Pharmacodynamics of evocalcet for secondary hyperparathyroidism in Japanese hemodialysis patients.

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.

Cinacalcet hydrochloride relieves hypercalcemia in Japanese patients with parathyroid cancer and intractable primary hyperparathyroidism.

Pharmacological treatment of hypercalcemia is essential for patients with parathyroid carcinoma and intractable primary hyperparathyroidism (PHPT). Use of the calcimimetic cinacalcet hydrochloride (cinacalcet) is an option to treat such patients. We investigated the efficacy and safety of cinacalcet in Japanese patients with parathyroid carcinoma and intractable PHPT. Five Japanese patients with parathyroid carcinoma and two with intractable PHPT were enrolled in an open-label, single-arm study consisting of titration and maintenance phases. Cinacalcet doses were titrated until the albumin-corrected serum calcium concentration decreased to 10.0 mg/dL or less or until dose escalation was considered not necessary or feasible. Serum calcium concentration at the baseline was 12.1 ± 1.3 mg/dL (mean ± standard deviation; range 10.4-14.6 mg/dL) and decreased to 10.1 ± 1.6 mg/dL (range 8.6-13.3 mg/dL) at the end of the titration phase with cinacalcet at a dosage of up to 75 mg three times a day. At the end of the titration phase, at least a 1 mg/dL reduction in serum calcium concentration from the baseline was observed in five patients (three with carcinoma and two with PHPT), and it decreased to the normocalcemic range in five patients (three with carcinoma and two with PHPT). Common adverse events were nausea and vomiting. One patient discontinued participation in the study because of an adverse event, liver disorder. Cinacalcet effectively relieved hypercalcemia in 60% of the Japanese patients with parathyroid carcinoma and might be effective in those with intractable PHPT. The drug might be tolerable and safe at a dosage of at most 75 mg three times a day.