It is well known that intravenous iron offers an effective, feasible route towards reducing the heavy burden of iron-deficiency anemia in both dialysis and non-dialysis CKD patients, even in the absence of ESA therapy.
Lu et al. reviewed the efficacy and safety of ferumoxytol in these patient populations. Unfortunately, I cannot consider this paper either an “independent work” or a “research article” because the authors simply copied most of the contents of the “prescribing information” for ferumoxytol regarding efficacy and safety, adding the method section of the published RCTs (without providing the adequate references or the trial registrations numbers: NCT00255424, NCT00255437, NCT00233597), and gave some personal comments in the discussion section. In addition, they did not comment on the cross-over trial with ferumoxytol (750 patients; NCT00255450), which represents almost half of the patients included in the safety evaluation of this iron formulation.
The authors consider that ferumoxytol does not require a test dose and appears to offer a good safety profile (in spite of the administration of up to 30 mg iron per second), but that long-term safety monitoring is mandatory, especially during maintenance treatment. They ask for trials evaluating clinical benefits beyond haemoglobin increase, such as improved cardiac function, improvement in performance status or quality of life, or reduction in ESA dosage (but they do not mention that these clinical benefits have been already investigated for other IV iron formulations, such as iron sucrose or ferric carboxymaltose). It would be also desirable to have trials comparing the efficacy of these iron formulations with others widely used. In this regard, the results of the ongoing trial “Ferumoxytol compared to iron sucrose for the treatment of iron deficiency anemia in adult subjects with chronic kidney disease (FIRST)” (NCT01052779) will be most welcome.
In conclusion, this paper (which does not necessarily represent the views of the FDA) does not add much to the literature. Readers can easily obtain this information from the few published studies and the prescribing information for ferumoxytol.
– Manuel Muoz