Iron management in end-stage renal disease

Repurposing ferumoxytol: Diagnostic and therapeutic applications of an FDA-approved nanoparticle

Ferumoxytol is an intravenous iron oxide nanoparticle formulation that has been approved by the U.S. Food and Drug Administration (FDA) for treating anemia in patients with chronic kidney disease. In recent years, ferumoxytol has also been demonstrated to have potential for many additional biomedical applications due to its excellent inherent physical properties, such as superparamagnetism, biocatalytic activity, and immunomodulatory behavior. With good safety and clearance profiles, ferumoxytol has been extensively utilized in both preclinical and clinical studies. Here, we first introduce the medical needs and the value of current iron oxide nanoparticle formulations in the market. We then focus on ferumoxytol nanoparticles and their physicochemical, diagnostic, and therapeutic properties. We include examples describing their use in various biomedical applications, including magnetic resonance imaging (MRI), multimodality imaging, iron deficiency treatment, immunotherapy, microbial biofilm treatment and drug delivery. Finally, we provide a brief conclusion and offer our perspectives on the current limitations and emerging applications of ferumoxytol in biomedicine. Overall, this review provides a comprehensive summary of the developments of ferumoxytol as an agent with diagnostic, therapeutic, and theranostic functionalities.

Safety and Efficacy of Total Dose Iron Dextran Administration in Patients on Home Renal Replacement Therapies

Objective

To determine the safety and efficacy of intravenous total dose iron (TDI) replacement in patients treated with home renal replacement therapy.

Design

Prospective open-label study on end points in the population studied.

Setting

Institutional outpatient home dialysis program.

Patients

The study included 20 end-stage renal disease (ESRD) patients, performing chronic peritoneal or home hemodialysis, with iron deficiency defined as ferritin < 100 ng/mL and/or an iron saturation < 20%.

Intervention

The total dose of iron dextran was calculated and infused at a rate not exceeding 6 mg/min. Hemoglobin, hematocrit, iron studies, and liver function tests (LFTs) were obtained before and 3 to 4 weeks after TDI infusion. Hematocrit of patients failing to achieve an increase in Hct over this period was re-examined 2 to 4 weeks later looking for a delayed response.

Main Outcome Measures

Primary end points for efficacy were changes in Hct, ferritin, and iron saturation. Toxicity was measured as reported immediate and delayed symptoms and elevated transaminases and/or alkaline phosphatase levels.

Results

A median iron dose of 1000 mg (range, 325 1500 mg) was administered. The infusions were generally well tolerated. Clinical adverse effects were seen in 2 patients weighing less than 50 kg. No increase in LFT results was seen. Hematocrit increased 2.2% (95% CI, 0.5% -3.9%) from 29.0% to 31.2% (p = 0.01) within 4 weeks of infusion. Significant increases also occurred in iron saturation (from 13% to 22%, p = 0.001) and ferritin (from 234 to 305 ng/mL, p = 0.008). Among the 9 patients who did not respond with a significant increase in Hct, 2 had a delayed response, increasing the overall response from 63% at 4 weeks to 71 %,8 weeks after TDI.lnadequate erythropoietin dosing and low-grade infectious/inflammatory disorders may have contributed to a poor response in several patients.

Conclusion

Total dose iron is a safe and effective means of restoring iron and erythropoietic response in ESRD patients weighing more than 50 kg who receive their renal replacement therapy at home.

The Absence of Toxicity in Intraperitoneal Iron Dextran Administration: A Functional and Histological Analysis

Objective

To determine the influence of iron dextran intraperitoneal administration on the function and histology of the peritoneum in rats undergoing chronic peritoneal dialysis.

Design

Prospective, randomized experimental study.

Materials

Fifty-four Sprague-Dawley rats were divided into five groups: 3 study groups -high dose group (H), n = 12; intermediate dose (M), n = 12; and low dose group (L), n = 12 a dialysis control group (D), n = 12; and a tissue control (C), n = 7.

Interventions

The study groups were given Dianeal containing iron dextran in a concentration of 0.5,0.25, and 0.125 mg/L (groups H, M, and L respectively). Group D was given standard Dianeal. Group C was never dialyzed.

Main Outcome Measures

A 2-hour peritoneal equilibrium test (PET) was performed on the eighth day, at 3 months, and at 6 months. After the final PET, the animals were sacrificed and the peritoneal membrane was evaluated by gross inspection and light microscopy (silver, prussian blue, and trichrome staining).

Results

Peritoneal transport of small solutes followed the same pattern in all groups, increasing over time. The peritonitis index was similar in the groups. No iron deposits or morphologic differences were seen in the gross inspection of the peritoneal cavity. No peritoneal iron deposition was detected in the histological analysis with prussian blue staining. No differences were noted in the light microscopic analysis of the mesothelial cell layer (silver staining), nor did the morphometric analysis of the submesothelial space show any differences in thickness between the groups.

Conclusion

These findings suggest the absence of toxic effects of iron dextran on the peritoneal cavity of rats in the concentrat ions studied. Further studies should be performed to evaluate the effectiveness of these dosages delivered intraperitoneally to maintain iron homeostasis.

Incidence of Peritonitis in Chronic Peritoneal Dialysis Patients Infused with Intravenous Iron Dextran

Background

The Dialysis Outcomes Quality Initiative (DOQI) guidelines, published in 1997, emphasize the need for careful monitoring of iron stores and for provision of adequate iron replacement therapy to achieve target goals of hemoglobin concentration in end-stage renal disease (ESRD) patients, especially those treated with recombinant erythropoietin (rHuEPO). Intravenous iron dextran (IVID) therapy, which has long been used in hemodialysis patients, is increasingly being used in chronic peritoneal dialysis (CPD) patients. In 1997, we began using this form of iron therapy for our CPD patients. However, because considerable data exists to show a relationship between iron metabolism and acute infections, we questioned whether IVID infusion placed our patients at greater risk for peritonitis, the leading cause of death and patient dropout from CPD therapy.

Objective

To evaluate the relationship between iron and infection, we studied episodes of peritonitis in CPD patients who were infused with IVID.

Design

In a retrospective study of adult CPD patients who received IVID during 1998, we investigated the occurrence of peritonitis episodes and the spectrum of causative organisms. Patients with a hemoglobin level of < 12.5 g/dL who also had a ferritin level < 100 ng/mL or a transferrin saturation level < 20% (or both) and who did not respond to oral iron therapy, were administered between 0.5 g and 1.0 g of IVID in an outpatient hospital setting. We calculated the expected and observed number of peritonitis episodes in these patients within 30, 60, and 90 days after infusion of IVID.

