January 5, 2010 — 根據一項於11月/12月更年期（Menopause）期刊上的隨機分派、雙盲、安慰劑控制第三期臨床研究結果，選擇性雌激素受體調控藥物bazedoxifene對於停經後骨質疏鬆女性可能是安全的。
來自諾福克東維吉尼亞醫學院的David F. Archer醫師與其同事們寫到，雖然目前對停經後骨質疏鬆症的藥物治療已經被證實是有效的，但許多藥物仍然有安全性以及/或是耐受性的擔憂，這限制或阻礙了成功的長期治療。SERMs類藥物（選擇性雌激素受體調控藥物）是停經後骨質疏鬆一個有潛力的治療藥物，因為它具有混合型功能雌激素受體作用劑與拮抗劑的活性。
Bazedoxifene May Be Safe for Postmenopausal Women With Osteoporosis
By Laurie Barclay, MD
Medscape Medical News
January 5, 2010 — The selective estrogen receptor modulator bazedoxifene may be safe for postmenopausal women with osteoporosis, according to the results of a randomized, double-blind, placebo-controlled phase 3 trial reported in the November/December issue of Menopause.
"Although current pharmacologic options for postmenopausal osteoporosis have been shown to be effective, many are associated with safety and/or tolerability concerns that may limit or hinder successful long-term therapy," write David F. Archer, MD, from the Eastern Virginia Medical School in Norfolk, and colleagues. "As a class, SERMs [selective estrogen receptor modulators] are appealing therapeutic agents for postmenopausal osteoporosis because of their mixed functional estrogen receptor agonist and antagonist activities."
The objective of the study was to assess the endometrial, ovarian, and breast safety of bazedoxifene when used to treat postmenopausal osteoporosis. Otherwise healthy women with osteoporosis, aged 55 to 85 years, were randomly assigned to treatment with bazedoxifene 20 or 40 mg, raloxifene 60 mg, or placebo daily for 3 years. Through 24 months, participants had periodic transvaginal ultrasonography and endometrial biopsy to determine endometrial and ovarian safety, and gynecologic and breast-related adverse events were recorded throughout the study.
At 12 or 24 months, overall endometrial thickness and the percentage of participants with endometrial thickness greater than 5 mm were not significantly different among groups, based on 753 participants with available transvaginal ultrasonography data. At 24 months, changes in the mean endometrial thickness from baseline were –0.07 ± 0.11 mm for women receiving bazedoxifene 20 mg, 0.10 ± 0.11 mm for women receiving bazedoxifene 40 mg, 0.16 ± 0.12 mm for women receiving raloxifene 60 mg, and –0.08 ± 0.11 mm in the placebo group.
Each group had 1 report of endometrial hyperplasia. Endometrial carcinoma was reported in no women in the bazedoxifene 20-mg group, in 2 in the bazedoxifene 40-mg group, in 2 in the raloxifene 60-mg group, and in 3 in the placebo group. The groups did not differ in clinically important changes from baseline in the number or size of ovarian cysts. Compared with the raloxifene group, the bazedoxifene groups had a significantly lower incidence of fibrocystic breast disease (P ? .05).
"Bazedoxifene was associated with a favorable endometrial, ovarian, and breast safety profile in postmenopausal women with osteoporosis," the study authors write. "Further clinical evaluation is currently ongoing to confirm the long-term safety and efficacy of bazedoxifene on the uterus and ovary."
Limitations of this study include follow-up limited to 2 years.
"Findings from this study of postmenopausal women with osteoporosis support those of previous preclinical and clinical studies of bazedoxifene, which have demonstrated the efficacy of bazedoxifene in preventing bone loss and reducing the risk of fracture without stimulation of the endometrium, ovaries, or breast," the study authors conclude. "Based on these results, bazedoxifene represents a promising therapeutic option for the prevention and treatment of postmenopausal osteoporosis."
Wyeth Research sponsored this study, funded editorial support for the writing of the article, employs 3 of the study authors, and has disclosed various financial relationships with 5 other study authors.
