Bazedoxifene/conjugated estrogens yielded low endometrial hyperplasia rates, improved BMD
Combination bazedoxifene and conjugated estrogens demonstrated low rates of endometrial hyperplasia, with improved lumbar spine and total hip bone mineral density in postmenopausal women, according to initial data published in the Journal of Clinical Endocrinology and Metabolism.
“It may offer particular advantages to women for whom endometrial safety is a key concern and those who do not want to initiate a therapy that contains progestins,” researchers wrote.
The developmental therapy appeared to be safe and well tolerated among postmenopausal women with an intact uterus (n=1,477; aged 40 to 65 years) seeking treatment for menopausal symptoms, according to JoAnn V. Pinkerton, MD, and colleagues.
JoAnn V. Pinkerton
Pinkerton, a professor of obstetrics and gynecology and director of the Midlife Health Center at the University of Virginia, and colleagues conducted the phase 3 SMART-5 trial to evaluate the endometrial safety of bazedoxifene/conjugated estrogens (Duavee, Pfizer) and BMD effects of the therapy vs. bazedoxifene alone, hormone therapy and placebo.
Patients were randomly assigned to oral bazedoxifene 20 mg/conjugated estrogens 0.45 mg or 0.625 mg; bazedoxifene 20 mg; conjugated estrogens 0.45 mg/medroxyprogesterone acetate 1.5 mg; or placebo.
At 12 months, the incidence for endometrial hyperplasia appeared low (<1%) and was similar among all groups.
Data indicated that the bazedoxifene/conjugated estrogens group demonstrated significantly greater increases in lumbar spine and total hip BMD vs. decreases recognized among those assigned to placebo (P<.001). In addition, the conjugated estrogens/medroxyprogesterone acetate group displayed an increased lumbar spine BMD vs. the bazedoxifene/conjugated estrogens group, according to data.
Furthermore, patients in the bazedoxifene/conjugated estrogens groups demonstrated a cumulative amenorrhea rate similar to patients on placebo and bazedoxifene. This was significantly greater compared with those administered conjugated estrogens/medroxyprogesterone acetate (P<.001), according to data.
Breast tenderness observed among patients in the bazedoxifene/conjugated estrogens group was similar in the placebo and bazedoxifene group, and significantly lower in patients assigned to conjugated estrogens/medroxyprogesterone acetate (P<.01), according to data.
There were no differences among groups in incidences of adverse events, treatment-emergent adverse events and serious adverse events, but more participants in the conjugated estrogens/medroxyprogesterone group (14.1%) discontinued treatment due to adverse events than other participants (7% to 7.6%), according to data.
Disclosure: The study was sponsored by Wyeth Research, which was acquired by Pfizer in 2009. Pinkerton reports consultancy, grants/research support, and/or travel funds from Bionova, Endoceutics, DepoMed, Noven Pharmaceuticals, Pfizer and Shionogi. See the study for a full list of all other researchers’ relevant financial disclosures.