Emerging therapies in osteoporosis

The approval of alendronate in 1994 marked a watershed in the treatment of osteoporosis. Before that time there was no therapy for which unequivocal proof of efficacy existed. Since then several more agents, all from the anti-resorptive class, have also been approved for use in the treatment of this disease and the range of indications for alendronate has been extended to include the prevention of osteoporosis in women with lesser degrees of bone loss, the treatment of glucocorticoid-induced osteoporosis and, most recently, the treatment of male osteoporosis. Despite this there are still several areas of unmet medical need in this disease, including the availability of well tolerated and convenient therapies and treatments that will go beyond the levels of efficacy offered by current therapies. An intense effort is now being directed towards meeting these unmet needs with the improvement of existing therapies and the development of novel agents that will provide superior long term benefit. Important and exciting drug targets are yielding novel compounds with anti-resorptive activity or anabolic effects to complement current anti-resorptives. Despite this effort considerable obstacles to the successful development of these compounds remain, not least the stringent safety requirements needed to provide an acceptable risk-to-benefit profile and the increasing difficulties of conducting placebo controlled studies in patients at high risk of fracture.