A randomized double-blind pilot study to evaluate the efficacy, safety, and tolerability of intravenous iron versus oral iron for the treatment of restless legs syndrome in patients with iron deficiency anemia

Restless legs syndrome (RLS) is a neurological disorder that can have a profound effect on sleep and quality of life. Idiopathic RLS is associated with brain iron insufficiency despite normal peripheral iron stores. There is, however, a five- to six-fold increase in prevalence of RLS in patients with iron deficiency anemia (IDA). Several open-label trials have demonstrated symptomatic improvement in RLS following treatment of IDA using oral or intravenous iron supplementation. To date, there have been no randomized double-blind controlled trials of intravenous iron compared with oral iron for the treatment of RLS patients with IDA. In the current study, oral ferrous sulfate and ferumoxytol were compared for efficacy and speed of response for treatment of RLS occurring in patients with IDA. The planned recruitment for this study was 70 patients with RLS and IDA, to be randomly assigned 1:1 to oral or intravenous iron, using double-blind, double-dummy procedures. At Week 6, the primary outcomes of Clinical Global Impression-Improvement score and change from baseline in the International Restless Legs Syndrome Study Group rating scale score were assessed. Due to challenges, performing the clinical trial during the COVID-19 pandemic, final-week data were found missing for 30 patients. As a result, in order to maintain the prespecified statistical analysis, an additional 30 patients were recruited. Both IV and oral iron were associated with a marked improvement in RLS symptoms, with no statistically significant difference between treatment groups. No serious adverse events were observed in either treatment group.

IV iron formulations and use in adults

Intravenous iron has become a major component of the therapeutic armamentarium for iron deficiency and iron deficiency anemia. The earliest formulations were associated with unacceptable toxicity. Newer formulations, with complex carbohydrate cores that bind elemental iron more tightly, allow the administration of full therapeutic doses in 15 to 60 minutes. Nonetheless, a folklore of danger, fueled by earlier formulations no longer available, continues to foment caution. Complement-mediated minor infusion reactions, referred to as complement activation-related pseudo-allergy, resolve without therapy. Inappropriate intervention with vasopressors and H1 blockers converts these minor reactions into hemodynamically significant adverse events. Four new formulations, low-molecular-weight iron dextran, ferumoxytol, ferric carboxymaltose, and ferric derisomaltose, all approved for the treatment of iron deficiency in a host of conditions, are now widely used with an excellent safety profile. Herein, the administration, safety, indications, and management of infusion reactions are discussed. Treatment-emergent hypophosphatemia, a newly recognized side effect for some formulations, is also reviewed. Based on the preponderance of published evidence, intravenous iron should be moved up-front for the treatment of iron deficiency and iron deficiency anemia in those conditions in which oral iron is suboptimal.

Neonatal outcomes from a randomized controlled trial of maternal treatment of iron deficiency anemia with intravenous ferumoxytol vs oral ferrous sulfate

BACKGROUND

Anemia in pregnancy is common worldwide and has known maternal risks. The relationship between the types of treatment offered for maternal anemia and the effects on the fetus and newborn are largely uninvestigated.

OBJECTIVE

This study aimed to investigate whether maternal treatment with intravenous ferumoxytol compared to oral ferrous sulfate results in an increase in neonatal hematologic and iron indices. These analyses were planned secondary outcomes and post hoc analysis from the trial with a primary outcome of change in maternal hemoglobin.

STUDY DESIGN

A randomized controlled trial including 124 participants with anemia by World Health Organization criteria was performed in which participants were allocated in a 1:1 ratio to either 2 infusions of 510 mg of intravenous ferumoxytol or 325 mg oral ferrous sulfate twice daily. Fetal monitoring was performed during each intravenous iron infusion. Standard univariable statistical techniques were used to compare groups and to investigate associations between maternal and neonatal hemoglobin and iron indices.

RESULTS

Cord blood hematological parameters were equivalent between groups. Hemoglobin was 15.7 g/dL vs 15.4 g/dL (P=.6) and hematocrit was 50.5% and 49.2% (P=.4) in those randomized to intravenous ferumoxytol and oral ferrous sulfate, respectively. Iron studies revealed higher cord blood ferritin concentrations in infants of participants treated with intravenous ferumoxytol (294 vs 186, P=.005). There were equivalent iron (158 vs 146, P=.4), transferrin (186 vs 196, P=.4) and total iron binding capacity (246 vs 244, P=1) in neonates of participants receiving intravenous vs oral treatment. There were no effects of the infusions observed on cardiotocography. Gestational age at birth was equivalent between groups. We noted a larger birthweight in neonates of participants treated with intravenous ferumoxytol (3215 g vs 3033 g, P=.09), which was not statistically significant. Post hoc analyses revealed a statistically significant correlation between neonatal ferritin and maternal hemoglobin (P=.006) and neonatal ferritin and maternal ferritin (P=.017) at admission for delivery.

