 The purpose of this study is to compare the time to hematopoietic response hemoglobin correction to 12 gdL or a greater than or equal to 2 gdL increase from baseline for subjects randomized to receive darbepoetin alfa with a front load dosing regimen to those receiving recombinant human erythropoietin rHuEPO with a weekly dose regimen during the 12-week comparative treatment period. 