Results

During the study period, 56 patients received 77 doses of IVID, with 14 patients requiring 2 or more infusions. Of the 77 doses, 71 were given as a 1-g bolus. The IVID was well tolerated by all patients. Within 90 days of IVID administration, 14 patients developed peritonitis: 6 episodes occurred within 30 days, 7 episodes occurred between 31 and 60 days, and 1 episode occurred between 61 and 90 days after the IVID dosing. The peritonitis rate for patients not receiving IVID was 1 episode per 13.7 patient-months. Taking this rate as the “expected” rate, the expected number of episodes of peritonitis for the study population was 5.6 episodes within 30 days, 11.2 episodes within 60 days, and 16.8 episodes within 90 days following IVID administration. The difference between the expected and observed rates of peritonitis in patients who were dosed with IVID was not statistically different. The spectrum of organisms seen in the peritonitis episodes in the study population was not significantly different from that seen in the peritonitis episodes in our CPD unit population.

Conclusions

There is evidence that IVID infusion therapy can improve anemia and reduce rHuEPO requirements in CPD patients, usually without adverse reaction and without exposing patients to an increased risk of peritonitis. More research is needed in the area of potential increased risk of infection in ESRD patients who are ( 1 ) infused with large doses of IVID, and ( 2 ) iron-overloaded.

Efficacy of a Low-Dose Intravenous Iron Sucrose Regimen in Peritoneal Dialysis Patients

Objective

Sufficient iron substitution leads to a decrease in the required recombinant human erythropoietin (rHuEPO) dose and/or an increased hematocrit in dialysis patients. Intravenous (IV) application of larger doses of iron sucrose may be associated with hyperferritinemia, appearance of catalytically free iron, and impaired phagocyte function. Therefore, we investigated the effectiveness of a low-dose IV iron regimen in peritoneal dialysis (PD) patients.

Patients and Interventions

Forty-five PD patients were followed over a period of 1 year. Serum ferritin, serum transferrin saturation, and hemoglobin were measured monthly. In cases of absolute iron deficiency (serum ferritin < 100 μg/L), 50 mg iron sucrose was given IV every second week. In cases of functional iron deficiency (ferritin ≥ 100 μg/L and transferrin saturation < 20%) and in iron repleted patients (ferritin ≥ 100 μg/L and transferrin saturation ≥ 20%), 50 mg IV iron sucrose was applied monthly. Iron therapy was stopped in cases of acute infection (until complete recovery) and when serum ferritin level was ≥ 600 μg/L.

Results

To analyze the influence of iron substitution on erythropoiesis and rHuEPO requirements, the EPO resistance index (ERI; quotient of rHuEPO dose in units/kilogram/week and hemoglobin in grams per deciliter) was calculated every 3 months. The ERI decreased significantly during the course of the study in the whole patient group ( p = 0.009) as well as in the subgroup of 21 patients with absolute iron deficiency ( p = 0.01). A nonsignificant decrease in the ERI was observed within the group of 14 iron repleted patients ( p = 0.5). There was no significant change in the ERI in 10 patients with functional iron deficiency ( p = 0.6).

Conclusion

The low-dose IV iron regimen used in this study substantially decreased rHuEPO requirements in patients with absolute iron deficiency and was effective in maintaining iron stores in iron repleted patients. However, in the absence of significant hyperparathyroidism, aluminum toxicity, or inadequate dialysis, it did not improve the ERI in patients with functional iron deficiency.

Is Absorption of High-Dose Oral Iron Sufficient in Peritoneal Dialysis Patients?

Objective

Iron supplementation plays a major role in erythropoietin-treated end-stage renal disease patients. For peritoneal dialysis (PD) patients, oral iron substitution is more convenient than intravenous therapy. However, disturbed iron absorption and adverse effects may be limiting factors for oral treatment. Nevertheless, we compared the response to a high-dose and low-dose oral iron absorption test between PD patients and healthy control subjects.

Patients and Interventions

In 34 PD patients and 15 healthy control subjects, blood samples were taken at baseline as well as 2, 4, and 8 hours after oral intake of 4 tablets iron sulfate (105 mg elemental iron per tablet). In a subgroup of 6 PD patients and 6 control subjects, the oral iron absorption test was repeated using 1 tablet iron sulfate.

Results

There was no significant difference in the increase in serum iron during the test between the two groups. As known for healthy subjects, iron absorption was significantly better in PD patients with absolute iron deficiency compared to those with functional iron deficiency. Iron-repleted PD patients showed the lowest iron absorption, indicating that a high dose of oral iron did not overwhelm the ability of the bowel tract to reject unneeded iron. Increasing the oral iron dose from 1 to 4 tablets was followed by a better response in a small subgroup of PD patients compared to control subjects. Side effects such as nausea and vomiting occurred more frequently during high-dose oral iron in control subjects than in PD patients (20% vs 8.8%).

Conclusion

High-dose oral iron is well absorbed in iron-depleted PD patients. This kind of oral iron therapy should be considered in some subgroups of PD patients with iron deficiency, particularly in those patients with poor vascularization of arm veins or intolerance to intravenous iron preparations.

Diagnosis of iron deficiency in hemodialysis patients: Usefulness of measuring reticulocyte hemoglobin equivalent

The evaluation of iron status in dialysis patients provides information essential to the planning of adequate recombinant human erythropoietin treatment. To diagnose iron deficiency in patients undergoing hemodialysis (HD), reticulocyte hemoglobin content and percentage of hypochromic red cells are incorporated into the European best practice guidelines on anemia management in chronic kidney disease (CKD), the mean reticulocyte hemoglobin content (Ret-HE) was proposed as alternatives to standard biochemical tests. Reticulocyte hemoglobin content and percentage of hypochromic red cells are incorporated into the European best practice guidelines on anemia management in CKD. Our aim was to assess the value of Ret-HE parameter, in terms of the sensitivity and specificity for detecting iron deficiency, in HD patients. We studied 50 patients undergoing HD three times weekly , to clarify the accuracy of Ret-HE in diagnosing iron deficiency in dialysis patients, we initially compared Ret-HE with such iron parameters as serum ferritin levels, transferrin saturation, and hypochromic red blood cell (Hypo%) which has been established as indicators of functional iron deficiency. Ret-HE mean value in anemic patients was (25.84 ± 4.23 pg) and had good correlation (P <0.001) between Ret-HE, serum iron, ferritin, transferrin, and transferin saturation in dialysis patients. Receiver operating characteristic curve analysis revealed, values of the area was 0.887, and at a cutoff value of 27.0 pg, a sensitivity of 90.4% and a specificity of 80.8% were achieved. The newly proposed Ret-HE can provide clinicians with information equivalent to iron deficiency anemia markers. Ret-HE is a new parameter that is easily measurable is suggested as reliable parameters for the study of erythropoiesis status in HD patients.