CONCLUSION

Neonates of participants who received intravenous ferumoxytol were born with higher ferritin concentrations in cord blood, at the same gestation with the same birthweight. Participants with higher hemoglobin and ferritin indices delivered infants with higher ferritin concentrations in cord blood.

Intravenous infusions of ferumoxytol compared to oral ferrous sulfate for the treatment of anemia in pregnancy: a randomized controlled trial

BACKGROUND

Iron-deficiency anemia in pregnancy is highly prevalent and presents significant risk to patients. Initial treatment is often with oral medication. We hypothesized that intravenous ferumoxytol would result in superior treatment of anemia as compared to oral ferrous sulfate.

OBJECTIVE

This study aimed to investigate whether 2 infusions of intravenous ferumoxytol are superior to the use of twice-daily oral ferrous sulfate for the treatment of iron-deficiency anemia in pregnancy.

STUDY DESIGN

A randomized controlled trial was performed in which participants with anemic (hemoglobin <11 g/dL and hematocrit <33%) were allocated to receive either 2 infusions of 510 mg of intravenous ferumoxytol approximately 7 days apart, or 325 mg oral ferrous sulfate twice daily from enrollment to the end of their pregnancy. Participants were randomized in a 1:1 ratio to each treatment. Our primary outcome was the change in maternal hemoglobin. Secondary outcomes included maternal iron indices, maternal safety, and maternal tolerability.

RESULTS

There were 124 participants (N=62 per group). In the intravenous iron group, the mean change in hemoglobin was 1.86 g/dL (95% confidence interval, 1.57 g/dL-2.14 g/dL) and in the oral group was 0.79 g/dL (95% confidence interval, 0.42 g/dL-1.17 g/dL) (P<.0001). The median change in ferritin between groups was 64.5 (range, 31-364) vs 8 (range, -436 to +167) (P=.0001). The median change in iron between groups was also statistically significant with 47.5 ug/dL (range, -133 ug/dL to +664 ug/dL) in the intravenous group vs 8.5 ug/dL (range, -313 ug/dL to +437 ug/dL) in the oral iron group (P=.001).

CONCLUSION

Intravenous ferumoxytol was well tolerated, and it was associated with statistically significant increases in maternal hemoglobin, hematocrit, iron, and ferritin compared to oral ferrous sulfate.

Association of iron infusion reactions with ABO blood type

OBJECTIVES

We sought to determine risk factors for iv iron infusion-related reactions (IRR), and identify strategies for iron repletion after IRR.

METHODS

We conducted a retrospective chart review of patients treated in the classical hematology clinic at Yale Cancer Center (n = 330 consecutive patients) from 2016 to 2021, who received iv ferumoxytol (60.3%), iron sucrose (14.8%), or iron dextran (10.9%).

RESULTS

The iv iron IRR was noted in 58 (17.6%) patients, 62.1% of whom had previously tolerated iv iron. The severity of IRR was mild in 22, moderate in 23, and severe in 11 patients. Most (72.4%) patients who experienced IRR tolerated a subsequent iv iron infusion. On multivariable analysis, a history of non-medication allergies was associated with greater odds of IRR (odds ratio [OR] 2.12, 95% confidence interval (CI): 1.16-3.87, p = .01). No patients with type AB blood, and few with type A blood (n = 6), had IRR; compared to type A or AB together, patients with type B (OR 5.00, 95% CI: 1.56-16.06, p = .007) or type O (OR 3.71, 95% CI: 1.44-9.55, p = .007) blood had greater odds of IRR.

CONCLUSIONS

This study highlights a possible association of blood type with iv iron IRR; prospective studies with larger patient numbers are warranted to explore this association.

Analysis of Adverse Events and Intravenous Iron Infusion Formulations in Adults With and Without Prior Infusion Reactions

IMPORTANCE

Although iron deficiency is common, it remains unclear which iron repletion strategy is associated with the lowest rate of infusion-related adverse events, and how patients with history of infusion reaction should be managed.

OBJECTIVE

To evaluate rates of infusion reactions among 4 commonly used intravenous iron repletion strategies and determine how readministration was managed in patients with history of reaction.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included all patients receiving intravenous iron infusion from January 1, 2015, to September 7, 2021, at 6 centers in Portland, Oregon. Participants included a total of 12 237 patients with iron deficiency, not restricted by etiology. Statistical analysis was performed from September to October 2021.

