A Study of Four Dosing Regimens of PROCRIT (Epoetin Alfa) in Patients With Chronic Kidney Disease. Protocol Addendum: Extension Study of Maintenance Therapy of PROCRIT (Epoetin Alfa) in Patients With Chronic Kidney Disease.

Inclusion Criteria:

• Patients must have CKD with Hg level <11 g/dL at study start
• must not have received any erythropoietic agents within 8 weeks of study start
• Patients with reproductive potential and their partners must practice an effective method of birth control (e.g., prescription oral contraceptives, contraceptive injections, intrauterine device, double-barrier method, contraceptive patch, partner sterilization) before entry and throughout the study, female subjects with reproductive potential must have a negative urine pregnancy test within 7 days of the first dose of epoetin alfa
• Patients must have signed informed consent documents indicating that they agree to participate in the study, including the completion of all study-related procedures and evaluations.

Protocol Addendum: Patients must have participated in the Main Protocol of this study and completed all study-related procedures

• Patients must have a Hb between 11-12 g/dL at baseline (measured by HemoCue)
• Patients must have CKD defined as glomerular filtration rate (GFR) >=15 to <=90 mL/min as determined using the Modification of Diet for Renal Disease (MDRD) equation.

Exclusion Criteria:

• No patients receiving dialysis or scheduled to receive dialysis during the course of the study
• No patients with a current diagnosis of poorly controlled hypertension after adequate antihypertensive therapy or those with severe congestive heart failure (New York Heart Association Class IV), or known severe stable or unstable coronary artery disease
• No patients receiving chemotherapy for cancer within 3 months prior to study start or expected during study participation
• No patients with a current diagnosis of anemia due to Vitamin B12 deficiencies, hemolysis, or gastrointestinal bleeding or a history of/or active blood or bleeding disorders (this includes but is not limited to porphyria, thalassemia, myelodysplastic syndrome, and sickle cell anemia. No patients with liver diseases or any other diseases known to cause anemia
• No patients with a past history of thrombotic vascular events, (including but not limited to stroke, transient ischemic attack, myocardial infarction, coronary artery disease, and deep venous thrombosis) within the past 5 years
• No patients with a life expectancy of <= 6 months
• No women who are currently pregnant or lactating. No patients previously unresponsive to erythropoietic agents.

Protocol Addendum: No patients with a transferrin saturation (TSAT) <20% and a ferritin <50 ng/mL

• No patients with an epoetin alfa dose reduction/hold within the past four weeks of treatment in the Main Protocol, for a Hb rate of rise (>1 g/dL over 1 or 2 consecutive weeks),or a Hb above 12 g/dL
• No patients with iron overload defined as a TSAT > 70% or a ferritin > 1000 ng/mL
• No patients with a serum albumin concentration < 2.6 g/dL, or unstable angina
• No patients with chemotherapy for cancer within 3 months prior to baseline or expected during open-label extension participation
• No patients with known solid tumor malignancy or with new onset seizures within 3 months or seizures not controlled by medication prior to baseline. No patients receiving transfusion of platelets or packed red blood cells within 28 days prior to the first dose of epoetin alfa. No patients who have been previously unresponsive to erythropoietic agents, including patients who were treatment failures during the Main Protocol.