Hyperphosphatemia In Chronic Kidney Disease Patients Research Articles

#5592 THE SODIUM PHOSPHATE COTRANSPORTER NAPI-IIB IS UPREGULATED AND EXPRESSED DE NOVO IN KIDNEYS OF PATIENTS WITH CHRONIC KIDNEYS DISEASE

Abstract Background and Aims Renal reabsorption of phosphate is mediated by 3 main transporters located in the luminal brush border membrane of the proximal tubule, namely NaPi-IIa (SLC34A1), NaPi-IIc (SLC34A3), and Pit2 (SLC20A2). The expression of all three proteins has been shown to be reduced in animal models of kidney disease [1]. Recently, we demonstrated that NaPi-IIb, a paralogue of the SLC34 subfamily that is mostly expressed in small intestine and lungs, is also expressed in the loop of Henle. Its mRNA expression is enhanced in rodent models of kidney injury. However, the expression of NaPi-IIb has not been characterized in humans and it is unknown whether NaPi-IIb is also upregulated in chronic kidney disease (CKD). Method In this study, we examined the localization of NaPi-IIa, IIb, and IIc in kidneys of control healthy individuals (kidney donors) (eGFR: 111.6 ± 22.9 ml/min/1.73m2) and patients with diabetic nephropathy (eGFR: 31.9 ± 7.7 ml/min/1.73m2), anti-glomerular basement membrane nephritis (anti-GMB) (eGFR: 27.2 ± 22.6 ml/min/1.73m2), and hypertensive nephropathy (eGFR: 31.5 ± 5.3 ml/min/1.73m2) by immunofluorescence. Moreover, we analyzed data from various transcriptome data bases from healthy individuals and patients with CKD. Results In kidneys from healthy donors, NaPi-IIb staining was restricted to thin and thick limbs of the loop of Henle, while AQP1 was observed in proximal tubules and descending thin limbs. NaPi-IIc was abundantly found in proximal tubule cells. In biopsies from patients, NaPi-IIb signal was also found in addition to thin and thick limbs in cells of the collecting duct and in many proximal tubules. In contrast, the staining of NaPi-IIc was reduced in all groups of patients with CKD. RNA expression data from the European Renal cDNA Bank (ERCB) confirmed our immunofluorescence findings. SLC34A2 (NaPi-IIb) mRNA was progressively more expressed in kidneys of patients with kidney disease of tubulointerstitial origin from CKD stages 1 to 5, while it was strongly upregulated from stage 4 onwards in CKD of glomerular origin. Single cell RNA sequencing data of patients with acute kidney injury and CKD [2] showed elevation of SLC34A2 expression in injured thick ascending limb, degenerative proximal tubule cells (14x higher, adj. p≪0.0001) (de novo expression), and descending thin limb (3.7x higher, adj. p≪0.0001). SLC34A1 (NaPi-IIa) expression levels were reduced in whole kidneys (ERCB data) and SLC34A1 and SLC34A3 expression also decreased in proximal tubule cells of patients with CKD. Conclusion The phosphate transporter NaPi-IIb is highly upregulated in kidneys from patients with various etiologies of CKD and its expression spreads to proximal tubule and collecting duct. In contrast, the expression of the main physiological phosphate transporters NaPi-IIa and NaPi-IIc is reduced in CKD. These findings may have implications for the development and maintenance of hyperphosphatemia in CKD patients and limit the use of specific NaPi-IIa and/or NaPi-IIc inhibitors in patients with CKD.

Efficacy of Lanthanum Carbonate and Sevelamer Carbonate as Phosphate Binders in Chronic Kidney Disease—A Comparative Clinical Study

