopausal Japanese women.

Raloxifene has been shown to increase bone mineral density and reduce the risk of vertebral fracture in postmenopausal women with osteoporosis. In this study, we report the results of the first prospective longitudinal study to evaluate the mean degree of mineralization of bone (MDMB) in a group of patients enrolled in the Multiple Outcomes of Raloxifene Evaluation trial. Patients were randomly assigned to one of three treatment groups: placebo (n = 24), raloxifene 60 mg/d (RLX60; n = 22), or raloxifene 120 mg/d (RLX120; n = 18). All patients received daily calcium (500 mg) and vitamin D(3) (400-600 IU) supplementation for the duration of the study. Iliac crest biopsies were taken at baseline and after 2 yr of treatment. Quantitative microradiography was used to analyze the biopsy specimens and revealed a statistically significant (P < 0.05) mean percentage increase in total MDMB of 7.0, 5.3, and 5% for RLX60-, RLX120-, and placebo-treated patients, respectively, compared with baseline. Raloxifene treatment was found to shift the distribution of total bone mineral to higher values of MDMB (RLX60, 29%; RLX120, 8%) with greater heterogeneity, compared with placebo. The profile of MDMB observed in biopsies after treatment with placebo and raloxifene, compared with baseline, closely resembles physiological premenopausal bone.