A randomized, active-control, pilot trial of front-loaded dosing regimens of darbepoetin-alfa for the treatment of patients with anemia during chemotherapy for malignant disease

Abstract

Background: Anemia in patients receiving chemotherapy can be ameliorated with recombinant human erythropoietin (rHuEPO), which is administered one to three times per week. Darbepoetin alpha, a new erythropoietic agent, has longer serum residence time, allowing it to be administered less frequently.

Methods: Patients (n = 127) were randomized to receive study drug for 12 weeks: either rHuEPO 40,000 U with escalations to 60,000 U for nonresponders or darbepoetin alpha at doses of 4.5 microg/kg per week until hemoglobin concentration >or= 12 g/dL, then 1.5 microg/kg per week (Group 1); 4.5 microg/kg per week for 4 weeks, then 2.25 microg/kg per week for 8 weeks (Group 2); or 4.5 microg/kg per week for 4 weeks, then 3.0 microg/kg every 2 weeks (Group 3). Efficacy was measured using the mean change in hemoglobin level, the proportion of patients achieving a hemoglobin response, the time to response, and the mean change in Functional Assessment of Cancer Therapy-Fatigue Scale scores. Safety was assessed by reports of adverse events.

Results: Overall, after 4 weeks of treatment, the mean change (95% confidence interval [95%CI]) in hemoglobin concentration was 0.53 g/dL (95%CI, 0.05-1.02 g/dL), 0.70 g/dL (95%CI, 0.11-1.29 g/dL), and 0.90 g/dL (95%CI, 0.47-1.33 g/dL) in darbepoetin alpha Groups 1, 2, and 3, respectively, and 0.39 g/dL (95%CI, - 0.22-1.00 g/dL) in the rHuEPO group. By the end of the study, the mean change (95%CI) in hemoglobin concentration was 1.35 g/dL (95%CI, 0.67-2.02 g/dL), 1.35 g/dL (95%CI, 0.57-2.12 g/dL), and 1.28 g/dL (95%CI, 0.84-1.73 g/dL) in darbepoetin alpha Groups 1, 2, and 3, respectively, and 1.03 g/dL (95%CI, 0.53-1.53 g/dL) in the rHuEPO group. The early erythropoietic response in patients who were treated with darbepoetin alpha was associated with an early and maintained reduction in patient-reported fatigue. The adverse event profile was comparable with all doses of darbepoetin alpha and rHuEPO.

Conclusions: Darbepoetin alpha, given as a front-loaded dose for 4 weeks and followed by lower and/or less frequent doses, appears to be efficacious and may decrease the time to response relative to treatment with rHuEPO.