Earlier Calcimimetic Use May Allow Better PTH Control in Hemodialysis

Calcimimetic doses required to achieve biochemical control were higher for patients initiating treatment at higher baseline PTH levels, investigators noted.

Initiating calcimimetic therapy earlier, at lower parathyroid hormone (PTH) levels, may permit better biochemical control in patients on hemodialysis (HD), investigators suggest.

In a real-world study of patients with secondary hyperparathyroidism (SHPT) receiving in-center HD, 677 initiated oral cinacalcet and 711 initiated intravenous etelcalcetide. At baseline, mean PTH, serum phosphorus, and corrected calcium were comparable between groups: 864 pg/mL, 5.9 mg/dL, and 9.3 mg/dL for the cinacalcet group and 804 pg/mL, 5.9 mg/dL, and 9.4 mg/dL for the etelcalcetide group, respectively.

John Mark Stephens, founder of Prima Health Analytics, Weymouth, Massachusetts, and colleagues examined biochemical control according to baseline PTH categories over 15 months of follow-up. Target range mean PTH was defined as less than 600 pg/mL. In the group with baseline PTH of 600 or higher but less than 800 pg/mL, the proportion of calcimimetic initiators who attained target PTH levels increased from 48% to 62% with cinacalcet and from 56% to 86% with etelcalcetide, the investigators reported in Hemodialysis International.

Fewer patients with higher baseline PTH levels attained the target. In the group with baseline PTH of 800 or higher but less than 1000 pg/mL, the proportion of patients with target-range PTH increased from 30% to 64% with cinacalcet and from 31% to 59% with etelcalcetide. Among patients with baseline PTH of 1000 pg/mL or more, the proportion with target-range PTH increased from 14% to 41% with cinacalcet and 12% to 58% with etelcalcetide. The investigators observed similar trends in subgroup analyses of persistent users.

Among 183 patients who switched from cinacalcet to etelcalcetide, the proportion of patients with in-target PTH increased from 22% in the month prior to the treatment change to 51% at 6 months. Adherence to cinacalcet could not be assessed.

Stephens’ team concluded that “regardless of calcimimetic used, patients initiating calcimimetics at higher baseline PTH had poorer biochemical control than patients starting at lower PTH, but required higher average calcimimetic doses, which translates to higher costs of managing SHPT than for patients initiated at lower baseline PTH.”

Disclosure: This research was supported by Amgen, Inc. Please see the original reference for a full list of disclosures.

Reference

Stephens JM, Fox KM, Desai P, Cheng S, Goodman WG, Kendrick JB. Calcimimetic use in US hemodialysis facilities in first 2 years after the launch of etelcalcetide: A descriptive analysis of real-world clinical practice and outcomes. Hemodial Int. 26(2):243-254. doi:10.1111/hdi.12996