Romosozumab is increasingly used for the treatment of severe osteoporosis. Uncertainty still exists regarding the optimal sequence of treatments and timing of romosozumab in relation to prior treatment in a real-world setting. This study aimed to evaluate real-world effects of romosozumab on bone mineral density (BMD) and bone turnover markers according to prior treatment.
We performed an audit of patients initiated on romosozumab after April 2021 who completed 12 months of treatment in a single center and affiliated private practices in Sydney. Data, including biochemistry and BMD were collected at baseline and 12 months. Patients were compared according to prior treatment: treatment naïve, prior bisphosphonate and prior denosumab use. The change in lumbar spine (LS), femoral neck (FN) and total hip (TH) BMD were analysed using ANCOVA adjusting for age and baseline BMD.
Out of 104 patients, 77 completed treatment, 28 were treatment naive, 29 transitioned from bisphosphonates and 20 patients transitioned from denosumab. Mean age was 72.4±11.9 years and 83% were female. Patients with prior denosumab use were significantly older and had higher fracture risk than other groups (Table.1). Treatment naïve patients had significantly higher LS BMD change (9.3%) when adjusted for age and baseline BMD; there was no significant difference between the bisphosphonate (5.9%) and denosumab (4.7%) groups (Table.2, Figure.1). There were no significant differences in change in FN or TH BMD between groups. Within those with prior denosumab use, change in LS BMD was inversely related to time since last denosumab dose (Figure.2).
Our study examined the real-world use of romosozumab in a single center. There was significantly greater change in LS BMD after adjusting for age and baseline LS BMD in the treatment naïve group compared to denosumab and bisphosphonate groups. Understanding how prior therapies affect BMD gains with romosozumab may affect treatment protocols.