(1) Background: Hyperphosphatemia is correlated with an increased rate of mortality and morbidity due to cardiovascular diseases in chronic kidney disease (CKD) patients. It can be improved by restricting dietary intake of phosphate and oral phosphate binders, such as lanthanum carbonate and sevelamer carbonate. (2) Objective: To evaluate the clinical efficacy of sevelamer carbonate in comparison to lanthanum carbonate as phosphate binders for the treatment of hyperphosphatemia in CKD patients. (3) Methods: A randomized control comparative clinical study was conducted for one year on 150 CKD patients associated with hyperphosphatemia, divided into two groups, i.e., Group 1 (n = 75) treated with sevelamer carbonate 800 mg thrice daily and Group 2 (n = 75) treated with lanthanum carbonate 500 mg thrice daily. The patients were assessed at the time of enrollment in the study, after three months and after six months from baseline for different parameters, i.e., complete blood count, liver function tests, renal function tests, electrolytes, and serum phosphate level. (4) Results: 150 CKD patients aged 51-60 participated in the study. The mean age of patients was 54 ± 4.6 years, and males (55.71%) were more common than females (44.29%). Hypertension was the common comorbidity in both groups with chronic kidney disease. After six months of treatment, the mean serum phosphate level was significantly decreased from 8.31 ± 0.09 mg/dL to 5.11 ± 0.18 (38%) in Group 1 and from 8.79 ± 0.28 mg/dl to 4.02 ± 0.12 (54%; p < 0.05) in Group 2, respectively. In both groups, no significant difference was found in other parameters such as parathyroid hormone, calcium, uric acid, LFT, RFT, CBC, etc. (5) Conclusion: Lanthanum carbonate is more efficacious in lowering serum phosphate concentrations and effectively managing hyperphosphatemia as compared to sevelamer carbonate.

Iron absorption and phosphate-lowering effects of ferric citrate hydrate are not influenced by gastric acid secretion inhibitors in patients with chronic kidney disease: a retrospective post hoc analysis

BackgroundFerric citrate hydrate (FC), an oral iron product is approved as iron preparation for iron deficiency anemia and phosphate binder for chronic kidney disease (CKD). We investigated whether gastric acid secretion inhibitors (GASI) influenced on iron absorption and phosphate-lowering effects of FC.MethodsTwo phase 3 studies of FC for treatment of hyperphosphatemia in CKD patients (non-dialysis-dependent, 12 weeks, and hemodialysis, 52 weeks), were retrospectively analyzed. Patients were divided into with or without concomitant GASI and levels of iron- and phosphate-related parameters were analyzed.ResultsIn non-dialysis study (FC, 60 patients; placebo, 30 patients), 14 FC patients and 14 placebo patients used GASI. No significant differences were found between the FC and placebo groups for adjusted mean differences (95% CI) of changes from baseline to end of treatment (EOT) in serum ferritin [104.84 ng/mL (35.97, 173.71) with GASI vs 145.30 ng/mL (96.34, 194.25) without GASI, P = 0.34], and transferrin saturation (TSAT) [12.56% (− 0.83, 25.95) with GASI vs 18.56% (8.15, 28.98) without GASI, P = 0.49]. In hemodialysis study, 95/180 patients used GASI. Mean changes (SD) from baseline to EOT in serum ferritin were 166.32 ng/mL (153.70) with GASI and 155.16 ng/mL (139.47) without GASI, and for TSAT were 16.60% (19.44) with GASI and 16.02% (18.81) without GASI. In both studies, there were no differences in the changes from baseline to EOT in serum phosphate between with and without GASI cohorts.ConclusionGASI did not influence on the changes in serum ferritin, TSAT and serum phosphate by FC administration.

Protein and Phosphate Intakes are Associated with Hyperphosphatemia in Hemodialysis Patients at Sanglah Hospital, Bali, Indonesia

Increased chronic kidney disease (CKD) mortality rate is significantly associated with increased blood phosphate levels. Hyperphosphatemia control is one of the main focuses in the management of hemodialysis (HD) patients. A high protein diet has been suggested to prevent malnutrition in hemodialysis patients. However, a high protein and phosphorus diet has the risk of increasing the phosphate level in the blood circulation, leading to a higher mortality rate of hemodialysis patients. This study aimed to prove that the level of protein and phosphate intake is associated with hyperphosphatemia in CKD patients with routine HD. This was cross-sectional analytical study conducted from September to October 2020 on 66 CKD patients who underwent hemodialysis. Subject characteristics and phosphorus and protein intake data were obtained from a questionnaire food recall adapted from the Food and Agriculture Organization of the United Nations. Data consumption patterns were processed using the nutritional survey software to obtain the nutritional values. Data were analyzed using the Chi-Square test to identify the relationship and risk between hyperphosphatemia and diet protein, phosphorus, and protein-phosphorus ratio. The confidence level in this study was 95%. There was a significant relationship between protein and phosphorus intake in hyperphosphatemia in CKD patients. The risk factors for hyperphosphatemia were high phosphorus intake (p=0.018; OR=3.886;95% CI: 1.212–12.460) and adequate protein intake (p=0.035; OR=3.674; 95% CI: 1.049-12.865). This study showed no significant relationship between phosphorus-protein ratio, protein-phosphorus ratio, and hyperphosphatemia incidence. In conclusion, high protein intake and excessive phosphorus intake provide a significant relationship to the incidence of hyperphosphatemia in CKD patients undergoing routine hemodialysis.

