Treatment for osteoporosis with teriparatide is associated with greater bone formation than treatment with zoledronic acid, according to a study published in the Journal of Bone and Mineral Research.1
A previously conducted phase 4 study in ambulatory postmenopausal women aged 55 to 89 years with osteoporosis compared anabolic therapy (teriparatide 20 µg/d subcutaneously) with antiresorptive therapy (zoledronic acid 5 mg/y intravenously) for up to 2 years.2
The 12-month primary study was randomized and double-blinded until the month-6 biopsy (teriparatide, n=28; zoledronic acid, n=30) and then became open label, followed by an optional 12-month extension with a month-24 biopsy (teriparatide, n=10; zoledronic acid, n=9).
In the current research, the investigators provide data on remodeling-based bone formation (RBF), modeling-based bone formation (MBF), and overflow MBF (oMBF; modeling overflow adjacent to RBF sites) in the cancellous, endocortical, and periosteal envelopes.1
Overall, they found that teriparatide treatment was associated with significantly greater bone formation of all types across all 3 bone envelopes (except periosteal oMBF) at 6 months vs zoledronic acid (all P <.001). In addition, RBF remained significantly elevated in the cancellous and endocortical envelopes at 24 months in patients receiving teriparatide vs zoledronic acid.
“These data support the view that zoledronic acid is a traditional antiremodeling agent and extend the notion that the effects of teriparatide in strengthening bone and reducing fracture rates is likely due to the formation of new bone primarily in association with bone remodeling, although MBF also contributes, particularly earlier during the course of treatment,” concluded the authors.1 Furthermore, these data demonstrate how the balance between MBF and RBF can be assessed for osteoporosis medications in development.
- Dempster DW, Zhou H, Ruff VA, Melby TE, Alam J, Taylor KA. Longitudinal effects of teriparatide or zoledronic acid on bone modeling- and remodeling-based formation in the SHOTZ study [published online November 30, 2017]. J Bone Miner Res. doi: 10.1002/jbmr.3350
- Dempster DW, Zhou H, Recker RR, et al. Skeletal histomorphometry in subjects on teriparatide or zoledronic acid therapy (SHOTZ) study: a randomized controlled trial. J Clin Endocrinol Metab. 2012;97(8):2799-2808.