Ferric Citrate Reduces Intravenous Iron and Erythropoiesis-Stimulating Agent Use in ESRD

UK kidney association clinical practice guideline: update of anaemia of chronic kidney disease

Anaemia is common in chronic kidney disease (CKD) encompassing non-dialysis dependent CKD (NDD-CKD) and dialysis dependent CKD (DD-CKD); people on peritoneal dialysis (PD) and haemodialysis (HD); and kidney transplant recipients (KTR). Iron deficiency and erythropoietin deficiency are the most common causes of anaemia in people with CKD, especially those requiring kidney replacement therapy (KRT). The Renal National Service Framework and National Institute for Health and Clinical Excellence in the UK, and Kidney Disease Improving Global Outcomes (KDIGO), all advocate treatment of anaemia in people with CKD. Blood transfusions are infrequently required, and newer therapies such as Hypoxia-Inducible Factor (HIF-PHI) stabilisers are now in current use. This guideline provides evidence based graded practice guidance on the use of iron; comments on iron deficiency without anaemia in people with CKD; provide further information on anaemia management in people with a transplant and provide guidance in the use of the new HIF-PHI drugs. It also provides audit and research recommendations.

Intravenous iron in chronic kidney disease without anaemia but iron deficiency: A scoping review

Iron deficiency (ID) is a prevalent complication of chronic kidney disease (CKD), often managed reactively when associated with anaemia. This scoping review evaluates the evidence supporting intravenous (IV) iron therapy in non-anaemic individuals with CKD and ID, focusing on safety, efficacy, and emerging therapeutic implications. Current diagnostic markers, including serum ferritin, transferrin saturation, and reticulocyte haemoglobin content, are reviewed alongside their limitations in the context of inflammation and variability. The pathophysiology of ID in CKD is explored, highlighting the roles of hepcidin, hypoxia-inducible factor pathways, and uraemic toxins. Comparative studies reveal that IV iron offers a more rapid correction of iron stores, improved compliance, and fewer gastrointestinal side effects compared to oral iron. Evidence from trials such as "iron and heart" and "iron and muscle" suggests potential benefits of IV iron on functional capacity and fatigue, though findings were statistically non-significant. Insights from heart failure trials support the safety and efficacy of IV iron in improving quality of life and reducing hospitalizations, with newer formulations like ferric derisomaltose demonstrating favourable safety profiles. This review underscores the need for standardized screening protocols for ID in CKD, even in the absence of anaemia, to facilitate earlier intervention. Future research should prioritise robust outcome measures, larger sample sizes, and person-specific treatment strategies to optimise dosing and administration frequency. Tailored approaches to IV iron therapy have the potential to significantly improve functional outcomes, quality of life, and long-term health in people with CKD.

Pathophysiology and therapies of CKD-associated secondary hyperparathyroidism

Uremic secondary hyperparathyroidism (SHP) refers to the biochemical abnormalities that characterize CKD-MBD. However, historically parathyroid hormone (PTH) is identified as the key culprit hormone and the essential biomarker of secondary hyperparathyroidism. SHP represents the adaptive response to several mineral abnormalities that initiate and maintain increased PTH secretion through classical mineral derangements and more recently elucidated hormonal dysregulations. Among classic factors involved in the pathogenesis of SHP, phosphate, calcium, and calcitriol have a prominent role. The discovery of new pathogenetic factors involved in the development of SHP (and the eventual CKD-MBD) including fibroblast growth factor-23 (FGF23) and klotho provides new hypothesis and perspectives to our understanding of this complex metabolic disturbance. Recently more than serum phosphate a critical role in regulating FGF23 synthesis and the progression of CKD is ascribed to phosphate pool, reflected by production of glycerol-3-phosphate and the formation of excessive CPP-2. Finally, also skeletal resistance to PTH action, due to dysregulation of the Wnt-β-catenin system and intestinal dysbiosis, affecting the PTH actions on bone are causal factor of SHP. Identifying all the actors at play is mandatory to allow the most precise therapeutic prescription in the individual patient. This paper aims to review, in particular, the pathophysiology of SHP, which is essential to envisage the eventual therapeutic options for the associated MBD.

Updates in Chronic Kidney Disease

Chronic kidney disease (CKD) affects approximately 14% of adults in the United States and is present in at least 10% of the population worldwide. Blood glucose and blood pressure control are imperative to adequately manage CKD as they are the only primary prevention measures for the condition. Recent changes in CKD evaluation and medication therapies that modify disease progression and aid in managing complications such as anemia of CKD have emerged, including a newly approved mineralocorticoid receptor antagonist and hypoxia-inducible factor-prolyl hydroxylase inhibitor, respectively. This focused update on CKD evaluation and management will review the most recent evidence and approved agents to support patients with CKD, including a review of glomerular filtration rate measurement methods such as CKD-EPI 2021 and utilization of cystatin C, Kidney Disease Improving Global Outcomes (KDIGO) guidelines, American Diabetes Association (ADA) guidelines, and primary literature supporting the use of newer agents in CKD. Checklists for managing blood pressure and blood glucose, CKD-mineral bone disorder, and anemia of CKD targeted for pharmacists are also provided. Additionally, a discussion of Centers for Medicare & Medicaid (CMS) coverage of agents approved for managing complications of CKD is included.

The Efficacy and Safety of Roxadustat for Anemia in Hemodialysis Patients with Chronic Kidney Disease: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Patients undergoing hemodialysis (HD) for chronic kidney disease (CKD) often encounter anemia. Roxadustat has not only undergone phase II-III clinical trials in patients suffering from CKD and undergoing HD; a number of post-marketing clinical studies have been conducted using the drug. This article was to assess the effectiveness and safety of roxadustat in managing anemia among patients with CKD undergoing HD.

METHODS

A thorough search was performed across eight databases, including PubMed, Web of Science, Cochrane Library, Embase, Wan Fang, China National Knowledge Infrastructure (CNKI), Chongqing VIP (CQ VIP), and SinoMed to identify randomized clinical trials (RCTs) examining the effectiveness and safety of roxadustat in managing anemia among individuals suffering from CKD and undergoing HD. This search included studies from the inception of these databases to April 2023.

RESULTS

Two phase II, one phase III, and 16 post-marketing studies with 1688 participants were included. Serum iron (SI), transferrin, and total iron-binding capacity (TIBC) levels changed from baseline (∆SI, ∆transferrin, and ∆TIBC) and were significantly more increased for roxadustat than for erythropoiesis-stimulating agents (ESAs): MD 2.55, (95% CI 1.51 to 3.60), p < 0.00001; MD 0.55, (95% CI 0.41 to 0.69), p < 0.00001; and MD 6.54, (95% CI 4.50 to 8.59), p < 0.00001, respectively. Roxadustat was not inferior to ESAs with regard to increasing Hb (∆Hb) levels [MD 1.17 (95% CI 0.71 to 1.63), p < 0.00001] (g/dL). No statistically significant distinctions of the ∆ferritin, ∆hepcidin, and transferrin saturation (TSAT) from baseline (∆TSAT) level were identified between roxadustat and ESAs. C-reactive protein (CRP) levels changed from baseline (∆CRP) and were significantly more reduced for roxadustat than for ESAs. As for safety, the analysis indicated no notable difference in the occurrence of adverse events (AEs) and serious adverse events (SAEs) between roxadustat and ESAs.

CONCLUSIONS

This meta-analysis demonstrated that roxadustat outperformed ESAs in enhancing SI, transferrin, and TIBC levels while also decreasing CRP levels. Roxadustat was not inferior to ESAs in terms of improving Hb levels and safety. These findings suggest that roxadustat was well tolerated and a potent alternative to ESAs in managing anemia among patients suffering from CKD and undergoing HD.

A Randomized Trial of the Impact of Ferric Citrate on Erythropoietin and Intravenous Iron Use in Patients Receiving Dialysis

INTRODUCTION

Ferric citrate (FC) is an FDA-approved iron-based phosphate binder for adults with dialysis-dependent chronic kidney disease. This study investigated the impact of FC as the primary phosphate-lowering therapy on utilization of erythropoiesis-stimulating agents (ESAs) and intravenous (IV) iron.

METHODS

In this randomized, open-label, active-controlled, multicenter study (NCT04922645), patients on dialysis and receiving ESAs were randomized to receive FC or remain on standard of care (SOC) phosphate-lowering therapy for up to 6 months. Primary endpoints were the difference in change from baseline to efficacy evaluation period (EEP) in mean monthly ESA and IV iron doses. Secondary endpoints included treatment differences in hemoglobin, phosphate, TSAT, and ferritin levels.

RESULTS

Two hundred nine patients were randomized to FC and had a day 1 dosing visit (n = 103) or SOC (n = 106). The two groups had similar baseline laboratory characteristics; however, atherosclerotic CV disease, peripheral vascular disease, and congestive heart failure were more common in the SOC group. The mean treatment difference in ESA monthly dose was -30.8 μg (FC vs. SOC; p = 0.02). An absolute though non-statistically significant change in mean monthly IV iron dose of -37.2 mg (p = 0.17) was observed with FC. Mean hemoglobin, TSAT, and ferritin all increased from baseline to the EEP with FC versus SOC. Serious adverse events occurred in 28% of patients receiving FC versus 37% in those receiving SOC.

CONCLUSIONS

In patients receiving dialysis, treatment with FC as compared to remaining on SOC phosphate binders resulted in reductions in mean monthly ESA and IV iron dose.

