Participants who are receiving SC or IV epoetin beta or darbepoetin alfa will receive monthly injections of methoxy polyethylene glycol-epoetin beta, with the starting dose of 120 or 200 micrograms calculated from the last weekly dose of epoetin beta or darbepoetin alfa previously administered, using the same route of administration (SC or IV). Thereafter, when the hemoglobin concentration will increase or decrease in a clinically significant amount, a dose adjustment will be performed according to specific provided guidance. Total duration of treatment will be up to 48 weeks.

Participants who are receiving SC or IV epoetin beta or darbepoetin alfa will continue to receive the same treatment (epoetin beta or darbepoetin alfa at the same dose, same administration intervals, and the same route of administration). When necessary, dose adjustments will be performed according to Summary of Product Characteristics (SmPC). Total duration of treatment will be up to 48 weeks.

Participants who are receiving SC or IV epoetin beta or darbepoetin alfa will receive monthly injections of methoxy polyethylene glycol-epoetin beta, with the starting dose of 120 or 200 micrograms calculated from the last weekly dose of epoetin beta or darbepoetin alfa previously administered, using the same route of administration (SC or IV). Thereafter, when the hemoglobin concentration will increase or decrease in a clinically significant amount, a dose adjustment will be performed according to specific provided guidance. Total duration of treatment will be up to 48 weeks.