EXPOSURES

Type of intravenous iron formulation and concurrent administration of diphenhydramine, epinephrine, famotidine, and/or hydrocortisone, used as surrogate maker of infusion reaction.

MAIN OUTCOMES AND MEASURES

Incidence of adverse events, including severe events requiring epinephrine, stratified by type of iron formulation, and in patients who received premedication or with history of infusion-related reaction receiving subsequent doses.

RESULTS

Among 35 737 unique iron infusions (12 237 patients [9480 (77.5%) women; 717 (5.9%) Black; 10 250 (83.7%) White; mean (SD) age of 51 (20) years]), comprising 22 309 iron sucrose doses, 9067 iron dextran total doses (1771 preceded by test dose, 56 test doses alone), 3147 ferumoxytol doses, and 1214 ferric carboxymaltose doses, incidence of adverse events was 3.9% (n = 1389; 95% CI, 3.7%-4.1%). Rate of infusion events differed among iron formulations: 4.3% (n = 970; 95% CI, 4.1%-4.6%) iron sucrose, 3.8% (n = 345, 95% CI: 3.4%-4.2%) iron dextran (test and full doses or test dose alone), 1.8% (n = 57; 95% CI, 1.4%-2.3%) ferumoxytol, and 1.4% (n = 17, 95% CI, 0.8%-2.3%) ferric carboxymaltose (P < .001). Severe adverse events were exceedingly rare with only 2 documented epinephrine administrations, both associated with iron dextran. Incidence of adverse events among those who received premedication was 23-fold higher compared with those who did not (38.6% vs 1.7%, χ21 = 7324.8; P < .001). Among 873 patients with history of infusion reaction who underwent readministration, the majority received the same formulation, which was associated with significantly higher reaction rate particularly if premedication was administered (68% [95% CI, 64%-72%] vs 32% [95% CI, 26%-41%], respectively), compared with those who received an alternate formulation (21% [95% CI, 11%-35%] vs 5% [95% CI, 2%-12%], respectively) (P < .001).

CONCLUSIONS AND RELEVANCE

These data, and the preponderance of published evidence, suggest that intravenous iron is generally well tolerated with exceedingly low risk of severe reaction, use of premedication and test doses are unnecessary, and that optimal prevention and management of infusion-related reactions warrant further study.

Implementing total-dose ferumoxytol in lieu of split-dose ferumoxytol

BACKGROUND

Ferumoxytol is Food and Drug Administration-approved as two 510 mg infusions. Retrospective and prospective reviews have established that a single 1020 mg infusion is as efficacious and safe as two 510 mg infusions.

OBJECTIVES

To transition our preferred intravenous iron infusion practice from two 510 mg infusions to a single 1020 mg ferumoxytol infusion.

PRACTICE DESCRIPTION

This is a prospective process improvement study conducted at Tripler Army Medical Center, a large academic medical center.

PRACTICE INNOVATION

We set up an evidence-based project to transition and monitor our preferred iron treatment of ferumoxytol from 2 doses to 1 dose.

EVALUATION METHODS

We collected efficacy and safety data for 188 unique patients receiving 228 infusions, of which 62 were single 1020 mg doses, and 166 were two 510 mg doses.

RESULTS

Comparing the 1020 mg dose in 62 patients with 166 patients treated with two 510 mg infusions, we found no increase in the rate of infusion reactions (4.8 % vs. 4.8 %) and comparable improvement in ferritin and hemoglobin (144 ng/mL vs. 140 ng/mL; P value = 0.874, and 1.8 g/dL vs. 1.9 g/dL; P value = 0.721, respectively).

CONCLUSION

Thus, we were able to successfully transition to total-dose ferumoxytol for iron-deficient anemia, effectively reducing patient treatment visits without any difference in safety or efficacy. Ferumoxytol 1020 mg infused intravenously over 30 minutes in 250 mL normal saline single dose is a viable, safe, and effective treatment for iron-deficiency anemia.