The safety and efficacy of ferumoxytol in the treatment of iron deficiency: a systematic review and meta-analysis

INTRODUCTION

Ferumoxytol is an intravenous (IV) iron formulation for treatment of iron deficiency (ID) that faced post-marketing reports of serious adverse events (SAEs).

OBJECTIVES

To determine the safety and efficacy of ferumoxytol compared to other iron formulations and placebo.

METHODS

We searched the Cochrane Library, Medline, and EMBASE from inception until February 2018 as well as trial registries and reference lists of relevant articles for randomized or quasi-randomized controlled trials.

RESULTS

The review included nine studies with 5691 participants. Studies were at low risk of bias. When comparing ferumoxytol to other IV iron formulations, there is moderate quality evidence (QE) of little to no difference in treatment emergent adverse events (TEAEs) (risk ratio [RR] 0.88, 95% confidence interval [CI] 0.80-0.97), treatment related adverse events (TRAEs) (RR 0.73, 95% CI 0.61-0.88), SAEs (RR 1.13, 95% CI 0.77-1.67), hypotension or hypersensitivity reactions (RR 0.58, 95% CI 0.31-1.09), or composite cardiovascular outcomes (RR 0.56, 95% CI 0.24-1.29), low QE of little to no difference in related SAEs (RR 0.55, 95% CI 0.05-6.16), and high QE of little to no difference in the number of patients with an increase in hemoglobin by at least 1 g/dL (RR 1.04, 95% CI 0.96-1.12). Ferumoxytol had less TEAEs compared to oral iron (RR 0.78, 95% CI 0.61-0.98), but more compared to placebo (RR 1.62, 95% CI 1.01-2.61).

DISCUSSION

Ferumoxytol is as efficacious and safe as alternative IV iron formulations with no clear safety concerns.

Diabetic nephropathy: An update on pathogenesis and drug development

Diabetic nephropathy (DN) is a major cause of end-stage renal disease and affects a large number of individuals with diabetes. However, the development of specific treatments for DN has not yet been identified. Hence, this review is concisely designed to understand the molecular pathways leading to DN in order to develop suitable therapeutic strategies. Extensive literature search have been carried in regard with the pathogenesis and pathophysiology of DN, drug targets and updates on clinical trials, the consequences associated with DN and the potential biomarkers for diagnosis and prediction of DN are discussed in this review. DN is characterised by microalbuminuria and macroalbuminuria, and morphological changes such as glomerular thickening, interstitial fibrosis, formation of nodular glomerulosclerosis and decreased endothelial cell fenestration. Besides, the involvement of renin-angiotensin-aldosterone system, inflammation and genetic factors are the key pathways in the progression of DN. In regard with drug development drugs targeted to epidermal growth factor, inflammatory cytokines, ACTH receptor and TGFβ1 receptors are in pipeline for clinical trials whereas, several drugs have also failed in phase III and phase IV of clinical trials due to lack of efficacy and severe adverse effect. The research on DN is limited with respect to its pathogenesis and drug development. Thus, a more detailed understanding of the pathogenesis of DN is very essential to progress in the drug development process.

Ferric Pyrophosphate Citrate: A Novel Iron Replacement Agent in Patients Undergoing Hemodialysis

Management of anemia remains an integral component in the care of patients with chronic kidney disease undergoing hemodialysis. In addition to erythropoiesis-stimulating agents, iron-replacement agents remain a key strategy for anemia treatment in this patient population. Ferric pyrophosphate citrate (FPC), a novel iron-replacement agent, was approved by the US Food and Drug Administration in January 2015 for use in adult patients receiving chronic hemodialysis (HD). This iron product is administered to patients on HD via the dialysate. The recently published, multicenter, randomized, placebo-controlled, phase 3 clinical trials found FPC to maintain hemoglobin level and iron balance in patients undergoing chronic HD. The mean hemoglobin level in these phase 3 clinical studies was maintained from baseline to the end of the treatment in the dialysate iron (FPC-treated) group, however, it decreased by 0.4 g/dL in the control group (P < 0.001). Adverse and serious adverse events were similar in both groups. Another recent study showed a significant reduction in the prescribed ESA dose at the end of treatment in the FPC-treated group compared with placebo. These studies have shown that FPC administered via the dialysate is efficacious and apparently well tolerated. In this article, in addition to reviewing the clinical studies evaluating the efficacy and safety of FPC, we propose a protocol for iron management in HD centers where FPC is to be used.

Intravenous iron and erythropoiesis-stimulating agents in haemodialysis: A systematic review and meta-analysis

AIM

Higher dosages of erythropoiesis-stimulating agents (ESAs) have been associated with adverse effects. Intravenous iron is used to optimize ESA response and reduces ESA doses in haemodialysis patients; this meta-analysis evaluates the magnitude of this effect.

METHODS

A literature search was performed using MEDLINE, Embase and the Cochrane Collaboration Central Register of Clinical Trials from inception until December 2014, to identify randomized controlled trials of intravenous iron and ESA, in patients undergoing haemodialysis for end-stage kidney disease. Dosing of IV iron in concordance with the Kidney Disease Improving Global Outcomes guidelines was considered optimal iron therapy.

RESULTS

Of the 28 randomized controlled trials identified, seven met the criteria for inclusion in the meta-analysis. Results of random-effects meta-analysis show a statistically significant weighted mean (95% CI) difference of -1733 [-3073, -392] units/week in ESA dose for optimal iron versus suboptimal iron. The weighted average change in ESA dose was a reduction of 23% (range -7% to -55%) attributable to appropriate dosing of intravenous iron. A comparison of intravenous iron versus oral iron/no iron (five trials) showed a greater reduction in ESA dose, although this did not reach statistical significance (weighted mean difference, 95% CI: -2,433 [-5183, 318] units/week). The weighted average change in ESA dose across the five trials was a reduction of 31% (range -8% to -55%).

CONCLUSION

Significant reductions in ESA dosing may be achieved with optimal intravenous iron usage in the haemodialysis population, and suboptimal iron use may require higher ESA dosing to manage anaemia.

Iron deficiency anemia in chronic liver disease: etiopathogenesis, diagnosis and treatment

Chronic liver disease is accompanied by multiple hematological abnormalities. Iron deficiency anemia is a frequent complication of advanced liver disease. The etiology is multifactorial, mostly due to chronic hemorrhage into the gastrointestinal tract. The diagnosis of iron deficiency anemia is very challenging, as simple laboratory methods, including serum iron, ferritin, transferrin saturation (Tsat), and mean corpuscular volume are affected by the liver disease itself or the cause of the disease, resulting in difficulty in the interpretation of the results. Several new parameters, such as red blood cell ferritin, serum transferrin receptor test and index, and hepcidin, have been studied for their utility in indicating true iron deficiency in combination with chronic liver disease. Once iron deficiency anemia is diagnosed, it should be treated with oral or parenteral iron as well as portal pressure reducing drugs. Blood transfusion is reserved for symptomatic anemia despite iron supplementation.

