Pediatric Chronic Kidney Disease Safety and Efficacy

- Age 6 to less than 18 years at screening - Diagnosed with CKD and SHPT receiving hemodialysis or peritoneal dialysis for ≥ 2 months before randomization - Dry weight ≥ 12.5 kg at screening - iPTH obtained from the central laboratory must be > 300 pg/mL (31.8 pmol/L) - Serum calcium (corrected) obtained from the central laboratory must be ≥ 8.8 mg/dL (2.2 mmol/L) - Serum phosphorus obtained from the central laboratory ≥ 4.0 mg/dL (1.3 mmol/L) for children 6 to less than 12 years old, or ≥ 3.5 mg/dL (1.1 mmol/L) for children 12 to less than 18 years old - Subjects already receiving vitamin D sterols (either calcitriol or a synthetic analog), a stable dose within the last 2 months prior to randomization - Subjects taking growth hormone, a stable dose defined as no change > than 20% in the last 2 months prior to randomization - Subjects on anti-convulsant medication must be on a stable dose for 3 months, and have a therapeutic blood level of the anti-convulsant at the time of randomization - Subjects must be on a dialysate calcium concentration of ≥ 2.5 mEq/L (1.25 mmol/L) for at least 2 months prior to randomization

- Underwent parathyroidectomy in the last 6 months - Anticipated parathyroidectomy within 6 months after randomization - Received therapy with cinacalcet (sensipar/mimpara) within the last month - A new onset of seizure or worsening of a pre-existing seizure disorder within the last 3 months - Scheduled date for kidney transplant from a known living donor that makes completion of the study unlikely