Anaemia in chronic kidney disease patients on dialysis treated by new form of intravenous iron

Ferumoxytol, a novel intravenous form of iron that permits rapid administration of large doses, has been shown to be effective for treating iron deficiency in chronic kidney disease (CKD) patients on dialysis, according to a clinical trial appearing in the February 2009 issue of the Clinical Journal of the American Society Nephrology (CJASN). The results indicate that this new agent may become an important treatment option for CKD patients.

Because blood is removed during dialysis, CKD patients undergoing this treatment often have anaemia, or low red blood cell counts. These patients also are often iron deficient and must receive supplemental iron. While current treatment guidelines recommend intravenous iron for these patients, many clinicians believe that oral iron is much safer than intravenous iron, which has been associated with hypersensitivity reactions and low blood pressure. However, a new form of intravenous iron, ferumoxytol, may be a safe and effective alternative to other forms of iron therapy. Ferumoxytol appears to contain less free iron and be less immunogenic than other intravenous forms of iron.

Robert Provenzano, MD, FASN, of St. John Hospital and Medical Center in Detroit, MI, and his colleagues conducted a phase three clinical trial that compared ferumoxytol with oral iron. The trial enrolled 230 anaemic patients with late stage CKD who were on dialysis. Patients received either two injections of 510 mg ferumoxytol within seven days or 200 mg oral iron daily for 21 days. The investigators measured the change in haemoglobin in patients from the start of the trial today 35.

The two injections of ferumoxytol led to significantly greater haemoglobin increases compared with oral iron supplementation. Specifically, ferumoxytol caused an average of 1.02 g/dL increase in haemoglobin at day 35 compared with 0.46 g/dL with oral iron. Also, twice as many ferumoxytol-treated patients than oral iron-treated patients achieved a ≥1 g/dL haemoglobin increase at day 35 (49.0% vs 25.0%). In addition, ferumoxytol was found to be well tolerated relative to oral iron, with 8.2% of ferumoxytol-treated subjects and 15.9% of oral iron-treated subjects experiencing adverse reactions considered by the investigator to be related to study treatment.

"Ferumoxytol administered as two rapid intravenous injections of 510 mg each within a week's time, led to significantly greater haemoglobin increases and was well tolerated as compared with oral iron," said Dr. Provenzano. He added that the study's findings also provide insight into factors that affect greater haemoglobin response to intravenous iron treatment, which makes ferumoxytol a potentially attractive treatment option for anaemic haemodialysis patients."

(Source: American Society of Nephrology: Clinical Journal of the American Society Nephrology: March 2009)