Phosphorus binding with ferric citrate is associated with fewer hospitalizations and reduced hospitalization costs

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.

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.

Recent and Emerging Therapies for Iron Deficiency in Anemia of CKD: A Review

Iron deficiency commonly contributes to the anemia affecting individuals with chronic kidney disease. Diagnostic criteria for iron deficiency in chronic kidney disease are explained. Mechanisms of functional and absolute iron deficiency and general treatment Principles as delineated in the Kidney Disease: Improving Global Outcomes guidelines are reviewed. Repletion of absolute iron deficits has progressed over time with the addition of better tolerated, more effective oral agents including ferric citrate, ferric maltol, and sucrosomial iron. Structural characteristics and trial data enabling regulatory approval of these novel oral agents are examined. Newer intravenous iron therapies including ferric carboxymaltose and ferric derisomaltose allow for fewer infusions and decreased risk of serious hypersensitivity reactions. Concerns about adverse events including cardiovascular events and infections are discussed. The potential risk of 6H syndrome due to these intravenous agents, including hypophosphatemia, osteomalacia, and pathologic fractures is emphasized. The proposed pathophysiology of 6H syndrome and hypophosphatemia is described. Ferric pyrophosphate citrate enables administration of iron for repletion through dialysate. Relative merits, costs, and risks of various iron agents such as hypersensitivity and 6H syndrome/hypophosphatemia are summarized.

Sucroferric Oxyhydroxide in Maintenance Hemodialysis: A Retrospective, Comparative Cohort Study

Rationale & Objective

High pill burden associates with reduced phosphate-binder adherence among dialysis patients, contributing to elevated serum phosphorus levels. We compared the real-world effectiveness of sucroferric oxyhydroxide (SO) versus other phosphate binders in hemodialysis patients over 2 years.

Study Design

Retrospective cohort study.

Setting & Participants

Adult in-center hemodialysis patients prescribed 2 years of uninterrupted SO therapy (maintenance SO; n = 222) compared with patients who discontinued SO therapy (discontinued SO; n = 596) within 90 days of first prescription and switched to other phosphate binder(s) for 2 years.

Exposures

Phosphate binders.

Outcomes

Achievement of serum phosphorus levels ≤ 5.5 mg/dL, pill burden, and hospitalizations.

Analytical Approach

Comparisons were made quarterly (Q1-Q8) between maintenance SO and discontinued SO using Poisson and mixed-effects linear regression.

Results

Patients achieving serum phosphorus levels ≤ 5.5 mg/dL increased from baseline in maintenance SO (46 [20.7%] to a maximum of 104 [46.8%; P < 0.001]) and discontinued SO (96 [16.1%] to a maximum of 201 [33.7%]; P < 0.001). 100 (45%) maintenance SO patients achieved target serum phosphorus levels at Q8 with 3.1 fewer pills per day from baseline (7.5 to 4.4 pills per day; P < 0.001), and 190 (31.9%) discontinued SO patients achieved serum phosphorus levels ≤ 5.5 mg/dL at Q8 with pill burden unchanged (9.1 to 9.3 pills per day; P = 0.3). Among all patients during 2 years, mean serum phosphorus levels decreased by -0.66 mg/dL and -0.45 mg/dL (maintenance SO vs discontinued SO; P = 0.014), and mean pill burden decreased in maintenance SO (8.5 to 5.1 pills per day; P < 0.001), but not in discontinued SO (11.6 to 10.9 pills per day; P = 0.2). The serum phosphorus level decrease with SO was confirmed in a sensitivity analysis including patients with SO therapy for 2 or fewer years. Compared with discontinued SO, maintenance SO patients had 35.6 fewer hospitalizations per 100 patient-years (incidence rate ratio, 0.75 [95% CI, 0.58-0.96]).

Limitations

No data for treatment indication, tolerance, or adherence.

Conclusions

Patients maintained on SO therapy were more likely to achieve target serum phosphorus levels, use 50% fewer phosphate-binder pills per day, and have fewer hospital admissions than patients switched to treatment with other binders.

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.

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.

