SAT-799 Significant One-Year Bone Mineral Density Gains Following a Single Dose of Romosozumab: Insights from Two Case Studies

Abstract Disclosure: H.L. Hofflich: None. M. Soliman: None. L. Eger: None. G. Woods: None. Introduction: Romosozumab is an anabolic medication that treats osteoporosis by increasing bone formation by inhibiting sclerostin. It is given once monthly for twelve months (FDA 2019). Here we report the one-year bone mineral density (BMD) gains following one dose of Romosozumab in two anabolic-naive patients. Case Presentation Patient 1 is a 76-year-old female diagnosed with osteoporosis in August 2023 and treated with Alendronate 70 mg daily for four months, followed by one dose of Romosozumab in April 2024, with no subsequent treatment. Between August 2023 and September 2024, she had statistically significant improvements in BMD at the lumbar spine (13.9%), right femur (7.9%), and left femur (9.6%). Patient 2 is a 67 year old female with osteoporosis treated with one dose of Romosozumab in January 2024 followed by one dose of Zoledronic acid in February 2024. Between September 2023 and December 2024, she had statistically significant improvements in BMD at the lumbar spine (17.1%) and the left femur (10.3%). Discussion: These two cases demonstrate significant one-year BMD improvements with just one dose of Romosozumab. These results are comparable to the BMD changes seen in the FRAME trial, which showed significant gains in BMD of the lumbar spine (13.3%), total hip (6.9%), and femoral neck (5.9%) after 12 doses (Cosman 2016). Considering the biological, histological, and clinical timeline that has been noted in the clinical trials for Romosozumab, it is plausible that rapid improvement in BMD may occur with fewer that twelve doses. In the FRAME and ARCH trials, the markers of bone formation peaked in month 1-2, and returned to baseline by month 9, offering a possible mechanism for a rapid anabolic response. (McClung 2014, Cosman 2016, Erikson 2022). Our cases are limited by a short follow-up period and confounded by the use of bisphosphonate medications in the time period studied. Learning Points 1. Our patients’ one-year BMD improvement after one dose of Romosozumab was similar to the one-year BMD improvement of clinical trial patients after twelve doses of Romosozumab. 2.There is a need for further research to determine whether shorter treatment courses could reduce fractures effectively, minimize side effects, and lower the cost of osteoporosis care. Presentation: Saturday, July 12, 2025