A study on switching from cinacalcet to etelcalcetide in hemodialysis patients with secondary hyperparathyroidism

Abstract

【Background】The Clinical Practice Guidelines for the Management of Chronic Kidney Disease-Mineral and Bone Disorders (CKD-MBD) 2012 recommend the use of cinacalcet hydrochloride, a calcimimetic, in hemodialysis patients with high parathyroid hormone (PTH) levels and normal or high serum phosphorus or calcium levels. Etelcalcetide, a new calcimimetic, is administered intravenously and can be eliminated by dialysis. Here, we investigated the characteristics of etelcalcetide in CKD-MBD patients. 【Methods】The subjects were hemodialysis outpatients with high PTH levels and high or normal serum phosphorus or calcium levels (≥8.4 mg/dL) who were being treated at our hospital. Etelcalcetide was administered to 50 patients. The endpoints were the corrected serum calcium level and the serum levels of phosphorus, intact PTH, tartrate-resistant acid phosphatase (TRACP)-5b, and bone-type alkaline phosphatase. The mean corrected serum calcium level and the serum levels of phosphorus and intact PTH at 24 weeks before the start of etelcalcetide treatment (pre-treatment values) were compared with those at 24 weeks after the start of treatment (post-treatment values). The endpoints were also compared among three treatment groups: the cinacalcet hydrochloride-free group (not treated with cinacalcet hydrochloride), low-dose cinacalcet hydrochloride/etelcalcetide group (switched from ≤25 mg/day cinacalcet hydrochloride to etelcalcetide), and high-dose cinacalcet hydrochloride/etelcalcetide group (switched from ≥26 mg/day cinacalcet hydrochloride to etelcalcetide). 【Results】The mean corrected serum calcium level and serum intact PTH level were significantly lower after treatment (p<0.01). In the low-dose cinacalcet hydrochloride/etelcalcetide group, the mean corrected serum calcium level (p<0.01) and serum intact PTH level (p<0.01) were significantly lower after treatment. No significant findings were obtained in the high-dose cinacalcet hydrochloride/etelcalcetide group. The intact PTH level tended to increase after treatment, although the difference was not significant. The mean etelcalcetide dose increased during the study period due to changes in the TRACP-5b level, and the estimated initial etelcalcetide dose was equivalent to 26-50 mg of cinacalcet hydrochloride. 【Conclusion】Our findings suggest that etelcalcetide might be an effective alternative treatment for secondary hyperparathyroidism when administered at an equivalent dose to cinacalcet hydrochloride.