Study to Evaluate Cinacalcet in Children With Chronic Kidney Disease

Inclusion Criteria: * Subject's parent, or legally acceptable guardian, must sign an Independent Ethics Committee (IEC) or Institutional Review Board (IRB) approved Informed Consent Form. * Subjects 28 days to \< 6 years of age with chronic kidney disease (CKD) and secondary hyperparathyroidism (sHPT) as diagnosed by principal investigators, undergoing hemodialysis or peritoneal dialysis at the time of screening (subjects 6 months or older should have been receiving dialysis for ≥ 1 months) and who have not received any cinacalcet HCl therapy for at least 2 weeks prior to dosing on Day 1 * Free of any disease or condition (other than those diseases or conditions related to their renal disease that, in the opinion of the investigator, would impact the subject's safety or the integrity of the study data). * Must weigh ≥ 6 kg at screening and at Day-1. * Must be at least 30 weeks of gestational age. * Physical examination must be acceptable to the investigator at screening and at Day -1. * Hemoglobin ≥ 8 g/dL at screening and at Day -1. * Serum calcium within age-appropriate normal ranges per the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKF KDOQI) guidelines at screening and at Day -1 * Normal or clinically acceptable electrocardiogram (ECG) (12-lead reporting RR, PR, QRS, and QTc intervals) at screening and at Day -1. * Clinical laboratory tests that are acceptable to the investigator at screening and at Day -1. Exclusion Criteria * Current or h…