EPIC(Effect of PhosLo on Phosphorus Levels in Chronic Kidney Disease)

Inclusion Criteria: * Non-dialyzed male or female patients with CKD, with a GFR of less than 30mL/min/1.73m² who have elevated serum phosphorus or who develop elevated serum phosphorus following washout from phosphorus-binding therapy. * Patients must have written informed consent * Negative serum pregnancy test if appropriate * Expected to be able to comply with protocol procedures and schedule Exclusion Criteria: * Unstable angina pectoris * Severe congestive heart failure * Severe liver dysfunction * Severe malnutrition * Severe hyperparathyroidism * AIDS (HIV positive subjects without AIDS are not excluded) * Active malignancy for which the subject is receiving chemotherapy or radiation * Subject unlikely to complete the study * History of obstructed bowels or hypersensitivity to any of the study medications or their components * History of swallowing disorders such as dysphagia (that would prevent the subject from taking the study drug) severe gastrointestinal motility disorders, or major GI tract surgery * Participation in an investigational drug or device trial within 30 days of randomization * Subjects on Vitamin D therapy * Subjects with acute symptoms, in the last month, or current radiographic evidence of kidney stones * Subjects who have undergone renal transplant or receiving dialysis * Or any condition with makes patient participation not in the patients best interest