Efficacy and Safety of Ferric Citrate on Hyperphosphatemia among Chinese Patients with Chronic Kidney Disease Undergoing Hemodialysis: A Phase III Multicenter Randomized Open-Label Active-Drug-Controlled Study

INTRODUCTION

Hyperphosphatemia in chronic kidney disease (CKD) patients is positively associated with mortality. Ferric citrate is a potent phosphorus binder that lowers serum phosphorus level and improves iron metabolism. We compared its efficacy and safety with active drugs in Chinese CKD patients with hemodialysis.

METHODS

Chinese patients undergoing hemodialysis were randomized into two treatment groups in a 1:1 ratio, receiving either ferric citrate or sevelamer carbonate, respectively, for 12 weeks. Serum phosphorus levels, calcium concentration, and iron metabolism parameters were evaluated every 2 weeks. Frequency and severity of adverse events were recorded.

RESULTS

217 (90.4%) patients completed the study with balanced demographic and baseline characteristics between two groups. Ferric citrate decreased the serum phosphorus level to 0.59 ± 0.54 mmol/L, comparable to 0.56 ± 0.62 mmol/L by sevelamer carbonate. There was no significant difference between two groups (p > 0.05) in the proportion of patients with serum phosphorus levels reaching the target range, the response rate to the study drug, and the changes of corrected serum calcium concentrations, and intact-PTH levels at the end of treatment. The change of iron metabolism indicators in the ferric citrate group was significantly higher than those in the sevelamer carbonate group. There are 47 (40.5%) patients in the ferric citrate group, and 26 (21.3%) patients in the sevelamer carbonate group experienced drug-related treatment emergent adverse events (TEAEs); most were mild and tolerable. Common drug-related TEAEs were gastrointestinal disorders, including diarrhea (12.9 vs. 2.5%), fecal discoloration (14.7 vs. 0%), and constipation (1.7 vs. 7.4%) in ferric citrate and sevelamer carbonate group.

CONCLUSION

Ferric citrate capsules have good efficacy and safety in the control of hyperphosphatemia in adult patients with CKD undergoing hemodialysis. Efficacy is not inferior to sevelamer carbonate. The TEAEs were mostly mild and tolerated by the patients.

Oral Iron Absorption of Ferric Citrate Hydrate and Hepcidin-25 in Hemodialysis Patients: A Prospective, Multicenter, Observational Riona-Oral Iron Absorption Trial

Oral ferric citrate hydrate (FCH) is effective for iron deficiencies in hemodialysis patients; however, how iron balance in the body affects iron absorption in the intestinal tract remains unclear. This prospective observational study (Riona-Oral Iron Absorption Trial, R-OIAT, UMIN 000031406) was conducted at 42 hemodialysis centers in Japan, wherein 268 hemodialysis patients without inflammation were enrolled and treated with a fixed amount of FCH for 6 months. We assessed the predictive value of hepcidin-25 for iron absorption and iron shift between ferritin (FTN) and red blood cells (RBCs) following FCH therapy. Serum iron changes at 2 h (ΔFe2h) after FCH ingestion were evaluated as iron absorption. The primary outcome was the quantitative delineation of iron variables with respect to ΔFe2h, and the secondary outcome was the description of the predictors of the body's iron balance. Generalized estimating equations (GEEs) were used to identify the determinants of iron absorption during each phase of FCH treatment. ΔFe2h increased when hepcidin-25 and TSAT decreased (-0.459, -0.643 to -0.276, p = 0.000; -0.648, -1.099 to -0.197, p = 0.005, respectively) in GEEs. FTN increased when RBCs decreased (-1.392, -1.749 to -1.035, p = 0.000) and hepcidin-25 increased (0.297, 0.239 to 0.355, p = 0.000). Limiting erythropoiesis to maintain hemoglobin levels induces RBC reduction in hemodialysis patients, resulting in increased hepcidin-25 and FTN levels. Hepcidin-25 production may prompt an iron shift from RBC iron to FTN iron, inhibiting iron absorption even with continued FCH intake.

Ferric citrate for the treatment of hyperphosphatemia and anemia in patients with chronic kidney disease: a meta-analysis of randomized clinical trials

BACKGROUND

Hyperphosphatemia and anemia, which are common complications of chronic kidney disease (CKD), can independently contribute to cardiovascular events. Several previous studies have found that the iron-based phosphate binder, ferric citrate (FC), could be beneficial to both hyperphosphatemia and anemia.

METHODS

Relevant literature from PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials (CCRCT) and MEDLINE databases were searched up to 21 February 2022, in order to conduct a meta-analysis to investigate the efficacy, safety and economic benefits of ferric citrate treatment in CKD patients with hyperphosphatemia and anemia. The meta-analysis was conducted independently by two reviewers using the RevMan software (version 5.3).

RESULTS

In total, this study included 16 randomized clinical trials (RCT) involving 1754 participants. The meta-analysis showed that ferric citrate could significantly reduce the serum phosphorus in CKD patients compared to the placebo control groups (MD -1.76 mg/dL, 95% CI (-2.78, -0.75); p = 0.0007). In contrast, the difference between ferric citrate treatment and active controls, such as non-iron-based phosphate binders, sevelamer, calcium carbonate, lanthanum carbonate and sodium ferrous citrate, was not statistically significant (MD - 0.09 mg/dL, 95% CI (-0.35, 0.17); p = 0.51). However, ferric citrate could effectively improve hemoglobin levels when compared to the active drug (MD 0.43 g/dL, 95% CI (0.04, 0.82); p = 0.03) and placebo groups (MD 0.39 g/dL, 95% CI (0.04, 0.73); p = 0.03). According to eight studies, ferric citrate was found to be cost-effective treatment in comparison to control drugs. Most of the adverse events (AE) following ferric citrate treatment were mild at most.

CONCLUSION

Collectively, our review suggests that iron-based phosphate binder, ferric citrate is an effective and safe treatment option for CKD patients with hyperphosphatemia and anemia. More importantly, this alternative treatment may also less expensive. Nevertheless, more scientific studies are warranted to validate our findings.

High-Dose Intravenous Iron with Either Ferric Carboxymaltose or Ferric Derisomaltose: A Benefit-Risk Assessment

The intravenous iron formulations ferric carboxymaltose (FCM) and ferric derisomaltose (FDI) offer the possibility of administering a large amount of iron in one infusion. This results in faster correction of anemia and the formulations being better tolerated than oral iron formulations. This triad of logistic advantages, improved patient convenience, and fast correction of anemia explains the fact that intravenous iron formulations nowadays are frequently prescribed worldwide in the treatment of iron deficiency anemia. However, these formulations may result in hypophosphatemia by inducing a strong increase in active fibroblast growth factor-23 (FGF-23), a hormone that stimulates renal phosphate excretion. This effect is much more pronounced with FCM than with FDI, and therefore the risk of developing hypophosphatemia is remarkably higher with FCM than with FDI. Repeated use of FCM may result in severe osteomalacia, which is characterized by bone pain, Looser zones (pseudofractures), and low-trauma fractures. Intravenous iron preparations are also associated with other adverse effects, of which hypersensitivity reactions are the most important and are usually the result of a non-allergic complement activation on nanoparticles of free labile iron-Complement Activation-Related Pseudo-Allergy (CARPA). The risk on these hypersensitivity reactions can be reduced by choosing a slow infusion rate. Severe hypersensitivity reactions were reported in < 1% of prospective trials and the incidence seems comparable between the two formulations. A practical guideline has been developed based on baseline serum phosphate concentrations and predisposing risk factors, derived from published cases and risk factor analyses from trials, in order to establish the safe use of these formulations.

Effects of ferric citrate and intravenous iron sucrose on markers of mineral, bone, and iron homeostasis in a rat model of CKD-MBD

BACKGROUND

Anemia and chronic kidney disease-mineral and bone disorder (CKD-MBD) are common and begin early in CKD. Limited studies have concurrently compared the effects of ferric citrate (FC) versus intravenous (IV) iron on CKD-MBD and iron homeostasis in moderate CKD.

METHODS

We tested the effects of 10 weeks of 2% FC versus IV iron sucrose in rats with moderate CKD (Cy/+ male rat) and untreated normal (NL) littermates. Outcomes included a comprehensive assessment of CKD-MBD, iron homeostasis and oxidative stress.

RESULTS

CKD rats had azotemia, elevated phosphorus, parathyroid hormone and fibroblast growth factor-23 (FGF23). Compared with untreated CKD rats, treatment with FC led to lower plasma phosphorus, intact FGF23 and a trend (P = 0.07) toward lower C-terminal FGF23. FC and IV iron equally reduced aorta and heart calcifications to levels similar to NL animals. Compared with NL animals, CKD animals had higher bone turnover, lower trabecular volume and no difference in mineralization; these were unaffected by either iron treatment. Rats treated with IV iron had cortical and bone mechanical properties similar to NL animals. FC increased the transferrin saturation rate compared with untreated CKD and NL rats. Neither iron treatment increased oxidative stress above that of untreated CKD.

CONCLUSIONS

Oral FC improved phosphorus homeostasis, some iron-related parameters and the production and cleavage of FGF23. The intermittent effect of low-dose IV iron sucrose on cardiovascular calcification and bone should be further explored in moderate-advanced CKD.

