Late Phase 2 Study of Paricalcitol Injection: Dose-response Study of Paricalcitol Injection in Chronic Kidney Disease Subjects Receiving Hemodialysis With Secondary Hyperparathyroidism (Examination of Initial Dose and Incremental Dose)

This multicenter, randomized, open-label trial consisted of 4 dose-adjustment regimens for paricalcitol injection (initial doses and dose adjustment ranges were 2 ± 1 µg, 2 ± 2 µg, 4 ± 1 µg, and 4 ± 2 µg) and 1 maxacalcitol regimen (initial dose and dose adjustment range was 5 µg ± 2.5 µg or 10 µg ± 2.5 µg) as a reference group. Subjects who met the inclusion criteria were randomized equally to 1 of the treatment groups with iPTH values at screening (< 500 pg/mL or ≥ 500 pg/mL) as a dynamic allocation factor. Study drugs were administered 3 times weekly (every other day) from the venous end of the hemodialysis circuit just before completion of the dialysis session. The initial doses were continued for 2 weeks, followed by dose adjustments (increase, maintenance, decrease, suspension, or resumption) by 1 µg or 2 µg units for the paricalcitol groups and by 2.5 µg units for the maxacalcitol group based on iPTH, calcium (adjusted), and phosphorus values every 2 weeks.

Subjects in the paricalcitol groups were to be suspended from treatment if their iPTH value decreased to < 60 pg/mL in accordance with the guidelines proposed by the Japanese Society of Dialysis Therapy for the treatment of secondary hyperparathyroidism in chronic dialysis patients (control goal value of 60-180 pg/mL for iPTH). The dose adjustment criteria based on iPTH values for the maxacalcitol group were set according to the prescribing information for maxacalcitol (suspended when iPTH decreased to ≤ 150 pg/mL).