Brown JP, et al. – Denosumab reduced bone resorption, increased BMD, and decreased new vertebral, hip, and nonvertebral fracture risk in postmenopausal women with osteoporosis in the FREEDOM trial. Denosumab treatment through 5 years resulted in normal bone quality with reduced bone turnover. These observations are consistent with its mechanism of action and associated with continued BMD increases and low fracture incidence.
- Consistent with its mechanism of action, transiliac crest bone biopsies from subjects treated with denosumab for 1 to 3 years demonstrated reduced bone turnover that was reversible upon treatment cessation.
- Long-term denosumab treatment for up to 6 years in the FREEDOM extension provides sustained bone turnover reduction and continued low fracture incidence.
- Here the authors evaluate 5 years of denosumab treatment on bone remodeling at the tissue level.
- Transiliac crest bone biopsies were obtained from 41 subjects (13 cross-over and 28 long-term from the FREEDOM placebo and denosumab groups, respectively) at year 2 of the FREEDOM extension, representing up to 5 years of denosumab treatment.
- Demographics for this subset were comparable to the overall extension cohort.
- The mean (SD) duration from the last denosumab dose to the first dose of tetracycline was 5.7 (0.5) months.
- Qualitative bone histology assessed in all biopsy samples was unremarkable, showing normally mineralized lamellar bone.
- Structural indices, including trabecular bone volume, number, and surface, were similar between cross-over and long-term groups.
- Bone resorption was decreased as reflected by eroded surface in cross-over and long-term subjects.
- A total of 11/13 (85%) cross-over subjects and 20/28 (71%) long-term subjects had specimens with double or single tetracycline label in trabecular and/or cortical compartments; specimens from 5 cross-over subjects and 10 long-term subjects were evaluable for dynamic trabecular bone parameters.
- Dynamic remodeling indices were low for both groups and consistent with reduced bone turnover with denosumab.