Erythropoiesis-independent effects of iron in chronic kidney disease

Chronic kidney disease (CKD) leads to alterations of iron metabolism, which contribute to the development of anemia and necessitates iron supplementation in patients with CKD. Elevated hepcidin accounts for a significant iron redistribution in CKD. Recent data indicate that these alterations in iron homeostasis coupled with therapeutic iron supplementation have pleiotropic effects on many organ systems in patients with CKD, far beyond the traditional hematologic effects of iron; these include effects of iron on inflammation, oxidative stress, kidney fibrosis, cardiovascular disease, CKD-mineral and bone disorder, and skeletal growth in children. The effects of iron supplementation appear to be largely dependent on the route of administration and on the specific iron preparation. Iron-based phosphate binders exemplify the opportunity for using iron for both traditional (anemia) and novel (hyperphosphatemia) indications. Further optimization of iron therapy in patients with CKD may inform new approaches to the treatment of CKD complications and potentially allow modification of disease progression.

The ins and outs of ferric citrate

Ferric citrate is used clinically for the treatment of hyperphosphatemia in patients with chronic kidney disease and is approved as an oral iron replacement product for patients with iron-deficiency anemia. In this issue of Kidney International, Hanudel and colleagues take advantage of genetic models with and without chronic kidney injury to demonstrate that the enteric absorption of iron delivered by ferric citrate is dependent on ferroportin expression and does not involve paracellular iron transport.

An update on phosphate binders for the treatment of hyperphosphatemia in chronic kidney disease patients on dialysis: a review of safety profiles

INTRODUCTION

Hyperphosphatemia is an inevitable complication for patients undergoing dialysis, as is the resulting need for treatment with phosphate binders. Currently, various phosphate binders are clinically available. In addition to their phosphate-lowering activity, individual phosphate binders have differing safety profiles and off-target actions.

AREAS COVERED

This paper reviews the safety of phosphate binders and issues to be resolved.

EXPERT OPINION

Calcium-based phosphate binders are well tolerated but may increase calcium overload risk. Sevelamer reduces serum cholesterol levels and exerts anti-inflammatory effects. Compared to sevelamer, bixalomer is associated with fewer gastrointestinal symptoms. Aluminum-containing binders, lanthanum carbonate, and sucroferric oxyhydroxide exhibit strong phosphate-lowering activity. Although ferric citrate reduces erythropoiesis-stimulating agents and intravenous iron doses, its use requires monitoring of iron metabolic markers to avoid overload. Occasionally, combined use of multiple phosphate binders can offer the advantages of each phosphate binder while minimizing their drawbacks; thus, this may be desirable according to individual patients' conditions and comorbidities. However, increased pill burden and nonadherence to phosphate binders emerge as new problems. We expect that novel therapeutic strategies will be developed to resolve these issues.

Ferric citrate hydrate is associated with a reduced cost of drugs and a smaller change in red blood cell distribution width

The ASTRIO study was a randomised, multicentre, 24-week study that compared the effects of ferric citrate hydrate (FC) and non-iron-based phosphate binders (control) on anaemia management in haemodialysis (HD) patients receiving erythropoiesis-stimulating agents (ESAs). In that study, FC reduced the doses of ESAs and intravenous iron without affecting haemoglobin (Hb); however, the cost-effectiveness of FC was unclear. We retrospectively implemented a cost-effectiveness analysis comparing the incremental cost-effectiveness ratios (ICERs) in FC (n = 42) and control (n = 40) groups in patients with serum phosphate and Hb controlled within the ranges of 3.5–6.0 mg/dL and 10–12 g/dL, respectively. Costs included drug costs of phosphate binders, ESAs, and intravenous iron. Elevated red cell distribution width (RDW) has been reported to be associated with mortality in HD patients and was therefore used as an effectiveness index. The mean (95% confidence interval) differences in drug costs and RDW between the FC and control groups were US$ − 421.36 (− 778.94 to − 63.78, p = 0.02) and − 0.83% (− 1.61 to – 0.05, p = 0.04), respectively. ICER indicated a decrease of US$ 507.66 per 1% decrease in RDW. FC was more cost-effective than non-iron-based phosphate binders. Iron absorbed via FC could promote erythropoiesis and contribute to renal anaemia treatment.

Treatment of Iron Deficiency Anemia in CKD and End-Stage Kidney Disease

Iron deficiency is common in individuals with chronic kidney disease and plays a major role in the development of anemia. Oral and intravenous iron agents are both available to replete iron in patients with chronic kidney disease diagnosed with iron deficiency. The choice of which agent to use is most often dictated by goals of therapy, tolerability, convenience, and response to prior therapy. Diminished absorption of iron in the gastrointestinal tract and a high incidence of gastrointestinal adverse effects can reduce the efficacy of oral iron agents, necessitating the use of i.v. iron formulations to treat iron deficiency anemia, particularly in patients requiring kidney replacement therapy. Newer oral agents may help to overcome these limitations and help treat iron deficiency in those not requiring kidney replacement therapy. Recent studies have provided new evidence that more aggressive repletion of iron in patients with chronic kidney disease requiring kidney replacement therapy may provide benefits with respect to anemia management and hard clinical outcomes such as cardiovascular disease and survival.

Phosphate and fibroblast growth factor 23 in diabetes

Diabetes is associated with a strongly elevated risk of cardiovascular disease, which is even more pronounced in patients with diabetic nephropathy. Currently available guideline-based efforts to correct traditional risk factors are only partly able to attenuate this risk, underlining the urge to identify novel treatment targets. Emerging data point towards a role for disturbances in phosphate metabolism in diabetes. In this review, we discuss the role of phosphate and the phosphate-regulating hormone fibroblast growth factor 23 (FGF23) in diabetes. We address deregulations of phosphate metabolism in patients with diabetes, including diabetic ketoacidosis. Moreover, we discuss potential adverse consequences of these deregulations, including the role of deregulated phosphate and glucose as drivers of vascular calcification propensity. Finally, we highlight potential treatment options to correct abnormalities in phosphate and FGF23. While further studies are needed to more precisely assess their clinical impact, deregulations in phosphate and FGF23 are promising potential target in diabetes and diabetic nephropathy.

Long-term efficacy and safety of iron-based phosphate binders, ferric citrate hydrate and sucroferric oxyhydroxide, in hemodialysis patients

PURPOSE

Iron-based phosphate binders, including ferric citrate hydrate (FCH) and sucroferric oxyhydroxide (SFOH), have been used for the treatment of hyperphosphatemia in end-stage renal disease patients on dialysis. However, the long-term efficacy and safety of these agents have not yet been clearly elucidated.

METHODS

Laboratory data of 56 hemodialysis patients who had been prescribed either FCH (n = 33) or SFOH (n = 23) were retrospectively examined.

RESULTS

We showed that both FCH and SFOH significantly and consistently decreased serum phosphate concentrations in the patients undergoing maintenance hemodialysis during the 36-month observation period. Serum levels of calcium, intact parathyroid hormone, as well as hemoglobin levels were unaltered. No overshoot of parameters of iron metabolism, such as transferrin saturation and serum ferritin levels, was observed, and serum ferritin level remained under 300 ng/mL in most patients. A trend towards decrease in the doses of erythropoiesis-stimulating agents used and frequency of intravenous iron use was observed in both treatment groups. No severe adverse drug reactions were observed in either the patients receiving FCH or SFOH.

CONCLUSION

The results of the present study suggest that the iron-based phosphate binders, FCH and SFOH, decrease serum phosphate concentrations consistently and are safe to use over the long-term in maintenance hemodialysis patients.

Anemia in Chronic Kidney Disease: From Pathophysiology and Current Treatments, to Future Agents

Anemia is a common complication in chronic kidney disease (CKD), and is associated with a reduced quality of life, and an increased morbidity and mortality. The mechanisms involved in anemia associated to CKD are diverse and complex. They include a decrease in endogenous erythropoietin (EPO) production, absolute and/or functional iron deficiency, and inflammation with increased hepcidin levels, among others. Patients are most commonly managed with oral or intravenous iron supplements and with erythropoiesis stimulating agents (ESA). However, these treatments have associated risks, and sometimes are insufficiently effective. Nonetheless, in the last years, there have been some remarkable advances in the treatment of CKD-related anemia, which have raised great expectations. On the one hand, a novel family of drugs has been developed: the hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs). These agents induce, among other effects, an increase in the production of endogenous EPO, improve iron availability and reduce hepcidin levels. Some of them have already received marketing authorization. On the other hand, recent clinical trials have elucidated important aspects of iron supplementation, which may change the treatment targets in the future. This article reviews the current knowledge of the pathophysiology CKD-related anemia, current and future therapies, the trends in patient management and the unmet goals.

Intestinal Chelators, Sorbants, and Gut-Derived Uremic Toxins

Chronic kidney disease (CKD) is a highly prevalent condition and is associated with a high comorbidity burden, polymedication, and a high mortality rate. A number of conventional and nonconventional risk factors for comorbidities and mortality in CKD have been identified. Among the nonconventional risk factors, uremic toxins are valuable therapeutic targets. The fact that some uremic toxins are gut-derived suggests that intestinal chelators might have a therapeutic effect. The phosphate binders used to prevent hyperphosphatemia in hemodialysis patients act by complexing inorganic phosphate in the gastrointestinal tract but might conceivably have a nonspecific action on gut-derived uremic toxins. Since phosphorous is a major nutrient for the survival and reproduction of bacteria, changes in its intestinal concentration may impact the gut microbiota’s activity and composition. Furthermore, AST-120 is an orally administered activated charcoal adsorbent that is widely used in Asian countries to specifically decrease uremic toxin levels. In this narrative review, we examine the latest data on the use of oral nonspecific and specific intestinal chelators to reduce levels of gut-derived uremic toxins.

