Bazedoxifene and Conjugated Equine Estrogen: A Combination Product for the Management of Vasomotor Symptoms and Osteoporosis Prevention Associated with Menopause

Bazedoxifene (BZA), a third-generation selective estrogen receptor modulator (SERM), has been combined with conjugated equine estrogen (CE) to create a tissue selective estrogen complex (TSEC) for the management of vasomotor symptoms (VMS) and the prevention of osteoporosis (OP) associated with menopause. Both of these outcomes of menopause contribute to significant negative effects on quality of life and increases in utilization of health care resources and dollars. Current treatment modalities for VMS and OP include estrogen therapy that requires the use of progestin in women who have a uterus to reduce the risk of endometrial hyperplasia and resultant cancer. However, progestin use results in nuisance bleeding as well as a further increased risk of breast cancer when combined with estrogen. And while SERMs can be used to prevent OP, their use alone has been shown to increase hot flashes. The combination of BZA and CE does not require progestin treatment with CE as the BZA component acts as an antagonist on endometrial tissue. The U.S. Food and Drug Administration approval of BZA/CE in 2013 was based on a series of five phase 3 studies known as the Selective estrogens, Menopause And Response to Therapy (SMART) trials. These trials, in their entirety, evaluated the impact of BZA/CE on VMS frequency and severity, bone mineral density, bone turnover markers, vaginal symptoms, lipid profiles, sleep, quality of life, breast density, and endometrial safety. The approved dose of BZA/CE is 20 mg BZA and 0.45 mg CE. Although this TSEC manages VMS while opposing breast and endometrial proliferation, preventing bone resorption, and improving lipid profiles, long-term experience with BZA/CE is currently lacking.