Safety and efficacy of ferumoxytol for the episodic treatment of iron deficiency anemia in patients with a history of unsatisfactory oral iron therapy: Results of a phase III, open-label, 6-month extension study

The Story of Ferumoxytol: Synthesis Production, Current Clinical Applications, and Therapeutic Potential

Ferumoxytol, approved by the U.S. Food and Drug Administration in 2009, is one of the intravenous iron oxide nanoparticles authorized for the treatment of iron deficiency in chronic kidney disease and end-stage renal disease. With its exceptional magnetic properties, catalytic activity, and immune activity, as well as good biocompatibility and safety, ferumoxytol has gained significant recognition in various biomedical diagnoses and treatments. Unlike most existing reviews on this topic, this review primarily focuses on the recent clinical and preclinical advances of ferumoxytol in disease treatment, spanning anemia, cancer, infectious inflammatory diseases, regenerative medicine application, magnetic stimulation for neural modulation, etc. Additionally, the newly discovered mechanisms associated with the biological effects of ferumoxytol are discussed, including its magnetic, catalytic, and immunomodulatory properties. Finally, the summary and future prospects concerning the treatment and application of ferumoxytol-based nanotherapeutics are presented.

Translational Molecular Imaging Tool of Vulnerable Carotid Plaque: Evaluate Effects of Statin Therapy on Plaque Inflammation and American Heart Association-Defined Risk Levels in Cuff-Implanted Apolipoprotein E-Deficient Mice

Identification of high-risk carotid plaques in asymptomatic patients remains a challenging but crucial step in stroke prevention. The challenge is to accurately monitor the development of high-risk carotid plaques and promptly identify patients, who are unresponsive to best medical therapy, and hence targeted for carotid surgical interventions to prevent stroke. Inflammation is a key operator in destabilisation of plaques prior to clinical sequelae. Currently, there is a lack of imaging tool in routine clinical practice, which allows assessment of inflammatory activity within the atherosclerotic plaque. Herein, we have used a periarterial cuff to generate a progressive carotid atherosclerosis model in apolipoprotein E-deficient mice. This model produced clinically relevant plaques with different levels of risk, fulfilling American Heart Association (AHA) classification, at specific timepoints and locations, along the same carotid artery. Exploiting this platform, we have developed smart molecular magnetic resonance imaging (MRI) probes consisting of dual-targeted microparticles of iron oxide (DT-MPIO) against VCAM-1 and P-selectin, to evaluate the anti-inflammatory effect of statin therapy on progressive carotid atherosclerosis. We demonstrated that in vivo DT-MPIO-enhanced MRI can (i) quantitatively track plaque inflammation from early to advanced stage; (ii) identify and characterise high-risk inflamed, vulnerable plaques; and (iii) monitor the response to statin therapy longitudinally. Moreover, this molecular imaging-defined therapeutic response was validated using AHA classification of human plaques, a clinically relevant parameter, approximating the clinical translation of this tool. Further development and translation of this molecular imaging tool into the clinical arena may potentially facilitate more accurate risk stratification, permitting timely identification of the high-risk patients for prophylactic carotid intervention, affording early opportunities for stroke prevention in the future.

Iron Oxide Nanoparticles: Physicochemical Characteristics and Historical Developments to Commercialization for Potential Technological Applications

Iron oxide nanoparticles (IONPs) have gained increasing attention in various biomedical and industrial sectors due to their physicochemical and magnetic properties. In the biomedical field, IONPs are being developed for enzyme/protein immobilization, magnetofection, cell labeling, DNA detection, and tissue engineering. However, in some established areas, such as magnetic resonance imaging (MRI), magnetic drug targeting (MDT), magnetic fluid hyperthermia (MFH), immunomagnetic separation (IMS), and magnetic particle imaging (MPI), IONPs have crossed from the research bench, received clinical approval, and have been commercialized. Additionally, in industrial sectors IONP-based fluids (ferrofluids) have been marketed in electronic and mechanical devices for some time. This review explores the historical evolution of IONPs to their current state in biomedical and industrial applications.

