Bone mineral density response to romosozumab in post-menopausal women: A prospective observational real-world study

Background: Romosozumab is approved in Europe for severe osteoporosis in postmenopausal women at high risk of fracture including older women, but whether bone mineral density (BMD) response varies with age remains unknown. Purpose: To examine BMD changes in a real-world cohort of older women treated with romosozumab. We hypothesized that younger, treatment-naive patients and those with lower baseline BMD might experience greater BMD improvements. Methods: Prospective observational study in one Italian and two Belgian centers. Multivariable linear and logistic regression models with imputation of missing data were used to determine the association between baseline variables and % BMD change or ≥ 3 % BMD increase after 12 months. Results: We included 186 postmenopausal women with a median age of 76 years (range 52-96), lumbar spine T-score of -2.8 (interquartile range - 3.4;-1.8), mean total hip T-score of -2.4 (± standard deviation 0.95) and femoral neck T-score of -2.7 (-3.2;-2.2). After 12 months of romosozumab, BMD increased +9.16 % and + 3.00 % at the lumbar spine and total hip, respectively. A ≥ 3 % BMD increase was observed in 80.4 % at the spine, 51 % at the hip and 46 % at the femoral neck. Lower baseline BMD was independently associated with greater total hip BMD response. There was no significant association of BMD responses with age. Conclusions: Baseline BMD was associated with total hip BMD response to romosozumab. Age itself was not associated with BMD differences. Our data support the effectiveness of romosozumab in older postmenopausal women in routine clinical practice.