Etelcalcetide Use during Maintenance Hemodialysis and Incidence of Parathyroidectomy after Kidney Transplantation

Introduction Etelcalcetide is an intravenous calcimimetic agent, effectively reducing parathyroid hormone levels in patients on maintenance hemodialysis (HD). The clinical impact of discontinuing etelcalcetide at the time of kidney transplantation is unknown. Methods We retrospectively reviewed all patients on hemodialysis meeting predefined criteria who received a kidney transplant at our institution between 01/01/2015 and 12/31/2022. The incidence of parathyroidectomy and the evolution of calcium, phosphate, and intact PTH levels after transplantation was analyzed according to the type of calcimimetic treatment before transplantation (cinacalcet versus etelcalcetide versus none). Results Overall, 372 patients (aged 53 [IQR 42-62] years) were included. At the time of transplantation, 35, 75, and 262 patients were under etelcalcetide, cinacalcet or no calcimimetic, respectively. After 1064 (IQR 367-1658) days, the incidence of parathyroidectomy in the etelcalcetide vs. cinacalcet vs. no calcimimetic group was 29% vs 12% vs 1%, respectively (p<0.001). Etelcalcetide was associated with an increased incidence of parathyroidectomy after adjustment for age, sex and HD vintage (HR 97.0, 95% CI 19.1-493.9, p<0.001). The incidence of parathyroidectomy was related to etelcalcetide dosage (6/11 [54.6%] in patients with ≥10 mg vs 4/24 [16.7%] in patients with <10 mg, p= 0.02). Moreover, peak calcium levels were higher (p<0.001) and parathyroidectomy was performed earlier (median 80 vs. 480 days, p<0.001) in the etelcalcetide compared with the cinacalcet group. Long-term graft function, graft loss and mortality were similar. Conclusion Etelcalcetide use during maintenance HD is associated with an increased incidence of early parathyroidectomy after transplantation compared to cinacalcet or no calcimimetic.