Open-label, randomized study of NESP in pediatric subjects 18 years of age or younger. Subjects will receive study drug (NESP or rHuEPO) for 28 weeks after a 2 week screening and baseline period. During the study, procedures include bloodwork for laboratory assessments and vital signs. Dose titration determined by hemoglobin values taken weekly during the study. Antibody samples taken at baseline and during the end of study assessments. A physical examination and laboratory tests will conclude the study.

Inclusion Criteria:

• 1 to 18 years of age
• ESRD receiving dialysis or CRI with eGFR less than 30 mL/min
• Baseline hemoglobin 9.5 - 12.5 g/dL and iron replete
• Stable rHuEPO therapy for 8 weeks

Exclusion Criteria:

• Scheduled for a living-related kidney transplant
• Uncontrolled blood pressure
• seizure activity
• Hyperparathyroidism
• Major surgery within 12 weeks or active inflammatory disease
• Currently receiving antibiotics
• Clinical evidence of malignancy
• Pregnant or breast-feeding