Effects of bazedoxifene/conjugated estrogens on the endometrium and bone: A randomized trial

Abstract

Objective: This phase 3 study evaluated the endometrial safety of bazedoxifene (BZA)/conjugated estrogens (CE) and bone mineral density (BMD) effects vs BZA alone, hormone therapy, and placebo (PBO). Methods: The Selective estrogens, Menopause, And Response to Therapy (SMART)-5 trial was a multicenter, randomized, double-blind, PBO- and active-controlled study in postmenopausal women with an intact uterus (N = 1843; aged 40-65 years) seeking treatment for menopausal symptoms. Subjects received daily oral BZA 20 mg/CE 0.45 or 0.625 mg, BZA 20 mg, CE 0.45 mg/ medroxyprogesterone acetate (MPA) 1.5 mg, or PBO. Primary endpoints were incidence of endometrial hyperplasia and percent change in lumbar spine BMD at 12 months. Secondary endpoints included additional osteoporosis parameters and assessments of tolerability and safety. Results: At 12 months, endometrial hyperplasia incidence was low (<1%) and similar among groups.TheBZA/CE groupshowedsignificantly greater increases in lumbar spineandtotal hipBMD vs decreases with PBO (P