ATLANTA – Patients with iron deficiency anemia (IDA) with a history of unsatisfactory oral iron therapy appear to benefit from treatment with intravenous (IV) ferumoxytol, according to results of two pivotal phase 3 randomized trials presented during the 54th American Society of Hematology Annual Meeting and Exposition.
“Ferumoxytol may provide an important treatment option and help meet the unmet medical need for patients with IDA with a history of unsatisfactory oral iron therapy or in whom oral iron cannot be used,” noted Saroj Vadhan-Raj, MD, of The University of Texas MD Anderson Cancer Center, Houston, TX, and colleagues, in reporting the results of the first study. This study included 808 subjects which were randomized 3:1 to IV ferumoxytol 1.02g, delivered as 2 doses of 510mg 5±3 days apart (n=608); or IV saline given as placebo (n=200).
“Ferumoxytol demonstrated superiority to placebo with 81.1% of subjects achieving an increase in hemoglobin of ≥2.0g/dL from baseline to week 5 compared with only 5.5% in the placebo group (treatment difference: 75.6%; P<0.0001),” she added. Mean change in hemoglobin in ferumoxytol‐treated subjects was 2.7g/dL, compared to a mean 0.1g/dL increase in subjects receiving placebo (treatment difference: 2.54g/dL; P<0.0001).
A reduction in fatigue, measured by the Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue score, was found to correlate with the rise in hemoglobin levels. At baseline, participants reported mean FACIT‐Fatigue levels of 24, comparable to those described in the medical literature for anemic cancer patients receiving chemotherapy. After treatment with ferumoxytol, subjects reported a significant improvement in fatigue scores with a mean 12-point increase from baseline to week 5 (P<0.0001).
The overall rate of serious adverse events (SAEs) was comparable between the two treatment groups, and two related SAEs of hypersensitivity, including one anaphylactic reaction, were reported in ferumoxytol‐treated patients.
The second study randomized subjects 2:1 to receive IV ferumoxytol 510 mg on day 1, followed by a second dose 2 to 8 days later (total dose 1.02) (n=406) or iron sucrose, 200 mg on 5 non-consecutive days over a 14-day period (n=199). Those treated with ferumoxytol achieved a significantly greater mean increase in hemoglobin of 2.7g/dL at week 5, compared to a 2.4g/dL increase for those treated with iron sucrose (P<0.013), noted David Hetze, MD, of Royal Adelaide Hospital, Adelaide, Australia, and colleagues. By week 5, 84% of ferumoxytol‐treated subjects achieved a >2.0g/dL increase in hemoglobin vs. 81% of those treated with iron sucrose.
In ferumoxytol‐treated subjects, overall rate of SAEs was higher, including one anaphylactoid reaction and one case of hypertension. No new safety signals were reported in either study.
The studies were supported by AMAG Pharmaceuticals, Inc., Lexington, MA. Ferumoxytol (Feraheme®) is currently indicated in the U.S. for the treatment of iron deficiency in adult patients with chronic kidney disease; approved dosing is two 510mg injections, three to eight days apart. Data from these two clinical trials will be the foundation for AMAG’s supplemental new drug application (sNDA), which the company said it expects to submit to the U.S. Food and Drug Administration this month.