Efficacy and Safety of Lanthanum Carbonate in Reducing Serum Phosphorus Levels in Subjects With Stage 3 and 4 Chronic Kidney Disease

Inclusion Criteria: * Under a physician's care for CKD for \> 2 months and are not expected to begin dialysis for 4 months * Screening estimated GFR of 15-59 mL/1.73 m2 * Serum phosphorus \>= 4.7 mg/d following washout Exclusion Criteria: * Requiring treatment with cinacalcet HCI or compounds containing phosphate, aluminum, calcium or magnesium * Rapidly progressing glomerulonephritis * Cirrhosis or other clinically significant liver diseases * Past or present uncontrolled peptic ulcer, Crohn's disease, malignancy or recent GI bleed