Among patients with osteoporosis who were at high risk for fracture, bone mineral density increased more in patients receiving teriparatide than in those receiving alendronate. (ClinicalTrials.gov number, NCT00051558 [ClinicalTrials.gov].).

Previous antiresorptive (AR) treatment may influence the response to teriparatide. We examined BMD response and safety in a subgroup of 503 postmenopausal women with osteoporosis who received teriparatide for 24 mo. Patients were divided into three groups based on their prior AR treatment: treatmentnaïve (n ‫ס‬ 84); pretreated with no evidence of inadequate treatment response (n ‫ס‬ 134); and pretreated showing an inadequate response to AR treatment (n ‫ס‬ 285), which was predefined based on the occurrence of fractures, persistent low BMD, and/or significant BMD loss while on therapy. Changes in BMD from baseline were analyzed using mixed model repeated measures. Lumbar spine BMD increased significantly from baseline at 6, 12, 18, and 24 mo in all three groups. The mean gain in spine BMD over 24 mo was greater in the treatment-naïve group (0.095 g/cm 2 ; 13.1%) than in the AR pretreated (0.074 g/cm 2 ; 10.2%; p < 0.005) and inadequate AR responder (0.071 g/cm 2 ; 9.8%; p < 0.001) groups. The corresponding increases in total hip BMD were 3.8%, 2.3%, and 2.3%, respectively. Early decreases in hip BMD in the inadequate AR responder group were reversed by 18 mo of treatment. Increases in BMD between 18 and 24 mo were highly significant. Nausea (13.3%) and arthralgia (11.7%) were the most commonly reported adverse events. Asymptomatic hypercalcemia was reported in 5.0% of patients. Teriparatide treatment for 24 mo is associated with a significant increase in BMD in patients with and without previous AR use. Prior AR treatment modestly blunted the BMD response to teriparatide. Safety was consistent with current prescribing label information.

Teriparatide induces positive effects on BMD and markers of bone formation in postmenopausal women with established osteoporosis, regardless of previous long-term exposure to antiresorptive therapies.

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We introduce a method for microstructural analysis of vertebral trabecular bone in vivo based on HRCT. When applied to monitor teriparatide treatment, changes in structural variables exceeded and were partially independent of changes in volumetric BMD.Introduction: Monitoring of osteoporosis therapy based solely on bone densitometry is insufficient to assess anti-fracture efficacy. Assessing bone microstructure in vivo is therefore of importance. We studied whether it is possible to monitor effects of teriparatide on vertebral trabecular microstructure independent of BMD by high-resolution CT (HRCT). Materials and Methods:In a subset of 65 postmenopausal women with established osteoporosis who participated in the EUROFORS study, HRCT scans of T 12 , quantitative CT of L 1 -L 3 , and DXA of L 1 -L 4 were performed after 0, 6, and 12 mo of teriparatide treatment (20 g/d). We compared BMD and 3D microstructural variables in three groups of women, based on prior antiresorptive treatment: treatment-naïve; pretreated; and pretreated women showing inadequate response to treatment. Results: We found statistically highly significant increases in most microstructural variables and BMD 6 mo after starting teriparatide. After 12 mo, apparent bone volume fraction (app. BV/TV) increased by 30.6 ± 4.4% (SE), and apparent trabecular number (app. Tb.N.) increased by 19.0 ± 3.2% compared with 6.4 ± 0.7% for areal and 19.3 ± 2.6% for volumetric BMD. The structural changes were partially independent of BMD as shown by a significantly larger standardized increase and a standardized long-term precision at least as good as DXA. Patients who had shown inadequate response to prior osteoporosis treatment did show improvements in BMD and structural measures comparable to treatment-naïve patients. Conclusions: HRCT is a feasible method for longitudinal microstructural analysis of human vertebrae in vivo, offers information beyond BMD, and is sufficiently precise to show profound effects of teriparatide after 12 mo.