Phosphate restriction using a processed clay mineral reduces vascular pathologies and microalbuminuria in rats with chronic renal failure

BackgroundThe progression of chronic kidney disease (CKD) is associated with an increasing risk of cardiovascular morbidity and mortality due to elevated serum phosphate levels. Besides low phosphate diets and hemodialysis, oral phosphate binders are prescribed to treat hyperphosphatemia in CKD patients. This study reports on a processed clay mineral as a novel and efficient phosphate sorbent with comparable efficacy of a clinically approved phosphate binder.Methods5/6 nephrectomized rats, which develop chronic renal failure (CRF), received a high phosphate and calcium diet supplemented with either a processed Montmorillonite-Illite clay mineral (pClM) or lanthanum carbonate (LaC) for 12 weeks. Levels of plasma uremic toxins, glomerular filtration rates and microalbuminuria were determined and the histomorphology of blood vessels and smooth muscle cells was analyzed.Results5/6 nephrectomy induced an increase in plasma uremic toxins levels and progressive proteinuria. Treatment of CRF rats with pClM decreased observed vascular pathologies such as vascular fibrosis, especially in coronary vessels. The transition of vascular smooth muscle cells from a contractile to a secretory phenotype was delayed. Moreover, pClM administration resulted in decreased blood creatinine and urea levels, and increased glomerular filtration rates, reduced microalbuminuria and eventually the mortality rate in CRF rats.ConclusionOur study reveals pClM as a potent phosphate binding agent with beneficial impacts on pathophysiological processes in an animal model of CKD. pClM effectively attenuates the progression of vascular damage and loss of renal function which are the most severe consequences of chronic renal failure.

Hyperphosphatemia increases inflammation to exacerbate anemia and skeletal muscle wasting independently of FGF23-FGFR4 signaling.

Elevations in plasma phosphate concentrations (hyperphosphatemia) occur in chronic kidney disease (CKD), in certain genetic disorders, and following the intake of a phosphate-rich diet. Whether hyperphosphatemia and/or associated changes in metabolic regulators, including elevations of fibroblast growth factor 23 (FGF23) directly contribute to specific complications of CKD is uncertain. Here, we report that similar to patients with CKD, mice with adenine-induced CKD develop inflammation, anemia, and skeletal muscle wasting. These complications are also observed in mice fed high phosphate diet even without CKD. Ablation of pathologic FGF23-FGFR4 signaling did not protect mice on an increased phosphate diet or mice with adenine-induced CKD from these sequelae. However, low phosphate diet ameliorated anemia and skeletal muscle wasting in a genetic mouse model of CKD. Our mechanistic in vitro studies indicate that phosphate elevations induce inflammatory signaling and increase hepcidin expression in hepatocytes, a potential causative link between hyperphosphatemia, anemia, and skeletal muscle dysfunction. Our study suggests that high phosphate intake, as caused by the consumption of processed food, may have harmful effects irrespective of pre-existing kidney injury, supporting not only the clinical utility of treating hyperphosphatemia in CKD patients but also arguing for limiting phosphate intake in healthy individuals.

A safety evaluation of sucroferric oxyhydroxide for the treatment of hyperphosphatemia

ABSTRACT Introduction Hyperphosphatemia is a common complication as chronic kidney disease (CKD) progresses and most patients undergoing dialysis are prescribed oral phosphate binder therapy to control serum phosphate concentrations. Sucroferric oxyhydroxide is an iron-based phosphate binder approved for the treatment of hyperphosphatemia in CKD patients on dialysis. Areas covered This article reviews key safety and effectiveness data for sucroferric oxyhydroxide from both prospective clinical trials and real-world observational studies. Expert opinion Sucroferric oxyhydroxide potently binds dietary phosphate in the gastrointestinal (GI) tract, resulting in effective reduction of serum phosphate concentrations with a relatively low daily pill burden. Data from clinical trials and real-world observational studies show sucroferric oxyhydroxide has a favorable safety and tolerability profile. The most frequent side effects observed with sucroferric oxyhydroxide are GI-related, mainly discolored (black) stools and mild or moderate transient diarrhea, both of which are manageable. There is minimal systemic iron absorption from sucroferric oxyhydroxide, and therefore the drug is associated with a low risk of iron accumulation. Sucroferric oxyhydroxide also displays low potential for drug–drug interactions with other commonly prescribed oral medications. Overall, sucroferric oxyhydroxide offers an effective and well-tolerated treatment option for the management of hyperphosphatemia.

