A Phase III, randomized, open-label trial of ferumoxytol compared with iron sucrose for the treatment of iron deficiency anemia in patients with a history of unsatisfactory oral iron therapy

Abstract

Iron deficiency anemia (IDA) is the most common form of anemia worldwide. Although oral iron is used as first-line treatment, many patients are unresponsive to or cannot take oral iron. This Phase III, open-label, non-inferiority study compared the efficacy and safety of ferumoxytol, a rapid, injectable intravenous (IV) iron product with low immunological reactivity and minimal detectable free iron, with IV iron sucrose in adults with IDA of any cause. Patients (N = 605) were randomized 2:1 to receive ferumoxytol (n = 406, two doses of 510 mg 5 ± 3 days apart) or iron sucrose (n = 199, five doses of 200 mg on five nonconsecutive days over 14 days) and followed for 5 weeks. Ferumoxytol demonstrated noninferiority to iron sucrose at the primary endpoint, the proportion of patients achieving a hemoglobin increase of ≥2 g dL(-1) at any time from Baseline to Week 5 (ferumoxytol, 84.0% [n = 406] vs. iron sucrose, 81.4% [n = 199]), with a noninferiority margin of 15%. Ferumoxytol was superior to iron sucrose (2.7 g dL(-1) vs. 2.4 g dL(-1) ) in the mean change in hemoglobin from Baseline to Week 5 (the alternative preplanned primary endpoint) with P = 0.0124. Transferrin saturation, quality-of-life measures, and safety outcomes were similar between the two treatment groups. Overall, ferumoxytol demonstrated comparable safety and efficacy to iron sucrose, suggesting that ferumoxytol may be a useful treatment option for patients with IDA in whom oral iron was unsatisfactory or could not be used.

Trial registration: ClinicalTrials.gov NCT01114204.

Figure 1

Proportion of patients with ≥2-g dL⁻¹ increase in Hgb at any time from Baseline to Week 5 (intent-to-treat population). *Treatment difference. BL, Baseline; CI, confidence interval; Hgb, hemoglobin.

Figure 2

Hemoglobin values over time in patients receiving ferumoxytol or iron sucrose for up to 5 weeks (intent-to-treat population).

Figure 3

LS mean change in Hgb from Baseline to Week 5 (intent-to-treat population). *Treatment difference. BL, baseline; CI, confidence interval; Hgb, hemoglobin; LS, least-squares.