Emerging drugs for postmenopausal osteoporosis

Postmenopausal osteoporosis (PMO) is a common skeletal disease with serious consequences due to fractures, including increased risk of disability and death. The risk of fractures can be reduced with medications that are currently available; however, these drugs are frequently not prescribed due to failure to recognize that a patient is at high risk for fracture; fear of adverse drug effects; or, sometimes, high cost. When these drugs are prescribed, long-term adherence to therapy is poor. Efforts to improve the clinical effectiveness of pharmacological therapies have included lengthening the interval between doses, simplifying drug administration, and manipulating the molecular structure of drugs in existing therapeutic classes. Recent improvement in understanding the pathophysiology of PMO at the molecular level has fostered the development of new therapeutic agents with novel mechanisms of action. This is a review of the data on the efficacy and safety of emerging drugs for the treatment of PMO, including agents with novel mechanisms of action (denosumab, odanacatib, antibody to sclerostin), new estrogen agonists/antagonists (lasofoxifene, bazedoxifene, arzoxifene), new delivery systems for existing drugs (salmon calcitonin, teriparaticle), and drug combinations given concurrently, sequentially, or cyclically. These new therapeutic agents, new delivery systems, and new methods of combining drugs may ultimately reduce the great personal and economic burden of osteoporotic fractures.