The impact of switching once-weekly teriparatide to denosumab in osteoporosis patients

Background: It has been reported that switching from daily (d) teriparatide (TPTD) to denosumab (DMAb) is effective for severe osteoporosis patients. However, there have been no reports about switching from weekly (w) TPTD to DMAb in patients with osteoporosis. Once-weekly 56.5-mu g TPTD treatment increases bone mineral density (BMD) and reduces fracture events. The objective of the current retrospective study was to elucidate the impact of switching w-TPTD to DMAb in patients with osteoporosis. Methods: In this study, 40 patients were treated with w-TPTD for 18 months and then switched to DMAb for 18 months. The sample included 2 men and 38 women with a mean age of 74.5 (60-85) years. Twenty-five subjects had primary osteoporosis, and 15 had secondary osteoporosis. The mean number of osteoporotic vertebral fractures was 4.1. Serum bone turnover markers and BMD were evaluated every 6 months. Results: Bone alkaline phosphatase (BAP) and tartrate resistant acid phosphatase 5b (TRACP5b), markers of bone formation and resorption respectively, were not significantly different in w-TPTD subjects at 18 months compared with those at baseline (p > 0.05), but BAP and TRACP5b in subjects treated with DMAb were significantly lower at 36 months compared with those at baseline (p < 0.05). BMD of the lumbar spine (LS), femoral neck (FN), and total hip (TH) increased by 12.3%, 2.5%, and 2.2% by 36 months with DMAb treatment, significantly higher than at baseline (p < 0.05). Changes in BMD of FN and TH in primary osteoporosis patients were significantly higher than in secondary osteoporosis patients at 18 months (w-TPTD) and 36 months (DMAb, p < 0.05). Conclusion: BMD significantly increased in osteoporosis patients switched from w-TPTD to DMAb. However, the impact of switching from w-TPTD to DMAb in secondary osteoporosis patients was not as great as in primary osteoporosis patients at the view points of changes in BMD of FN and TH. (C) 2018 Published by Elsevier B.V. on behalf of The Japanese Orthopaedic Association.