Non-calcium-containing phosphate binders: comparing efficacy, safety, and other clinical effects

Health Economic Benefits of Introducing Sucroferric Oxyhydroxide in the Treatment of Patients with Chronic Kidney Disease under Dialysis in the Kingdom of Saudi Arabia

Hyperphosphatemia is an electrolyte disorder highly prevalent in patients with chronic kidney disease undergoing hemodialysis (HD) that usually requires treatment with oral phosphate binders (PBs). Sucroferric oxyhydroxide (SO) is a calcium-free, iron-based PB indicated for the control of serum phosphorus. In the real-world setting, SO has shown clinical effectiveness with a lower pill burden and has also been associated with reduced hospital admission rates. This study aims to assess the potential economic benefits resulting from the introduction of SO to the health-care setting of the Kingdom of Saudi Arabia (KSA). An economic analysis using data from a retrospective real-world study that compared HD patients with uninterrupted SO prescriptions with patients who discontinued SO and switched to other PBs (oPBs). Annual drug costs for the estimated PB-eligible population in KSA were quantified. Costs per responder were estimated for all treatments. Hospital admissions' incidence rates were converted into annual inpatient cost savings and were deducted from drug costs to estimate the annual economic effect of SO versus oPBs. Sensitivity and breakeven analyses were also conducted. The eligible population for PB therapy in KSA was estimated at n = 14,748. Treating therapy-eligible populations exclusively with SO was estimated to generate annual inpatient cost-savings of SAR 107.4-119.4 million compared to treating the population with oPBs. The estimated economic effect signified overall annual savings ranging from SAR 82.8 to SAR 94.8 million when the population is treated with SO. Sensitivity analyses showed persistent cost savings. The estimated benefit-cost ratios showed that for every SAR 1 spent on SO, the expected return on investment was SAR 4.4-4.9. SO is an effective therapy that may result in substantial cost savings from reducing hospital admission costs that are attributable to hyperphosphatemia among HD patients.

Systematic review and meta-analysis of potential pleiotropic effects of sevelamer in chronic kidney disease: Beyond phosphate control

Sevelamer, has been shown to have many pleiotropic actions on lipid panel, various inflammatory markers, and blood glucose levels in chronic kidney disease patients. We conducted a systematic review and meta-analysis to compare these pleiotropic effects of sevelamer to other phosphate binders used in chronic kidney disease patients. The relevant randomized controlled trials published from 1 January 2001 to 31 November 2019 on the following databases: Cochrane Central Register of Controlled Trials published in The Cochrane Library, PubMed, Scopus and Google Scholar were identified. All the included studies were independently assessed for eligibility and risk of bias. The modified data extraction form of Cochrane was used. This review included 44 studies for qualitative analysis and 28 reports for quantitative analysis. A meta-analysis of three studies (n = 180) showed that glycated haemoglobin had significantly decreased in sevelamer-treated patients (MD: 0.5%; p = <.001). Compared with calcium-based phosphate binders, sevelamer showed a significant reduction in low-density lipoprotein (MD: -19.43 mg/dL; p = <.001) and total cholesterol (MD: -19.98 mg/dL; p < .001). A significant increase in high-density lipoprotein (MD: 1.29 mg/dL; p = .05) was also prominent in sevelamer treated patients. However, we were not able to observe a significant change in other biochemical parameters such as TG, CRP, hs-CRP, FGF-23, IL-6 and albumin as, no statistically significant difference was observed.

Estimating hospital inpatient cost-savings with sucroferric oxyhydroxide in patients on chronic hemodialysis in five European countries: a cost analysis

AIMS

Hyperphosphatemia is common among patients with advanced chronic kidney disease (CKD) undergoing dialysis. The iron-based phosphate binder (PB), sucroferric oxyhydroxide (SO), has a low daily pill burden and is indicated for the control of serum phosphorus in these patients. In a retrospective database study, hemodialysis patients switched to long-term SO therapy had fewer hospitalizations compared with patients switched to other PB therapies. This economic analysis aimed to quantify potential cost-savings of reduced hospitalizations associated with SO for healthcare systems in five European countries.

