The purpose of this study is to evaluate the long term safety and efficacy of thrice weekly intravenous (IV) administration of etelcalcetide in the treatment of secondary hyperparathyroidism (SHPT) in patients receiving hemodialysis who had completed 12 weeks of treatment with etelcalcetide in parent study 20120331 (KAI-4169-005; NCT01414114).