Study to Evaluate the Safety and Tolerability of KRX-0502 (Ferric Citrate) in Children With Iron Deficiency Anemia Associated With Non-Dialysis Dependent Chronic Kidney Disease

A 24-Week, Open-Label, Randomized, 2-Arm Study to Evaluate the Safety and Tolerability of KRX-0502 (Ferric Citrate) in Children With Iron Deficiency Anemia Associated With Non-Dialysis Dependent Chronic Kidney Disease

This study will be conducted to evaluate the safety and tolerability of ferric citrate in pediatric participants with iron deficiency anemia (IDA) associated with non-dialysis dependent chronic kidney disease (NDD-CKD).

Inclusion Criteria:

• Age 6 years to <18 years at Screening
• Body Weight ≥12 kilograms (kg) at Screening
• Chronic kidney disease (CKD) stage 3 to 5, not on dialysis, with estimated glomerular filtration rate (eGFR) <60 milliliters per minute (mL/min)/1.73 meters squared (m^2) utilizing the "Bedside Schwartz" equation
• Hemoglobin (Hgb) ≥8.5 and ≤11.5 grams per deciliter (g/dL) at Screening
• Transferrin saturation (TSAT) ≤25% at Screening
• Ferritin ≤200 nanograms per milliliter (ng/mL) at Screening

Exclusion Criteria:

• Serum phosphorus level at Screening:

  • 6 to <13 years: ≤4.0 milligrams per deciliter (mg/dL);
  • 13 to <18 years: ≤2.7 mg/dL

• Liver transaminases (aspartate aminotransferase [AST] and/or alanine aminotransferase [ALT]) ˃3× the upper limit of normal at Screening

• Active significant gastrointestinal (GI) disorder, including overt gastrointestinal (GI) bleeding or active inflammatory bowel disease

• Unable to swallow pills

• Anemia due to causes other than iron deficiency anemia (IDA) of CKD

• Intravenous iron therapy or blood transfusion within 4 weeks before the Screening visit

• Participants with a functioning organ transplant

• Receipt of any investigational drug within 4 weeks before Screening

• Phosphate binder use during the Screening period