Iron Therapy in Chronic Kidney Disease: Days of Future Past

Anemia affects millions of patients with chronic kidney disease (CKD) and prompt iron supplementation can lead to reductions in the required dose of erythropoiesis-stimulating agents, thereby reducing medical costs. Oral and intravenous (IV) traditional iron preparations are considered far from ideal, primarily due to gastrointestinal intolerability and the potential risk of infusion reactions, respectively. Fortunately, the emergence of novel iron replacement therapies has engendered a paradigm shift in the treatment of iron deficiency anemia in patients with CKD. For example, oral ferric citrate is an efficacious and safe phosphate binder that increases iron stores to maintain hemoglobin levels. Additional benefits include reductions in fibroblast growth factor 23 levels and the activation of 1,25 dihydroxyvitamin D. The new-generation IV iron preparations ferumoxytol, iron isomaltoside 1000, and ferric carboxymaltose are characterized by a reduced risk of infusion reactions and are clinically well tolerated as a rapid high-dose infusion. In patients undergoing hemodialysis (HD), ferric pyrophosphate citrate (FPC) administered through dialysate enables the replacement of ongoing uremic and HD-related iron loss. FPC transports iron directly to transferrin, bypassing the reticuloendothelial system and avoiding iron sequestration. Moreover, this paper summarizes recent advancements of hypoxia-inducible factor prolyl hydroxylase inhibitors and future perspectives in renal anemia management.

Iron kinetics following treatment with sucroferric oxyhydroxide or ferric citrate in healthy rats and models of anaemia, iron overload or inflammation

Background

The iron-based phosphate binders, sucroferric oxyhydroxide (SFOH) and ferric citrate (FC), effectively lower serum phosphorus in clinical studies, but gastrointestinal iron absorption from these agents appears to differ. We compared iron uptake and tissue accumulation during treatment with SFOH or FC using experimental rat models.

Methods

Iron uptake was evaluated during an 8-h period following oral administration of SFOH, FC, ferrous sulphate (oral iron supplement) or control (methylcellulose vehicle) in rat models of anaemia, iron overload and inflammation. A 13-week study evaluated the effects of SFOH and FC on iron accumulation in different organs.

Results

In the pharmacokinetic experiments, there was a minimal increase in serum iron with SFOH versus control during the 8-h post-treatment period in the iron overload and inflammation rat models, whereas a moderate increase was observed in the anaemia model. Significantly greater increases (P < 0.05) in serum iron were observed with FC versus SFOH in the rat models of anaemia and inflammation. In the 13-week iron accumulation study, total liver iron content was significantly higher in rats receiving FC versus SFOH (P < 0.01), whereas liver iron content did not differ between rats in the SFOH and control groups.

Conclusions

Iron uptake was higher from FC versus SFOH following a single dose in anaemia, iron overload and inflammation rat models and 13 weeks of treatment in normal rats. These observations likely relate to different physicochemical properties of SFOH and FC and suggest distinct mechanisms of iron absorption from these two phosphate binders.

Ferric citrate in the management of hyperphosphataemia and iron deficiency anaemia: A meta-analysis in patients with chronic kidney disease

AIMS

Phosphate-lowering effects of ferric citrate were reported in several clinical trials, but mostly in small-scale studies. The aim of this meta-analysis was to investigate the efficacy and safety of ferric citrate in controlling hyperphosphataemia and iron-deficiency anaemia in chronic kidney disease (CKD) patients.

METHODS

PubMed, Embase and Cochrane Library were searched for clinical trials that enrolled CKD patients receiving ferric citrate for hyperphosphataemia. Two investigators performed systematic literature search to identify eligible studies, evaluated risk of bias and extracted relevant data.

RESULTS

Sixteen studies were included in the meta-analysis. Phosphate-lowering effects of ferric citrate were greater compared to no active treatment (standardized mean difference [SMD] = -1.15; P < 0.001) and comparable to other phosphate binders (SMD = 0.03; P = 0.61). Calcium concentrations post ferric citrate treatment did not differ compared to no active treatment (SMD = 0.15; P = 0.21) but were significantly lower compared to other phosphate binders (SMD = -0.14; P = 0.01). These led to significant reductions in calcium-phosphorus product with ferric citrate versus no active control (SMD = -1.02; P < 0.001) but no difference versus active control (SMD = -0.01; P = 0.93). Intact parathyroid hormone showed no substantial between-group difference in both comparison against no active and active controls. Ferric citrate improved iron stores and anaemia parameters, but increased risk of diarrhoea, abdominal pain and discoloured faeces.

CONCLUSION

Ferric citrate was effective in lowering phosphorus and phosphorus-calcium product versus no active treatment and had comparable effects versus other phosphate binders. Calcium levels were significantly lower with ferric citrate than with other phosphate-lowering treatment. Ferric citrate had additive effects on iron repletion and anaemia control and was associated with mostly gastrointestinal side effects.

Iron Deficiency in Chronic Kidney Disease: Updates on Pathophysiology, Diagnosis, and Treatment

Anemia is a complication that affects a majority of individuals with advanced CKD. Although relative deficiency of erythropoietin production is the major driver of anemia in CKD, iron deficiency stands out among the mechanisms contributing to the impaired erythropoiesis in the setting of reduced kidney function. Iron deficiency plays a significant role in anemia in CKD. This may be due to a true paucity of iron stores (absolute iron deficiency) or a relative (functional) deficiency which prevents the use of available iron stores. Several risk factors contribute to absolute and functional iron deficiency in CKD, including blood losses, impaired iron absorption, and chronic inflammation. The traditional biomarkers used for the diagnosis of iron-deficiency anemia (IDA) in patients with CKD have limitations, leading to persistent challenges in the detection and monitoring of IDA in these patients. Here, we review the pathophysiology and available diagnostic tests for IDA in CKD, we discuss the literature that has informed the current practice guidelines for the treatment of IDA in CKD, and we summarize the available oral and intravenous (IV) iron formulations for the treatment of IDA in CKD. Two important issues are addressed, including the potential risks of a more liberal approach to iron supplementation as well as the potential risks and benefits of IV versus oral iron supplementation in patients with CKD.

Regulation and Effects of FGF23 in Chronic Kidney Disease

Chronic kidney disease (CKD) is a global health epidemic that accelerates cardiovascular disease, increases risk of infection, and causes anemia and bone disease, among other complications that collectively increase risk of premature death. Alterations in calcium and phosphate homeostasis have long been considered nontraditional risk factors for many of the most morbid outcomes of CKD. The discovery of fibroblast growth factor 23 (FGF23), which revolutionized the diagnosis and treatment of rare hereditary disorders of FGF23 excess that cause hypophosphatemic rickets, has also driven major paradigm shifts in our understanding of the pathophysiology and downstream end-organ complications of disordered mineral metabolism in CKD. As research of FGF23 in CKD has rapidly advanced, major new questions about its regulation and effects continuously emerge. These are promoting exciting innovations in laboratory, patient-oriented, and epidemiological research and stimulating clinical trials of new therapies and repurposing of existing ones to target FGF23.

Controversies in the Management of Secondary Hyperparathyroidism in Chronic Kidney Disease

Secondary hyperparathyroidism is a frequent complication of chronic kidney disease that begins early in the course of renal insufficiency as an adaptive response to maintain mineral homeostasis. This complex disorder affects the bone, leading to an increase in fracture risk and is associated with increased risks of vascular calcification and mortality. PURPOSE OF REVIEW: In this review, we examine the different strategies available to manage secondary hyperparathyroidism. Particularly, we focus on the adequate control of serum phosphorus by restricting intake and the use of phosphate binders, correction of hypocalcemia while minimizing calcium burden, and reduction in PTH levels through the use of vitamin D sterols and calcimimetics. RECENT FINDINGS: It was observed that although numerous agents directed at the correction of these abnormalities have demonstrated effectiveness on biochemical markers, there is still a relative scarcity of studies demonstrating treatment effectiveness as measured by hard clinical outcomes. In addition, most agents have side effects that may limit their use, even in patients in which the treatment has demonstrated efficacy in controlling these parameters. There is still controversy as to what therapeutic regimens to choose for a particular patient and what parameter should be used to follow their effects, including outcomes, side effects, pill burden, and costs, among others. In the present article, we analyze controversial aspects of the different therapeutic agents available. Although many tools and regimens are available, no one by itself is enough for an adequate management of the patient. But rather, combined therapy and individualization of approaches are recommended for better results. We suggest that new studies analyzing the effectiveness of therapeutic approaches to the management of secondary hyperparathyroidism should be directed not only to controlling parathyroid hormone levels but also to the evaluation of long-term outcomes, based on modification of morbidity, mortality, and end organ impact, while reducing side effects and controlling costs, among others.

Infectious complications and mortality associated with the use of IV iron therapy: a systematic review and meta-analysis

BACKGROUND

Parental iron is used to optimize hemoglobin and enhance erythropoiesis in end-stage renal disease along with erythropoietin-stimulating agents. Safety of iron has been debated extensively and there is no definite evidence whether parenteral iron increases the risk of infections and mortality. We performed this meta-analysis to evaluate the incidence of infectious complications, hospitalizations and mortality with use of parenteral iron.

METHODS

Medical electronic databases [PubMed, EMBASE, Scopus, Web of Science, and cochrane central register for controlled clinical trials (CENTRAL)] were queried for studies that investigated the association between intravenous iron administration and infection in hemodialysis patients. 24 studies (8 Randomized control trials (RCTs) and 16 observational studies) were considered for qualitative and quantitative analysis.

