All mean Hb values recorded during the evaluation period were calculated and subtracted from the mean baseline Hb value for each participant. The percentage of participants maintaining their mean Hemoglobin (Hb) concentration within +/- 1 gram/deciliter (g/dL) of their reference Hb and between 10.5 -12.5 g/dL is presented during the EEP. The EEP is defined as Week 16 to Week 24

Per protocol (PP) population included participants except who didn't meet inclusion criterion relative to consent, stable baseline Hb values, iron status, epoetin maintenance, and who met exclusion criterion of hemoglobinopathies/hemolysis, bleeding, >3 recorded Hb, missing drug administration, other ESA, blood transfusion during the DTP or EEP.

A time adjusted mean change in Hb concentration was calculated using an area under the curve approach, for both periods separately. Change in Hb concentration between the baseline and evaluation periods was calculated by subtracting the calculated average baseline Hb value from the average evaluation period Hb value. All blood samples for Hb measurements were taken prior to study drug administration. Analysis used last observation carried forward (LOCF) for missing Hb values to correct for the impact of early dropouts. The baseline period is defined as Week -4 to Week -1. The EEP is defined as Week 16 to Week 24

The Intent-to-Treat (ITT) population included all the participants who received at least one dose of C.E.R.A. and for whom data for at least one follow-up variable is available.

All mean Hb values recorded during the EEP were calculated. The percentage of participants maintaining their average Hb concentration within the targeted range 10.5-12.5 g/dL during the EEP were reported. The EEP is defined as Week 16 to Week 24

The ITT population included all the participants who received at least one dose of C.E.R.A. and for whom data for at least one follow-up variable is available.

The mean number of days the participant spent within the Hb range 10.5-12.5 g/dL during the EEP was reported. The EEP is defined as Week 16 to Week 24

The ITT population included all the participants who received at least one dose of C.E.R.A. and for whom data for at least one follow-up variable is available. Of the 199 participants, analysis was conducted on 184 participants, as 15 participants did not maintain their hemoglobin, within range of 10.5-12.5 g/dL during the EEP.

The number of participants who required dose adjustments of C.E.R.A were categorized as; 1. No dose change; 2. Any dose change: a. Dose increase only; b. Dose decrease only; c. Dose increase and increase; 3. Only one dose, all of which were recorded during DTP, EEP and LTSP. DTP is defined as Week 1 to Week 16, EEP is defined as Week 16 to Week 24 and LTSP is defined as Week 24 to Week 44

The ITT population included all the participants who received at least one dose of C.E.R.A. and for whom data for at least one follow-up variable is available. . Data for the participants present at the time of assessment was used for analysis i.e. for DTP- 199, EEP-183, LTSP-178 respectively.

The number of participants who underwent red blood cell transfusion was reported

The safety population was defined as all participants who received at least one dose of the trial medication and underwent a safety follow-up, whether withdrawn prematurely or not.