MATERIALS AND METHODS

All-cause hospital admissions incidence data were sourced from a real-world retrospective database study comparing adult, in-center hemodialysis patients maintained on 2 years of SO therapy (mSO) versus patients who discontinued SO (dSO) within 90 days of their first prescription and switched to other PBs. A literature search was conducted to determine the cost per hospital admission for dialysis patients in the healthcare setting of each European country. A cost-model combined the incidence rate of all-cause hospital admissions and the cost per admission to estimate the country-specific inpatient costs for the mSO and dSO groups.

RESULTS

Annual inpatient cost-savings per patient in the mSO group versus the dSO group were €1,201, €2,097, €2,059, €1,512, and €3,068 in France, Germany, Italy, Spain, and the UK, respectively. When annual PB drug costs per patient were considered, the net annual economic cost-savings per patient were €327, €1,585, €1,022, €1,100, and €2,204, respectively.

LIMITATIONS

Hospital admissions data used in the analysis were observational in nature and derived from a US hemodialysis patient population; the effect of SO therapy on hospitalization rates for US and European hemodialysis patients may differ. The analysis did not consider indirect healthcare costs associated with hospitalizations.

CONCLUSION

SO therapy may offer substantial inpatient cost-savings by reducing all-cause hospital admissions attributable to uncontrolled hyperphosphatemia.

Plasma p-cresol lowering effect of sevelamer in non-dialysis CKD patients: evidence from a randomized controlled trial

BACKGROUND

The accumulation of p-cresol, a metabolic product of aromatic amino acids generated by intestinal microbiome, increases the cardiovascular risk in chronic kidney disease (CKD) patients. Therefore, therapeutic strategies to reduce plasma p-cresol levels are highly demanded. It has been reported that the phosphate binder sevelamer (SEV) sequesters p-cresol in vitro, while in vivo studies on dialysis patients showed controversial results. Aim of our study was to evaluate the effect of SEV on p-cresol levels in non-dialysis CKD patients.

METHODS

This was a single-blind, randomized placebo-controlled trial (Registration number NCT02199444) carried on 69 CKD patients (stage 3-5, not on dialysis), randomly assigned (1:1) to receive either SEV or placebo for 3 months. Total p-cresol serum levels were evaluated at baseline (T0), and 1 (T1) and 3 months (T3) after treatment start. The primary end-point was to evaluate the effect of SEV on p-cresol levels.

RESULTS

Compared to baseline (T0, 7.4 ± 2.7 mg/mL), p-cresol mean concentration was significantly reduced in SEV patients after one (- 2.06 mg/mL, 95% CI - 2.62 to - 1.50 mg/mL; p < 0.001) and 3 months of treatment (- 3.97 mg/mL, 95% CI - 4.53 to - 3.41 mg/mL; p < 0.001); no change of plasma p-cresol concentration was recorded in placebo-treated patients. Moreover, P and LDL values were reduced after 3 months of treatment by SEV but not placebo.

CONCLUSIONS

In conclusion, our study represents the first evidence that SEV is effective in reducing p-cresol levels in CKD patients in conservative treatment, and confirms its beneficial effects on inflammation and lipid pattern.

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.

Chitosan-Fe (III) Complex as a Phosphate Chelator in Uraemic Rats: A Novel Treatment Option

