Treating Osteoporosis in Postmenopausal Women

New Orleans—According to an analysis of clinical trials, bazedoxifene is effective as a second-line therapy for postmenopausal women who have osteoporosis, although the drug is not cost-effective compared with raloxifene. Bazedoxifene and raloxifene are selective estrogen receptor modulators (SERMs), and raloxifene is the only SERM approved by the US Food and Drug Administration (FDA) to treat osteoporosis. Results were presented at the ASHP meeting in a poster titled Clinical and Economic Review of Bazedoxifene as a Cost-Effective Alternative to Raloxifene for the Treatment of Osteoporosis in Postmenopausal Women with a High Risk of Fractures. The authors noted that 8 million of the 10 million people in the United States with osteoporosis are postmenopausal women ≥55 years of age, and by 2025, treating osteoporotic fractures will cost an estimated $25.3 billion. They also cited guidelines from the American Association of Clinical Endocrinologists that recommend using SERMs as a second-line treatment for osteoporosis when bisphosphonate therapy is contraindicated in postmenopausal women. Bazedoxifene, an investigational agent, is being developed to lower the risk of venous thromboembolism in this population. To find safety, cost, and efficacy data pertaining to the 2 drugs, the authors conducted a MEDLINE search for articles through April 2011. After excluding trials that used bazedoxifene/conjugated estrogen combinations, they narrowed the results to 9 studies. They also obtained information from the FDA, National Osteoporosis Foundation, and European Medicines Agency. Although there was no economic comparison between the drugs in the United States, a study compared the cost-effectiveness of bazedoxifene with placebo in France, Germany, Italy, Spain, Sweden, and the United Kingdom. Bazedoxifene was a potential cost-effective option in European countries, although the cost per quality-adjusted life-year varied based on the population’s fracture risk, which was measured by a fracture risk assessment tool. A limitation of the study was that it evaluated data from the Multiple Outcomes of Raloxifene study that enrolled mostly women with low bone mineral density (BMD) or a prior vertebral fracture. The authors evaluated three phase 3 trials, including a 6-month study that found patients treated with bazedoxifene had a 0.41% increase in BMD at the lumbar spine compared with a 0.32% decrease in patients who took placebo (P<.01). There were also significant differences in BMD at the femoral neck, femoral trochanter, and total hip. Another phase 3 trial looked at the efficacy of bazedoxifene in reducing new vertebral fracture risk in postmenopausal women with osteoporosis. The 3-year randomized study found that patients who took 20 mg/day of bazedoxifene, 40 mg/day of bazedoxifene, or 60 mg/day of raloxifene had a significant reduction in the incidence of radiographically confirmed vertebral fractures compared with a placebo group (P<.05 in all comparisons). The final phase 3 trial lasted 2 years and concluded that patients who took 10 mg of bazedoxifene, 20 mg of bazedoxifene, 40 mg of bazedoxifene, or 60 mg of raloxifene significantly reduced total cholesterol and low-density lipoprotein cholesterol compared with placebo (P<.05 in all comparisons). The most common adverse events associated with bazedoxifene were headache, infection, pain, back pain, and arthralgia. After analyzing all 9 studies, the authors concluded that bazedoxifene was effective at improving BMD in the lumbar spine, total hip, femoral neck, and femoral trochanter regions. The drug also decreased the incidence of new vertebral fractures.