Ascertain the Optimal Starting Dose of Mircera Given Subcutaneously for Maintenance Treatment of Anemia in Pediatric Patients With Chronic Kidney Disease on Dialysis or Not Yet on Dialysis.

Inclusion Criteria:

- Pediatric participants 3 months to 17 years of age with clinically stable chronic
renal anemia

- CKD with estimated glomerular filtration rate (eGFR) of < 45 mL/min/1.73 m2
(determined by the Bedside Schwartz formula) or dialysis treatment for at least 8
weeks before the first dose of Mircera

- For participants on peritoneal dialysis (PD): a weekly Kt/V≥ 1.8

- For participants on HD: adequate HD, urea reduction ratio (URR) > 65% or Kt/V > 1.2
for participants on HD three times per week.

Participants with fewer than or more than three HD sessions per week should have a weekly
Kt/V≥ 3.6.

- Baseline Hb concentration 10.0-12.0 g/dL determined from the mean of two Hb values
measured at Visit 1 (Week -3) and Visit 2 (Week -1)

- Stable SC maintenance treatment with epoetin alfa, epoetin beta, or darbepoetin alfa
with the same dosing interval for at least 6 weeks before the first dose of Mircera

- Stable dose of epoetin alfa, epoetin beta, or darbepoetin alfa treatment with no
weekly dose change > 25% (increase or decrease) for at least 4 weeks before the first
dose of Mircera

- Adequate iron status defined as ferritin≥100 ng/mL or transferrin saturation (TSAT)≥
20% (or percentage of hypochromic red cells < 10%); mean of two values measured during
screening.

Exclusion Criteria:

- Overt gastrointestinal bleeding within 8 weeks before screening or during the
screening period

- RBC transfusions within 8 weeks before screening or during the screening period

- Hemoglobinopathies (e.g., homozygous sickle-cell disease, thalassemia of all types)
Hemolytic anemia, Active malignant disease

- PD subjects with an episode of peritonitis within the past 30 days prior to screening
and/or during the screening period

- Uncontrolled or symptomatic inflammatory disease (e.g., systemic lupus erythematosus)

- Uncontrolled hypertension as assessed by the investigator

- Epileptic seizures within 3 months prior to screening and during the screening period

- Administration of any investigational drug within 4 weeks prior to screening or
planned during the study

- Severe hyperparathyroidism (intact parathyroid hormone [PTH]≥ 1000 pg/mL or whole PTH≥
500 pg/mL) or biopsy-proven bone marrow fibrosis

- Kidney transplant with use of immunosuppressive therapies known to exacerbate anemia

- Known hypersensitivity to recombinant human erythropoietin (EPO), polyethylene glycol,
or any constituent of the study drug formulation

- Anti-EPO antibody (AEAB)-mediated pure red cell aplasia (PRCA) or history of AEAB
mediated PRCA or positive AEAB test result in the absence of PRCA

- High likelihood of early withdrawal or interruption of the study (e.g., planned living
donor kidney transplant within 5 months of study start)

- Planned elective surgery during the entire study period