Study of HEMAX PFS Versus EPREX/ ERYPO® in Predialysis Chronic Kidney Disease

Inclusion Criteria: * Patients older than 18 years * Patients with pre-dialysis chronic renal failure (CRF) defined by a glomerular filtration rate (calculated with the Modification of Diet in Renal Disease Study formula) ≥15 ml/ min and \<60 ml/ min, by 1.73 m2 * Anemic patients that should be treated and levels of hemoglobin \<10.5 g/dl and ≥ 7.5 g/dl. * Patients that have the will and capacity to sign a written inform consent. * Post-menopause women for at least 2 years, or sterile by surgery for at least 6 months. Women of childbearing age must have a negative pregnancy test at baseline and be willing to get an adequate method of contraception. Exclusion Criteria: * Patients that are planned to be on dialysis or have a renal transplant in the following 6 months. * Transferrin iron Saturation \< 20%. * Etiology of renal failure (as secondary to autoimmune diseases) that, to the judge to the physician, can affect the normal development of the protocol. * Active bleeding or history of hemorrhage that have led to a significative decrease of hematocrit in the last 30 days. * Non-controlled hypertension (≥160 mm Hg of systolic pressure and/or ≥100 mm Hg of diastolic pressure with anti-hypertensive treatment). * Anemia caused by any other cause than renal disease. * Having a transfusion in the last 3 months before basal visit or during screening. * Treatment with an erythropoiesis stimulant in the last 3 months before basal visit or screening. * Increase risk of thromboembolic disease: history of arterial thromboembolia (stroke, transient ischemic attack, Acute coronary syndrome, etc.) in the last 6 months or venous in the last 12 months before screening; surgery in the last month before screening; prolong immobilization or orthopedic surgery programmed in the following 6 months or any other condition that to the judge of the investigator can increase the risk of thromboembolism. * Hematological disease or myelodysplastic syndrome or history of hematological neoplasm or solid tumor in the last 5 years. * History of congestive heart failure * Pregnancy or breast feeding * Refuse to participate in the protocol or any medical condition, that in the investigator opinion, is significant to prevent the participant from being included in the trial.