Bone Abstracts

Background: Romosozumab, a sclerostin inhibitor with dual anabolic and antiresorptive effects, is licensed for severe postmenopausal osteoporosis at high fracture risk. Randomised controlled trials (FRAME, ARCH) demonstrate substantial BMD gains, particularly at the lumbar spine (LS); however, real-world data on treatment completion, BMD gains, bone turnover marker (BTM) trajectories, and sequential therapy adherence remain scarce.

Methods: We carried out a retrospective clinical audit of patients offered romosozumab (June 2023-April 2025) at a tertiary Endocrine Bone unit. Patients were categorised as completers (12-month course) or non-completers. BMD was measured by DXA at LS, femoral neck (FN), and total hip (TH); percentage change was calculated from raw g/cm² values. Serum P1NP and urine NTx were measured at baseline, mid-treatment, and treatment completion. BMD-BTM correlations were assessed using Spearman test. Prior and sequential therapy were recorded.

Results: Fifty-nine patients were included; 53 (89.8%) completed the full course, comparable to RCT completion rates. Among completers, romosozumab produced significant mean BMD increases at all measured sites: LS 13.4%, FN 3.3%, TH 3.4% (all P 0.001), with 96% of patients demonstrating LS improvement (Table 1). P1NP rose significantly from baseline at mid-treatment (mean 72.3%, P 0.0003) before returning to near-baseline at month-12 (-4.7%; P 0.61); NTx showed no significant change overall. Higher baseline NTx positively correlated with LS (r 0.44, P 0.005) and TH BMD responses (r 0.48, P 0.003), while higher baseline P1NP correlated with higher LS BMD gains (r 0.31, P 0.046). All 53 completers received sequential antiresorptive therapy (bisphosphonate 71.7%, denosumab 28.3%).

Conclusion: In routine clinical practice, romosozumab achieves BMD gains comparable to RCTs, with high completion rates and universal sequential antiresorptive therapy, reflecting robust clinical governance. Notably, higher pre-treatment bone turnover independently predicts greater BMD response, with potential utility for patient counselling and treatment monitoring in specialist bone services.