Ferric Citrate in Managing Serum Phosphorus and Iron Deficiency in Anemic Chronic Kidney Disease (CKD) Subjects Not on Dialysis

• Change in ferritin levels from baseline to end of treatment [ Time Frame: 12 Weeks ] [ Designated as safety issue: No ]
• Change in TSAT (transferrin saturation) from baseline to end of treatment [ Time Frame: 12 Weeks ] [ Designated as safety issue: No ]
• Change in serum phosphorus levels from baseline to end of treatment [ Time Frame: 12 Weeks ] [ Designated as safety issue: No ]

• Rates of adverse events overall and by organ system class, preferred term, severity, and suspected relationship to study drug by treatment assignment as a measure of safety and tolerability [ Time Frame: Approximately 16 weeks ] [ Designated as safety issue: Yes ]
  SAEs will be monitored for an additional 28 days after last study visit.
• Type of concomitant medications used by treatment assignment as a measure of safety [ Time Frame: Approximately 16 weeks ] [ Designated as safety issue: Yes ]
• Change in sequential blood chemistries by treatment assignment as a measure of safety [ Time Frame: 12 Weeks ] [ Designated as safety issue: Yes ]
• Change in hemoglobin levels from baseline to end of treatment by treatment assignment as a measure of safety [ Time Frame: 12 Weeks ] [ Designated as safety issue: No ]

The purpose of this study is to determine if KRX-0502 (ferric citrate) is a safe and effective treatment for the management of serum phosphorus levels and iron deficiency in anemic chronic kidney disease (CKD) subjects not on dialysis. Total length of treatment is approximately 12 weeks.

This is a randomized, double-blind, placebo-controlled, three-period, multi-center clinical trial. Following a Screening and Qualification Period and a two-week Washout Period (for those subjects entering the study on a phosphate binder), eligible subjects will be randomized in a 1:1 ratio to receive either KRX-0502 (ferric citrate) or placebo for up to approximately 12 weeks. The purpose of this study is to determine if KRX-0502 (ferric citrate) is a safe and effective treatment for the management of serum phosphorus levels and iron deficiency in anemic CKD subjects not on dialysis.

• Iron Deficiency
• Iron Deficiency Anemia

• Experimental: Ferric Citrate
  Ferric citrate will be taken with or within one hour of meals or snacks. The dose of ferric citrate will depend on the patient's serum phosphorus results at each treatment visit.
  Intervention: Drug: Ferric Citrate
• Placebo Comparator: Placebo
  Placebo will be taken with or within one hour of meals or snacks. The number of placebo pills will depend on the patient's serum phosphorus results at each treatment visit.

Inclusion Criteria:

• Stage III to V Chronic Kidney Disease
• Serum Phosphorus 4.0-6.0 mg/dL prior to Randomization
• Ferritin 300 ng/mL or less
• TSAT 30% or less
• Hemoglobin 9.5-11.5 g/dL
• Must consume a minimum of 2 meals per day

Exclusion Criteria:

• Parathyroidectomy within 24 weeks of study
• GI bleed or inflammatory bowel disease within 12 weeks of study
• Requirement for dialysis or kidney injury within 8 weeks of study
• Absolute requirement for oral iron, IV iron, Erythropoiesis-Stimulating Agent, blood transfusions, and Sensipar during the study
• Absolute requirement for calcium-, magnesium-, or aluminum-containing drugs with meals
• Absolute requirement for vitamin C, niacin, or nicotinamide outside of multivitamins
• History of hemochromatosis
• Allergy to iron products
• History of malignancy in last 5 years