Efficacy and tolerability of bazedoxifene in Mexican women with osteoporosis: a subgroup analysis of a randomized phase 3 trial.

OBJECTIVE: Bazedoxifene (BZA) is a selective estrogen receptor modulator that reduces fracture risk and bone turnover in postmenopausal women with osteoporosis. This analysis evaluated BZA's effects on bone mineral density (BMD) and bone turnover in Mexican women with osteoporosis from the global pivotal trial (Study Evaluating Bazedoxifene Acetate in Osteoporosis in Postmenopausal Women).

METHODS: In this 3-year, phase 3, randomized, double-blind trial, healthy postmenopausal women with osteoporosis (N = 7,492) received BZA 20 or 40 mg/d, raloxifene 60 mg/d, or placebo. The subanalyses of Mexican women assessed serum concentrations of osteocalcin and collagen type 1 C-telopeptide, BMD, and tolerability with BZA 20 mg/d versus placebo.

RESULTS: In the Mexican subgroup (BZA, n = 39; placebo, n = 37) at month 12, BZA 20 mg/d produced significant (P < 0.001) percentage decreases from baseline in osteocalcin (-40.5 vs -18.5) and C-telopeptide (-45.7 vs -29.4). For BZA versus placebo, percentage change in BMD from baseline to month 36 was 3.3 versus 0.64 for lumbar spine, -0.18 versus -1.8 for total hip, 0.21 versus -2.6 for femoral neck, and -0.55 versus -1.4 for femoral trochanter; differences were not statistically significant. Results were comparable to the overall study population in which differences were statistically significant. Common adverse events (≥20%) included arthralgia, back pain, gastritis, headache, influenza, and pain; none led to study withdrawal.

CONCLUSIONS: In Mexican women with osteoporosis, BZA was well tolerated and seems to produce BMD changes comparable to the global phase 3 population, although differences versus placebo were not statistically significant in this smaller subgroup.