Development of Molecular Magnetic Resonance Imaging Tools for Risk Stratification of Carotid Atherosclerotic Disease Using Dual-Targeted Microparticles of Iron Oxide

Identification of patients with high-risk asymptomatic carotid plaques remains a challenging but crucial step in stroke prevention. Inflammation is the key factor that drives plaque instability. Currently, there is no imaging tool in routine clinical practice to assess the inflammatory status within atherosclerotic plaques. We have developed a molecular magnetic resonance imaging (MRI) tool to quantitatively report the inflammatory activity in atherosclerosis using dual-targeted microparticles of iron oxide (DT-MPIO) against P-selectin and VCAM-1 as a smart MRI probe. A periarterial cuff was used to generate plaques with varying degree of phenotypes, inflammation and risk levels at specific locations along the same single carotid artery in an Apolipoprotein-E-deficient mouse model. Using this platform, we demonstrated that in vivo DT-MPIO-enhanced MRI can (i) target high-risk vulnerable plaques, (ii) differentiate the heterogeneity (i.e. high vs intermediate vs low-risk plaques) within the asymptomatic plaque population and (iii) quantitatively report the inflammatory activity of local plaques in carotid artery. This novel molecular MRI tool may allow characterisation of plaque vulnerability and quantitative reporting of inflammatory status in atherosclerosis. This would permit accurate risk stratification by identifying high-risk asymptomatic individual patients for prophylactic carotid intervention, expediting early stroke prevention and paving the way for personalised management of carotid atherosclerotic disease.

Toxicity assessment of superparamagnetic iron oxide nanoparticles in different tissues

Superparamagnetic iron oxide nanoparticles (SPIONs) have been employed in several biomedical applications where they facilitate both diagnostic and therapeutic aims. Although the potential benefits of SPIONs with different surface chemistry and conjugated targeting ligands/proteins are considerable, complicated interactions between these nanoparticles (NPs) and cells leading to toxic impacts could limit their clinical applications. Hence, elevation of our knowledge regarding the SPION-related toxicity is necessary. Here, the present review article will consider current studies and compare the potential toxic effect of SPIONs with or without identical surface chemistries on different cell lines. It centers on cellular and molecular mechanisms underlying toxicity of SPIONs. Likewise, emphasis is being dedicated for toxicity of SPIONs in various cell lines, in vitro and animal models, in vivo.

Ferumoxytol for the treatment of iron deficiency anemia

INTRODUCTION

Ferumoxytol is a superparamagnetic molecule originally developed as a contrast agent for magnetic resonance imaging. Elemental iron is contained within the carbohydrate core and is released slowly after infusion allowing a large dose of iron to be administered in a short period of time. Ferumoxytol, originally approved for iron deficiency in chronic kidney disease, received a broad label for any cause of iron deficiency after oral iron intolerance or in those circumstances when oral iron is ineffective or harmful. Areas covered: The chemistry, pharmacology and pharmacokinetics of ferumoxytol were reviewed. Retrospective, observational, and prospective phase II and III trials were reviewed. When appropriate, comparative safety and efficacy parameters were reported. Differentiation between minor infusion reactions and more severe hypersensitivity reactions that may lead to anaphylaxis is described. Expert commentary: Ferumoxytol is a safe and effective iron formulation providing a means of iron repletion in persons with iron deficiency with or without anemia. Relative to iron sucrose, ferric gluconate, and iron dextran and similar to ferric carboxymaltose and iron isomaltoside, ferumoxytol yields relatively low quantities of labile free iron. Hypersensitivity and anaphylaxis is extremely rare. Hypophosphatemia with ferumoxytol's administration is extremely rare. Optimal strategies for application of ferumoxytol-enhanced imaging and full replacement dosing in a single setting remain to be determined.

Cost-effectiveness analysis of intravenous ferumoxytol for the treatment of iron deficiency anemia in adult patients with non-dialysis-dependent chronic kidney disease in the USA

OBJECTIVE

Ferumoxytol has demonstrated superior efficacy compared with oral iron in treating iron deficiency anemia in chronic kidney disease (CKD) patients. However, an economic evaluation of ferumoxytol has not been conducted. The aim of this study was to analyze the cost-effectiveness of treating iron deficiency anemia in adult non-dialysis-dependent CKD patients with ferumoxytol as compared with oral iron, alone or in combination with erythropoietin-stimulating agents (ESAs).