Multicenter Safety and Practice for Off-Label Diagnostic Use of Ferumoxytol in MRI

Background Ferumoxytol is approved for use in the treatment of iron deficiency anemia, but it can serve as an alternative to gadolinium-based contrast agents. On the basis of postmarketing surveillance data, the Food and Drug Administration issued a black box warning regarding the risks of rare but serious acute hypersensitivity reactions during fast high-dose injection (510 mg iron in 17 seconds) for therapeutic use. Whereas single-center safety data for diagnostic use have been positive, multicenter data are lacking. Purpose To report multicenter safety data for off-label diagnostic ferumoxytol use. Materials and Methods The multicenter ferumoxytol MRI registry was established as an open-label nonrandomized surveillance databank without industry involvement. Each center monitored all ferumoxytol administrations, classified adverse events (AEs) using the National Cancer Institute Common Terminology Criteria for Adverse Events (grade 1-5), and assessed the relationship of AEs to ferumoxytol administration. AEs related to or possibly related to ferumoxytol injection were considered adverse reactions. The core laboratory adjudicated the AEs and classified them with the American College of Radiology (ACR) classification. Analysis of variance was used to compare vital signs. Results Between January 2003 and October 2018, 3215 patients (median age, 58 years; range, 1 day to 96 years; 1897 male patients) received 4240 ferumoxytol injections for MRI. Ferumoxytol dose ranged from 1 to 11 mg per kilogram of body weight (≤510 mg iron; rate ≤45 mg iron/sec). There were no systematic changes in vital signs after ferumoxytol administration (P > .05). No severe, life-threatening, or fatal AEs occurred. Eighty-three (1.9%) of 4240 AEs were related or possibly related to ferumoxytol infusions (75 mild [1.8%], eight moderate [0.2%]). Thirty-one AEs were classified as allergiclike reactions using ACR criteria but were consistent with minor infusion reactions observed with parenteral iron. Conclusion Diagnostic ferumoxytol use was well tolerated, associated with no serious adverse events, and implicated in few adverse reactions. Registry results indicate a positive safety profile for ferumoxytol use in MRI. © RSNA, 2019 Online supplemental material is available for this article.

The Efficacy of Ferumoxytol for Iron Deficiency Anemia: A Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

This systematic review and meta-analysis aims to explore the influence of ferumoxytol versus placebo on iron deficiency anemia.

METHODS

We search for randomized controlled trials (RCTs) assessing the effect of ferumoxytol on iron deficiency anemia on PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases. This meta-analysis is performed using the random-effects model.

RESULTS

Four RCTs are included in the meta-analysis. Compared with the control group for iron deficiency anemia, intravenous ferumoxytol can significantly improve the proportion of patients with a ≥20 g/L hemoglobin (Hb) increase (RR = 18.43; 95% CI = 7.29-46.57; p < 0.00001), the proportion of patients with an Hb level ≥120 g/L (RR = 18.55; 95% CI = 8.66-39.72; p < 0.00001), transferrin saturation (mean difference = 11.08; 95% CI = 9.86-12.31; p < 0.00001) and FACIT-fatigue score (mean difference = 4.60; 95% CI = 3.21-6.00; p < 0.00001), but has no remarkable influence on adverse events (RR = 1.33; 95% CI = 0.84-2.10; p = 0.22), serious adverse events (RR = 1.22; 95% CI = 0.74-2.02; p = 0.44), and death (RR = 0.32; 95% CI = 0.05-1.95; p = 0.22).

CONCLUSIONS

Intravenous ferumoxytol can provide the important benefits for iron deficiency anemia.

Adverse Reactions After Intravenous Iron Infusion Among Inflammatory Bowel Disease Patients in the United States, 2010-2014

Background

Anemia is a frequent complication of Crohn's disease (CD) and ulcerative colitis (UC), collectively known as inflammatory bowel disease (IBD). Intravenous (IV) iron is recommended as the initial therapy for patients with clinically active IBD, severe anemia, and intolerance to oral iron. IV iron is associated with serious adverse effects including a black box warning for anaphylaxis with iron dextran and ferumoxytol. We aimed to examine the occurrence of adverse reactions including anaphylaxis after IV iron infusions in a large database of US IBD patients.

Methods

We performed a retrospective analysis for encounters occurring between 2010 and 2014 in MarketScan, a US commercial claims database. We assessed the following adverse events: anaphylactic shock, bronchospasm, and hypotension among IBD patients receiving ferumoxytol, iron dextran, ferric gluconate, iron sucrose, and ferric carboxymaltose. We calculated the adverse event rate per 1000 infusions within 7 days of IV iron infusion.

Results

In our study cohort of 6151 IBD patients (38.4% UC), 37 168 IV iron infusions were given (median, 3 infusions). There were very few adverse events; only 1.3% of IBD patients experienced any adverse reaction. The incident rate per 1000 infusions for any adverse event among IBD patients was highest among those receiving ferumoxytol (2.54, 95% confidence interval [CI], 1.26-5.11), ferric gluconate (1.85; 95% CI, 1.03-3.35), iron sucrose (1.74; 95% CI, 1.09-2.78), and iron dextran (0.96; 95% CI, 0.43-2.13). There were 0.24 anaphylactic shock events per 1000 IV iron infusions.

