MON-809 "Strengthening Bones, Supporting Lives: Romosozumab in Osteoporosis Management for Marfan Syndrome"

Abstract Disclosure: S. Shanthosh Kumar: None. Z. Shafique: None. K. Selk: None. Introduction: We present a case reporting clinically significant outcome in management of osteoporosis with Romosozumab in a 61 year old female with a history of Marfan Syndrome (MFS). CASE PRESENTATION Our patient has medical history remarkable for Marfan syndrome, osteoporosis, remote history of grave’s disease(1996) treated with radioactive iodine ablation, primary hyperparathyroidism with surgical cure(2012), and post-menopausal status at age 50. For osteoporosis, patient was previously on alendronate followed by raloxifene with a combined treatment course of approximately 15 years. A baseline DEXA scan was not available, however, a repeat study in 2023 demonstrated a bone mineral density (BMD) of 0.761 g/cm2 (T score -3.5) at the lumbar spine and 0.647 g/cm2 (T score -2.8) at the left femoral neck. Her parathyroid hormone, phosphorus, calcium, thyroid, and serum electrophoresis testing were unrevealing. Given the severity of osteoporosis, she was deemed a candidate for an anabolic agent, Romosozumab. Following completion of monthly infusions of Romosozumab for 12 months, a repeat DEXA scan in 2024 showed an interval increase in BMD at the lumbar spine (0.830 g/cm2, T score -2.9) and hip (femoral neck 0.736, T score -2.2) with the least significant change indicating this was a significant change. CASE DISCUSSION MFS is an autosomal dominant condition resulting from a mutation in the fibrillin-1 gene. Affected adults have lower axial bone mineral density, specifically in their lumbar spine and hip. Risk of osteoporosis and fracture risk has been reported to be higher in patients with MFS as compared to matched reference populations. Affected individuals are now living longer and therefore, addressing fracture risk reduction is imperative. Although she had received treatment with both alendronate and raloxifene, these two agents were unsuccessful in effectively halting bone loss and facilitating bone formation. Although our patient also had multiple other risk factors as mentioned earlier, these were promptly identified and received definitive therapy, thereby making them less likely to lead to ongoing progression. Romosozumab is a humanized monoclonal antibody with anabolic and antiresorptive benefits. It binds and inhibits sclerostin thereby promoting bone formation and inhibiting bone resorption. Given the severity of her osteoporosis, our patient completed a 12-month course of therapy without any significant side effects and was found to have clinically significant improvement in her axial bone mineral density. Conclusion To our knowledge, there are no case reports on use of Romosozumab in the MFS population with osteoporosis. This case report highlights this therapy as a possible effective therapeutic intervention but also recognizes the need for ongoing research to establish standard and effective treatment guidelines for management of osteoporosis in MFS. Presentation: Monday, July 14, 2025