Ferumoxytol: a new intravenous iron preparation for the treatment of iron deficiency anemia in patients with chronic kidney disease.

Ferumoxytol is an intravenous iron preparation for treatment of the anemia of chronic kidney disease (CKD). It is a carbohydrate-coated, superparamagnetic iron oxide nanoparticle. Because little free iron is present in the preparation, doses of 510 mg have been administered safely in as little as 17 seconds. Two prospective, randomized studies compared two doses of ferumoxytol 510 mg given in 5 +/- 3 days with 3 weeks of oral iron 200 mg/day (as ferrous fumarate) in anemic patients with CKD. One study enrolled 304 patients with stages 1-5 CKD (predialysis), and the other study enrolled 230 patients with stage 5D CKD (undergoing hemodialysis). In both studies, a greater increase in hemoglobin level from baseline to end of study (day 35) was noted in patients who received ferumoxytol compared with those who received oral iron (mean +/- SD 0.82 +/- 1.24 vs 0.16 +/- 1.02 g/dl in patients with stages 1-5 CKD and 1.02 +/- 1.13 vs 0.46 +/- 1.06 g/dl in patients with stage 5D CKD, p<0.001). A greater proportion of both predialysis and hemodialysis patients who received ferumoxytol had hemoglobin level increases from baseline of 1 g/dl or more compared with those who received oral iron (p<0.001). In a prospective, double-blind, crossover study of more than 700 patients with CKD stages 1-5D that compared the safety of ferumoxytol with normal saline injection, the rates of treatment-related adverse events were 5.2% and 4.5%, respectively. Serious treatment-related adverse events were seen in one patient in each treatment group. The most common adverse events with ferumoxytol occurred at the injection site (bruising, pain, swelling, erythema). Dizziness, nausea, pruritus, headache, and fatigue occurred in less than 2% of patients receiving ferumoxytol, with a similar frequency noted after administration of normal saline. In short-term studies, intravenous ferumoxytol was safely and rapidly administered, and was more effective than oral iron therapy in increasing hemoglobin levels in anemic patients with CKD. Long-term clinical trials with clinical outcomes and studies comparing ferumoxytol with other parenteral iron agents will help define the role of ferumoxytol in treating the anemia of CKD.