Conclusions

About 1.3 of 100 IBD patients ever developed any adverse event. Because adverse reactions are rare, physicians should be encouraged to adhere to recommended guidelines for iron replacement among anemic IBD patients. 10.1093/ibd/izy063_video1izy063.video15768853346001.

Novel contrast mixture achieves contrast resolution of human bladder wall suitable for T1 mapping: applications in interstitial cystitis and beyond

PURPOSE

Instillation of novel contrast mixture (NCM) was recently shown to improve the contrast resolution of rat bladder wall with high contrast-to-noise ratio (CNR). Here, the clinical safety and the feasibility of NCM-enhanced MRI to achieve artifact-free visualization of human bladder wall suitable for quantitative measurement of the magnetic resonance (MR) longitudinal relaxation time (T1) was assessed.

METHODS

Six female subjects [two controls and two with Hunner-type interstitial cystitis IC and two with non-Hunner-type IC] consented for MRI at 3 T before and after instillation of NCM [4 mM gadobutrol and 5 mM ferumoxytol in 50 mL of sterile water for injection]. Single breath-hold fast MR acquisition in large readout bandwidth for 5-mm-thick single slice with variable flip angle was applied to minimize the motion and chemical shift artifacts in measurements of bladder wall thickness (BWT), CNR and T1 from 20 pixels.

RESULTS

NCM instillation in subjects did not evoke pain or discomfort. Fourfold increase in bladder wall CNR (*p < 0.02) and pixel size of 0.35 mm with minimal influence of artifacts allowed accurate determination of bladder wall thinning ~ 0.46 mm from 50 mL NCM (*p < 0.05). Pre-contrast bladder wall T1 of 1544 ± 34.2 ms was shortened to 860.09 ± 13.95 ms in Hunner-type IC (*p < 0.0001) relative to only 1257.42 ± 20.59 and 1258.16 ± 6.16 ms in non-Hunner-type IC and controls, respectively.

CONCLUSION

Findings demonstrate the safety and feasibility of NCM-enhanced MRI to achieve artifact-free differential contrast and spatial resolution of human bladder wall, which is suitable for measuring BWT and pixel-wise measurement of T1 in post-contrast setting.

What Does the Boxed Warning Tell Us? Safe Practice of Using Ferumoxytol as an MRI Contrast Agent

BACKGROUND AND PURPOSE

Despite the label change and the FDA's boxed warning added to the Feraheme (ferumoxytol) label in March 2015, radiologists have shown increasing interest in using ferumoxytol as an MR imaging contrast agent as a supplement or alternative to gadolinium. The goals of this study were to provide information regarding ferumoxytol safety as an imaging agent in a single center and to assess how the Feraheme label change may affect this potential, currently off-label indication.

MATERIALS AND METHODS

This retrospective study evaluated the overall frequency of ferumoxytol-related adverse events when used for CNS MR imaging. Patients with various CNS pathologies were enrolled in institutional review board-approved imaging studies. Ferumoxytol was administered as multiple rapid bolus injections. The risk of adverse events was correlated with demographic data/medical history.

RESULTS

The safety of 671 ferumoxytol-enhanced MR studies in 331 patients was analyzed. No anaphylactic, life-threatening, or fatal (grade 4 or 5) adverse events were recorded. The overall proportion of ferumoxytol-related grade 1-3 adverse events was 10.6% (8.6% occurring within 48 hours), including hypertension (2.38%), nausea (1.64%), diarrhea (1.04%), and headache (1.04%). History of 1 or 2 allergies was associated with an increased risk of adverse events (14.61% versus 7.51% [no history]; P = .007).

CONCLUSIONS

The frequency of mild ferumoxytol-related adverse events was comparable with literature results, and no serious adverse event was recorded. Although the recommendations in the boxed warning should be followed, serious adverse events appear to be rare, and with proper precautions, ferumoxytol may be a valuable MR imaging agent.

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.

