This single arm study will assess the efficacy and safety of monthly administration of subcutaneous methoxy polyethylene glycol-epoetin beta (Mircera) when administered for the maintenance of hemoglobin levels in participants with chronic renal anemia, not on dialysis. Participants currently receiving treatment with subcutaneous epoetin or darbepoetin alfa will receive monthly subcutaneous injections of methoxy polyethylene glycol-epoetin beta, with the starting dose (120 or 200 micrograms) calculated from the last weekly dose of epoetin beta or darbepoetin alfa previously administered.

Inclusion Criteria:

• chronic kidney disease stage 3 or 4, with chronic renal anemia, not requiring dialysis;
• continuous stable subcutaneous maintenance Erythropoietin-Stimulating Agent (ESA) therapy during previous month.

Exclusion Criteria:

• transfusion of red blood cells during previous 2 months;
• significant acute or chronic bleeding;
• poorly controlled hypertension.