Phosphate retention and hyperphosphataemia are associated with increased mortality in patients with chronic kidney disease (CKD). We tested the use of cross-linked iron chitosan III (CH-FeCl) as a potential phosphate chelator in rats with CKD. We evaluated 96 animals, divided equally into four groups (control, CKD, CH-FeCl and CKD/CH-FeCl), over 7 weeks. We induced CKD by feeding animals an adenine-enriched diet (0.75% in the first 4 weeks and 0.1% in the following 3 weeks). We administered 30 mg/kg daily of the test polymer, by gavage, from the third week until the end of the study. All animals received a diet supplemented with 1% phosphorus. Uraemia was confirmed by the increase in serum creatinine in week 4 (36.24 ± 18.56 versus 144.98 ± 22.1 μmol/L; p = 0.0001) and week 7 (41.55 ± 22.1 versus 83.98 ± 18.56 μmol/L; p = 0.001) in CKD animals. Rats from the CKD group treated with CH-FeCl had a 54.5% reduction in serum phosphate (6.10 ± 2.23 versus 2.78 ± 0.55 mmol/L) compared to a reduction of 25.6% in the untreated CKD group (4.75 ± 1.45 versus 3.52 ± 0.74 mmol/L, p = 0.021), between week 4 and week 7. At week 7, renal function in both CKD groups was similar (serum creatinine: 83.98 ± 18.56 versus 83.10 ± 23.87 μmol/L, p = 0.888); however, the CH-FeCl-treated rats had a reduction in phosphate overload measured by fractional phosphate excretion (FEPi) (0.71 ± 0.2 versus 0.4 ± 0.16, p = 0.006) compared to the untreated CKD group. Our study demonstrated that CH-FeCl had an efficient chelating action on phosphate.

Lanthanum carbonate: safety data after 10 years

Despite 10 years of post-marketing safety monitoring of the phosphate binder lanthanum carbonate, concerns about aluminium-like accumulation and toxicity persist. Here, we present a concise overview of the safety profile of lanthanum carbonate and interim results from a 5-year observational database study (SPD405-404; ClinicalTrials.gov identifier: NCT00567723). The pharmacokinetic paradigms of lanthanum and aluminium are different in that lanthanum is minimally absorbed and eliminated via the hepatobiliary pathway, whereas aluminium shows appreciable absorption and is eliminated by the kidneys. Randomised prospective studies of paired bone biopsies revealed no evidence of accumulation or toxicity in patients treated with lanthanum carbonate. Patients treated with lanthanum carbonate for up to 6 years showed no clinically relevant changes in liver enzyme or bilirubin levels. Lanthanum does not cross the intact blood-brain barrier. The most common adverse effects are mild/moderate nausea, diarrhoea and flatulence. An interim Kaplan-Meier analysis of SPD405-404 data from the United States Renal Data System revealed that the median 5-year survival was 51.6 months (95% CI: 49.1, 54.2) in patients who received lanthanum carbonate (test group), 48.9 months (95% CI: 47.3, 50.5) in patients treated with other phosphate binders (concomitant therapy control group) and 40.3 months (95% CI: 38.9, 41.5) in patients before the availability of lanthanum carbonate (historical control group). Bone fracture rates were 5.9%, 6.7% and 6.4%, respectively. After more than 850 000 person-years of worldwide patient exposure, there is no evidence that lanthanum carbonate is associated with adverse safety outcomes in patients with end-stage renal disease.

Cost effectiveness of lanthanum carbonate in chronic kidney disease patients in Spain before and during dialysis

AIMS

In Spain, the first line treatment of hyperphosphatemia in Chronic Kidney Disease (CKD) consists of calcium-based phosphate binders (CB). However, their use is associated with vascular calcification and an increased mortality risk. The aim of this study was to assess the incremental cost-effectiveness of second-line Lanthanum Carbonate (LC) treatment in patients not responding to CB (calcium carbonate and calcium acetate).

MATERIAL AND METHODS

A lifetime Markov model was developed considering three health states (predialysis, dialysis and death). Transitions between states and efficacy data were obtained from randomized clinical trials and the European Dialysis and Transplant Association Annual report. Mortality rate was adjusted with the relative risk related to serum phosphorus levels. According to the Spanish healthcare system perspective, only medical direct costs were considered. Dialysis costs (2013 prices in Euros) were obtained from diagnosis-related groups. Drug costs were derived from ex-factory prices, adjusted with 7.5% mandatory rebate. Quality of life estimates were based on a published systematic review. Costs and benefits were discounted at 3%. Deterministic and probabilistic sensitivity analyses (PSA) were conducted.