METHODS

A decision analytic model compared health outcomes and costs associated with 5-week outpatient treatment of adult non-dialysis-dependent CKD patients with ferumoxytol or oral iron, each as monotherapy or in combination with ESAs in the USA. Direct costs include the following: drug acquisition and administration, adverse events, and medical management. Efficacy was determined as mean increase in hemoglobin (g/dL) from baseline over the 5-week period. Clinical inputs were derived from patient-level data from two Phase III randomized controlled trials of ferumoxytol vs. oral iron in non-dialysis-dependent CKD patients, and cost inputs from RED BOOK™ and Centers for Medicare and Medicaid Services data. Sensitivity analyses were performed to identify cost drivers and assess the stability of results.

RESULTS

The 5-week treatment cost was $2,489, $5,216, $1,298, and $4,263 per patient for ferumoxytol, ferumoxytol with ESAs, oral iron, and oral iron with ESAs, respectively. The corresponding incremental costs per g/dL increase in hemoglobin, relative to ferumoxytol alone, were $398, $3,558, and $4,768 per patient. Efficacy was the main driver of cost-effectiveness for all treatments. Adverse event and medical management costs were the principal drivers of oral iron monotherapy costs, while drug acquisition substantially contributed to the overall cost for the remaining treatments.

CONCLUSION

These results suggest that ferumoxytol is a cost-effective treatment for iron deficiency anemia in non-dialysis-dependent CKD patients over a 5-week period compared with oral iron with or without ESAs. Ferumoxytol is more cost-effective as monotherapy.

Current and potential imaging applications of ferumoxytol for magnetic resonance imaging

Contrast-enhanced magnetic resonance imaging is a commonly used diagnostic tool. Compared with standard gadolinium-based contrast agents, ferumoxytol (Feraheme, AMAG Pharmaceuticals, Waltham, MA), used as an alternative contrast medium, is feasible in patients with impaired renal function. Other attractive imaging features of i.v. ferumoxytol include a prolonged blood pool phase and delayed intracellular uptake. With its unique pharmacologic, metabolic, and imaging properties, ferumoxytol may play a crucial role in future magnetic resonance imaging of the central nervous system, various organs outside the central nervous system, and the cardiovascular system. Preclinical and clinical studies have demonstrated the overall safety and effectiveness of this novel contrast agent, with rarely occurring anaphylactoid reactions. The purpose of this review is to describe the general and organ-specific properties of ferumoxytol, as well as the advantages and potential pitfalls associated with its use in magnetic resonance imaging. To more fully demonstrate the applications of ferumoxytol throughout the body, an imaging atlas was created and is available online as supplementary material.

Intravenous Ferumoxytol in Pediatric Patients With Iron Deficiency Anemia

Background: Iron deficiency anemia (IDA) is common in children. Limited data exist on the efficacy and safety of ferumoxytol in children. Objective: To assess the efficacy of 10 mg/kg dose given over 15-60 minutes in correcting IDA and report any adverse drug reactions (ADRs). Methods: We conducted a retrospective review of all patients who received ferumoxytol infusions for the management of IDA by the Pediatric Blood Management Program between October 2010 and March 2015. Results: A total of 110 infusions were given to 54 patients. Compared with baseline preinfusion hemoglobin (Hb; 9.2 ± 1.9 g/dL), a significant rise was seen at 1 week and 4 weeks postinfusion (11.5 ± 1.5 and 11.8 ± 1.7 g/dL, respectively, P < 0.001). Also, a significant rise in serum ferritin at 1 week and 4 weeks postinfusion was seen (51 ± 71 vs 192 ± 148 and 89 ± 135 ng/mL, P < 0.001 and <0.035, respectively). Patients who concomitantly received erythropoietin had a significantly larger Hb rise from baseline than those who did not at 4 weeks (2.7 ± 2.2 vs 1.6 ± 1.1 g/dL, P < 0.017). ADRs included pruritus (n = 1), urticaria (n = 1), and multisymptom episodes (n = 3) that included shortness of breath, chest tightness, back pain, and epigastric cramping that responded to therapy with IV diphenhydramine and methylprednisolone. Conclusion: Ferumoxytol was effective in treating IDA in our small study. Slow infusion rate and close monitoring allowed early detection of the infrequent ADRs.