Mineral and bone disorders in conventional hemodialysis: Challenges and solutions

Despite the advent of cinacalcet and noncalcium-containing phosphate binders, controlling the progression of vascular calcification (VC) is still challenging. Recent reports demonstrate that carbamylation driven by high urea concentration aggravates VC, suggesting the importance of adequate dialysis in retarding its progression. Theoretically, other promising measures include the use of iron-based phosphate binders, vitamin K, and magnesium supplements, which should be investigated in future randomized controlled trials (RCTs), ideally with hard outcomes. While incidence of hip fracture in patients on dialysis is decreasing in the United States and Japan (possibly owing to better control of PTH levels by cinacalcet) it remains much higher than that in the general population. Many drugs used in the treatment of osteoporosis, including bisphosphonate, raloxifene, denosumab, and teriparatide can, under specific conditions, increase bone mineral density (BMD), which is associated with a lower fracture rate. However, the efficacy of these drugs in reducing the fracture rate remains to be proven in hemodialysis (HD) patients, given their adverse effects such as severe hypocalcemia and resultant worsening of secondary hyperparathyroidism. Some clinical studies have shown that cinacalcet, lanthanum carbonate, and sevelamer reduce mortality in elderly patients on HD, suggesting the benefits of reducing PTH and serum phosphate levels. However, the target ranges of PTH and phosphate levels are based solely on observational studies. This is also the case when treating low PTH levels by decreasing vitamin D or calcium load. RCTs with hard clinical endpoints comparing different targets are necessary in the future.

Net Budgetary Impact of Ferric Citrate as a First-Line Phosphate Binder for the Treatment of Hyperphosphatemia: A Markov Microsimulation Model

Ferric citrate (FC) has demonstrated efficacy as a phosphate binder and reduces the requirements for erythropoiesis-stimulating agents (ESAs) and intravenous (IV) iron in dialysis patients. We developed a net budgetary impact model to evaluate FC vs. other phosphate binders from the vantage of a large dialysis provider. We used a Markov microsimulation model to simulate mutually referential longitudinal effects between serum phosphate and phosphate binder dose; categories of these defined health states. Health states probabilistically determined treatment attendance and utilization of ESA and IV iron. We derived model inputs from a retrospective analysis of incident phosphate binder users from a large dialysis organization (January 2011-June 2013) and incorporated treatment effects of FC from a phase III trial. The model was run over a 1-year time horizon. We considered fixed costs of providing dialysis; costs of administering ESA and IV iron; and payment rates for dialysis, ESAs, and IV iron. In the base-case model, FC had a net budgetary impact (savings) of +US$213,223/year per 100 patients treated vs. standard of care. One-way sensitivity analyses showed a net budgetary impact of up to +US$316,296/year per 100 patients treated when higher hemoglobin levels observed with FC translated into a 30% additional ESA dose reduction, and up to +US$223,281/year per 100 patients treated when effects on missed treatment rates were varied. Two-way sensitivity analyses in which acquisition costs for ESA and IV iron were varied showed a net budgetary impact of +US$104,840 to +US$213,223/year per 100 patients treated. FC as a first-line phosphate binder would likely yield substantive savings vs. standard of care under current reimbursement.

Clinical features of CKD-MBD in Japan: cohort studies and registry

Randomized controlled trials (RCTs) are essential for evidence-based medicine; however, cohort studies and registries provide an important information about risk factors and, hence, shed light on the target of laboratory parameters. The uniqueness of the current Japanese CKD-MBD guidelines lies in the lower target range of intact parathyroid hormone levels than those used in other countries, which is based on analyses of the nationwide Japan Renal Data Registry. Cohort studies were also useful in exploring risk factors of renal outcome in predialysis patients. It was revealed that low vitamin D status (very prevalent in Japan) and high fibroblast growth factor 23 (FGF23) levels predict poor renal outcome. The reported association of FGF23 levels with left ventricular hypertrophy (LVH) and heart failure observed in cohort studies may support the idea of adding the 4th component of CKD-MBD, namely, "LVH" to the three original components. When it is not feasible to conduct RCTs regarding intervention, we have no choice but to rely on observational studies with sophisticated analysis methods, such as facility-level analysis and marginal structural model minimizing indication bias. Observational studies conducted in Japan revealed that the side effects of medications for CKD-MBD, resultant compliance, and effective doses in terms of hard outcome in Japanese patients were found to be different from those in other countries. For example, the MBD-5D study confirmed the benefit of cinacalcet in terms of mortality despite its median dose of only 25 mg/day. These data are very helpful for future guidelines specific to Japanese patients with CKD.

Emerging drugs for the treatment of kidney disease-induced anemia

INTRODUCTION

Anemia has been remained one of the most characteristic and visible manifestations of chronic renal failure. Correction of anemia requires two main treatment strategies: increased stimulation of erythropoiesis, and maintenance of an adequate iron supply to the bone marrow.