Hyperphosphatemia and Cardiovascular Disease.

Hyperphosphatemia or even serum phosphate levels within the “normal laboratory range” are highly associated with increased cardiovascular disease risk and mortality in the general population and patients suffering from chronic kidney disease (CKD). As the kidney function declines, serum phosphate levels rise and subsequently induce the development of hypertension, vascular calcification, cardiac valvular calcification, atherosclerosis, left ventricular hypertrophy and myocardial fibrosis by distinct mechanisms. Therefore, phosphate is considered as a promising therapeutic target to improve the cardiovascular outcome in CKD patients. The current therapeutic strategies are based on dietary and pharmacological reduction of serum phosphate levels to prevent hyperphosphatemia in CKD patients. Large randomized clinical trials with hard endpoints are urgently needed to establish a causal relationship between phosphate excess and cardiovascular disease (CVD) and to determine if lowering serum phosphate constitutes an effective intervention for the prevention and treatment of CVD.

Phosphate binders in chronic kidney disease: an updated narrative review of recent data.

Chronic kidney disease (CKD) is frequently accompanied by hyperphosphatemia. High serum phosphate usually requires dietary measures, adequate dialysis prescription and/or phosphate binders. For this narrative review a PubMed searched was undertaken to identify new publications on phosphate binders that had been published between January 2015 and July 2019. The present review summarizes this most recent information on dietary measures and their problems in treating hyperphosphatemia in CKD patients, overall effects of phosphate binders on cardiovascular mortality and morbidity, adherence to phosphate binder therapy as well as new data on specific aspects of the various phosphate binders on the market: calcium-containing phosphate binders, polymeric phosphate binders (sevelamer, bixalomer, colestilan), magnesium-containing phosphate binders, lanthanum carbonate, ferric citrate, sucroferric oxyhydroxide, and new compounds in development, in particular drugs targeting intestinal phosphate transporters.

FGF23 and Phosphate-Cardiovascular Toxins in CKD.

Elevated levels of fibroblast growth factor 23 (FGF23) and phosphate are highly associated with increased cardiovascular disease and mortality in patients suffering from chronic kidney disease (CKD). As the kidney function declines, serum phosphate levels rise and subsequently induce the secretion of the phosphaturic hormone FGF23. In early stages of CKD, FGF23 prevents the increase of serum phosphate levels and thereby attenuates phosphate-induced vascular calcification, whereas in end-stage kidney disease, FGF23 fails to maintain phosphate homeostasis. Both hyperphosphatemia and elevated FGF23 levels promote the development of hypertension, vascular calcification, and left ventricular hypertrophy by distinct mechanisms. Therefore, FGF23 and phosphate are considered promising therapeutic targets to improve the cardiovascular outcome in CKD patients. Previous therapeutic strategies are based on dietary and pharmacological reduction of serum phosphate, and consequently FGF23 levels. However, clinical trials proving the effects on the cardiovascular outcome are lacking. Recent publications provide evidence for new promising therapeutic interventions, such as magnesium supplementation and direct targeting of phosphate and FGF receptors to prevent toxicity of FGF23 and hyperphosphatemia in CKD patients.