A Review of Ferric Pyrophosphate Citrate (Triferic) Use in Hemodialysis Patients

PURPOSE

The objective of this short review is to evaluate the efficacy of ferric pyrophosphate citrate and to determine its place in therapy based on the current published literature.

METHODS

A literature search was conducted and pared down to yield 4 placebo controlled Phase II and III clinically relevant trials.

FINDINGS

Ferric pyrophosphate citrate is a new intradialytic iron supplementation product that has been found to reduce the dose of erythropoiesis-stimulating agents and intravenous iron supplementation and to increase serum ferritin concentrations.

IMPLICATIONS

This agent may be administered to patients with stage 5 chronic kidney disease receiving hemodialysis as a new iron supplementation option to maintain hemoglobin, transferrin saturation, and ferritin concentrations.

New Options for Iron Supplementation in Maintenance Hemodialysis Patients

End-stage renal disease results in anemia caused by shortened erythrocyte survival, erythropoietin deficiency, hepcidin-mediated impairment of intestinal absorption and iron release, recurrent blood loss, and impaired responsiveness to erythropoiesis-stimulating agents (ESAs). Iron malabsorption renders oral iron products generally ineffective, and intravenous (IV) iron supplementation is required in most patients receiving maintenance hemodialysis (HD). IV iron is administered at doses far exceeding normal intestinal iron absorption. Moreover, by bypassing physiologic safeguards, indiscriminate use of IV iron overwhelms transferrin, imposing stress on the reticuloendothelial system that can have long-term adverse consequences. Unlike conventional oral iron preparations, ferric citrate has recently been shown to be effective in increasing serum ferritin, hemoglobin, and transferrin saturation values while significantly reducing IV iron and ESA requirements in patients treated with HD. Ferric pyrophosphate citrate is a novel iron salt delivered by dialysate; by directly reaching transferrin, its obviates the need for storing administered iron and increases transferrin saturation without increasing serum ferritin levels. Ferric pyrophosphate citrate trials have demonstrated effective iron delivery and stable hemoglobin levels with significant reductions in ESA and IV iron requirements. To date, the long-term safety of using these routes of iron administration in patients receiving HD has not been compared to IV iron and therefore awaits future investigations.

Comparative Short-term Safety of Sodium Ferric Gluconate Versus Iron Sucrose in Hemodialysis Patients

BACKGROUND

Despite different pharmacologic properties, little is known about the comparative safety of sodium ferric gluconate versus iron sucrose in hemodialysis patients.

STUDY DESIGN

Retrospective cohort study using the clinical database of a large dialysis provider (2004-2005) merged with administrative data from the US Renal Data System.

SETTING & PARTICIPANTS

66,207 patients with Medicare coverage who received center-based hemodialysis.

PREDICTORS

Iron formulation use assessed during repeated 1-month exposure periods (n=278,357).

OUTCOMES

All-cause mortality, infection-related hospitalizations and mortality, and cardiovascular-related hospitalizations and mortality occurring during a 3-month follow-up period.

MEASUREMENTS

For all outcomes, we estimated 90-day risk differences between the formulations using propensity score weighting of Kaplan-Meier functions, which controlled for a wide range of demographic, clinical, and laboratory variables. Risk differences were also estimated within various clinically important subgroups.

RESULTS

Ferric gluconate was administered in 11.4%; iron sucrose, in 48.9%; and no iron in 39.7% of the periods. Risks for most study outcomes did not differ between ferric gluconate and iron sucrose; however, among patients with a hemodialysis catheter, use of ferric gluconate was associated with a slightly decreased risk for both infection-related death (risk difference, -0.3%; 95% CI, -0.5% to 0.0%) and infection-related hospitalization (risk difference, -1.5%; 95% CI, -2.3% to -0.6%). Bolus dosing was associated with an increase in infection-related events among both ferric gluconate and iron sucrose users.

LIMITATIONS

Residual confounding and outcome measurement error.

CONCLUSIONS

Overall, the 2 iron formulations studied exhibited similar safety profiles; however, ferric gluconate was associated with a slightly decreased risk for infection-related outcomes compared to iron sucrose among patients with a hemodialysis catheter. These associations should be explored further using other data or study designs.

Effects of carnitine on oxidative stress response to intravenous iron administration to patients with CKD: impact of haptoglobin phenotype

BACKGROUND

Anemia is a common disorder in CKD patients. It is largely attributed to decreased erythropoietin (EPO) production and iron deficiency. Therefore, besides EPO, therapy includes iron replenishment. However, the latter induces oxidative stress. Haptoglobin (Hp) protein is the main line of defense against the oxidative effects of Hemoglobin/Iron. There are 3 genotypes: 1-1, 2-1 and 2-2. Hp 2-2 protein is inferior to Hp 1-1 as antioxidant. So far, there is no evidence whether haptoglobin phenotype affects iron-induced oxidative stress in CKD patients. Therefore, the present study examines the influence of carnitine treatment on the intravenous iron administration (IVIR)-induced oxidative stress in CKD patients, and whether Hp phenotype affects this response.

METHODS

TRIAL REGISTRATION

Current Controlled Trials ISRCTN5700858. This study included 26 anemic (Hb = 10.23 ± 0.28) CKD patients (stages 3-4) that were given a weekly IVIR (Sodium ferric gluconate, [125 mg/100 ml] for 8 weeks, and during weeks 5-8 also received Carnitine (20 mg/kg, IV) prior to IVIR. Weekly blood samples were drawn before and after each IVIR for Hp phenotype, C-reactive protein (CRP), advanced oxidative protein products (AOPP), neutrophil gelatinase-associated lipocalin (NGAL), besides complete blood count and biochemical analyses.

RESULTS

Eight percent of CKD patients were Hp1-1, 19 % Hp2-1, and 73 % Hp2-2. IVIR for 4 weeks did not increase hemoglobin levels, yet worsened the oxidative burden as was evident by elevated plasma levels of AOPP. The highest increase in AOPP was observed in Hp2-2 patients. Simultaneous administration of Carnitine with IVIR abolished the IVIR-induced oxidative stress as evident by preventing the elevations in AOPP and NGAL, preferentially in patients with Hp2-2 phenotype.

CONCLUSIONS

This study demonstrates that Hp2-2 is a significant risk factor for IVIR-induced oxidative stress in CKD patients. Our finding, that co-administration of Carnitine with IVIR preferentially attenuates the adverse consequences of IVIR, suggests a role for Carnitine therapy in these patients.