RESULTS

At the end of simulation, costs per patient with LC therapy were 1,169 and 5,044 with CB alone. 4.653 Quality Adjusted Life Years (QALYs) were gained per patient treated with LC, and 4.579 QALYs with CB. CB therapy is dominated by the LC strategy (i.e. lower costs, higher QALYs). Assuming a 30,000/QALY threshold, LC was dominant in 100% of PSA simulations.

CONCLUSIONS

LC is a cost-effective second line treatment of hyperphosphatemia in CKD patients irrespective of dialysis status in Spain.

The future of phosphate binders: a perspective on novel therapeutics

Chronic kidney disease-mineral bone disorder (CKD-MBD) is a common complication of CKD. The therapeutic strategies for the treatment of CKD-MBD include phosphate binders, active vitamin D analogs and calcimimetics. The first class of drugs provided nephrologists with a range of phosphate binders that are able to decrease circulating phosphate and parathyroid hormone but involve some tolerability and safety issues. In the past 2 years, new phosphate binders have been launched and others are still under development. Serum phosphate increases only in the late stages of CKD but clinical abnormalities begin to occur earlier when multiple mechanisms try to compensate for the progressive reduced ability of the kidney to eliminate phosphorus with urine. Accordingly, starting phosphate binders when phosphatemia reaches values higher than normal may represent a late therapeutic approach. Serum phosphorus is not the ideal biomarker for the diagnosis and treatment of phosphate imbalance. This role could be better played by fibroblast growth factor 23, whose serum concentrations rise earlier in CKD. A more detailed knowledge of the mechanisms underlying CKD-MBD development will provide new therapeutic targets and then new perspectives for the treatment of phosphate imbalance in the future.

The role of the gastrointestinal tract in phosphate homeostasis in health and chronic kidney disease

Purpose of review

For a number of years, there has been increasing interest in the concept of directly targeting intestinal phosphate transport to control hyperphosphatemia in chronic kidney disease. However, progress has been slow due to the paucity of information on the mechanisms involved in intestinal phosphate absorption. This editorial highlights the most recent developments in our understanding of this process and the role of the intestine in the maintenance of phosphate balance.

Recent findings

Recent studies in NaPi-IIb knockout mice have confirmed that this transport protein plays a significant role in intestinal phosphate absorption and is critical in the proposed feed-forward mechanism between the small intestine and kidney, which helps to maintain normal phosphate balance and steady-state plasma phosphate concentrations. In addition, renal failure-induced hyperphosphatemia is attenuated in NaPi-IIb knockout mice, confirming that NaPi-IIb is a suitable target in the prevention and treatment of hyperphosphatemia.

Summary

Recent findings suggest that consumption of processed foods containing phosphate preservatives may lead to excessive phosphate exposure (if not overload), toxicity, and cardiovascular disease in the general population, as well as in patients with declining renal function. Therefore, establishing more effective ways of targeting the intestine to limit dietary phosphate absorption could have wide-reaching health benefits.

The effects of colestilan versus placebo and sevelamer in patients with CKD 5D and hyperphosphataemia: a 1-year prospective randomized study

BACKGROUND

This study compared the effects of short-term titrated colestilan (a novel non-absorbable, non-calcium, phosphate binder) with placebo, and evaluated the safety and efficacy of colestilan over 1 year compared with sevelamer, in patients with chronic kidney disease (CKD) 5D.

METHODS

This prospective multicentre study comprised a 4-week phosphate binder washout period, a 16-week short-term, flexible-dose, treatment period (including a 4-week placebo-controlled withdrawal period) and a 40-week extension treatment phase.

