Gynecologic Safety of Conjugated Estrogens Plus Bazedoxifene: Pooled Analysis of Five Phase 3 Trials

Abstract Objective: To evaluate gynecologic safety of conjugated estrogens/bazedoxifene treatment for menopausal symptoms and osteoporosis prevention in nonhysterectomized women. Materials and Methods: We pooled data from five randomized, placebo-controlled trials of conjugated estrogens 0.625 mg/bazedoxifene 20 mg (n = 1583), conjugated estrogens 0.45 mg/bazedoxifene 20 mg (n = 1585), and placebo (n = 1241). Gynecologic safety was evaluated by pelvic examination, Papanicolaou smear, endometrial biopsy, transvaginal ultrasound, mammogram, adverse events, and diary records of vaginal bleeding and breast pain/tenderness. Incidence rates and relative risks (RR) versus placebo were calculated with inverse variance weighting. Data for conjugated estrogens 0.45 mg/medroxyprogesterone acetate 1.5 mg, an active comparator in two trials (n = 399), are included for comparison. Results: Endometrial hyperplasia occurred in <1% (n = 4 [0.3%], 2 [0.2%], 1 [0.5%], and 2 [0.2%] for conjugated estrogens 0.625 mg/bazedoxif...