SAN FRANCISCO—Ferumoxytol, a novel IV iron replacement drug, may be more effective than oral iron in hemodialysis patients receiving anemia treatment with an erythropoiesis-stimulating agent (ESA), according to study findings presented here at Renal Week 2007.
In an open-label randomized study, patients who received ferumoxytol had a significantly greater increase in hemoglobin (Hb) levels at Day 35 compared with patients who received oral iron (1.02 vs. 0.46 g/dL). In addition, a higher proportion of ferumoxytol-treated patients achieved 1g/dL increase in Hb or greater at Day 35 compared with oral iron (49.1% vs. 25.0%).
As early as Day 21, ferumoxytol recipients experienced a significantly greater rise in Hb levels compared with the oral iron group (0.71 vs. 0.35 g/dL). The overall adverse event rate was lower with ferumoxytol than oral iron (49.1% vs. 56.5%). Related adverse events, which included diarrhea, constipation, nausea and vomiting, were almost half as frequent in the ferumoxytol group (8.2% vs. 15.9%).
“These findings suggest that IV ferumoxytol can be given safely and effectively to increase hemoglobin and increase iron stores,” said study investigator Robert Provenzano, MD, chief of the section of nephrology at St. John Hospital and Medical Center in Detroit and associate clinical professor of medicine at Wayne State University School of Medicine in Detroit.
“What is new here is that we can administer a large amount of iron safely as an IV bolus to dialysis patients with a predictable increase in iron levels as well as hemoglobin.”
The National Kidney Foundation (NKF) guidelines currently recommend IV iron replacement in hemodialysis patients to maintain serum ferritin levels greater than 200 ng/mL and transferrin saturation (TSAT) greater than 20%. Studies have shown that IV iron replacement therapy may lead to a greater increase in Hb compared with oral iron and to a reduction in ESA doses.
The study by Dr. Provenzano and his colleagues randomized 230 hemodialysis patients receiving ESA treatment (mean age, 60 years) at 44 centers across the United States. The demographic and baseline clinical characteristics were similar in the two treatment groups, as were baseline Hb, transferrin saturation, and ferritin levels. A total of 114 patients (50% male) received two 510 mg of ferumoxytol with hemodialysis (no more than five days apart) and 116 (62%) received 200 mg elemental oral iron for 21 days.
Ferumoxytol is a superparamagnetic iron oxide nanoparticle with a polyglucose sorbitol carboxymethylether coating designed to limit immunogenicity. Each vial contains 30 mg/mL of iron and 44 mg/mL of mannitol.
Overall, ferumoxytol resulted in significantly greater increases in Hb levels compared with oral iron. The researchers observed one treatment-related serious adverse event in the ferumoxytol group and none in the oral iron group. The one event was an episode of hypotension in an 82-year-old man; it was transient without associated chest pain or respiratory distress.
“We now know that we can use ferumoxytol in much higher doses than other iron products allowing for less frequent dosing and more patient convenience,” said Dr. Provenzano, who is on the editorial advisory board of Renal & Urology News.