PHILADELPHIA—Ferumoxytol has an efficacy comparable to iron sucrose in treating iron deficiency anemia in patients with chronic kidney disease (CKD), but is associated with lower adverse event (AE) rates, according to the findings a head-to-head comparison of the two formulations presented at Kidney Week 2011.
In addition, ferumoxytol treatment requires fewer administrations, which could translate into a clinical resource savings for patients with iron deficiency anemia requiring iron treatment, researchers stated.
Ferumoxytol is an intravenous (IV) iron preparation approved in June 2009. It consists of an iron oxide with a unique carbohydrate coating designed to limit immunogenicity. Unlike other IV iron preparations, a full course of ferumoxytol (1.02 g) requires only two IV injections of 510 mg. Iron sucrose is administered IV either by slow injection or by infusion.
The head-to-head comparison study enrolled 162 patients with CKD stage 1-5 and 5D, with subjects randomly assigned to receive either ferumoxytol or iron sucrose. All patients assigned to the ferumoxytol group received two IV injections of 510 mg within five days for a cumulative dose of 1.02 g. Hemodialysis patients assigned to iron sucrose received a total cumulative dose of 1.0 g administered as 100 mg doses at 10 consecutive dialysis sessions within three weeks; non-dialysis patients received a total cumulative dose of 1.0 g administered as 200 mg doses at five nonconsecutive visits within about 14 days.
For the study, Iain C. Macdougall, MD, of King’s College Hospital in London, and collaborators randomized 80 patients to receive ferumoxytol and 82 to receive iron sucrose. The mean change in hemoglobin from baseline to week 5 was 0.71 g/dL for ferumoxytol and 0.61 g/dL for iron sucrose. Ferumoxytol-treated patients had a more rapid rise in the mean Hb values compared with iron sucrose recipients. Results also showed that about 50% of the ferumoxytol group experienced a 1 g/dL or greater rise in Hb at any time from baseline to week 5 compared with 42% of the iron sucrose group. The time in days to an Hb response (either a 1 g/dL or greater increase or an achieved level of 12 g/dL or greater from baseline) was on average 4.4 days earlier in the ferumoxytol recipients compared with those treated with iron sucrose (28.5 vs. 32.9 days, respectively).
The ferumoxytol group had lower AE rates than the iron sucrose group (48% vs. 65%) and lower rates of AEs leading to drug discontinuation (1% vs. 5%).
The observed lower rate of AEs in the ferumoxytol recipients may relate to the fewer IV iron exposures required to deliver 1 gram of iron with this drug compared with iron sucrose (two vs. four or 10 doses), according to the researchers.