AREAS COVERED

Erythropoiesis activating agents became a mainstay in the treatment of renal anemia for more than 25 years. Recently, there have been several attempts to introduce new drugs to stimulate erythropoiesis or affect the hepcidin-ferroportin pathway. Orally available hypoxia-inducible factor (HIF) stabilizing compounds are attractive alternatives. They not only increase hemoglobin, but also suppress hepcidin production and improve iron availability. Novel iron preparations, may also help to ameliorate anemia, with acceptable safety profile and other beneficial properties such a phosphate binding.

EXPERT OPINION

One should be aware of potential risks and benefits of novel sophisticated therapies and their role in the management of renal anemia remain to be established. In particular HIF stabilizers needs to be proven safe, or even safer than ESAs, in large long-term safety studies testing hard end points, due its ubiquitous nature and the regulation of variety of biological processes potentially leading to unexpected side effects. Besides safety, cost-effectiveness appears the major issue in the modern world, including nephrology.

Ferric Citrate in Patients With Chronic Kidney Disease

Ferric citrate (FC) is an iron-containing phosphate binder that has been shown to effectively decrease serum phosphate, increase hemoglobin, and replete iron stores in patients with chronic kidney disease. Intestinal absorption of iron from FC results in increases in serum iron, ferritin, and transferrin saturation, effects that occur over 12 to 24 weeks and subsequently appear to plateau. As a result, use of erythropoiesis-stimulating agents and intravenous iron is reduced significantly and in clinical trials in patients receiving hemodialysis, the majority of subjects were able to discontinue intravenous iron use completely. One-year safety data have indicated that FC-treated subjects have reduced rates of hospitalization and reduced serious adverse events related to gastrointestinal, infectious, and cardiovascular causes, although the mechanism for this finding is unclear. The large doses of oral iron administered and lack of precise information on relative absorption over time or on the potential effect of FC on intestinal epithelial function should prompt continued clinical investigation. Although not yet approved for use in the United States for patients with non-dialysis-dependent chronic kidney disease, FC is a welcome addition to the available treatment options for decreasing phosphate concentrations. The multifaceted favorable effects on anemia and phosphate in combination with the erythropoiesis-stimulating agent and intravenous iron-sparing data support the use of FC as a first-line treatment option when phosphate-decreasing therapy is indicated.

We Give Too Much Intravenous Iron

Dialysis patients have absolute and functional iron deficiencies. Traditionally, oral iron preparations have been insufficient to maintain iron stores to support erythropoiesis, especially in the setting of the ubiquitous use of erythropoiesis-stimulating agents. This has led to the widespread adoption of intravenous iron protocols designed to maintain iron stores at levels that are much higher than for patients not on dialysis. These protocols are often developed by dialysis providers and may be largely independent of the treating nephrologist. Concerns about multiple risks associated with the use of intravenous iron persist. Despite this, mean ferritin levels in the United States have risen, partly due to more intravenous iron use and partly due to reduced erythropoiesis-stimulating agent use. Questions about the relationship of intravenous iron to infection, cardiac, and hepatobiliary risks remain. The failure of oral iron preparations to maintain iron stores continues to prompt the use of intravenous iron. Recently, studies with oral ferric citrate as a phosphate binder have shown improved iron stores and maintenance of hemoglobin, and studies with soluble ferric pyrophosphate added to dialysate have shown both maintenance of iron stores and hemoglobin. With new iron options that affect iron stores in dialysis patients, the use of intravenous iron and its potential risks may wane.

Iron-based phosphate binders--a new element in management of hyperphosphatemia

INTRODUCTION

Management of serum phosphorus in patients with chronic kidney disease remains a significant clinical challenge. A pivotal component of the clinical approach to maintaining serum phosphorus concentrations towards the normal range is the use of phosphate binding agents in addition to comprehensive dietary counseling. The available agents work similarly by capitalizing on a cation within the agent to bind negatively charged phosphorus, forming an insoluble complex and reducing ingested phosphorus absorption. Despite several effective options for phosphate binder therapies, patient adherence remains an issue, mainly due to adverse effect profiles and large daily pill burdens.

AREAS COVERED

Two new iron-based phosphate binder therapies have recently become available in the United States, sucroferric oxyhydroxide and ferric citrate. These agents have both been shown to effectively reduce serum phosphorus comparably to widely used calcium-based binders and sevelamer salts.

EXPERT OPINION

The two new iron-based binders differ substantially with regard to phosphate binding chemistry and iron absorption profiles. Their place in therapy is still evolving and the impact of pill burden, gastrointestinal adverse effect profiles, potential cost reduction of anemia therapies and physiologic effects of long-term iron exposure need to be further evaluated.