RESULTS

All-cause mortality Data from 6 RCTs show that high-dose IV iron conferred 17% less all-cause mortality compared to controls; however, this outcome was not statistically significant (OR = 0.83, CI [0.7, 1.01], p = 0.07). Nine observational studies were pooled under the random effects model due to significant heterogeneity (I² = 83%, p < 0.001). The overall HR showed increased risk of all-cause mortality in the high-dose group but was statistically non-significant (HR = 1.1, CI [1, 1.22], p = 0.06). Infections Four RCTs with no heterogeneity among their data (I² = 0%, p = 0.61). Under the fixed effect model, there was no difference in the infection rate between high-dose iron and control group (OR = 0.97, CI [0.82, 1.16], p = 0.77); eight observational studies with significant heterogeneity and utilizing random effects model. Summary HR showed increased yet non-significant risk of infection in the high-dose group (HR = 1.13, CI [0.99, 1.28], p = 0.07) Hospitalization 1 RCT and six observational studies provided data for the rate of all-cause hospitalization. There was marked heterogeneity among observational studies. RCT showed no significant difference between high-dose iron and controls in the rate of hospitalization (OR = 1.03, CI [0.87, 1.23], p = 0.71). Summary HR for observational data showed increased rate of hospitalization in the high-dose group; however, this effect was not statistically significant (HR = 1.11, CI [0.99, 1.24], p = 0.07). Cardiovascular events One RCT compared the rate of adverse cardiovascular events between high-dose and low-dose iron. No significant difference was observed between the two groups (22.3% vs 25.6%, p = 0.12). Six heterogeneous observational studies (I² = 65%, p < 0.001) reported on the rate of cardiovascular events. No significant difference was observed between high-dose iron and controls (HR = 1.18, CI [0.89, 1.57], p = 0.24).

CONCLUSION

High-dose parenteral iron does not seem to be associated with higher risk of infection, all-cause mortality, increased hospitalization or increased cardiovascular events on analysis of RCTs. Observational studies show increased risk for all-cause mortality, infections and hospitalizations that were not statistically significant and were associated with significant heterogeneity.

Ferric citrate reduces fibroblast growth factor 23 levels and improves renal and cardiac function in a mouse model of chronic kidney disease

Iron deficiency, anemia, hyperphosphatemia, and increased fibroblast growth factor 23 (FGF23) are common and interrelated complications of chronic kidney disease (CKD) that are linked to CKD progression, cardiovascular disease and death. Ferric citrate is an oral phosphate binder that decreases dietary phosphate absorption and serum FGF23 concentrations while increasing iron stores and hemoglobin in patients with CKD. Here we compared the effects of ferric citrate administration versus a mineral sufficient control diet using the Col4a3 knockout mouse model of progressive CKD and age-matched wild-type mice. Ferric citrate was given to knockout mice for four weeks beginning at six weeks of age when they had overt CKD, or for six weeks beginning at four weeks of age when they had early CKD. Ten-week-old knockout mice on the control diet showed overt iron deficiency, anemia, hyperphosphatemia, increased serum FGF23, hypertension, decreased kidney function, and left ventricular systolic dysfunction. Ferric citrate rescued iron deficiency and anemia in knockout mice regardless of the timing of treatment initiation. Circulating levels and bone expression of FGF23 were reduced in knockout mice given ferric citrate with more pronounced reductions observed when ferric citrate was initiated in early CKD. Ferric citrate decreased serum phosphate only when it was initiated in early CKD. While ferric citrate mitigated systolic dysfunction in knockout mice regardless of timing of treatment initiation, early initiation of ferric citrate also reduced renal fibrosis and proteinuria, improved kidney function, and prolonged life span. Thus, initiation of ferric citrate treatment early in the course of murine CKD lowered FGF23, slowed CKD progression, improved cardiac function and significantly improved survival.

Anemia and iron deficiency among chronic kidney disease Stages 3-5ND patients in the Chronic Kidney Disease Outcomes and Practice Patterns Study: often unmeasured, variably treated

Background

International variation in anemia assessment and management practices in chronic kidney disease (CKD) is poorly understood.

Methods

We performed a cross-sectional analysis of anemia laboratory monitoring, prevalence and management in the prospective Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps). A total of 6766 participants with CKD Stages 3a–5ND from nephrology clinics in Brazil, France, Germany and the USA were included.

Results

Among patients with anemia (hemoglobin <12 g/dL), 36–58% in Brazil, the USA and Germany had repeat hemoglobin measured and 40–61% had iron indices measured within 3 months of the index hemoglobin measurement. Anemia was more common in the USA and Brazil than in France and Germany across CKD stages. Higher ferritin and lower iron saturation (TSAT) levels were observed with lower hemoglobin levels, and higher ferritin with more advanced CKD. The proportion of anemic patients with ferritin <100 ng/mL or TSAT <20% ranged from 42% in Brazil to 53% in France and Germany, and of these patients, over 40% in Brazil, Germany and the USA, compared with 27% in France, were treated with oral or intravenous iron within 3 months after hemoglobin measurement. The proportion of patients with hemoglobin <10 g/dL treated with erythropoiesis-stimulating agents ranged from 28% in the USA to 57% in Germany.

Conclusions

Hemoglobin and iron stores are measured less frequently than per guidelines. Among all regions, there was a substantial proportion of anemic patients with iron deficiency who were not treated with iron, highlighting an area for practice improvement in CKD care.

Strategies for Phosphate Control in Patients With CKD

Hyperphosphatemia is a common complication in patients with chronic kidney disease (CKD), particularly in those requiring renal replacement therapy. The importance of controlling serum phosphate has long been recognized based on observational epidemiological studies that linked increased phosphate levels to adverse outcomes and higher mortality risk. Experimental data further supported the role of phosphate in the development of bone and cardiovascular diseases. Recent advances in our understanding of the mechanisms involved in phosphate homeostasis have made it clear that the serum phosphate concentration depends on a complex interplay among the kidneys, intestinal tract, and bone, and is tightly regulated by a complex endocrine system. Moreover, the source of dietary phosphate and the use of phosphate-based additives in industrialized foods are additional factors that are of particular importance in CKD. Not surprisingly, the management of hyperphosphatemia is difficult, and, despite a multifaceted approach, it remains unsuccessful in many patients. An additional issue is the fact that the supposedly beneficial effect of phosphate lowering on hard clinical outcomes in interventional trials is a matter of ongoing debate. In this review, we discuss currently available treatment approaches for controlling hyperphosphatemia, including dietary phosphate restriction, reduction of intestinal phosphate absorption, phosphate removal by dialysis, and management of renal osteodystrophy, with particular focus on practical challenges and limitations, and on potential benefits and harms.

Novel Oral Iron Therapies for Iron Deficiency Anemia in Chronic Kidney Disease

Iron deficiency anemia (IDA) is a frequent complication of chronic kidney disease (CKD) and is associated with adverse outcomes in these patients. Patients with CKD and IDA remain largely undertreated. Conventional oral iron agents are insufficiently effective due to poor absorption and cause gastrointestinal side effects; thus, novel oral iron preparations are needed. This article covers current treatment guidelines for patients with anemia and CKD and clinical trial data for iron-repletion agents currently in use, as well as for novel oral iron therapies in development. Ferric citrate, a novel oral iron-repletion agent approved for patients with non-dialysis-dependent CKD and IDA, demonstrated improvements in hemoglobin levels and iron parameters, with good tolerability in patients with non-dialysis-dependent CKD. When used as a phosphate binder, ferric citrate also improves hemoglobin and iron parameters in dialysis-dependent CKD, but additional trials are needed to evaluate its efficacy as an iron-repletion agent in this setting. Other novel oral iron preparations in development for IDA in patients with CKD include ferric maltol, which is approved in Europe and the United States for IDA in adult patients, and sucrosomial iron, which has been evaluated in IDA associated with CKD and several other clinical settings.

Randomised clinical trial of ferric citrate hydrate on anaemia management in haemodialysis patients with hyperphosphataemia: ASTRIO study

Ferric citrate hydrate (FC) is an iron-based phosphate binder approved for hyperphosphataemia in patients with chronic kidney disease. We conducted a randomised controlled trial to evaluate the effects of FC on anaemia management in haemodialysis patients with hyperphosphataemia. We 1:1 randomised 93 patients who were undergoing haemodialysis and being treated with non-iron-based phosphate binders and erythropoiesis-stimulating agents (ESA) to receive 24 weeks of FC or to continue their non-iron-based phosphate binders (control) in a multicentre, open-label, parallel-design. Phosphate level was controlled within target range (3.5–6.0 mg/dL). The primary endpoint was change in ESA dose from baseline to end of treatment. Secondary endpoints were changes in red blood cell, iron and mineral, and bone-related parameters. Compared with control, FC reduced ESA dose [mean change (SD), −1211.8 (3609.5) versus +1195 (6662.8) IU/week; P = 0.03] without significant differences in haemoglobin. FC decreased red blood cell distribution width (RDW) compared with control. While there were no changes in serum phosphate, FC reduced C-terminal fibroblast growth factor (FGF) 23 compared with control. The incidence of adverse events did not differ significantly between groups. Despite unchanged phosphate and haemoglobin levels, FC reduced ESA dose, RDW, and C-terminal FGF23 compared with control.

