Preference for monthly darbepoetin alfa dosing in patients with chronic kidney disease not receiving dialysis

OBJECTIVE: To determine patient preference for once-weekly Epoetin alfa versus once-monthly (QM) darbepoetin alfa in patients with chronic kidney disease (CKD) not receiving dialysis. METHODS: AMPS (Aranesp Monthly Preference Study) consisted of two studies of similar design, each with a 2-week screening/baseline period, a 20-week QM darbepoetin alfa dosing period, and an 8-week follow-up period. Patients aged > or = 18 years had a nephrologist-reported diagnosis of CKD but were not receiving dialysis, and were required to have at least two hemoglobin levels within 10-12 g/dL and to have been receiving a stable dose (< 25% change) of once-weekly or once-every-other-weekly Epoetin alfa for at least 8 weeks. At week 21, patients could continue on QM darbepoetin alfa or revert back to their previous Epoetin alfa regimen. The primary analysis assessed patient preference at week 21 for QM darbepoetin alfa versus previous once-weekly Epoetin alfa. RESULTS: AMPS enrolled 442 patients: 54% were female, 67% were Caucasian, and mean (SD) age was 68.3 (13.5) years. At week 21, 346 patients remained on study. Of the patients converted from once-weekly Epoetin alfa, 86% (138/161) preferred darbepoetin alfa QM, and of all patients who expressed a preference, regardless of previous Epoetin alfa dosing frequency, 96% (305/319) preferred QM darbepoetin alfa. Mean (SD) hemoglobin at week 29 of the study was similar to mean hemoglobin at baseline (for those who completed the study and were receiving QM darbepoetin alfa at week 29: 11.2 [1.1] g/dL at week 29 versus 11.4 [0.7] g/dL at baseline). QM darbepoetin alfa was well tolerated. CONCLUSION: These data show that the majority of study patients preferred QM darbepoetin alfa to more frequent Epoetin alfa, and that QM darbepoetin alfa maintained hemoglobin levels at week 29 and was well tolerated over the study period. The single-item questionnaire could be a potential limitation of this study and further investigation with a multi-question instrument may be helpful in confirming these results.