Romosozumab in postmenopausal women with classical Osteogenesis imperfecta

This study explored whether Romosozumab, an anti-sclerostin antibody, can improve bone quality in women with Osteogenesis imperfecta. After 12 months, spinal areal bone mineral density increased, showing a beneficial treatment effect, although changes in hip bone density and bone structure were less pronounced than in women with severe osteoporosis. PURPOSE: Osteogenesis imperfecta (OI) is the most common hereditary bone disorder, characterized by increased bone fragility and impaired bone quality, but pharmacological treatment is limited. Ongoing clinical trials investigate monoclonal anti-sclerostin antibodies for OI patients, offering new hope for reducing bone fragility by increasing bone mass. METHODS: Postmenopausal women with either OI (n = 5) or severe osteoporosis (OPO, n = 10) receiving Romosozumab monthly (210 mg s.c.) for 12 months were analyzed retrospectively. Clinical assessments were performed at baseline, after 6 months, and after 12 months. Bone mass and structure were evaluated at baseline and after 12 months of treatment. In addition, serum and urine markers of bone turnover were analyzed at each time point. RESULTS: The mean age of the participants was 53.6 ± 8.9 years for OI patients and 57.2 ± 5.8 years for OPO patients (p = 0.444). After 12 months of Romosozumab treatment, spinal aBMD and osteocalcin increased significantly in OI patients, indicating an anabolic response. HR-pQCT analysis revealed no statistically significant microstructural changes in patients with OI, although trends and moderate effect sizes suggested potential improvements. In patients with OPO, we observed a more pronounced response of bone turnover markers with greater aBMD gains at both the spine and femur, as well as significant improvements in bone microstructure, particularly at the tibia. CONCLUSIONS: Romosozumab treatment in postmenopausal women with OI resulted in a significant increase in spinal aBMD, though the effect on hip aBMD and peripheral bone microstructure was limited in contrast to postmenopausal osteoporosis.