101 UTILITY OF BONE TURNOVER MARKERS IN GUIDING ZOLEDRONIC ACID THERAPY AFTER STOPPING DENOSUMAB

Abstract Background Denosumab is commonly used to treat osteoporosis, but drug holidays are not an option, with a risk of rebound bone loss and vertebral fractures on stopping. However, data therapy safety efficacy lacking beyond 10-years switching treatment bisphosphonates may be appropriate for some patients. Recent guidelines suggest Zoledronic Acid if stopping Denosumab, consideration second dose based subsequent Bone Turnover Markers (BTM). We aimed assess BTM older patients transitioned acid after Denosumab. Methods Patients who received 6 months their last final injection were identified at our health clinic. compared versus 3 post administration. measured was cross linked C-Telopeptide type I collagen (CTX ) (ng/ml). Results 48 included (mean age 70.6 years 90% female, mean 4.6 years). Mean CTX baseline 0.09 0.29 3-months difference 0.20, P <0.001). 40% (19) had >0.30 (above the therapeutic range) in those, 0.45. Duration prior therapy, or did predict either change rises above 0.30. Conclusion All significant elevation transitioning acid. high proportion (40%) rise range. such infusion suppress resorption loss. This highlights value using guiding cessation. find any predictors greater turnover sample size small likely underpowered.