Dosing patterns, drug costs, and hematologic outcome in anemic patients with chronic kidney disease switching from darbepoetin alfa to epoetin alfa.

OBJECTIVE

To compare real-world dosing patterns, drug costs, and hematologic outcome in anemic chronic kidney disease (CKD) patients, not receiving dialysis, who switched from darbepoetin alfa (DARB) to epoetin alfa (EPO) in a community practice setting.

RESEARCH DESIGN AND METHODS

This retrospective observational chart review from a US nephrology clinic included 153 anemic CKD patients > or = 18 years of age who did not receive dialysis during the study period, switched from DARB to EPO between 8/2003 and 8/2005, and received > or = 2 doses of both agents. Paired t-test and McNemar's chi-square were performed comparing pre-switch and post-switch outcomes.

RESULTS

Mean interval between doses increased from 24.3 +/- 11.1 days with DARB to 28.8 +/- 19.8 days with EPO (p = 0.001). Weighted mean pre-switch weekly dose for DARB was 25 mug, while weighted mean post-switch weekly dose for EPO was 7090 Units, resulting in a dose ratio (Units EPO:microg DARB) of 287:1. These doses resulted in mean weekly costs of $110 (DARB) and $86 (EPO). Mean hemoglobin (Hb) levels increased over time from 10.8 g/dL at 6 months pre-switch to 11.1 g/dL 6 months after EPO initiation (p = 0.0132). Mean Hb levels were > 11 g/dL, but below 12 g/dL, while patients received EPO.

CONCLUSIONS

Patients switching from DARB to EPO had a greater mean interval between doses, lower drug costs, and consistently maintained recommended Hb levels over time.

LIMITATIONS

The reverse direction (EPO to DARB) was not investigated. Although treatment outcomes were not assessed in a randomized, controlled setting, the study's observational nature provided actual evidence in a real-world setting.