Sustained nonvertebral fragility fracture risk reduction after discontinuation of teriparatide treatment

Introduction: Treatment with teriparatide [rhPTH(1-34)] 20 and 40 mu g once-daily subcutaneous dosing significantly reduced the risk of nonvertebral fragility fractures over a median exposure of 19 months. Materials and Methods: All participants in the Fracture Prevention Trial were invited to participate in a follow-up study. Prior treatment assignments were revealed, and patients were able to receive osteoporosis treatments without restriction. Results: Approximately 60% of the 1262 patients received an osteoporosis treatment at some time during follow-up, with greater use in the former placebo group than in the combined former teriparatide group (p < 0.05). The hazard ratios for nonvertebral fragility fractures in each teriparatide group relative to placebo were statistically significant for the 50-month period including treatment and follow-up (p < 0.03). In the follow-up period, the hazard ratio was significantly different between the 40 mu g and combined groups versus placebo but not for the 20 mu g group versus placebo. However, the 20 and 40 mu g groups were not different from each other. Kaplan-Meier analysis of time to fracture showed that the fracture incidence in the former placebo and teriparatide groups diverged during the 50-month period including teriparatide treatment and follow-up (P = 0.009). Total hip and femoral neck BMD decreased in teriparatide-treated patients who had no follow-up treatment; BMD remained stable or further increased in patients who received a bisphosphonate after teriparatide treatment. Conclusions: While the study design is observational, the results support a sustained effect of teriparatide in reducing the risk of nonvertebral fragility fractures up to 30 months after discontinuation of treatment.