Pathophysiology of anemia in chronic kidney diseases: A review

Backgroud. Anemia is one of the laboratory and clinical findings of chronic kidney diseases (CKD). The presence of anemia in patients with CKD has a wide range of clinically important consequences. Some of the symptoms that were previously attributed to reduced renal function are, in fact, a consequence of anemia. Anemia contributes to increased cardiac output, the development of left ventricular hypertrophy, angina, and congestive heart failure. According to current knowledge, anemia also contributes to the progression of CKD and is one of the factors that contribute to the high morbidity and mortality in patients with chronic renal failure and their reduced survival.

METHODS

MEDLINE search was performed to collect both original and review articles addressing anemia in CKD, pathophysiology of renal anemia, erythropoiesis, erythropoietin, iron metabolism, inflammation, malnutrition, drugs, renal replacement therapy and anemia management

CONCLUSION

The present review summarized current knowledge in the field of the pathophysiology of renel anemia. Understanding the pathophysiology of anemia in CKD is crucial for the optimal treatment of anemia according to recent clinical practice guidelines and recommendation, and correct recognition of causes of resistence to treatment of erythropoietin stimulating agents (ESA).

Approaches to inverse-probability-of-treatment--weighted estimation with concurrent treatments

OBJECTIVES

In a setting with two concurrent treatments, inverse-probability-of-treatment weights can be used to estimate the joint treatment effects or the marginal effect of one treatment while taking the other to be a confounder. We explore these two approaches in a study of intravenous iron use in hemodialysis patients treated concurrently with epoetin alfa (EPO).

STUDY DESIGN AND SETTING

We linked US Renal Data System data with electronic health records (2004-2008) from a large dialysis provider. Using a retrospective cohort design with 776,203 records from 117,050 regular hemodialysis patients, we examined a composite outcome: mortality, myocardial infarction, or stroke.

RESULTS

With EPO as a joint treatment, inverse-probability-of-treatment weights were unstable, confidence intervals for treatment effects were wide, covariate balance was unsatisfactory, and the treatment and outcome models were sensitive to omission of the baseline EPO covariate. By handling EPO exposure as a confounder instead of a joint treatment, we derived stable weights and balanced treatment groups on measured covariates.

CONCLUSIONS

In settings with concurrent treatments, if only one treatment is of interest, then including the other in the treatment model as a confounder may result in more stable treatment effect estimates. Otherwise, extreme weights may necessitate additional analysis steps.

Ferric carboxymaltose in patients with iron-deficiency anemia and impaired renal function: the REPAIR-IDA trial

BACKGROUND

Iron-deficiency anemia in non-dialysis-dependent chronic kidney disease (NDD-CKD) frequently requires parenteral iron replacement, but existing therapies often require multiple administrations. We evaluated the efficacy and cardiovascular safety of ferric carboxymaltose (FCM), a non-dextran parenteral iron permitting large single-dose infusions, versus iron sucrose in patients with iron-deficiency anemia and NDD-CKD.

METHODS

A total of 2584 participants were randomized to two doses of FCM 750 mg in one week, or iron sucrose 200 mg administered in up to five infusions in 14 days. The primary efficacy endpoint was the mean change to highest hemoglobin from baseline to Day 56. The primary composite safety endpoint included all-cause mortality, nonfatal myocardial infarction, nonfatal stroke, unstable angina, congestive heart failure, arrhythmias and hyper- and hypotensive events.

RESULTS

The mean hemoglobin increase was 1.13 g/dL in the FCM group and 0.92 g/dL in the iron sucrose group (95% CI, 0.13-0.28). Similar results were observed across all subgroups, except Stage 2 CKD. More subjects in the FCM group achieved a hemoglobin increase of ≥ 1.0 g/dL between baseline and Day 56 (48.6 versus 41.0%; 95% CI, 3.6-11.6%). There was no significant difference between FCM and iron sucrose recipients with respect to the primary composite safety endpoint, including the major adverse cardiac events of death, myocardial infarction, or stroke. A significant difference in the number of protocol-defined, predominantly transient hypertensive episodes was observed in the FCM group.

CONCLUSIONS

Two 750-mg infusions of FCM are a safe and effective alternative to multiple lower dose iron sucrose infusions in NDD-CKD patients with iron-deficiency anemia.

Transferrin changes in haemodialysed patients

Transferrin (Tf) is a glycoprotein responsible for iron transport in the human body. Physiologically in reaction with Concanavalin A, Tf occurs in four distinct variants Tf1, Tf2, Tf3 (apo-Tf) and Tf4. It was reported recently that Tf is changing, particularly during acute phase response, taking place among others in end-stage renal disease. In this study, we wanted to find the answer to three main questions: firstly, how Tf is changing in patients treated with maintenance haemodialysis (mHD), secondly, whether there are any Tf changes in the course of mHD treatment, and thirdly, what factors can affect Tf microheterogeneity in these patients. Studies were performed on 80 haemodialysed patients and 21 healthy volunteers. The Tf concentration was determined by the rocket immunoelectrophoresis, and its microheterogeneity was assessed by the ConA crossed immunoaffinity electrophoresis. During the annual observation of the distribution of the Tf variants, we have found both changes of the percentage contents of all Tf variants in the whole Tf concentration and a significant decrease in Tf2, Tf3 and Tf4 serum concentrations. Moreover, we found that decrease in the renal function, duration of mHD, and inflammation may contribute to these above-mentioned changes, which are probably the factors that should be taken into account when explaining the mechanisms of persistence of anaemia in haemodialysed patients.

Decisive indicator for gastrointestinal workup in anemic patients with nondialysis chronic kidney disease

BACKGROUND

Anemia and iron deficiency are universal problems in patients with chronic kidney disease (CKD). However, decisive indicator to guide the further gastrointestinal (GI) workup has not been determined.

METHODS

We included 104 anemic patients with nondialysis-dependent CKD stages 3-5 (38 patients at stage 3, 26 patients at stage 4, and 40 patients at stage 5). Hemoglobin, serum ferritin, transferrin saturation (TSAT), mean corpuscular volume (MCV), and corrected reticulocyte count data were assessed to evaluate diagnostic utility for bleeding-related GI lesions, which were identified by esophagogastroduodenoscopy and colonoscopy.

RESULTS

Bleeding-related GI lesions were found in 55 (52.9%) patients, and patients with stage 5 CKD had a higher prevalence of gastric lesions than patients with CKD stage 3 or 4 (all p < 0.05). The areas under the receiver operating characteristic curves used to predict bleeding-related lesions were 0.69 for TSAT (p = 0.002) and 0.61 for serum ferritin (p = 0.085). The sensitivity and specificity of a cutoff value for TSAT < 20% were 0.59 and 0.74, respectively. Hemoglobin, MCV, and corrected reticulocyte levels had no significant diagnostic utility. On multivariable logistic regression, the chance of GI lesions increased by 6% for each 1% reduction in TSAT and increased 4.1-fold for patients with CKD stage 5 (all p < 0.05).

