OBJECTIVES To examine epoetin alfa (EPO) and darbepoetin alfa (DARB) drug utilization in cancer chemotherapy patients before and after ESA coverage limitations by the Centers for Medicare and Medicaid Services National Coverage Determination (NCD). METHODS Medical claims from the Ingenix Impact National Managed Care Database were analyzed. Patients included in the study were ³18 years, had ³1 claim for cancer, were newly initiated on EPO or DARB, and received chemotherapy during ESA treatment. Patients initiating ESA therapy between 8/2006-12/2006 (pre-NCD) were compared with those initiating between August 2007-December 2007 (post-NCD). The number of patients treated, dose per injection, cumulative drug utilization during the first 16 weeks of therapy, and dose ratio (cumulative dose EPO: DARB) were compared between the two groups. RESULTS A total of 3951 ESA treatment episodes were identified (pre-NCD: 3046; post-NCD: 905). Patients in the post-NCD group were generally older (pre-NCD: 56.2 years; post-NCD: 58.7 years; p<0.0001) than the pre-NCD group. The number of patients receiving ESA in the post-NCD relative to pre-NCD period decreased by 61% (from 1057 to 411 patients) for EPO and 75% (from 1989 to 494 patients) for DARB. Furthermore, among the subset of treated patients in each period, total dose administered per patient within 16 weeks of treatment initiation decreased by 20% (Units: pre-NCD 251,902 vs. post-NCD 200,635) for EPO and 13% (mcg: pre-NCD 917 vs post-NCD 801) for DARB, despite stable dose per injection pre- and post-NCD. The EPO: DARB dose ratio was higher in the pre-NCD group (274:1) than the post-NCD group (250:1). CONCLUSIONS Recent changes to ESA coverage policy appear to have decreased ESA utilization and the corresponding EPO: DARB dose ratio. Further research is warranted to assess this impact on the demand for blood transfusions.