A Study to Evaluate the Safety (Compared to Iron Sucrose), Efficacy and Pharmacokinetics of Ferumoxytol for the Treatment of Iron Deficiency Anemia (IDA) in Pediatric Subjects With Chronic Kidney Disease (CKD)

Inclusion Criteria:

1. Male or female 2 years to <18 years of age at time of consent

2. Has IDA defined as: a) hemoglobin <12.0 g/dL and b) with either transferrinsaturation (TSAT) <40% or ferritin <100 ng/mL; or considered to be at risk ofdevelopment of IDA, i.e., TSAT<20% with falling hemoglobin during the preceding 2months and a history of hemoglobin <12 g/dL

3. Has Chronic Kidney Disease defined as one of the following:

4. on chronic hemodialysis;

5. receiving chronic peritoneal dialysis;

6. estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m2;

7. has evidence of structural and/or functional abnormalities e.g., persistentalbuminuria, abnormal urine sediment, electrolyte and other abnormalities dueto tubular disorders for > 3 months.

8. For patients other than hemodialysis dependent CKD patients, documented history ofunsatisfactory oral iron therapy or in whom oral iron cannot be tolerated, or forwhom oral iron is considered medically inappropriate

9. All subjects (female and male) of childbearing potential who are sexually activemust be on an effective method of birth control for at least 1 month prior to Day 1Dosing and agree to remain on birth control until completion of the study

Exclusion Criteria:

1. Known hypersensitivity reaction to any component of ferumoxytol and iron sucrose

2. History of allergy to intravenous (IV) iron

3. History of multiple drug allergies (>2)

4. Low systolic blood pressure (Age 1-9 years <70 + [age in years x 2] mmHg, Age 10-17years <90 mmHg)

5. Hemoglobin ≤7.0 g/dL

6. Serum ferritin level >600 ng/mL