CONCLUSIONS

TSAT is a useful indicator for determining the GI workup in anemic patients with nondialysis-dependent CKD stages 3-5. Stage 5 CKD is independently associated with bleeding-related lesions and TSAT should be used cautiously in these patients.

Ferumoxytol for the treatment of iron deficiency

Intravenous iron is standard for dialysis-associated anemia and its use is rising dramatically in other settings. Except for the dextrans, full iron replacement requires multiple visits. Nonetheless, safety concerns abound. Ferumoxytol, a recently approved modified dextran with a carbohydrate core that tightly binds the iron moiety, decreasing free iron and ostensibly increasing safety, was approved by the US FDA, in June 2009, for the treatment of iron deficiency associated with chronic kidney disease and end-stage renal disease. This formulation, uniquely, can be administered in a large dose as a short intravenous injection of 1 min or less, markedly facilitating care. Recent post-marketing safety issues have been raised resulting in a change in the package insert. This article examines existing clinical data and posits reasons for the labeling change. Potential future use of this formulation is opined.

Introducing iron isomaltoside 1000 (Monofer®)-development rationale and clinical experience

Patients with chronic kidney disease (CKD) often suffer from iron deficiency anaemia necessitating treatment with intravenous (IV) iron. Several studies demonstrate that oral iron is insufficient in these patients and that IV supplementation is a more effective treatment. Until now, use of available parenteral iron preparations has been limited by dosing schedules and the need, in some cases, for a test dose, and despite the availability of a range of different IV iron compounds, there is still a need for improved compounds. The new IV iron, iron isomaltoside 1000 Monofer®, is composed of iron and chemically modified isomalto-oligosaccharides which have a mean molecular weight of 1000 Da and consist predominantly of 3–5 glucose units. In contrast to dextrans, the carbohydrate isomaltoside 1000 is a linear and unbranched structure with theoretically a low immunological potential. Hence, a test dose is not necessary. Iron isomaltoside 1000 contains strongly bound iron within the iron–isomaltoside formulation, which enables a controlled slow release of bioavailable iron to the iron-binding proteins, with potentially a reduced risk of free iron toxicity. This allows flexible dosing including high and rapid dosing securing convenient iron therapy for a wide range of patients. The development of Monofer® has been enthusiastically acknowledged by clinicians, and in 2009, there has been fast approval by European authorities via a decentralized registration procedure. This new IV iron is currently being marketed in several European countries.

This article describes the development rationale and summarizes the clinical data assessing the use of iron isomaltoside 1000 administered without a test dose by either repeated bolus injections or fast high single iron infusions [defined as total dose infusion (TDI)] to patients suffering from CKD. Since CKD is associated with a high prevalence of cardiovascular disease, data from a small trial applying high single doses of iron isomatoside 1000 in patients with chronic heart failure (CHF) are also reviewed. Collectively, the available data demonstrate adequate efficacy and a good safety profile of iron isomaltoside 1000 in CKD and CHF patients even when administered without a test dose and as single rapid high-dose infusions.

Effect of intravenous saccharated ferric oxide on serum FGF23 and mineral metabolism in hemodialysis patients

BACKGROUND/AIMS

Fibroblast growth factor-23 (FGF23) plays a central role in the development of hypophosphatemia and inappropriately low 1,25-dihydroxyvitamin D induced by iron therapy for iron-deficiency anemia. The aim of this study was to examine the effect of intravenous saccharated ferric oxide on serum FGF23 levels and mineral metabolism in hemodialysis patients.

METHODS

This prospective study enrolled 27 hemodialysis patients who had iron-deficiency anemia defined by a hemoglobin concentration < 10.5 g/dl and serum ferritin < 100 ng/ml. Intravenous saccharated ferric oxide at a dose of 40 mg was administered three times weekly over 3 weeks. The dose of active vitamin D and phosphate binders was kept unchanged. Serum FGF23, intact parathyroid hormone (PTH) and other parameters were prospectively monitored for 5 weeks.

RESULTS

Serum FGF23 levels were markedly elevated [3,453 (338-6,383) pg/ml] at baseline. After 3 weeks of intravenous saccharated ferric oxide treatment, serum FGF23 further increased to 4,701 (1,251-14,396) pg/ml, and returned to the baseline values after 2 weeks of observation. There was also a significant decrease in intact PTH but no changes in serum calcium and phosphorus.

CONCLUSIONS

Intravenous saccharated ferric oxide induces further increase in elevated FGF23 levels in hemodialysis patients. This increase does not induce hypophosphatemia and inappropriately low 1,25-dihydroxyvitamin D in the absence of functioning kidney, but may result in transient PTH suppression - possibly by directly acting on the parathyroid.

Effectiveness of oral iron to manage anemia in long-term hemodialysis patients with the use of ultrapure dialysate

The aim of this study was to evaluate the effectiveness of oral iron to manage anemia in long-term hemodialysis (HD) patients using ultrapure dialysate. This study was prospectively conducted on 23 patients (11 males and 12 females; median age 60 years, range 35-81) who underwent HD in our hospital from March to September 2007. The patients were randomly assigned to two treatment groups. The first group of 11 patients received ferrous fumarate 305 mg per oral tablet once a day, while the second group of 12 patients received infusions of 50 mg iron in a 0.9% sodium chloride solution. At the end of the 6-month treatment, patients receiving oral iron and intravenous iron had a significant increase in transferrin saturation from baseline (20.1±8.9 to 29.7±7.2; p=0.011 and 17.4±6.1 to 33.7±8.6; p=0.0001, respectively) and ferritin (32.6±15.4 to 115.4±28.2; p=0.0001 and 57.8±26.7 to 183.5±47.5; p=0.0002, respectively). In both groups, hemoglobin, hematocrit and dry weight were increased, but did not reach statistical significance. Moreover, both groups showed a significant reduction in the mean weekly erythropoietin dose from baseline (5,590.9±1,513.6 to 3,727.3±1,618.1; p=0.011 and 6,775.8±2,292.2 to 4,375.0±2,473.7; p=0.027, respectively). Oral iron is indeed as effective as intravenous iron in managing anemia in HD patients using ultrapure dialysate.