Mechanism of Action and Clinical Attributes of Auryxia® (Ferric Citrate)

Chronic kidney disease (CKD) is a major cause of morbidity and premature mortality and represents a significant global public health issue. Underlying this burden are the many complications of CKD, including mineral and bone disorders, anemia, and accelerated cardiovascular disease. Hyperphosphatemia and elevated levels of fibroblast growth factor 23 (FGF23) have been identified as key independent risk factors for the adverse cardiovascular outcomes that frequently occur in patients with CKD. Auryxia® (ferric citrate; Keryx Biopharmaceuticals, Inc., Boston, MA, USA) is an iron-based compound with distinctive chemical characteristics and a mechanism of action that render it dually effective as a therapy in patients with CKD; it has been approved as a phosphate binder for the control of serum phosphate levels in adult CKD patients treated with dialysis and as an iron replacement product for the treatment of iron deficiency anemia in adult CKD patients not treated with dialysis. This review focuses on Auryxia, its mechanism of action, and the clinical attributes that differentiate it from other, non-pharmaceutical-grade, commercially available forms of ferric citrate and from other commonly used phosphate binder and iron supplement therapies for patients with CKD. Consistent with the chemistry and mechanism of action of Auryxia, multiple clinical studies have demonstrated its efficacy in both lowering serum phosphate levels and improving iron parameters in patients with CKD. Levels of FGF23 decrease significantly with Auryxia treatment, but the effects associated with the cardiovascular system remain to be evaluated in longer-term studies.

Regional prescription surveillance of phosphate binders in the western Saitama area: the substantial role of ferric citrate hydrate in improving serum phosphorus levels and erythropoiesis

BACKGROUND

In April 2015, five types of phosphate binders (PBs) were available by prescription in Japan, namely calcium carbonate, sevelamer hydrochloride, lanthanum carbonate, bixalomer, and ferric citrate hydrate (FeC). FeC reduces serum phosphorus levels and increases the body's iron stores. However, it is unclear whether FeC lowers serum phosphorus relative to other agents in a regional practical setting.

METHODS

We performed a retrospective observational cohort study of regional hemodialysis surveillance in the western Saitama area of Japan, which included 1374 hemodialysis patients enrolled from 32 satellite dialysis units. The clinical data and prescribing information were retrospectively collected and analyzed. The difference in serum phosphorus among the groups administered five types of PBs (new or additional) from April to September 2015 was the primary outcome.

RESULTS

As of April 2015, the median values of serum phosphorus, corrected calcium, and intact parathyroid hormone were 5.4 mg/dL, 9.1 mg/dL, and 147 pg/dL, respectively (N = 1374). Unexpectedly, with an increase in the number of PBs administered, serum phosphorous levels increased (p < 0.001). The significant changes in the serum phosphorus and hemoglobin levels were associated with the prescription of FeC but not with that of the other PBs.

CONCLUSIONS

This regional survey suggests that serum phosphorus is well managed and that FeC has the potential to reduce the serum phosphorus level relative to other PBs and to ameliorates anemia.

Phosphate Binder, Ferric Citrate, Attenuates Anemia, Renal Dysfunction, Oxidative Stress, Inflammation, and Fibrosis in 5/6 Nephrectomized CKD Rats

Chronic kidney disease (CKD) causes anemia and impairs intestinal iron absorption. However, use of the phosphate binder ferric citrate (FC) increases body iron stores and hemoglobin levels in CKD patients. By intensifying oxidative stress and inflammation iron overload resulting from excessive use of intravenous iron can accelerate CKD progression. The present study explored the route of absorption and tissue distribution of iron with FC administration and its effect on renal function, histology, and inflammatory, oxidative, and fibrosis pathways in CKD rats. Male Sprague Dawley rats were randomized to sham-operated control (CTL) group and 5/6 nephrectomized (CKD) groups fed either regular or 4% FC-supplemented diets for 6 weeks. Animals were then sacrificed, and blood and target tissues were harvested and processed. The untreated CKD rats exhibited anemia, hypertension, upregulation of renal tissue inflammatory, oxidative, and fibrotic pathways, impaired nuclear translocation, and downregulation of Nrf2's target gene products and depletion of colonic epithelial tight junction proteins. FC administration raised serum iron, improved anemia, attenuated hyperphosphatemia, partially improved renal function, reduced oxidative stress, inflammation, and fibrosis, and restored colonic epithelial zonula occludens-1 protein abundance. Tissue iron staining detected presence of iron in epithelial cells and subepithelium of colon and in renal proximal tubules. In conclusion ferric citrate administration resulted in modest amelioration of renal function and histology and partial improvements of fibrosis, inflammation, and oxidative stress in the kidney tissues of CKD rats.

Evaluation of changes in ferritin levels during sucroferric oxyhydroxide treatment

Background

A sub-analysis of a Phase III study was conducted to identify factors that might predict increased ferritin levels during long-term sucroferric oxyhydroxide (SO) treatment in hemodialysis patients.

Methods

The open-label, multicenter, Phase III study assessed the efficacy and safety of SO 750–3000 mg/day for 52 weeks in Japanese patients with chronic renal failure and hyperphosphatemia. A total of 125 of 161 patients from the Phase III trial, and who had data for ferritin levels after 28 weeks of SO treatment, were evaluated.

Results

Baseline ferritin was the strongest contributor (P < 0.0001) to ferritin increases during SO treatment. By Week 28, there were significant differences (P < 0.05/3) in ferritin increases between patients with higher [quartile 4 (Q4)] versus lower (Q1, Q2 and Q3) baseline ferritin. An erythropoiesis-stimulating agent dosage reduction was observed in patients with the lowest baseline ferritin level (Q1), and only slight reductions were noted in the other patient subsets. SO dosages administered to patients in baseline ferritin quartiles Q2, Q3 and Q4 were comparable throughout the study with slight fluctuations. SO dosages in Q1 were considerably lower than those in the other quartiles.

Conclusions

In summary, of the baseline variables found to predict increased ferritin, and changes in iron-related parameters, during SO treatment in Japanese chronic kidney disease patients undergoing hemodialysis, baseline ferritin was the most relevant variable.

Phosphate binders for preventing and treating chronic kidney disease-mineral and bone disorder (CKD-MBD)

BACKGROUND

Phosphate binders are used to reduce positive phosphate balance and to lower serum phosphate levels for people with chronic kidney disease (CKD) with the aim to prevent progression of chronic kidney disease-mineral and bone disorder (CKD-MBD). This is an update of a review first published in 2011.

OBJECTIVES

The aim of this review was to assess the benefits and harms of phosphate binders for people with CKD with particular reference to relevant biochemical end-points, musculoskeletal and cardiovascular morbidity, hospitalisation, and death.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 12 July 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or quasi-RCTs of adults with CKD of any GFR category comparing a phosphate binder to another phosphate binder, placebo or usual care to lower serum phosphate. Outcomes included all-cause and cardiovascular death, myocardial infarction, stroke, adverse events, vascular calcification and bone fracture, and surrogates for such outcomes including serum phosphate, parathyroid hormone (PTH), and FGF23.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies for inclusion and extracted study data. We applied the Cochrane 'Risk of Bias' tool and used the GRADE process to assess evidence certainty. We estimated treatment effects using random-effects meta-analysis. Results were expressed as risk ratios (RR) for dichotomous outcomes together with 95% confidence intervals (CI) or mean differences (MD) or standardised MD (SMD) for continuous outcomes.

MAIN RESULTS

We included 104 studies involving 13,744 adults. Sixty-nine new studies were added to this 2018 update.Most placebo or usual care controlled studies were among participants with CKD G2 to G5 not requiring dialysis (15/25 studies involving 1467 participants) while most head to head studies involved participants with CKD G5D treated with dialysis (74/81 studies involving 10,364 participants). Overall, seven studies compared sevelamer with placebo or usual care (667 participants), seven compared lanthanum to placebo or usual care (515 participants), three compared iron to placebo or usual care (422 participants), and four compared calcium to placebo or usual care (278 participants). Thirty studies compared sevelamer to calcium (5424 participants), and fourteen studies compared lanthanum to calcium (1690 participants). No study compared iron-based binders to calcium. The remaining studies evaluated comparisons between sevelamer (hydrochloride or carbonate), sevelamer plus calcium, lanthanum, iron (ferric citrate, sucroferric oxyhydroxide, stabilised polynuclear iron(III)-oxyhydroxide), calcium (acetate, ketoglutarate, carbonate), bixalomer, colestilan, magnesium (carbonate), magnesium plus calcium, aluminium hydroxide, sucralfate, the inhibitor of phosphate absorption nicotinamide, placebo, or usual care without binder. In 82 studies, treatment was evaluated among adults with CKD G5D treated with haemodialysis or peritoneal dialysis, while in 22 studies, treatment was evaluated among participants with CKD G2 to G5. The duration of study follow-up ranged from 8 weeks to 36 months (median 3.7 months). The sample size ranged from 8 to 2103 participants (median 69). The mean age ranged between 42.6 and 68.9 years.Random sequence generation and allocation concealment were low risk in 25 and 15 studies, respectively. Twenty-seven studies reported low risk methods for blinding of participants, investigators, and outcome assessors. Thirty-one studies were at low risk of attrition bias and 69 studies were at low risk of selective reporting bias.In CKD G2 to G5, compared with placebo or usual care, sevelamer, lanthanum, iron and calcium-based phosphate binders had uncertain or inestimable effects on death (all causes), cardiovascular death, myocardial infarction, stroke, fracture, or coronary artery calcification. Sevelamer may lead to constipation (RR 6.92, CI 2.24 to 21.4; low certainty) and lanthanum (RR 2.98, CI 1.21 to 7.30, moderate certainty) and iron-based binders (RR 2.66, CI 1.15 to 6.12, moderate certainty) probably increased constipation compared with placebo or usual care. Lanthanum may result in vomiting (RR 3.72, CI 1.36 to 10.18, low certainty). Iron-based binders probably result in diarrhoea (RR 2.81, CI 1.18 to 6.68, high certainty), while the risks of other adverse events for all binders were uncertain.In CKD G5D sevelamer may lead to lower death (all causes) (RR 0.53, CI 0.30 to 0.91, low certainty) and induce less hypercalcaemia (RR 0.30, CI 0.20 to 0.43, low certainty) when compared with calcium-based binders, and has uncertain or inestimable effects on cardiovascular death, myocardial infarction, stroke, fracture, or coronary artery calcification. The finding of lower death with sevelamer compared with calcium was present when the analysis was restricted to studies at low risk of bias (RR 0.50, CI 0.32 to 0.77). In absolute terms, sevelamer may lower risk of death (all causes) from 210 per 1000 to 105 per 1000 over a follow-up of up to 36 months, compared to calcium-based binders. Compared with calcium-based binders, lanthanum had uncertain effects with respect to all-cause or cardiovascular death, myocardial infarction, stroke, fracture, or coronary artery calcification and probably had reduced risks of treatment-related hypercalcaemia (RR 0.16, CI 0.06 to 0.43, low certainty). There were no head-to-head studies of iron-based binders compared with calcium. The paucity of placebo-controlled studies in CKD G5D has led to uncertainty about the effects of phosphate binders on patient-important outcomes compared with placebo.It is uncertain whether the effects of binders on clinically-relevant outcomes were different for patients who were and were not treated with dialysis in subgroup analyses.

