Forteo was FDA approved for osteoporosis in 2002. Teriparatide is recombinant parathyroid hormone, identical to the 34 N-terminal amino acids of human parathyroid hormone (PTH). Teriparatide is administered as a subcutaneous injection. Unlike other treatments for osteoporosis that primarily reduce bone turnover, teriparatide reduces bone turnover, stimulates the formation of new bone, and increases bone mass.
Body and co-workers (2002) compared the effects of teriparatide and alendronate on BMD, non-vertebral fracture incidence, and bone turnover in 146 postmenopausal women with osteoporosis. Women were randomized to either once-daily subcutaneous injections of teriparatide 40 mcg plus oral placebo (n = 73) or oral alendronate 10 mg plus placebo injection (n = 73). Median duration of treatment was 14 months. At 3 months, teriparatide increased lumbar spine BMD significantly more than did alendronate. Lumbar spine-BMD increased by 12.2% in the teriparatide group and 5.6% in the alendronate group. Teriparatide increased femoral neck BMD and total body bone mineral significantly more than did alendronate, but BMD at the one-third distal radius decreased, compared with alendronate. Non-vertebral fracture incidence was significantly lower in the teriparatide group than in the alendronate group. Both treatments were well tolerated despite transient mild asymptomatic hypercalcemia with teriparatide treatment. These investigators concluded that teriparatide, a bone-forming agent, increased BMD at most sites and decreased non-vertebral fractures more than alendronate. However, more comparative studies are needed to validate this finding.
The Canadian Coordinating Office of Health Technology Assessment (Shulka, 2003) reached the following conclusions about teriparatide: “Although placebo-controlled trials show that teriparatide can reduce fractures, there is little information on its efficacy compared to available alternatives. In the United States, the Food and Drug Administration highlighted concerns about teriparatide’s carcinogenic effects in rats. Company-sponsored studies have been voluntarily stopped … Because of safety concerns and the lack of efficacy and effectiveness data, it is difficult to define teriparatide’s role in the treatment of osteoporosis. This is compounded by the possible long-term antagonizing effect of bisphosphonates on teriparatide’s bone-forming properties.”
Body JJ, Gaich GA, Scheele WH, et al. A randomized double-blind trial to compare the efficacy of teriparatide [recombinant human parathyroid hormone (1-34)] with alendronate in postmenopausal women with osteoporosis. J Clin Endocrinol Metab. 2002;87(10):4528-4535.
Nevitt MC, Chen P, Dore RK, et al. Reduced risk of back pain following teriparatide treatment: A meta-analysis. Osteoporosis Int. 2006:17(2):273-280.
Stevenson M, Lloyd Jones M, De Nigris E, et al. A systematic review and economic evaluation of alendronate, etidronate, risedronate, raloxifene and teriparatide for the prevention and treatment of postmenopausal osteoporosis. Health Technol Assess. 2005;9(22):1-160.