Bazedoxifene effects on the reproductive tract in postmenopausal women at risk for osteoporosis

Menopause. 2009 Nov-Dec;16(6):1102-8. doi: 10.1097/gme.0b013e3181a816be.


Objective: The aim of this study was to examine the endometrial, ovarian, and breast safety of bazedoxifene, a novel selective estrogen-receptor modulator, in postmenopausal women at risk for osteoporosis.

Methods: Healthy postmenopausal women (N = 1,583; mean age, 57.6 y) with lumbar spine or femoral neck bone mineral density T scores between -1 and -2.5 and/or other clinical risk factors for osteoporosis were enrolled in a 24-month, phase 3, randomized, double-blind, placebo- and active-controlled trial. They received daily treatment with bazedoxifene 10, 20, or 40 mg; placebo; or raloxifene 60 mg. Reproductive safety assessments included periodic transvaginal ultrasound measurements of endometrial thickness, ovarian volume, and presence of ovarian cysts; periodic endometrial biopsies; and adverse event reporting.

Results: Bazedoxifene was not associated with a significant change from baseline in mean endometrial thickness at month 24. The percentage of participants with a change from baseline in endometrial thickness or endometrial thickness greater than 5 mm at month 24 was similar among groups. There was no consensus diagnosis of endometrial hyperplasia or malignancy in the bazedoxifene or raloxifene groups; the rates of other histologic findings, including endometrial polyps, were low (<5%) and similar among groups. No significant between-group differences were found in the change from baseline in ovarian volume, number or size of ovarian cysts, or incidence of ovarian cancer. Reports of breast pain (<4%) and breast cancer (<1%) were low and evenly distributed among groups.

Conclusion: A favorable endometrial, ovarian, and breast safety profile was found after 2 years of treatment with bazedoxifene in healthy, recently postmenopausal women at risk for osteoporosis.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bone Density
  • Breast / drug effects*
  • Breast Neoplasms / chemically induced
  • Breast Neoplasms / epidemiology
  • Double-Blind Method
  • Endometrial Hyperplasia / chemically induced
  • Endometrial Hyperplasia / epidemiology
  • Endometrial Neoplasms / chemically induced
  • Endometrial Neoplasms / epidemiology
  • Endometrium / diagnostic imaging
  • Endometrium / drug effects*
  • Female
  • Humans
  • Indoles / administration & dosage
  • Indoles / adverse effects*
  • Middle Aged
  • Osteoporosis, Postmenopausal / prevention & control*
  • Ovarian Cysts / chemically induced
  • Ovarian Cysts / epidemiology
  • Ovarian Neoplasms / chemically induced
  • Ovarian Neoplasms / epidemiology
  • Ovary / diagnostic imaging
  • Ovary / drug effects*
  • Placebos
  • Postmenopause
  • Risk Factors
  • Selective Estrogen Receptor Modulators / adverse effects*
  • Ultrasonography


  • Indoles
  • Placebos
  • Selective Estrogen Receptor Modulators
  • bazedoxifene