AUTHORS' CONCLUSIONS

In studies of adults with CKD G5D treated with dialysis, sevelamer may lower death (all causes) compared to calcium-based binders and incur less treatment-related hypercalcaemia, while we found no clinically important benefits of any phosphate binder on cardiovascular death, myocardial infarction, stroke, fracture or coronary artery calcification. The effects of binders on patient-important outcomes compared to placebo are uncertain. In patients with CKD G2 to G5, the effects of sevelamer, lanthanum, and iron-based phosphate binders on cardiovascular, vascular calcification, and bone outcomes compared to placebo or usual care, are also uncertain and they may incur constipation, while iron-based binders may lead to diarrhoea.

Sucroferric oxyhydroxide for the treatment of hyperphosphatemia

INTRODUCTION

Sucroferric oxyhydroxide is a non-calcium, iron-based phosphate binder indicated for the treatment of hyperphosphatemia in patients with chronic kidney disease undergoing dialysis. Areas covered: Herein, the preclinical development and clinical data for sucroferric oxyhydroxide are reviewed, including the key data from the Phase III registration study and the latest evidence from the real-world clinical setting. Expert opinion: Sucroferric oxyhydroxide displays potent phosphate-binding capacity and clinical studies demonstrate its effectiveness for the long-term reduction of serum phosphorus levels in dialysis patients. Observational study data also show that sucroferric oxyhydroxide provides effective serum phosphorus control for hyperphosphatemic patients in the real-world clinical setting. The serum phosphorus reductions with sucroferric oxyhydroxide can be achieved with a relatively low pill burden in comparison with other phosphate binders, which may translate into better treatment adherence in clinical practice. The Phase III data also indicate that sucroferric oxyhydroxide has a favorable impact on other chronic kidney disease-related mineral bone disease parameters, including a fibroblast growth factor-23-lowering effect. Sucroferric oxyhydroxide is well tolerated and associated with low systemic iron absorption, minimizing the potential for iron accumulation or overload. These attributes render sucroferric oxyhydroxide an attractive non-calcium-containing phosphate binder for the treatment of hyperphosphatemia.

Sucroferric oxyhydroxide decreases serum phosphorus level and fibroblast growth factor 23 and improves renal anemia in hemodialysis patients

Objective

Sucroferric oxyhydroxide, a novel iron-based phosphate-binder, has been shown to have beneficial effects in lowering serum phosphorus levels and improving renal anemia in clinical studies. Although an effect of this agent on fibroblast growth factor 23 (FGF23) has been reported in an animal study, there is little clinical data supporting this finding. This study aimed to evaluate the effect on chronic kidney disease-mineral and bone disorder, FGF23, renal anemia, iron-related parameters, adverse events of sucroferric oxyhydroxide in hemodialysis patients.

Results

Hemodialysis patients, receiving existing hyperphosphatemia drugs with insufficient benefit, were administered sucroferric oxyhydroxide with/without calcium carbonate for 16 weeks. Serum phosphorus level declined rapidly in Week 8 (p < 0.0001) and this decrease persisted until Week 16 (p < 0.0001). FGF23 decreased (p = 0.0412, Week 16), and hemoglobin increased (p < 0.0001, Week 16). Cumulative dose of erythropoiesis-stimulating agents (p = 0.0122, Week 16), and intravenous iron (p = 0.0233, Week 12) decreased. All adverse reactions were mild, and diarrhea was the most frequently observed adverse reaction (16.7%). Therefore, hyperphosphatemia treatment with sucroferric oxyhydroxide may safely improve serum phosphorus level, renal anemia, FGF23, and other factors that affect the prognosis of hemodialysis patients.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3483-6) contains supplementary material, which is available to authorized users.

Anemia management in chronic kidney disease and dialysis: a narrative review

PURPOSE OF REVIEW

This review describes the current state of anemia management with erythropoietin (EPO)-stimulating agents and iron supplementation in both chronic kidney disease and dialysis patients, with a focus on novel therapies.

RECENT FINDINGS

We review the benefits and risks of EPO-stimulating agents, focusing on health-related quality of life and the uncertainties regarding optimal iron utilization in patients with kidney disease. We discuss novel therapies for iron supplementation including iron-based phosphate binders and dialysate iron delivery as well as alternatives to EPO-stimulating agents including hypoxia-inducible factor prolyl hydroxylase inhibitors.

SUMMARY

Individualization of hemoglobin targets using EPO-stimulating agents and iron supplementation may be considered in younger, healthier patients with kidney disease to improve health-related quality of life. Optimal iron utilization in kidney disease patients is unclear, but novel iron base phosphate binders and dialysate iron delivery may play a role in intravenous iron avoidance and its potential complications. Phase 3 randomized controlled trials of hypoxia-inducible factor prolyl hydroxylase inhibitors are ongoing and are promising new alternatives to EPO-stimulating agents and their known adverse effects.

Iron-related parameters in dialysis patients treated with sucroferric oxyhydroxide

Background

Sucroferric oxyhydroxide is a non-calcium, iron-based phosphate binder indicated for the treatment of hyperphosphataemia in adult dialysis patients. This post hoc analysis of a randomized, 24-week Phase 3 study and its 28-week extension was performed to evaluate the long-term effect of sucroferric oxyhydroxide on iron parameters.

Methods

A total of 1059 patients were randomized to sucroferric oxyhydroxide 1.0-3.0 g/day (n = 710) or sevelamer carbonate ('sevelamer') 2.4-14.4 g/day (n = 349) for up to 52 weeks. The current analysis only included patients who completed 52 weeks of continuous treatment (n = 549). Changes in iron-related parameters and anti-anaemic product use during the study were measured.

Results

Some changes in iron-related parameters across both treatment groups were observed during the first 24 weeks of the study, and to a lesser extent with longer-term treatment. There were small, but significantly greater increases in mean transferrin saturation (TSAT) and haemoglobin levels with sucroferric oxyhydroxide versus sevelamer during the first 24 weeks (change in TSAT: +4.6% versus +0.6%, P = 0.003; change in haemoglobin: +1.6 g/L versus -1.1 g/L, P = 0.037). Mean serum ferritin concentrations also increased from Weeks 0 to 24 with sucroferric oxyhydroxide and sevelamer (+119 ng/mL and +56.2 ng/mL respectively; no statistically significant difference between groups). In both treatment groups, ferritin concentrations increased to a greater extent in the overall study population [>70% of whom received concomitant intravenous (IV) iron], compared with the subset of patients who did not receive IV iron therapy during the study. The pattern of anti-anaemic product use was similar in both treatment groups, with a trend towards higher use of IV iron and erythropoiesis-stimulating agents with sevelamer.

Conclusions

Initial increases in some iron-related parameters were observed in both treatment groups but were more pronounced with sucroferric oxyhydroxide. These differences between treatment groups with respect to changes in iron parameters are likely due to minimal iron absorption from sucroferric oxyhydroxide.

Ferric citrate controls serum phosphorus in dialysis patients: retrospective data

Ferric citrate is an approved phosphate binder for use in patients with chronic kidney disease on dialysis. Clinical trials demonstrated that ferric citrate controlled serum phosphorus levels and increased iron stores. The aim of this retrospective chart review was to evaluate real-world bone mineral and anemia parameter data from patients treated with ferric citrate. 92 adult dialysis patients taking ferric citrate (average starting dose of 6 tablets/day) for at least 6 months were included. Bone mineral, anemia, and iron biomarker levels were extracted from patient medical records before and during the first 6 months of ferric citrate treatment; 21 (23%) patients were phosphate binder naïve, and 71 (77%) patients had been on other phosphate binders. Before starting ferric citrate, 22% of patients had serum phosphorus ≤ 5.5 mg/dL, increasing to 65% of patients at 6 months of treatment (month 6). Mean (standard error of the mean (SEM)) baseline serum phosphorus was 6.55 ± 0.17 mg/dL decreasing to 5.40 ± 0.17 mg/dL at month 6. Mean (SEM) baseline hemoglobin, ferritin, and transferrin saturation were 10.6 ± 0.2 g/dL, 734 ± 65 ng/mL, and 27.1 ± 1.6%, respectively, and 11.1 ± 0.2 g/dL, 947 ± 66 ng/mL, and 37 ± 1.9%, respectively, at month 6. The serum phosphorus and anemia biomarker levels observed in this retrospective chart review were similar to those seen in clinical trials.