Diagnosis of iron deficiency in patients undergoing hemodialysis

To diagnose iron deficiency in patients undergoing hemodialysis, the percentage of hypochromic RBCs (with cellular hemoglobin concentration <280 g/L [HYPO%]) and mean reticulocyte hemoglobin content (CHret) provided by the Siemens ADVIA 120 and 2120 analyzers (Siemens Diagnostic Solutions, Tarrytown, NY) were proposed as alternatives to biochemical tests. Sysmex, with its XE-5000 analyzer (Sysmex, Kobe, Japan), also proposed the percentage of erythrocytes with cellular hemoglobin content lower than 17 pg (%Hypo-He) and equivalent of the mean reticulocyte hemoglobin content (Ret-He) with similar clinical applications. Our aim was to verify the clinical usefulness of the biochemical and cellular parameters as predictors of iron deficiency in patients undergoing long-term hemodialysis. We studied 69 patients undergoing hemodialysis 3 times weekly. The baseline values of serum ferritin and percentage of transferrin saturation were poor predictors of iron responsiveness. Better ability was demonstrated by reticulocyte indices (area under the curve [AUC], 0.74 for CHret and 0.72 for Ret-He; best cutoff values, 31.2 and 30.6 pg, respectively) and erythrocyte parameters (AUC, 0.72 for HYPO% and 0.68 for %Hypo-He; best cutoff values, 5.8 and 2.7, respectively). The newly proposed Ret-He and %Hypo-He can provide clinicians with information equivalent to CHret and HYPO%.

Association of ESA hypo-responsiveness and haemoglobin variability with mortality in haemodialysis patients

BACKGROUND

Anaemia is a common complication in dialysis patients. In most cases, it is treated with erythropoietin-stimulating agents (ESA). It is not entirely clear whether the variability of haemoglobin caused by changing ESA response is associated with increased mortality. Therefore, we conducted a retrospective cohort study to evaluate ESA responsiveness and haemoglobin variability in association with mortality.

METHODS

We used the Austrian dialysis and transplant registry, and identified 932 patients who were on maintenance haemodialysis in the years 2005-08 with recorded weekly ESA doses and haemoglobin concentrations. ESA response was defined as a positive regression slope over the observation period. Cox regression analysis with spline functions and purposeful variable selection algorithms were used.

RESULTS

Adjusted Cox regression analysis showed an increased mortality risk in subjects with wide ranges of haemoglobin variability (from <10 to >12 g/dL) (HR = 2.38, 95% CI 1.20-4.71, P = 0.013). Furthermore, patients that never reached haemoglobin levels >10 g/dL despite ESA therapy exhibited the highest risk of mortality (HR = 6.37, 95% CI 2.15-18.82, P < 0.001). ESA hypo-responsiveness was associated with increased risk of mortality in the low as well as high haemoglobin ranges [HR = 2.06, 95% CI 1.49-2.86 at haemoglobin of 9.5 g/dL and HR = 1.64, 95% CI 0.68-3.92 at 13.5 g/dL both vs. 11 g/dL (reference)]. ESA dose equivalents >16,000 units per week were associated with increased mortality in ESA responders (HR = 1.30, 95% CI 1.02-1.64). However, in hypo-responders, mortality is not associated with ESA dose (HR = 1.02, 95% CI 0.87-1.20) [both at weekly ESA dose of 20,000 units vs. 16,000 (reference)].

CONCLUSIONS

These findings suggest that the risk of mortality of haemodialysis patients requiring ESA therapy is lowest if the haemoglobin concentration is stably maintained in the range between 10 and 12 g/dL with weekly ESA dose equivalents <16,000 units.

Ferumoxytol: a new intravenous iron preparation for the treatment of iron deficiency anemia in patients with chronic kidney disease

Ferumoxytol is an intravenous iron preparation for treatment of the anemia of chronic kidney disease (CKD). It is a carbohydrate-coated, superparamagnetic iron oxide nanoparticle. Because little free iron is present in the preparation, doses of 510 mg have been administered safely in as little as 17 seconds. Two prospective, randomized studies compared two doses of ferumoxytol 510 mg given in 5 +/- 3 days with 3 weeks of oral iron 200 mg/day (as ferrous fumarate) in anemic patients with CKD. One study enrolled 304 patients with stages 1-5 CKD (predialysis), and the other study enrolled 230 patients with stage 5D CKD (undergoing hemodialysis). In both studies, a greater increase in hemoglobin level from baseline to end of study (day 35) was noted in patients who received ferumoxytol compared with those who received oral iron (mean +/- SD 0.82 +/- 1.24 vs 0.16 +/- 1.02 g/dl in patients with stages 1-5 CKD and 1.02 +/- 1.13 vs 0.46 +/- 1.06 g/dl in patients with stage 5D CKD, p<0.001). A greater proportion of both predialysis and hemodialysis patients who received ferumoxytol had hemoglobin level increases from baseline of 1 g/dl or more compared with those who received oral iron (p<0.001). In a prospective, double-blind, crossover study of more than 700 patients with CKD stages 1-5D that compared the safety of ferumoxytol with normal saline injection, the rates of treatment-related adverse events were 5.2% and 4.5%, respectively. Serious treatment-related adverse events were seen in one patient in each treatment group. The most common adverse events with ferumoxytol occurred at the injection site (bruising, pain, swelling, erythema). Dizziness, nausea, pruritus, headache, and fatigue occurred in less than 2% of patients receiving ferumoxytol, with a similar frequency noted after administration of normal saline. In short-term studies, intravenous ferumoxytol was safely and rapidly administered, and was more effective than oral iron therapy in increasing hemoglobin levels in anemic patients with CKD. Long-term clinical trials with clinical outcomes and studies comparing ferumoxytol with other parenteral iron agents will help define the role of ferumoxytol in treating the anemia of CKD.

Iron supplementation in the non-dialysis chronic kidney disease (ND-CKD) patient: oral or intravenous?

BACKGROUND

The management of iron-deficiency anaemia in patients with non-dialysis chronic kidney disease (ND-CKD) remains controversial, particularly regarding the use of oral versus intravenous iron supplementation.

METHODS

A PubMed search from 1970 to February 2009 was conducted to identify relevant research articles.

FINDINGS

Iron supplementation is advisable for all iron-deficient CKD patients receiving erythropoiesis stimulating agents (ESAs), and intravenous iron may be preferable to oral iron. However, there is also a growing body of data indicating that iron supplementation may avoid or delay the need for ESA therapy in some ND-CKD patients. In each of four randomised trials that included ND-CKD patients without ESA, the haemoglobin response was greater with i.v. versus oral iron. Moreover, some ND-CKD patients who remain anaemic on oral iron may subsequently respond to i.v. iron. Newer preparations (ferric carboxymaltose and ferumoxytol) permit rapid, high-dose administration. In a randomised study, a single 15-minute injection of ferric carboxymaltose, with up to two additional doses as required, resulted in 53.2% of ND-CKD patients achieving > or =1 g/dL increase in haemoglobin by day 56 without ESA, compared to 29.9% of patients given oral iron supplements. Two large, randomised, ongoing trials will address the important question of whether i.v. or oral iron supplementation affects the progression of renal dysfunction. While i.v. iron is more costly than oral iron, the cost differential over time may be lower than widely believed, and i.v. therapy avoids the poor absorption, gastrointestinal intolerance and non-compliance associated with oral preparations. In terms of safety, true anaphylaxis does not occur with modern preparations such as iron sucrose and iron gluconate. The novel preparations ferric carboxymaltose and ferumoxytol do not require a test dose and appear to offer a good safety profile, but long-term safety monitoring is mandatory.