High-phosphate induced vascular calcification is reduced by iron citrate through inhibition of extracellular matrix osteo-chondrogenic shift in VSMCs

BackgroundHigh serum phosphate (Pi) levels strongly associate with cardiovascular morbidity and mortality in chronic kidney disease (CKD) patients with vascular calcification playing a major role in the pathogenesis of related cardiovascular disease. High-Pi challenged vascular smooth muscle cells (VSMCs) undergo simil-osteoblastic transformation and actively deposit calcium-phosphate crystals. Iron-based Pi-binders are used to treat hyperphosphatemia in CKD patients. MethodsIn this study, we investigated the direct effect of iron citrate on extracellular matrix (ECM) modification induced by high-Pi, following either prophylactic or therapeutic approach. ResultsIron prophylactically prevents and therapeutically blocks high-Pi induced calcification. Masson’s staining highlights the changes of muscular ECM that after high-Pi stimulation becomes fibrotic and which modifications are prevented or partially reverted by iron. Interestingly, iron preserves glycogen granules and either prevents or partially reverts the formation of non-glycogen granules induced by high-Pi. In parallel, iron addition is able to either prevent or block the high-Pi induced acid mucin deposition. Iron inhibited calcification also by preventing exosome osteo-chondrogenic shift by reducing phosphate load (0,61 ± 0.04vs0,45 ± 0.05, PivsPi + Fe, p < 0,05, nmol Pi/mg protein) and inducing miRNA 30c (0.62 ± 0.05vs3.07 ± 0.62; PivsPi + Fe, p < 0.01, relative expression). Studying aortic rings, we found that iron significantly either prevents or reverts the high-Pi induced collagen deposition and the elastin decrease, preserving elastin structure (0.7 ± 0.1 vs 1.2 ± 0.1; Pi vs Pi + Fe, p < 0.05, elastin mRNA relative expression). ConclusionsIron directly either prevents or partially reverts the high-Pi induced osteo-chondrocytic shift of ECM. The protection of muscular nature of VSMC ECM may be one of the mechanisms elucidating the anti-calcific effect of iron.

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.

Effects of Expelling of Induced Hypersalivation on Serum Phosphorus, Urea and Creatinine Levels in End Stage Renal Disease Patients

Introduction: Saliva has hundreds of components that may serve to detect systemic diseases or as evidence of exposure to various harmful substances, as well as provide biomarkers of health and disease status. Pilocarpine has effects on serum urea, creatinine and phosphorus in patients with chronic kidney disease (CKD) and patients with End Stage Renal Disease (ESRD) on hemodialysis. Pilocarpine is a parasympathomimetic drug used to induce hypersalivation. Parasympathetic stimulation leads to acetylcholine (ACh) release into the salivary acinar cells. ACh causes the salivary gland to release kallikrein, an enzyme that converts kininogen to lysyl-bradykinin. Lysyl-bradykinin acts upon blood vessels and capillaries of the salivary gland to generate vasodilation and increased capillary permeability respectively. The resulting increased blood flow to the acini allows production of more saliva. Aim of work: To determine the effects of expelling induced hyper salivation on serum Phosphorus, urea and creatinine levels in CKD and ESRD patients. Materials and Methods: It is a case control study which included 80 patients divided into Group A: 40 patients with End Stage Renal Disease on Hemodialysis for at least six months in Assiut University Hospital and Group B: 40 patients with Chronic Kidney Disease (stage 3,4) on conservative medical treatment. Both groups were complaining of hyperphosphatemia. Their ages ranged from 18 to 60 years old with mean age ± SD (51 ± 11) pilocarpine mouth washer (4% concentration, 5 ml pilocarpine which equals 13 mg, three times daily) is given for two months. Results:. After pilocarpine intake; there was a decrease in serum phosphorus level in CKD patients (33%) than those with ESRD (30%). But there was a decrease in serum creatinine level in ESRD patients (23%) than those with CKD patients (15%). The two groups had the same percentage of decrease in blood urea level (40%). In salivary measures after pilocarpine intake; one hundred percent increase in phosphorus excretion in both group but patients with ESRD showed more creatinine excretion compared to patients with CKD (84% vs. 60%). CKD patients had more urea excretion in saliva versus to patients with ESRD (100% and 55%) respectively. Conclusion: Pilocarpine has a role in improving hyperphosphatemia in CKD patients and ESRD patients, also pilocarpine led to decrease in serum urea and creatinine levels so it can be used as an adjuvant therapy in CKD and ESRD patients.

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

AIMSIn 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 methodsA 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.ResultsAt 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.ConclusionsLC is a cost-effective second line treatment of hyperphosphatemia in CKD patients irrespective of dialysis status in Spain.

Iron-based phosphate binders: do they offer advantages over currently available phosphate binders?