RESULTS

At Week 16 (the end of the 4-week placebo-controlled withdrawal period), serum phosphorus level was 0.43 mmol/L (1.32 mg/dL) lower with colestilan than placebo (P < 0.001; primary end point). Serum LDL-C level was also lower with colestilan than with placebo (P < 0.001). Both colestilan and sevelamer produced significant reductions from baseline in serum phosphorus levels (P < 0.001), maintained for 1 year, and the proportion of patients achieving target levels of ≤1.78 mmol/L (5.5 mg/dL) or ≤1.95 mmol/L (6.0 mg/dL) at study end were similar (65.3 and 73.3%, respectively, for colestilan, and 66.9 and 77.4%, respectively, for sevelamer). Serum calcium level remained stable in the colestilan group but tended to increase slightly in the sevelamer group (end-of-study increase of 0.035 mmol/L over baseline). Both binders produced similar reductions from baseline in LDL-C level (P < 0.001), and responder rates after 1 year, using a target of <1.83 mmol/L (70 mg/dL) or <2.59 mmol/L (100 mg/dL) were similar in both groups (50.7 and 85.3% for colestilan and 54.0 and 80.6% for sevelamer). Colestilan was generally well tolerated.

CONCLUSIONS

Colestilan is effective and safe for the treatment of hyperphosphataemia in patients with CKD 5D, and affords similar long-term phosphorus and cholesterol reductions/responder rates to sevelamer.

The real-world dose-relativity of sevelamer hydrochloride and lanthanum carbonate monotherapy in patients with end-stage renal disease

INTRODUCTION

Sevelamer hydrochloride (SH) and lanthanum carbonate (LC) are calcium-free phosphate binders used for the management of hyperphosphatemia in patients with end-stage renal disease (ESRD). The objective of this analysis was to evaluate the real-world dose-relativity between SH and LC monotherapy in US patients with ESRD.

METHODS

This was a post hoc analysis of a 16-week, real-world study (Vemuri et al. in BMC Nephrol 12:49, 2011) of the efficacy of conversion to LC monotherapy from other phosphate binders. The SH:LC dose-relativity ratio, based on the mean daily dose, was calculated in the subset of patients from the Vemuri study who converted from SH to LC monotherapy and had available SH and LC dose data.

RESULTS

A total of 950 patients converted from SH to LC monotherapy and had recorded dose data. The post hoc analysis population comprised 691 patients with available dose data for both SH at baseline and LC at week 16. The mean (SD) serum phosphate level at baseline was 5.91 (1.66) mg/dL. After conversion to LC monotherapy for 16 weeks, the mean (SD) serum phosphate level was 5.93 (1.85) mg/dL. The mean (SD) daily baseline SH dose was 7,703 (3,642) mg and the mean (SD) daily LC dose at week 16 was 2,800 (939) mg (9.6 versus 2.8 tablets, respectively; P < 0.0001), resulting in a SH:LC dose-relativity ratio of 2.8. The median individual patient SH:LC dose-relativity ratio was 2.6 (95% CI 2.6-2.8). Across baseline SH dose subgroups (2,400-4,800, >4,800-7,200, >7,200-9,600, and >9,600 mg/day), the mean daily SH dose was 4,051, 7,047, 9,253, and 13,150 mg, respectively. In comparison, the mean daily LC dose was 2,445-3,156 mg. Thus, patients requiring baseline SH doses >7,200 mg/day (41% of the analysis population) had higher SH:LC dose-relativity ratios of 3.1-4.2 (median individual patient ratios 3.1-4.0).

CONCLUSION

In this post hoc analysis of real-world dose-relativity, the overall SH:LC dose-relativity ratio was 2.8 (median individual patient ratio 2.6 (95% CI 2.6-2.8). These findings are consistent with the World Health Organization-defined daily dose and previous studies of the relative phosphate binding capacity of the two drugs. Patients requiring SH doses >7,200 mg/day had higher SH:LC dose-relativities of 3.1-4.2 (median individual patient ratios 3.1-4.0). These findings have implications for the tablet burden and cost-effectiveness of SH and LC in the treatment of hyperphosphatemia.