This was a 24-week, randomized, multicenter, open-label, controlled study. Participants were randomized into one of two treatment arms; oral administration of cinacalcet daily in addition to standard of care treatment, or standard of care alone. Randomization was stratified by age group (6 to < 12 and 12 to < 18 years of age). All participants received standard of care which could include therapy with Vitamin D sterols, calcium supplementation, and phosphate binders.