Relative Incidence of Acute Adverse Events with Ferumoxytol Compared to Other Intravenous Iron Compounds: A Matched Cohort Study

Concerns persist about adverse reactions to intravenous (IV) iron. We aimed to determine the relative safety of ferumoxytol compared to other IV iron compounds. This retrospective cohort study with propensity-score matching for patients and drug doses used the Medicare 20% random sample to identify patients (1) without chronic kidney disease (non-CKD) and (2) with non-dialysis-dependent chronic kidney disease (NDD-CKD) who received a first dose of IV iron in 2010–2012. Exposures were ferumoxytol, iron sucrose, sodium ferric gluconate, or iron dextran. Outcomes were hypersensitivity symptoms, anaphylaxis, emergency department (ED) encounters, hospitalizations, and death after acute IV iron exposure. In the primary analysis for reactions on the day of or following exposure, there was no difference in hypersensitivity symptoms (hazard ratio 1.04, 95% confidence interval 0.94–1.16) or hypotension (0.83, 0.52–1.34) between 4289 non-CKD ferumoxytol users and an equal number of users of other compounds; results were similar for 7358 NDD-CKD patients and an equal number of controls. All-cause ED encounters or hospitalizations were less common in both the non-CKD (0.56, 0.45–0.70) and NDD-CKD ferumoxytol-treated patients (0.83, 0.71–0.95). Fewer than 10 deaths occurred in both the non-CKD and NDD-CKD ferumoxytol users and in matched controls; the hazard for death did not differ significantly between ferumoxytol users and controls in the non-CKD patients (2.00, 0.33–11.97) or in the NDD-CKD patients (0.25, 0.04–1.52). Multiple sensitivity analyses showed similar results. Ferumoxytol did not appear to be associated with more adverse reactions than other compounds for the treatment of iron-deficiency anemia in both non-CKD and NDD-CKD patients.

Comparative Risk of Anaphylactic Reactions Associated With Intravenous Iron Products

IMPORTANCE

All intravenous (IV) iron products are associated with anaphylaxis, but the comparative safety of each product has not been well established.

OBJECTIVE

To compare the risk of anaphylaxis among marketed IV iron products.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective new user cohort study of IV iron recipients (n = 688,183) enrolled in the US fee-for-service Medicare program from January 2003 to December 2013. Analyses involving ferumoxytol were limited to the period January 2010 to December 2013.

EXPOSURES

Administrations of IV iron dextran, gluconate, sucrose, or ferumoxytol as reported in outpatient Medicare claims data.

MAIN OUTCOMES AND MEASURES

Anaphylaxis was identified using a prespecified and validated algorithm defined with standard diagnosis and procedure codes and applied to both inpatient and outpatient Medicare claims. The absolute and relative risks of anaphylaxis were estimated, adjusting for imbalances among treatment groups.

RESULTS

A total of 274 anaphylaxis cases were identified at first exposure, with an additional 170 incident anaphylaxis cases identified during subsequent IV iron administrations. The risk for anaphylaxis at first exposure was 68 per 100,000 persons for iron dextran (95% CI, 57.8-78.7 per 100,000) and 24 per 100,000 persons for all nondextran IV iron products combined (iron sucrose, gluconate, and ferumoxytol) (95% CI, 20.0-29.5 per 100,000) , with an adjusted odds ratio (OR) of 2.6 (95% CI, 2.0-3.3; P < .001). At first exposure, when compared with iron sucrose, the adjusted OR of anaphylaxis for iron dextran was 3.6 (95% CI, 2.4-5.4); for iron gluconate, 2.0 (95% CI 1.2, 3.5); and for ferumoxytol, 2.2 (95% CI, 1.1-4.3). The estimated cumulative anaphylaxis risk following total iron repletion of 1000 mg administered within a 12-week period was highest with iron dextran (82 per 100,000 persons, 95% CI, 70.5- 93.1) and lowest with iron sucrose (21 per 100,000 persons, 95% CI, 15.3- 26.4).

CONCLUSIONS AND RELEVANCE

Among patients in the US Medicare nondialysis population with first exposure to IV iron, the risk of anaphylaxis was highest for iron dextran and lowest for iron sucrose.

Safety and effectiveness of ferumoxytol in hemodialysis patients at 3 dialysis chains in the United States over a 12-month period

BACKGROUND

Intravenous (IV) iron is the treatment of choice for iron-deficiency anemia (IDA) in patients with dialysis-dependent chronic kidney disease (DD-CKD). However, IV iron products have been associated with serious adverse events (SAEs), including anaphylactoid reactions. Ferumoxytol is an IV iron preparation that can be injected over a short period of time. Although randomized clinical trials support ferumoxytol's efficacy and safety, additional insights may be drawn from the acquisition of long-term, repeat dosing efficacy and safety data in a real-world setting.

OBJECTIVE

The goal of this study was to characterize the effectiveness and safety profile of ferumoxytol as administered to adult DD-CKD patients with IDA in a real-world setting. The ability of ferumoxytol to maintain hemoglobin (Hb), transferrin saturation (TSAT), and ferritin treatment targets established by the 2006 Kidney Disease Outcomes Quality Initiative guidelines was determined in 3 medium-sized US-based dialysis chains.