Ferric Citrate, an Iron-Based Phosphate Binder, Reduces Health Care Costs in Patients on Dialysis Based on Randomized Clinical Trial Data

BACKGROUND

Patients with end-stage renal disease (ESRD) require phosphate binders for hyperphosphatemia and erythropoiesis-stimulating agents (ESAs) and intravenous (i.v.) iron for anemia. Ferric citrate (FC) is a novel, iron-based phosphate binder that increases iron stores and decreases i.v. iron and ESA usage while maintaining hemoglobin levels, and may decrease the cost of ESRD care. The study objectives were to (1) quantify differences in ESA and i.v. iron usage among ESRD patients receiving FC compared with active control (AC) (sevelamer carbonate and/or calcium acetate) on the basis of data from a 52-week phase III clinical trial and (2) standardize trial data to the general United States (US) ESRD population and calculate the potential impact of FC on ESRD cost/patient/year in the USA.

STUDY DESIGN

The study was a randomized, controlled clinical trial.

SETTING AND POPULATION

A total of 441 adult subjects with ESRD who received FC or AC for 52 weeks were included.

MODEL, PERSPECTIVE, AND TIMELINE

Differences in ESA and i.v. iron usage between the treatment groups were modeled over time using generalized linear mixed models and zero-inflated Poisson models. Trends were modeled via logarithmic curves, and utilization patterns were applied to the general dialysis population to estimate expected resource savings.

OUTCOMES

Study outcomes were costs saved/patient/year using FC versus AC (US dollars).

RESULTS

Our model suggests an annual decrease of 129,106 U of ESAs and 1960 mg of i.v. iron per patient in the second year after a switch from AC to FC. Applying 2013 Medicare pricing, this would save $1585 in ESAs and $516 in i.v. iron: a total of $2101/patient/year; these savings would be expected to double for managed care plans.

LIMITATIONS

The projections were made on 1 year of trial data.

CONCLUSIONS

Phosphate binding with FC reduces i.v. iron and ESA usage. Given the high cost burden of ESRD, our model demonstrates significant potential cost savings.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT01191255) http://clinicaltrials.gov/ct2/show/NCT01191255 .

The Phosphate Binder Ferric Citrate and Mineral Metabolism and Inflammatory Markers in Maintenance Dialysis Patients: Results From Prespecified Analyses of a Randomized Clinical Trial

BACKGROUND

Phosphate binders are the cornerstone of hyperphosphatemia management in dialysis patients. Ferric citrate is an iron-based oral phosphate binder that effectively lowers serum phosphorus levels.

STUDY DESIGN

52-week, open-label, phase 3, randomized, controlled trial for safety-profile assessment.

SETTING & PARTICIPANTS

Maintenance dialysis patients with serum phosphorus levels ≥6.0 mg/dL after washout of prior phosphate binders.

INTERVENTION

2:1 randomization to ferric citrate or active control (sevelamer carbonate and/or calcium acetate).

OUTCOMES

Changes in mineral bone disease, protein-energy wasting/inflammation, and occurrence of adverse events after 1 year.

MEASUREMENTS

Serum calcium, intact parathyroid hormone, phosphorus, aluminum, white blood cell count, percentage of lymphocytes, serum urea nitrogen, and bicarbonate.

RESULTS

There were 292 participants randomly assigned to ferric citrate, and 149, to active control. Groups were well matched. For mean changes from baseline, phosphorus levels decreased similarly in the ferric citrate and active control groups (-2.04±1.99 [SD] vs -2.18±2.25 mg/dL, respectively; P=0.9); serum calcium levels increased similarly in the ferric citrate and active control groups (0.22±0.90 vs 0.31±0.95 mg/dL; P=0.2). Hypercalcemia occurred in 4 participants receiving calcium acetate. Parathyroid hormone levels decreased similarly in the ferric citrate and active control groups (-167.1±399.8 vs -152.7±392.1 pg/mL; P=0.8). Serum albumin, bicarbonate, serum urea nitrogen, white blood cell count and percentage of lymphocytes, and aluminum values were similar between ferric citrate and active control. Total and low-density lipoprotein cholesterol levels were lower in participants receiving sevelamer than those receiving ferric citrate and calcium acetate. Fewer participants randomly assigned to ferric citrate had serious adverse events compared with active control.

LIMITATIONS

Open-label study, few peritoneal dialysis patients.

CONCLUSIONS

Ferric citrate was associated with similar phosphorus control compared to active control, with similar effects on markers of bone and mineral metabolism in dialysis patients. There was no evidence of protein-energy wasting/inflammation or aluminum toxicity, and fewer participants randomly assigned to ferric citrate had serious adverse events. Ferric citrate is an effective phosphate binder with a safety profile comparable to sevelamer and calcium acetate.