SAT-788 Use of Romosozumab for Osteoporosis in Β-Thalassemia Major

Abstract Disclosure: C. Ng: None. N. Samad: None. A. Trinh: None. F. Milat: None. P. Wong: None. Thalassemia bone disease is a common and severe complication of β-thalassemia major (TM), resulting from marrow expansion, hormonal deficiency including hypogonadism, iron toxicity and increased bone turnover. These factors contribute to reduced bone mineral density (BMD) and increased susceptibility to minimal trauma fracture (MTF). Optimal transfusions/iron chelation therapy, management of hormone deficiencies and antiresorptive therapies are the cornerstone of management. There are currently no reports examining the efficacy of the anabolic Romosozumab in TM. We report the use of Romosozumab in 2 patients with TM and severe osteoporosis. A 65-year-old male with TM on deferoxamine chelation, also had small vessel vasculitis requiring high doses of corticosteroids. He had severe osteoporosis, with a T-score of -4.0 at lumbar spine and a 12% loss of BMD over 2 years. Despite 5 years of zoledronic acid (ZA) treatment, there was ongoing decline in BMD at both lumbar spine and hip and he sustained a new L3 fracture. Following 12 months of Romosozumab, there was a significant improvement in BMD of 42% at the lumbar spine, 12% at the femoral neck and 12% at the total hip with T-scores of -1.5, -1.5 and -1.4 at those sites respectively. He tolerated Romosozumab well and is currently undergoing consolidation treatment with ZA. A 58-year-old Jehovah’s Witness male with TM, osteoporosis and multiple fractures had been treated with various osteoporosis therapies over 20 years, including bisphosphonates, strontium ranelate and denosumab. However, this patient continued to suffer MTF and progressive declines in BMD. Even after switching from 6-monthly to 3-monthly denosumab, his bone turnover markers remained elevated (C-telopeptide: 470ng/L; normal range 150-800ng/L) and he sustained supracondylar femoral and humeral fractures following a fall. Romosozumab was then initiated and was well tolerated. He achieved an increase in procollagen type 1 propeptide (P1NP) from 34μg/L to 130μg/L at 3-4 months (normal range 15-70 µg/L). A follow-up DXA scan after 12 months of treatment demonstrated a 6% improvement in BMD at the right hip (T-score: -2.9) and stability at the lumbar spine. This is the first case series of Romosozumab in the treatment of osteoporosis in patients with TM. The observed BMD gains were significant despite previous prolonged exposure to anti-resorptive therapy, and thus represents a promising treatment option in patients with TM and osteoporosis. A clinical trial to confirm these benefits is required. Presentation: Saturday, July 12, 2025