3846 Imminent fracture rates whilst on anabolic treatment for osteoporosis

Abstract Introduction Osteoporosis affects approximately 3.5 million individuals in the UK, resulting in over 500,000 fragility fractures annually. An initial fracture significantly increases the risk of subsequent fractures, particularly in very high-risk patients. Current clinical guidelines advocate a ‘treat-to-target’ strategy, recommending anabolic treatment for individuals at very high risk of fracture. The objective of this study was to evaluate biochemical safety, service delivery efficiency, and imminent fracture risk among osteoporosis patients receiving anabolic agents. Methods We conducted a retrospective review of Aneurin Bevan Fracture Liaison Service (AB-FLS) between August 2023 and June 2025. Of the initial 71 patients identified, 62 patients who received Romosozumab were included in the final analysis. Three Romosozumab patients were excluded due to disengagement from follow-up or declining treatment. Patients treated with Teriparatide (n = 5) and Abaloparatide (n = 1) were excluded due to small sample sizes. Data collected included patient demographics, fracture types, T-scores at the spine and femoral neck, biochemical markers (serum calcium, alkaline phosphatase (ALP), 25-hydroxyvitamin D [Vit D]), service metrics (waiting times from initial consultation to treatment initiation), incidence of hypocalcaemia (calcium <2.20 mmol/L), ALP elevation (>25% from baseline), vitamin D deficiency (<50 nmol/L), re-fracture incidence, and mortality. Results Mean age for all women (n = 62) was 72 years (range 40–83), 58% were vertebral, 24% were wrist/arm. Mean T-score at spine and femoral neck were − 3.20 (range − 5.39 to −0.70) and − 2.65 (range − 4.40 to −0.90) respectively. Median treatment initiation time post-initial consultation was 42 days (interquartile range 35–78 days). Biochemically, hypocalcaemia occurred in only 1 patient (1.6%) at the 4-month follow-up. Significant ALP elevations (>25%) were most common at 2 months (45%, 28/62) and gradually declined over subsequent follow-ups. Pre-treatment vitamin D deficiency was present in nine patients, all of whom received supplementation. Four patients (6.5%) experienced re-fracture between 84 to 275 days (mean 167 days). No mortality was recorded post initiation of anabolic. Conclusion Romosozumab treatment demonstrated good biochemical safety profiles and a low incidence of hypocalcaemia. We observed delays of nearly 6 weeks in treatment initiation for very high-risk patients. Given the observed imminent fracture risk of 6.5% whilst on treatment, efforts to reduce treatment delays by introducing stronger partnerships working with a dedicated FLS Pharmacists could be tested.