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 sever…