Raloxifene: results from the MORE study.

Raloxifene is the first Selective Estrogen Receptor Modulator (SERM) approved for the prevention and treatment of osteoporosis in postmenopausal women. Acting as an estrogen agonist in the skeleton and on lipid metabolism, raloxifene maintains bone mineral density (BMD) and prevents new vertebral fractures while improving the lipid profile in postmenopausal women. In an osteoporosis prevention study, 601 women without osteoporosis, aged 45 to 60 years, were assigned to receive a placebo or raloxifene 30, 60, or 150 mg/day. All women received calcium (400 to 600 mg/day). Raloxifene 60 mg increased BMD by 2.4% at both the lumbar spine and hip compared with the placebo at 36 months. More importantly, however, raloxifene significantly reduced the risk of new vertebral fractures in Multiple Outcomes of Raloxifene Evaluation (MORE), a placebo-controlled, double-blind randomized trial of 7705 postmenopausal women with osteoporosis. The women, with a mean age of 66.5 years, and with hip or spine T-score <-2.5 and/or prevalent vertebral fractures, were assigned to receive either a placebo or 60 mg or 120 mg of raloxifene. All women were provided supplemental calcium (500 mg/day) and vitamin D (400 IU/day). After 36 months, raloxifene 60 mg/day and 120 mg/day, reduced the risk of new vertebral fractures by 55% (RR 0.45, 95% CI 0.3, 0.7; p<0.001), and 40% (RR 0.60, CI 0.4, 0.9) in women without prevalent baseline fractures, respectively; and by 31% (RR 0.7, 95% CI 0.6, 0.9; p<0.001), and 49% (RR 0.5, CI 0.4, 0.6) in women with prevalent baseline fractures compared with the placebo. There was no difference in the proportion of women reporting non-traumatic, non - spine fractures among women receiving raloxifene compared to the placebo-treated women. Compared with placebo, BMD increased after 36 months by 2.1 and 2.6% at the femoral neck and spine, respectively, in the 60mg raloxifene group, and by 2.4 and 2.7% at the femoral neck and spine, respectively, in the 120mg raloxifene group. By 40 months of follow-up, there was a higher rate of deep venous thrombosis (38 cases) and pulmonary embolus (17 cases) in the combined raloxifene groups than in the placebo group (5 and 3 cases,), with a relative risk of 3.1, (CI 1.5-6.2). By 40 months, 54 women had a confirmed diagnosis of breast cancer with a relative risk compared to placebo of 0.35, (CI, 0.21-0.58). Raloxifene therapy for 3 years maintains BMD in healthy postmenopausal women and significantly reduces the risk of new vertebral fractures by about half in postmenopausal women with osteoporosis. Raloxifene also reduces the risk of breast cancer by 65% in postmenopausal women with osteoporosis thus providing a new choice for addressing postmenopausal health concerns.