Once-weekly teriparatide reduces the risk of vertebral fracture in patients with various fracture risks: subgroup analysis of the Teriparatide Once-Weekly Efficacy Research (TOWER) trial.

Once-weekly teriparatide (human parathyroid hormone [1-34]) (56.5 μg for 72 weeks) injections provided a vertebral fracture risk reduction in Japanese osteoporotic patients evaluated in the Teriparatide Once-Weekly Efficacy Research (TOWER) trial. Using data from the TOWER trial, a subgroup analysis was performed to study the efficacy of once-weekly teriparatide for a variety of baseline clinical risk factors in placebo (n = 281) and teriparatide (n = 261) groups. Significant fracture risk reductions were observed in the subgroups of individuals aged <75 years [relative risk (RR) 0.06, p = 0.007] and ≥75 years (RR 0.32, p = 0.015). A significant risk reduction was observed among patients with prevalent vertebral fracture in the subgroup with 1 (RR 0.08, p = 0.015) or ≥2 (RR 0.29, p = 0.009) prevalent vertebral fractures, and in those with grade 3 deformity (RR 0.26, p = 0.003). Significant risk reduction was observed in the subgroup with lumbar bone mineral density (BMD) < -2.5 SD (RR 0.25, p = 0.035). In the teriparatide group, no incident fracture was observed in the subgroups with a prevalent vertebral fracture number of 0, with grade 0-2 vertebral deformity, or with lumbar BMD ≥2.5 SD. Significant risk reduction was observed in all of the bone turnover marker and estimated glomerular filtration rate subgroups. In conclusion, once-weekly 56.5 μg teriparatide injection reduced the vertebral fracture risk in patients with varying degrees of fracture risk, age, vertebral fracture number and grade, bone turnover level, and renal function.

RCT Entities:   Population Interventions Outcomes