#3579 an initial low-dose etelcalcetide approach is effective and cost-saving in hemodialysis patients with moderate secondary hyperparathyroidism

Abstract Background and Aims Etelcalcetide (ETC) is an intravenous calcimimetic approved for the management of secondary hyperparathyroidism (sHPT) in hemodialysis (HD) patients, with benefits in terms of reduction of FGF23 levels and prevention of progression of left ventricular hypertrophy. The label recommendation is a starting dose of 5 mg after HD, to be titrated every 4 weeks according to parathyroid hormone (PTH) and calcium levels. However, it remains unclear what dosage is best to start with and, thus, how this treatment can be implemented in a real-life setting. The aim of this study was to assess the efficacy and cost-effectiveness of ETC started at lower doses than those suggested by the manufacturer in patients with moderate sHPT. Methods This is a retrospective observational study comparing two different initial ETC dosing strategies, a “Low-dose approach” (LD, ETC starting dose<10 mg/week) and a “Classic approach” (CL, ETC starting dose≥10 mg/week), in terms of effects on CKD-MBD related biomarkers and costs during the first year of prescription. The study was conducted on HD patients with basal PTH between 500 and 1500 ng/l, treated with ETC for at least 3 months between 2018 and 2022 at ASST Spedali Civili di Brescia. Monthly monitoring of serum calcium, phosphorus and PTH was performed in both groups for dose adjustment. Results Overall, 53 patients were identified, 24 in the LD and 29 in the CL group. Both groups showed similar baseline characteristics (Table 1). Median follow-up was 52 weeks, during which 4 patients (one in the LD and three in the CL group) discontinued ETC (Table 1). At the end of follow-up, 92% of patients in the LD and 90% in the CL group achieved a decrease in PTH ≥30% compared to baseline, with median PTH levels of 282 (207 - 332) and 294 (151 – 382) ng/l, respectively (p = 0.825). Other CKD-MBD biochemical parameters were comparable between the two groups at all timepoints (Figure 1). The median of average ETC weekly doses per patient was 7.6 (6.2 – 10.2) mg in the LD and 10.6 (9.7 – 15) mg in the CL group (p<0.001). During follow-up, the median ETC dose remained stable in the LD group, while partially decreasing in the CL group (Figure 1). Use of paricalcitol was comparable in both groups. At cost analysis, the median of average ETC weekly costs per patient was €36.6 (29.6 – 50.0) in the LD and €50.5 (46.4 – 71.7) in the CL group (p<0.001). This translates into an average yearly cost per patient of €1909 and €2635 using the LD and CL approach, respectively, with a saving of €726 per patient-year in favour of the LD strategy. Conclusion In this retrospective study in HD patients with moderate sHPT, we showed that starting ETC at a lower dose than the one suggested by the manufacturer is as effective as the classic approach in terms of control of CKD-MBD parameters, with a significant reduction in treatment costs. Future prospective studies will be needed to validate the results in bigger cohorts, test whether these benefits can extend beyond the first year of treatment and assess the effects on FGF23 levels and other relevant clinical outcomes.