Abstract Background and Aims Patients on hemodialysis (HD) show a high incidence of secondary hyperparathyroidism (SHPT). An inadequate control of this condition increases morbidity and mortality, most of the times due to lack of adherence to the treatment. There is currently an available intravenous calciomimetic drug that could be an alternative to improve the prognosis and management of SHPT. Objectives To analyze the switch from cinacalcet to etelcalcetide in patients with a poor control of SHPT. Method: A descriptive observational study was carried out with patients on HD with iPTH levels over 400 pg/mL who had previously been treated with cinacalcet for at least 6 months and then with etelcalcetide for a year. The analysis assessed their basal characteristics, the evolution of their analytical parameters (calcium/phosphorus/iPTH) and their comorbidity, and a questionnaire was completed to observe their adherence to treatment. Results The study included 34 patients; average age 65±15 years (58% men); hemodialysis time 84±69 months. The main comorbidities were: 97% hypertension; 44% diabetes; and 47% heart disease. The average basal dose of cinacalcet was 62±26 mg/session, and the average dose of etelcalcetide was 2.8±2.6 mg/session. Over the 12 months of treatment with etelcalcetide a better control of iPTH was observed (from 681±279 to 291±190, p=0.004), with a decrease of iPTH by >50% in 79% of the patients. There were no significant changes in the levels of albumin, calcium or magnesium, but a significant decrease was observed in the levels of phosphorus, Ca x P product and alkaline phosphatase. 44% of the patients showed hypocalcemia after 6 months of treatment, which was asymptomatic in all cases and was corrected with an increase in the oral administration of calcium (44%) or with a change of dialysate [Ca] concentration (50%). None of the patients reported clinical intolerance with etelcalcetide. Table 1: Conclusion