Postmenopausal Osteoporosis: Current and Future Treatment Options

primarily driven by hospitalizations related to fractures resulting from osteoporosis; costs range from $15,500 for any osteoporosis-related hospitalization to $17,383 for an osteoporosis fracture-related admission. In the absence of a fragility fracture, a diagnosis of osteoporosis can be made with a measurement of BMD. The expression of BMD, compared with the reference mean, is known as the T-score. According to World Health Organization (WHO) guidelines, osteoporosis is indicated by BMD that is 2.5 standard deviations (SDs) or more below the reference mean for a young adult female. Thus, osteoporosis would be defined as a T-score of –2.5 or below (e.g., – 3.0). A T-score above –2.5 (e.g., –1.0) would not be defined as osteoporosis in the absence of a fragility fracture. Although low BMD is an important diagnostic criterion for osteoporosis, it is also an independent risk factor for fracture. Additional independent risk factors include low weight or low body mass index (BMI), advancing age, corticosteroid use, a history of fractures, a family history of hip fractures, and secondary osteoporosis associated with disorders such as rheumatoid arthritis (Table 1). Lifestyle factors, including current smoking, excessive alcohol consumption of more than 2 units (approximately two drinks of alcohol) per day, have also been independently associated with osteoporotic fractures. The presence of multiple risk factors substantially increases the overall rate of fractures. For example, the incidence of fractures for patients with zero to two independent risk factors, in addition to a low BMD T-score, is 2.6 hip fractures per 1,000. The rate of hip fracture for those with low BMD and five or more additional risk factors is 27.3 per 1,000. WHO has identified the cumulative role of risk factors for fractures and has generated a model estimating the 10-year probability of an osteoporotic fracture based on these risk factors. A number of therapeutic options are available for treating bone loss and, ultimately, for avoiding fractures, and several promising agents are in development. More recent evidence has advanced our scientific understanding of why these agents help improve bone mass and structural quality, thus preventing fractures, and this new information is influencing current treatment opinions. However, new therapeutic alternatives and philosophies should consider pharmacoeconomic data that incorporate risk reduction in terms of baseline risks to ensure that the products used are cost-effective. New approaches and economic considerations could change the way health care organizations shape their formularies and recommended treatment guidelines for postmenopausal osteoporosis (PMO). Our objective was to conduct a thorough review of recent clinical trial and pharmacoeconomic literature related to osteoporoABSTRACT Purpose: Postmenopausal osteoporosis (PMO) is a significant health and economic burden on the U.S. Costs related to osteoporosis are approximately $14 billion per year, driven primarily by fractures. We undertook a review of clinical trial and pharmacoeconomic literature related to PMO to summarize efficacy and cost-effectiveness data for current and future pharmaceutical treatment options. Methods: We searched Medline, International Pharmaceutical Abstracts, Business Source Premier, and Research Digest (published by the International Society for Pharmacoeconomics and Outcomes Research) for articles from 1995 to 2006 using osteoporosis-related terms. We selected articles for review if they focused on a PMO population, if they were stratified by sex and age to identify the PMO population, if they reported fracture endpoints, or if they covered U.S. pharmacoeconomic data. Results: Current pharmacotherapy for PMO includes antiresorptive agents (bisphosphonates, selective estrogen receptor modulators, and calcitonin), which reduce bone turnover, and anabolic agents (parathyroid hormone), which stimulate bone development. Antiresorptive products reduce vertebral fracture rates by 30% to 70% and are cost-effective in preventing fractures in women with osteoporosis and low bone mineral density (BMD) or with a previous fragility fracture. Teriparatide, a parathyroid hormone (PTH) reduces vertebral fracture rates by 65% to 69%, although cost-effectiveness is limited to high-risk patients of advanced age or with very low BMD. Promising products under review include strontium ranelate, available for PMO outside the U.S., and PTH (1-84), an anabolic agent. Conclusion: Antiresorptive agents are cost-effective for preventing fractures in women with osteoporosis, but they might not offer enough protection in high-risk populations. Thus, there is a cost-effective place for an anabolic agent in the highest-risk patients. Strontium ranelate and PTH (1-84) may offer additional therapeutic options in preventing fractures in PMO.