METHODS

This retrospective, observational study was conducted to examine laboratory and dosing data for all patients who received any dose of ferumoxytol at 3 US-based dialysis chains over a 12-month period. Investigators and/or physicians from each of the chains also made independent determinations regarding the seriousness of any adverse event (AE). Special attention was paid to the incidence and types of AEs and SAEs that were potentially associated with ferumoxytol.

RESULTS

Over the 12-month observation period, 8666 patients (mean [SD] age in chains A, B and C, 63.9 [14.8], 63.9 [14.9] and 63.6 [15.1], respectively), were treated with 33,358 doses of ferumoxytol across the 3 chains. Treatment with ferumoxytol corresponded to an increased mean monthly Hb level relative to baseline (0.13-0.69 g/dL) and led to an increase in the proportion of patients maintained within the target Hb range of 10 to 12 g/dL (61%-72%). Ferumoxytol was also associated with increases in TSAT and ferritin that stabilized throughout the observation period. Incidence of AEs was similar across the 3 chains; between 0.07% and 1.77% of all patients treated at each chain experienced an AE associated with ferumoxytol administration. SAEs were reported in 0.2% of patients. The most common AEs reported (≥6 patients) were nausea (0.37% of patients), pruritus (0.29%), vomiting (0.25%), hypotension (0.21%), and dyspnea (0.20%). Two patients (0.02%) experienced anaphylactoid reactions. The AE profile of ferumoxytol remained consistent with that reported from controlled clinical trials.

CONCLUSIONS

These long-term data, which include repeat dosing in a large number of DD-CKD patients with IDA in a real-world setting, confirm the effectiveness of ferumoxytol in increasing and maintaining Hb levels within the target range and with favorable assessments of long-term safety.

[Importance of the different i.v. iron generations for everyday medical practice]

BACKGROUND

Iron deficiency and anaemia occur in particular in women or as comorbid conditions to a varietyof chronic diseases. Besides oral preparations, parenteral iron therapies are also available for the treatment of iron deficiency or anaemia. In the light of the growing importance and increasing number of parenteral iron preparations, theirpharmacology and application as well as the chronology of their approvals and thecharacteristicsof the various preparations are presented herefor comparison.

METHOD

Review.

RESULTS

To date, there are three different generations of parenteral iron preparations, which differ in terms of stability, safety and dosage. In particular, the active substances of the third generation, ferric carboxymaltose, iron isomaltoside and ferumoxytol are characterised by high complex stability and comparable safety, also allowing rapid application of high doses of iron.

CONCLUSIONS

High molecular weight iron dextran, as a representative of 1st generation iron preparations, should no longer be used if possible, as more recent i.v. iron preparations are available with considerably lower risk of serious anaphylactic reactions. Ferrous gluconate and iron sucrose, as representatives of the 2nd generation, are very efficient preparations, but they require frequent visits to the clinic or the doctor, as they may only be administered in low doses because of labile iron complexes. The three 3rd generation parenteral iron formulations have advantages in handling in everyday practice, since they offer comparably good safety profiles, high complex stability and thus the possibility of rapid application of high doses of iron up to the total cumulative dose. Furthermore, test doses are not required with these preparations, which also simplifies their use.

FDA report: Ferumoxytol for intravenous iron therapy in adult patients with chronic kidney disease

On June 30, 2009, the United States Food and Drug Administration (FDA) approved ferumoxytol (Feraheme injection, AMAG Pharmaceuticals), an iron-containing product for intravenous (IV) administration, for the treatment of iron deficiency anemia in adult patients with chronic kidney disease (CKD). The safety and efficacy of ferumoxytol were assessed in three randomized, open-label, controlled clinical trials. Two trials evaluated patients with nondialysis dependent CKD and a third trial assessed patients undergoing hemodialysis. Randomization was either to ferumoxytol or oral iron. Ferumoxytol was administered as two 510 mg IV injections, separated by 3-8 days. Oral iron, Ferro-Sequels, was administered at a dose of 100 mg twice daily for 21 days. In all three clinical trials, ferumoxytol administration increased the mean blood hemoglobin (Hgb) concentrations by approximately 1.0 g/dL over the 35 day period, a mean increase that was greater than what was observed in patients receiving oral iron. Patients receiving ferumoxytol also had increases in blood transferrin saturation (TSAT) and ferritin values. For the proposed ferumoxytol dosing regimen, 4.9% of patients had serum ferritin >or=800 ng/mL and TSAT >or=50% post-treatment. The most important ferumoxytol safety concerns were hypersensitivity reactions and/or hypotension. Anaphylaxis or anaphylactoid reactions were reported in 0.2% of subjects, and other adverse reactions potentially associated with hypersensitivity (e.g., pruritus, rash, urticaria, or wheezing) were reported in 3.7%. Hypotension was observed in 1.9%, including three patients with serious hypotensive reactions. Ferumoxytol administration may transiently affect the diagnostic ability of magnetic resonance imaging and the drug label provides further information regarding this effect.

