OBJECTIVES: This study described control of parathyroid hormone (PTH), and corresponding corrected calcium (Ca) and phosphorous in adults initiating calcimimetics during 2018 in small dialysis organizations after the introduction of etelcalcetide.

METHODS: This retrospective study using Visonex® Clarity electronic health records between 10/1/2017 and 12/31/2019 identified adults ≥18 years of age receiving in-center hemodialysis as either a cinacalcet or etelcalcetide initiator based on their first calcimimetic use in 2018 (index date) with no prior calcimimetic use in the 3 months pre-index date. Patients were stratified by PTH at baseline and were followed for 15 months from index date. Sub-groups of patients who were persistent on a single calcimimetic for 15 months and of patients who switched from cinacalcet to etelcalcetide were also analyzed.

RESULTS: 677 patients initiated cinacalcet and 711 initiated etelcalcetide. Mean PTH (pg/mL), phosphorus and Ca (mg/dL) at baseline were 864, 5.9 and 9.3 for cinacalcet and 804, 5.9 and 9.4 for etelcalcetide. Over 15 months of follow-up the proportion of initiators with baseline PTH 600-<800 considered “in-target” (monthly average PTH <600) increased from 48% to 62% with cinacalcet and from 56% to 86% with etelcalcetide; among those with baseline PTH 800-<1000, the proportion increased from 30% to 64% with cinacalcet and 31% to 59% with etelcalcetide; and among those with baseline PTH ≥1000 this proportion increased from 14% to 41% with cinacalcet and 12% to 58% with etelcalcetide. A similar pattern was observed for persistent users (n=646). For patients switching from cinacalcet to etelcalcetide (n=183), the proportion of patients considered “in-target” increased from 22% in the month prior to switch to 51% in month 6 post-switch.

CONCLUSIONS: Patients initiating calcimimetics at higher baseline PTH had poorer biomarker control than patients starting at lower PTH. Patients switched from cinacalcet to etelcalcetide had improvements in PTH control post-switch.