Pharmacodynamics of evocalcet for secondary hyperparathyroidism in Japanese hemodialysis patients

Abstract

Background: This study investigated the pharmacokinetics, pharmacodynamics, and safety of multiple doses of evocalcet in Japanese secondary hyperparathyroidism (SHPT) patients receiving hemodialysis. Methods: In this multicenter, open-label study, conducted between August 2013 and March 2014, 27 patients received multiple doses of 1 and 4 mg evocalcet for 14 days, followed by an extension period of multiple doses of 8 and 12 mg evocalcet for 7 days using an intra-patient dose escalation protocol. Pharmacodynamic parameters consisted of measurement of intact parathyroid hormone (PTH), serum-corrected calcium, serum phosphorus and intact fibroblast growth factor 23 concentrations. Safety was assessed by analysis of adverse events. Results: Plasma evocalcet levels reached steady state 3 days after the first day of administration. Pharmacodynamic analyses showed that evocalcet effectively reduced intact PTH and serum-corrected calcium levels. Adverse events (AEs) occurred in 29.6 and 62.5% of patients receiving multiple doses of 1 or 4 mg, respectively. The AE ‘blood calcium decreased’ occurred in eight patients (33.0%) after multiple doses of 4 mg. All events were mild, except for one patient with a moderate AE (abnormal liver function) and one patient with a severe adverse drug reaction (blood calcium decreased). Conclusion: Multiple doses of evocalcet reduced intact PTH levels with a concomitant decrease in serum calcium levels. Evocalcet was well tolerated in SHPT patients receiving hemodialysis.