A phase 3, multicentre, randomized, double-blind, placebo-controlled, parallel-group study to evaluate the efficacy and safety of etelcalcetide (ONO-5163/AMG 416), a novel intravenous calcimimetic, for secondary hyperparathyroidism in Japanese haemodialysis patients.

Background: Secondary hyperparathyroidism (SHPT) is a major complication associated with chronic kidney disease. We evaluated the efficacy and safety of etelcalcetide (ONO-5163/AMG 416), a novel intravenous calcimimetic, in Japanese haemodialysis patients with SHPT.

Methods: In this phase 3, multicentre, randomized, double-blind, placebo-controlled, parallel-group study, etelcalcetide was administered three times per week at an initial dose of 5 mg, and subsequently adjusted to doses between 2.5 and 15 mg at 4-week intervals for 12 weeks. A total of 155 SHPT patients with serum intact parathyroid hormone (iPTH) levels ≥300 pg/mL were assigned to receive etelcalcetide (n = 78) or placebo (n = 77). The primary endpoint was the proportion of patients with decreased serum iPTH to the target range proposed by the Japanese Society for Dialysis Therapy (60-240 pg/mL). The major secondary endpoint was the proportion of patients with ≥30% reductions in serum iPTH from baseline.

Results: The proportion of patients meeting the primary endpoint was significantly higher for etelcalcetide (59.0%) versus placebo (1.3%). Similarly, the proportion of patients meeting the major secondary endpoint was significantly higher for etelcalcetide (76.9%) versus placebo (5.2%). Serum albumin-corrected calcium, phosphorus and intact fibroblast growth factor-23 levels were decreased in the etelcalcetide group. Nausea, vomiting and symptomatic hypocalcaemia were mild with etelcalcetide. Serious adverse events related to etelcalcetide were not observed.

Conclusions: This study demonstrated the efficacy and safety of etelcalcetide. As the only available intravenous calcium-sensing receptor agonist, etelcalcetide is likely to provide a new treatment option for SHPT in haemodialysis patients.