A 7-year randomized, placebo-controlled trial assessing the long-term efficacy and safety of bazedoxifene in postmenopausal women with osteoporosis: effects on bone density and fracture.

OBJECTIVE: In a 3-year randomized, double-blind, osteoporosis treatment study (N = 7,492), bazedoxifene 20 mg and bazedoxifene 40 mg significantly (P < 0.05) reduced the risk of new vertebral fractures by 42% and 37%, respectively, compared with placebo in postmenopausal women with osteoporosis. This study evaluated the long-term (7-y) efficacy and safety of bazedoxifene in generally healthy postmenopausal women with osteoporosis.

METHODS: This was a second 2-year extension of the 3-year multicenter outpatient core study. During extension I (years 4-5), women receiving bazedoxifene 40 mg transitioned to bazedoxifene 20 mg. In extension II (years 6-7; N = 1,530), all bazedoxifene-treated women continued bazedoxifene 20 mg. Main outcome measures included year 7 endpoints: incidences of new vertebral and nonvertebral fractures, bone mineral density changes, and safety assessments.

RESULTS: At 7 years, the cumulative incidences of new vertebral fractures were significantly lower in the bazedoxifene (6.4%) and bazedoxifene 20 mg (7.6%) groups than in the placebo group (9.9%); the relative risk reductions were 36.5% and 30.4%, respectively (both P < 0.001). Bazedoxifene had no effect on the overall incidence of nonvertebral fractures (bazedoxifene, 11.2%; bazedoxifene 20 mg, 12.0%; placebo, 10.8%). The mean changes from baseline in lumbar spine bone mineral density were 2.95%, 2.73%, and 2.19%, respectively. Seven-year decreases in total hip bone mineral density were significantly smaller in the bazedoxifene (-1.15%) and bazedoxifene 20 mg (-1.19%) groups than in the placebo group (-2.53%; P ≤ 0.002). Bazedoxifene showed a favorable safety/tolerability profile across 7 years, with similar adverse events, serious adverse events, and study discontinuations in all groups.

CONCLUSIONS: Efficacy and safety of bazedoxifene are sustained across 7 years in postmenopausal women with osteoporosis.