Increased cardiovascular morbidity and mortality has been associated with the hyperphosphatemia seen in patients with end-stage chronic kidney disease (CKD). Oral phosphate binders are prescribed in these patients to prevent intestinal absorption of dietary phosphate and reduce serum phosphate. In prospective observational cohorts they have shown to decrease all-cause and cardiovascular mortality risk. Different problems have been associated with currently available phosphate binders as positive calcium balance and impaired outcomes with calcium-based phosphate binders or increased costs with non-calcium-based phosphate binders. Iron-based phosphate binders represent a new class of phosphate binders. Several iron-based phosphate binders have undergone testing in clinical trials. Ferric citrate (JTT-751) and sucroferric oxyhydroxide (PA21) are the two iron-based binders that have passed to the clinical field after being found safe and effective in decreasing serum phosphate. Iron from ferric citrate is partially absorbed compared to sucroferric oxyhydroxide. Ferric citrate usage could result in an important reduction in erythropoiesis-stimulating agent (ESA) and IV iron usage, resulting in significant cost savings. Sucroferric oxyhydroxide was effective in lowering serum phosphorus in dialysis patients with similar efficacy to sevelamer carbonate, but with lower pill burden, and better adherence. Ferric citrate may be more suited for the treatment of chronic hyperphosphatemia in CKD patients requiring iron supplements but its use may have been hampered by potential aluminum overload, as citrate facilitates its absorption; sucroferric oxyhydroxide may be more suited for hyperphosphatemic CKD patients not requiring iron supplementation, with low pill burden.

Efficacy and safety of lanthanum carbonate in pre-dialysis CKD patients with hyperphosphatemia: a randomized trial.

Lanthanum carbonate (LC), an effective non-calcium phosphate binder is widely used to manage hyperphosphatemia in patients with chronic kidney disease (CKD) on dialysis. Recently, the additional indication for control of hyperphosphatemia in CKD patients not on dialysis has been approved. A multicenter, randomized, double-blind, placebo-controlled trial to confirm the efficacy and safety of LC in Japanese hyperphosphatemic stage 4 - 5 CKD patients not on dialysis. After a 4-week run-in period, 143 eligible subjects with serum phosphate levels of 5.6 - 11.0 mg/dL were randomized (2 : 1) to receive LC or placebo (88 vs. 55) for 8 weeks; 119 subjects completed the study (76 vs. 43). The starting LC dose was 750 mg/day, which was then up-titrated to 2,250 mg/day as needed while tolerated. Primary efficacy analysis was performed on the intent-to-treat (ITT) population of 141 patients (86 vs. 55). LC produced a significantly greater reduction in serum phosphate level compared with placebo after 8 weeks of treatment (difference, 0.97 (95% CI: 0.58, 1.37) mg/ dL; p < 0.0001). The cumulative proportion of subjects with controlled phosphate levels ≤ 4.6 mg/dL was higher in the LC group than the placebo group (59.56% vs. 10.46%). LC caused significantly greater reductions in serum Ca × P product and urinary phosphate excretion compared with placebo. The safety profile of LC was similar to that of placebo. This study demonstrated the effectiveness of LC to control hyperphosphatemia in pre-dialysis CKD patients.

Next-generation phosphate binders: focus on iron-based binders.

Phosphate excess is associated with increased mortality in patients with chronic kidney disease (CKD) and has recently been linked to accelerated aging. Oral phosphate binders are prescribed to patients with CKD to prevent absorption of dietary phosphate. Currently available binders have been associated with impaired outcomes (calcium-based binders) or are expensive (non-calcium-based binders). Iron-based phosphate binders represent a new class of phosphate binders. Four iron-based phosphate binders have undergone testing in clinical trials. The development of fermagate and SBR759 is currently on hold due to suboptimal and adverse effect profiles in at least some clinical trials. Ferric citrate and sucroferric oxyhydroxide (PA21) are at different stages of application for regulatory approval after being found safe and efficacious in decreasing serum phosphate. Iron from ferric citrate is more readily absorbed than that from sucroferric oxyhydroxide. Sucroferric oxyhydroxide was launched in the USA in 2014 for the treatment of hyperphosphatemia in adult dialysis patients. Ferric citrate may be more suited for chronic treatment of hyperphosphatemia in CKD patients requiring iron supplements but its use may have to be limited in time because of potential for iron overload in patients not needing iron or not receiving erythropoiesis-stimulating agents. In contrast, sucroferric oxyhydroxide may be more suited for hyperphosphatemic CKD patients not requiring iron supplements.