Ferric Citrate Supplementation Reduces Red-Blood-Cell Aggregation and Improves CD163+ Macrophage-Mediated Hemoglobin Metabolism in a Rat Model of High-Fat-Diet-Induced Obesity

SCOPE

In adults, >90% of the daily iron requirement is derived from macrophage-mediated heme iron, recycling from senescent red blood cells (RBCs) or free hemoglobin (Hb). Currently, the effects of pharmacological doses of iron supplementation on RBCs and heme iron recycling in obesity are unclear.

METHODS AND RESULTS

Sprague Dawley rats are fed a standard diet or a 50% high-fat diet (HFD) with (0.25, 1, and 2 g of ferric iron per kg diet) or without ferric citrate supplementation for 12 weeks. Ferric iron increases hepatic iron accumulation in macrophages and hepatocyte-like cells. Compared with rats that received the standard diet, HFD-fed rats exhibit higher RBC aggregation and serum-free Hb levels but lower LVV-hemorphin-7 levels. These effects are reversed by ferric citrate supplementation. Immunofluorescent staining reveals that ferric iron increases the expression of hepatic CD163+ macrophages and heme oxygenase (HO)-1. A further analysis reveals the dose-related effects of ferric iron on hepatic globin degradation proteins (cathepsin D and glyoxalase 1), cytochrome p450 reductase expression, and HO-1 enzyme activity.

CONCLUSIONS

Ferric citrate supplementation reduces RBC aggregation and improves CD163+ macrophage-mediated Hb metabolism in HFD-induced obese rats. These findings suggest that ferric citrate may be explored as an alternative treatment method for RBC dysfunction.

Anemia in Peritoneal Dialysis Patients; Iron Repletion, Current and Future Therapies

Iron deficiency, both functional and absolute, is common in patients with chronic kidney disease (CKD), especially those requiring dialysis. Guidelines advocate treatment of iron-deficiency anemia in patients with CKD and those on peritoneal dialysis (PD). Oral iron is often insufficient and slow to improve hemoglobin concentrations because of high hepcidin levels causing impaired absorption and mobilization, while intravenous (IV) supplementation replenishes and maintains iron stores more effectively and is now standard practice (Kidney Disease Improving Global Outcomes [KDIGO] 2012 guidelines). However, there still remain concerns about the effects of labile iron and possible increased risk of infections for this group of patients.To date, the majority of published studies have focused on hemodialysis (HD) patients; very limited data are available regarding patients on PD. This review summarizes the rationale for iron therapy, methods of treatment, potential adverse effects, and long-term concerns in PD patients. In addition we highlight some interesting potential future therapies under study.

Iatrogenic iron overload and its potential consequences in patients on hemodialysis

Iron overload was considered rare in hemodialysis patients until recently, but its clinical frequency is now increasingly recognized. The liver is the main site of iron storage and the liver iron concentration (LIC) is closely correlated with total iron stores in patients with secondary hemosiderosis and genetic hemochromatosis. Magnetic resonance imaging (MRI) is now the gold standard method for estimating and monitoring LIC. Studies of LIC in hemodialysis patients by magnetic susceptometry thirteen years ago and recently by quantitative MRI have demonstrated a relation between the risk of iron overload and the use of intravenous (IV) iron products prescribed at doses determined by the iron biomarker cutoffs contained in current anemia management guidelines. These findings have challenged the validity of both iron biomarker cutoffs and current clinical guidelines, especially with respect to recommended IV iron doses. Moreover, three recent long-term observational studies suggested that excessive IV iron doses might be associated with an increased risk of cardiovascular events and death in hemodialysis patients. It has been hypothesized that iatrogenic iron overload in the era of erythropoiesis-stimulating agents might silently increase complications in dialysis patients without creating obvious, clinical signs and symptoms. High hepcidin-25 levels were recently linked to fatal and nonfatal cardiovascular events in dialysis patients. It has been postulated that the main pathophysiological pathway leading to these events might involve the pleiotropic master hormone hepcidin, which regulates iron metabolism, leading to activation of macrophages in atherosclerotic plaques and then to clinical cardiovascular events. Thus, the potential iron overload toxicity linked to chronic administration of IV iron therapy is now becoming one of the most controversial topics in the management of anemia in hemodialysis patients.

Oral Ferric Citrate Hydrate Associated With Less Oxidative Stress Than Intravenous Saccharated Ferric Oxide

Introduction

A recent study suggested that orally dosed ferric citrate hydrate (FC) corrects renal anemia in patients on hemodialysis (HD), suggesting biological differences in effects of iron supplementation using different routes of administration. To address this issue, the present study compared oral FC with i.v. saccharated ferric oxide (FO) in stable HD patients.

Methods

Participants comprised 6 patients administered 3 consecutive protocols in the first HD session of the week in a fasting state: nothing given, as control (C); oral load of FC (480 mg iron), and 5 minutes of i.v. FO (40 mg iron). Iron dynamics in the body and biological impact on redox-inflammation status during the study (6 hours) were examined.

Results

Significant increases in serum iron and transferrin saturation were seen with both FC and FO. Regarding total iron-binding capacity as the sum of serum iron and unsaturated iron-binding capacity, no changes were found in FC, whereas significant increases were seen in FO (appearance of non–transferrin-binding iron [NTBI]), despite the lower serum iron levels in FO. Compared with C, increases were seen in serum myeloperoxidase (oxidative marker) with accompanying significant decreases in thioredoxin (antioxidant) in FO, whereas no changes were found in FC.

Conclusion

Oral FC differs from i.v. FO in areas such as less NTBI generation and less induction of oxidative stress. The result indicates potential clinical benefits of oral FC in terms of iron supplementation for renal anemia in HD patients.

Safety and efficacy of ferric citrate in phosphate reduction and iron supplementation in patients with chronic kidney disease

Ferric citrate has been reported to have the potential to reduce phosphate and increase iron availability in patients with chronic kidney disease. In the present study, we evaluated its safety and efficacy in phosphate reduction and iron supplementation in chronic kidney disease stage 3-5 requiring dialysis patients. We systematically searched for clinical trials published in PubMed, Medline, and Cochrane databases. Only randomized controlled trials on the effects of ferric citrate in chronic kidney disease stage 3–5 requiring dialysis patients were selected. The primary outcomes were changes in serum phosphate, calcium, and anemia-related parameters. The secondary outcomes were the adverse effects of ferric citrate. Nine studies providing data on 1755 patients were included in the meta-analysis. Ferric citrate significantly reduced serum phosphate compared with placebo (mean difference, –1.39; 95% confidence interval, –2.12 to –0.66) and had a non-inferior effect compared with active treatment. Furthermore, ferric citrate significantly improved hemoglobin, transferrin saturation and ferritin. Adverse effects of constipation did not differ significantly between ferric citrate and placebo or active treatment. This review provides evidence that ferric citrate effectively alleviates hyperphosphatemia and iron deficiency in patients with chronic kidney disease stage 3–5 requiring dialysis patients. However, the included studies did not have cardiovascular complications or mortality information and could not assess whether ferric citrate affected the risk of all-cause death or cardiovascular complications in patients with chronic kidney disease. Further studies are required to assess whether the long-term use of ferric citrate can reduce the risk of cardiovascular events and all-cause mortality.

Iron-based phosphate binders: a paradigm shift in the treatment of hyperphosphatemic anemic CKD patients?

The partial correction of anemia and the normalization of phosphate and blood pressure are the mainstay of treatment of patients with chronic kidney disease (CKD). Available anti-hypertensive drugs, erythropoiesis stimulating agents (ESAs) and iron supplements have resolved quite satisfactorily the goal of controlling hypertension and partially correcting anemia. Unfortunately, the treatment of hyperphosphatemia is still far from resolved. Phosphate binders have poor tolerability and/or limited efficacy, leading to the prescription of many tablets that achieve only a mild-to-moderate effect. Moreover, increased consumption of tablets is associated with increased low tolerability, thus jeopardizing patient compliance and, in turn, the efficacy of phosphate binding. Compared to calcium-free binders, the cheaper calcium salts increase the risk of hypercalcemia, calciphylaxis and vascular calcification and possibly all-cause mortality. Calcium-free phosphate binders decrease serum phosphate levels without increasing the serum calcium concentration. The higher phosphate-binding efficacy of lanthanum carbonate compared to sevelamer should be balanced against its lack of pleiotropic effects on lipid metabolism and inflammation and the accumulation in bones. New iron-based phosphate binders are available. In addition to their phosphate binding capacity, they could also be useful to treat anemia. Iron citrate is seeking for such an indication because its iron absorption is significant. This could be of clinical importance, particularly in CKD patients not on dialysis, obviating the need for extra oral iron administration and possibly favoring compliance. In conclusion, the use of iron-based phosphate binders with significant iron absorption properties could represent a novel paradigm for correcting anemia and hyperphosphatemia in CKD patients.