LAUSR

Secondary hyperparathyroidism (sHPT) is a frequent complication in haemodialysis patients and is associated with all-cause mortality, cardiovascular morbidity and mortality, and bone fractures. Clinical trials have demonstrated the efficacy of etelcalcitide in treating sHPT; however, concerns about hypocalcemia remain, underscoring the need for more real-world data to guide clinical practice. This study provides a real-world perspective on the role of etelcalcitide in optimising metabolic outcomes and symptom management in patients with sHPT and mid-range serum parathyroid hormone (PTH) levels receiving haemodialysis at Northwick Park Hospital dialysis unit in London. A retrospective review was conducted of adult haemodialysis patients with sHPT receiving etelcalcitide between December 2023 and December 2024. All patients were either unsuitable for or declined parathyroidectomy. Dose and duration of etelcalcitide, changes in laboratory parameters, and adverse events were recorded. The primary outcome was the change in serum PTH levels at the end of data collection compared with baseline pre-treatment levels. 49 patients were included in the study. The median duration on renal replacement therapy was 5.0 years (interquartile range, IQR 3–9), and the median duration on etelcalcitide was 1.0 years (IQR 0.9–2.0). Patients were either calcimimetic naïve (73.5%) or switched from oral cinacalcet (26.5%). 47 patients (95.9%) had pre-treatment serum PTH levels less than 300 pmol/L. The median starting dose of etelcalcitide was 7.5 mg per week and was titrated as required in increments of 2.5–5 mg. The median percentage reduction in serum PTH from pre-treatment levels to December 2024 was 73.4% (IQR 36.9–85.9), from a median of 130.0 pmol/L (IQR 95.6–180.0) to 38.3 pmol/L (IQR 17.2–77.8). Linear regression analysis revealed no significant difference when stratified by duration on etelcalcitide (p = 0.13), initial etelcalcitide dose (p = 0.90), prior calcimimetic use (p = 0.14), or baseline PTH levels (p = 0.28). Of the 29 patients who had been on etelcalcitide for more than 1 year, 26 achieved greater than 30% reduction in PTH levels from baseline. 14 patients who had been on etelcalcitide for more than 2 years achieved a median reduction of 47.2% (IQR 24.9–68.8) in alkaline phosphatase (ALP) levels, from a median ALP of 223.0 IU/L (IQR 152.0–396.0) to 115.0 IU/L (IQR 89.5–148.5). While 17 patients (34.9%) developed hypocalcemia of less than 2 mmol/L, none were reported as symptomatic. 10 patients (20.4%) had interruptions to etelcalcitide administration due to hypocalcemia or over-suppression of PTH levels. Etelcalcitide is an effective and safe option to improve biochemical parameters of sHPT in our dialysis population. Although hypocalcemia was common, close monitoring with prompt corrective intervention i.e. increase in calcium supplementation or active vitamin D, or dose reduction and discontinuation of etelcalcitide where necessary, ensured that this did not cause significant morbidity. Our results indicate that etelcalcitide is effective for patients with mid-range PTH levels of less than 300 pmol/L. The improvement in ALP levels suggests a reduction in bone turnover after treatment with etelcalcitide. Further study is needed to evaluate whether this translates to longer-term improvement in mortality, morbidity, and patient-reported outcomes in sHPT.