A modeled economic evaluation of sevelamer for treatment of hyperphosphatemia associated with chronic kidney disease among patients on dialysis in the United Kingdom

Objective:There is limited information regarding the cost-effectiveness of sevelamer for the treatment of hyperphosphatemia in chronic kidney disease (CKD) patients on dialysis in the UK. Using a UK National Health Service (NHS) perspective and final results of the Dialysis Clinical Outcomes Revisited (DCOR) study, an evaluation was performed to determine the cost-effectiveness of sevelamer compared to calcium-based phosphate binders for the first-line treatment of hyperphosphatemia in CKD patients on dialysis.Methods:A Markov model was developed to estimate life years, quality-adjusted life years (QALYs), costs, incremental cost per life year (LY) gained, and QALY gained. Treatment-specific overall survival up to 44 months, hospitalizations, and resource utilization were derived from the DCOR study. Survival was extrapolated to a lifetime horizon using Weibull regression analysis. Unit costs and utility estimates specific to the UK were obtained from the published literature. Sub-group analyses were conducted based on data reported from the DCOR study for increasing age cut-points. Outcomes and costs were modeled for a lifetime horizon.Results:In the base case analysis, the use of sevelamer resulted in a gain of ∼0.73 LYs and 0.44 QALYs per patient (discounted at 3.5% per year). Total per-patient costs were higher for sevelamer, resulting in an incremental cost of £22,157 per QALY gained and £13,427 per LY gained (in £2009). Increasingly favorable cost per QALY ratios were observed with increasing age cut-points, ranging from £15,864 for patients ≥45 to £13,296 for patients ≥65 years of age. Results were most sensitive to assumptions regarding overall survival and the inclusion of dialysis costs. Key limitations of the analysis included the use of non-UK trial data for survival and hospitalizations, and the exclusion of quality-of-life impacts associated with hospitalization.Conclusions:In CKD patients receiving dialysis, treatment of hyperphosphatemia with sevelamer offers good value for money compared with calcium-based binders.

Optimising the treatment of hyperphosphatemia and vascular calcification in chronic kidney disease

Accelerated atherosclerosis and vascular calcifications (VC) play a central role in the pathogenesis of cardiovascular disease in chronic kidney disease (CKD) patients. Mineral metabolism disorders and increased serum calcium-phosphate product have been recently investigated as inducing factors of cardiovascular calcification. In fact, cardiovascular disease in renal failure appears greatly associated with bone metabolism alterations. Recently, the treatment of hyperphosphatemia in CKD patients changed from either calcium- or aluminium-based phosphate-binders to new free-calcium and aluminium phosphate binders, such as sevelamer hydrochloride and lanthanum carbonate. Therefore, control of serum phosphate in CKD patients becomes crucial in preventing increases in calcium-phosphate product, secondary hyperparathyroidism and ultimately VC.

Clinical Consequences and Novel Therapy of Hyperphosphatemia: Lanthanum Carbonate for Dialysis Patients

Vascular calcification is a very common event in patients affected by diabetes and chronic kidney disease (CKD). Recently, it has been well documented that abnormalities in mineral and bone metabolism in CKD patients associate with increased morbidity and mortality. Elevated serum phosphate and calcium-phosphate product levels play an important role in the pathogenesis of vascular mineralization in uremic patients and also appear to be associated with increased cardiovascular mortality. Together with classical passive precipitation of calcium-phosphate in soft tissues, during the last decade it has been demonstrated that inorganic phosphate may cause extraskeletal calcification directly through a real "ossification" of the tunica media in the vasculature of CKD patients. Therefore, control of phosphate retention is now an even more crucial target of treatment in patients affected by chronic kidney disease. The "classical" treatment of secondary hyperparathyroidism and hyperphosphatemia in CKD patients consists of either calcium or aluminium based phosphate-binders and calcitriol administration. Unfortunately, this "old generation" therapy is not free of complications. Patents are also reported discussing the role of derivatives of Lanthanum carbonate hydrates are also used for the treatment of hyperphosphataemia in patients with renal failure. New calcium- and aluminium-free phosphate binders, such as sevelamer hydrochloride and lanthanum carbonate, can be used to treat hyperphosphatemia and secondary hyperparathyroidism, reduce atherosclerotic process, and prevent vascular calcification in CKD patients.