CONCLUSIONS

Intravenous iron offers an effective, feasible route towards reducing the heavy burden of iron-deficiency anaemia in the non-dialysis CKD patient, even in the absence of ESA therapy.

Ferumoxytol as an intravenous iron replacement therapy in hemodialysis patients

BACKGROUND AND OBJECTIVES

Intravenous iron is a key component of anemia management for chronic kidney disease (CKD). Ferumoxytol is a unique intravenous iron product that can be administered as a rapid injection in doses up to 510 mg.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a randomized, open-label, controlled, multicenter Phase 3 trial to evaluate the safety and efficacy of intravenous ferumoxytol compared with oral iron. Anemic patients with CKD stage 5D on hemodialysis and on a stable erythropoiesis-stimulating agent regimen received either two injections of 510 mg of ferumoxytol within 7 d (n = 114) or 200 mg elemental oral iron daily for 21 d (n = 116). The primary efficacy endpoint was the change in hemoglobin from baseline to day 35. Safety was closely monitored.

RESULTS

Ferumoxytol resulted in a mean increase in hemoglobin of 1.02 +/- 1.13 g/dl at day 35 compared with 0.46 +/- 1.06 g/dl with oral iron (P = 0.0002). Twice as many ferumoxytol-treated patients than oral iron-treated patients achieved a > or =1 g/dl hemoglobin increase at day 35 (P = 0.0002). There was a greater mean increase in transferrin saturation (TSAT) with ferumoxytol compared with oral iron at day 35 (P < 0.0001). The larger hemoglobin increase after ferumoxytol compared with oral iron at day 35 persisted after adjustment for baseline hemoglobin, TSAT, and serum ferritin. Overall adverse event rates were comparable between groups.

CONCLUSIONS

In patients on hemodialysis, rapid intravenous injection of 510 mg of ferumoxytol led to significantly greater hemoglobin increases compared with oral iron, with comparable tolerability.

Iron indices in chronic kidney disease in the National Health and Nutritional Examination Survey 1988-2004

BACKGROUND AND OBJECTIVES

Anemia is a common and early complication of nondialysis chronic kidney disease (CKD). One contributing factor is iron deficiency, which may be particularly problematic during erythropoietin replacement therapy. The aim of this study was to examine the prevalence of iron deficiency in nondialysis CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The National Health and Nutritional Examination Survey (NHANES) data for NHANES III (1988 to 1994) and subsequent NHANES 2-yr datasets, 1999 to 2000, 2001 to 2002, and 2003 to 2004 were analyzed for individuals >18 yr old.

RESULTS

It was found that low levels of iron tests [either serum ferritin < 100 ng/ml or transferrin saturation (TSAT) < 20%] were present in most patients with reduced creatinine clearance (CrCl). The percentage of low iron tests was higher among women than men, present in 57.8 to 58.8% of men and 69.9 to 72.8% of women (P < 0.001). With declining levels of CrCl, in women, TSAT levels decreased, whereas, surprisingly, serum ferritin tended to progressively increase. The percentage of anemic subjects increased progressively with declining quartiles of TSAT but was unrelated to serum ferritin quartiles.

CONCLUSIONS

It was found that low levels of iron tests, following National Kidney Foundation/Kidney Disease Outcomes Quality Initiative guidelines (either serum ferritin < 100 ng/ml or TSAT < 20%) were present in most patients with reduced CrCl.

Safety of ferumoxytol in patients with anemia and CKD

BACKGROUND

Iron deficiency anemia is a common complication in patients with chronic kidney disease (CKD). Currently available intravenous (IV) iron replacement therapies have either inconvenient regimens of administration or adverse event profiles that limit their utility in the outpatient setting. Ferumoxytol is a novel, semisynthetic, carbohydrate-coated, superparamagnetic iron oxide nanoparticle that is administered IV as an injection. The main objective of this study was to assess the safety of ferumoxytol for the treatment of patients with CKD stages 1 to 5 and 5D.

STUDY DESIGN

Phase 3, randomized, double-blind, placebo-controlled, crossover, multicenter study of a single 510-mg dose of ferumoxytol versus saline as placebo.

SETTING & PARTICIPANTS

750 patients with CKD stages 1 to 5 and 5D.

INTERVENTION

An IV injection of either 17 mL of ferumoxytol or saline placebo over 17 seconds on day 0 and the alternate agent on day 7.

OUTCOMES & MEASUREMENTS

Descriptive comparison of adverse events, laboratory tests, and vital signs.

RESULTS

Of 750 randomly assigned patients with CKD, 60% were not on dialysis therapy. 713 patients received ferumoxytol, and 711 received placebo. There were 420 adverse events reported; 242 in 152 patients (21.3%) with ferumoxytol and 178 in 119 patients (16.7%) with placebo. The incidence of related adverse events was 5.2% with ferumoxytol and 4.5% with placebo. The most common related adverse events after each treatment included symptoms related to the injection/infusion site, dizziness, pruritus, headache, fatigue, and nausea. Serious adverse events occurred in 21 patients (2.9%) after ferumoxytol and 13 patients (1.8%) after placebo. Serious related adverse events were observed in 1 patient (0.1%) after each treatment. There was no meaningful decrease in blood pressure after administration of ferumoxytol or placebo.

LIMITATIONS

Follow-up was 7 days after each study treatment.

CONCLUSIONS

Ferumoxytol is well tolerated and has a safety profile similar to placebo in anemic patients with CKD stages 1 to 5 and 5D.

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.

Upper limit of serum ferritin: misinterpretation of the 2006 KDOQI anemia guidelines

Intravenous iron treatment in hemodialysis patients improves response to recombinant human erythropoietin and facilitates achievement of targets for hemoglobin and hematocrit. Excessive treatment, however, could expose patients to risks related to iron overload and oxidative stress. Therefore, international treatment guidelines generally recommend that intravenous (i.v.) iron be discontinued when serum ferritin is >500-1,000 ng/ml. In the current review, relevant issues that inform decisions as to what levels of serum ferritin should be used as the upper limit for treatment are considered. A conclusion is reached that the current published literature is inadequate for developing evidence-based guidelines on this issue. Instead, clinical judgment is critical to properly weigh risks and benefits of i.v. iron treatment, and to determine whether iron treatment is appropriate for a given patient with higher levels of iron tests.