Randomized trial of intravenous iron supplementation in patients with chemotherapy-related anemia without iron deficiency treated with darbepoetin alfa

Abstract

Purpose: Unresponsiveness to erythropoiesis-stimulating agents, occurring in 30% to 50% of patients, is a major limitation to the treatment of chemotherapy-related anemia. We have prospectively evaluated whether intravenous iron can increase the proportion of patients with chemotherapy-related anemia who respond to darbepoetin. Patients and Methods: Between December 2004 and February 2006, 149 patients with lung, gynecologic, breast, and colorectal cancers and ≥ 12 weeks of planned chemotherapy were enrolled from 33 institutions. Patients were required to have hemoglobin ≤ 11 g/L and no absolute or functional iron deficiency. All patients received darbepoetin 150 μg subcutaneously once weekly for 12 weeks and were randomly assigned to sodium ferric gluconate 125 mg intravenously (IV) weekly for the first 6 weeks (n = 73) or no iron (n = 76). Primary end point of the study was the percentage of patients achieving hematopoietic response (hemoglobin ≥ 12 g/dL or ≥ 2 g/dL increase). Results: Hematopoietic response by intention-to-treat analysis was 76.7% (95%CI, 65.4% to 85.8%) in the darbepoetin/iron group and 61.8% (95%CI, 50.0% to 72.7%) in the darbepoetin group (P = .0495). Among patients fulfilling eligibility criteria and having received at least four darbepoetin administrations, hematopoietic responses in the darbepoetin/iron group (n = 53) and in the darbepoetinonly group (n = 50) were 92.5% (95% CI, 81.8% to 97.9%) and 70% (95% CI, 55.4% to 82.1%), respectively (P = .0033). Increase of hemoglobin during treatment period showed a time profile favoring darbepoetin/iron with statistically significant effect from week 5 on. The safety profile was comparable in the two arms. Conclusion: In patients with chemotherapy-related anemia and no iron deficiency, IV iron supplementation significantly reduces treatment failures to darbepoetin without additional toxicity. © 2008 by American Society of Clinical Oncology.