Reduction of Vertebral Fracture Risk in Postmenopausal Women With Osteoporosis Treated With RaloxifeneResults From a 3-Year Randomized Clinical Trial

Abstract

Raloxifene hydrochloride is a nonsteroidal benzothiophene that binds to estrogen receptors and inhibits bone resorption without stimulating the uterine endometrium in postmenopausal women.¹ However, the effect of raloxifene on the risk of fracture is not known. Observational studies in postmenopausal women have suggested that long-term estrogen therapy reduces the incidence of fracture,^2,3 but the efficacy ofestrogen in reducing fractures has been demonstrated in only 1 small prospective study.⁴ In addition, in the US Breast Cancer Prevention Trial,⁵ tamoxifen citrate, another selective estrogen receptor modulator, appeared to have a favorable effect on the incidence of fractures. The Multiple Outcomes of Raloxifene Evaluation (MORE) study was undertaken in 1994 primarily to examine the effect of raloxifene on the skeleton. We report herein the results of measurements of bone mineral density and assessment for fractures from a planned 36-month interim analysis.