Ferumoxytol for the treatment of anemia in chronic kidney disease

Iron deficiency anemia is a common occurrence in patients with chronic kidney disease and many patients do not respond well to supplementation with oral iron. There are now five intravenous iron preparations available for use in the chronic kidney disease patient, with ferumoxytol being the most recently approved agent. As opposed to previously available intravenous irons, ferumoxytol has the advantage of not needing a test dose, allowing a large dose of iron (510 mg) to be given in a short period of time by bolus injection, and no reported cases of anaphylaxis. Ferumoxytol has advantages for use in the outpatient setting to treat iron deficiency, in patients with chronic kidney disease not yet on dialysis and in patients on peritoneal dialysis. The use of ferumoxytol in the hemodialysis population where thrice weekly intravenous access is the norm is less clear. Cost-effectiveness studies and post-approval studies on ferumoxytol as well as changes in the cost structure of dialysis reimbursement will likely have a large impact on the use of this new agent.

Ferumoxytol for treating iron deficiency anemia in CKD

Iron deficiency is an important cause of anemia in patients with chronic kidney disease (CKD), but intravenous iron is infrequently used among patients who are not on dialysis. Ferumoxytol is a novel intravenous iron product that can be administered as a rapid injection. This Phase III trial randomly assigned 304 patients with CKD in a 3:1 ratio to two 510-mg doses of intravenous ferumoxytol within 5 +/- 3 d or 200 mg of elemental oral iron daily for 21 d. The increase in hemoglobin at day 35, the primary efficacy end point, was 0.82 +/- 1.24 g/dl with ferumoxytol and 0.16 +/- 1.02 g/dl with oral iron (P < 0.0001). Among patients who were not receiving erythropoiesis-stimulating agents, hemoglobin increased 0.62 +/- 1.02 g/dl with ferumoxytol and 0.13 +/- 0.93 g/dl with oral iron. Among patients who were receiving erythropoiesis-stimulating agents, hemoglobin increased 1.16 +/- 1.49 g/dl with ferumoxytol and 0.19 +/- 1.14 g/dl with oral iron. Treatment-related adverse events occurred in 10.6% of patients who were treated with ferumoxytol and 24.0% of those who were treated with oral iron; none was serious. In summary, a regimen of two doses of 510 mg of intravenous ferumoxytol administered rapidly within 5 +/- 3 d was well tolerated and had the intended therapeutic effect. This regimen may offer a new, efficient option to treat iron deficiency anemia in patients with CKD.

The safety and efficacy of ferumoxytol therapy in anemic chronic kidney disease patients

BACKGROUND

Administration of safe and effective iron therapy in patients with chronic kidney disease is a time consuming process. This phase II clinical trial studied ferumoxytol, a semi-synthetic carbohydrate-coated iron oxide administered by rapid intravenous injection to anemic chronic kidney disease patients (predialysis or undergoing peritoneal dialysis).

METHODS

Inclusion criteria included hemoglobin < or =12.5 g/dL and transferrin saturation < or =35%. Twenty-one adult patients were randomized to receive ferumoxytol in a regimen of 4 doses of 255 mg iron in 2 weeks or 2 doses of 510 mg iron in 1 to 2 weeks. Ferumoxytol was administered at a rate of up to 30 mg iron/sec.

RESULTS

The maximum hemoglobin response following ferumoxytol administration occurred at 6 weeks, increasing from a baseline of 10.4 +/- 1.3 g/dL to 11.4 +/- 1.2 g/dL (P < 0.05). Ferritin increased from a baseline of 232 +/- 216 ng/mL to a maximum of 931 +/- 361 ng/mL at 2 weeks (P < 0.05), while the baseline transferrin saturation increased from 21 +/- 10% to 37 +/- 22% at 1 week (P < 0.05). Seven adverse events in 5 patients during this trial were deemed possibly related to ferumoxytol, none serious. These events included constipation, chills, tingling, a gastrointestinal viral syndrome, delayed pruritic erythematous rash, and transient pain at the injection site.

CONCLUSION

Although larger studies are required, this small study demonstrates that ferumoxytol can be safe and effective in increasing iron stores, is associated with an increased hemoglobin response, and is well tolerated at a rapid infusion rate.