Effect of Sucroferric Oxyhydroxide on Fibroblast Growth Factor 23 Levels in Hemodialysis Patients

Etelcalcetide and Paricalcitol in Chronic Kidney Disease: When the Target Is Inflammation

Introduction: secondary hyperparathyroidism (SHP) is frequent in patients with chronic kidney disease (CKD), particularly in those in dialysis. To treat this complication, the current options available include phosphorus restriction, phosphate binders, the inhibition of parathyroid hormone (PTH) synthesis and secretion by the supplementation of vitamin D or VDR activators, or the use of calcimimetics. Beyond the control of PTH, the effects of the treatment of SHP on other biomarkers of risk may represent an additional benefit for this population. In this study, we explore the benefits of current SHP treatment options, mainly paricalcitol and/or etelcalcetide in the inflammatory state of hemodialysis (HD) patients. Results: the study finally included 142 maintenance HD patients (5 patients were excluded) followed for 6 months (dialysis vintage 26 ± 30 months, mean age 70 years old, 73% women, 81% Spanish white, 47% diabetic). In this case, 52 patients were on regular treatment with paricalcitol for SHP and 25 patients were eligible to initiate etelcalcetide. The baseline serum levels of Ca, P, PTH, Ferritin, albumin, C-reactive protein (CRP), and other variables were measured. We found serum PTH levels showed an improvement after the treatment with etelcalcetide again paricalcitol and no treatment (p < 0.04). Of note, serum levels of CRP were significantly lower in a small group of patients (n = 11) receiving paricalcitol + etelcalcetide compared to paricalcitol or etelcalcetide alone. The proportion of patients with CRP within target ranges (≤1.0 mg/dL) increased significantly after combined treatment (p < 0.001). Conclusions: etelcalcetide proved to safely reduce the PTH levels without significant adverse events and the possibility of a synergic anti-inflammatory effect with the simultaneous use of Paricalcitol in HD patients.

Effectiveness of fibroblast growth factor 23 lowering modalities in chronic kidney disease: a systematic review and meta-analysis

INTRODUCTION

The heightened fibroblast growth factor 23 (FGF23) level in patients with chronic kidney disease (CKD) is associated with increased cardiovascular disease and mortality. We performed a systematic review and meta-analysis to synthesize the available strategies to reduce FGF23 in CKD patients.

METHODS

We conducted a meta-analysis by searching the databases of MEDLINE, Scopus, and Cochrane Central Register of Controlled Trials for randomized controlled trials (RCTs) and single-arm studies that examined the effects of dietary phosphate restriction, phosphate binders, iron supplements, calcimimetics, parathyroidectomy, dialysis techniques, and the outcome of preservation of residual renal function (RRF) on FGF23 levels in CKD patients. Random-effects model meta-analyses were used to compute changes in the outcome of interests.

RESULTS

A total of 41 articles (7590 patients), comprising 36 RCTs, 5 prospective studies were included in this meta-analysis. Dietary phosphate restriction less than 800 mg per day yielded insignificant effect on FGF23 reduction. Interestingly sevelamer, lanthanum, iron-based phosphate binders, and iron supplement significantly lowered FGF23 levels. In CKD patients with secondary hyperparathyroidism, calcimimetics prescription could significantly reduce FGF23 levels, while surgical parathyroidectomy had no significant effect. In dialysis patients, preservation of RRF and hemoperfusion as well as hemodiafiltration provided a significant decrease in FGF23 levels.

CONCLUSIONS

The present meta-analysis demonstrated that non-calcium-based phosphate binders including sevelamer, lanthanum, and iron-based phosphate binders, iron supplements, calcimimetics, hemoperfusion, and preservation of RRF could effectively reduce FGF23 in CKD patients.

Using iron-based phosphate binders in phosphate reduction and anemia improvement in patients receiving dialysis: a meta-analysis of randomized controlled trials

PURPOSE

A study was conducted to determine whether iron-based phosphate binders (IBPBs) need to be preferred for hyperphosphatemia and anemia management in patients on dialysis.

METHODS

For this meta-analysis, we searched PubMed, Embase, and Cochrane Central Register of Controlled Trials for randomized controlled trials that evaluated the efficacy and safety of IBPBs in decreasing phosphate and correcting anemia in dialysis patients.

RESULTS

Nineteen trials comprising 4719 participants were included. Compared with placebo, serum phosphate decreased significantly after treatment with ferric citrate (FC), fermagate (one study), and SBR759 (one study). Hemoglobin increased significantly after treatment with FC and sucroferric oxyhydroxide (PA21). In addition, FC and PA21 reduced serum intact parathyroid hormone (iPTH) and increased ferritin and transferrin saturation, but SBR759 did not. Compared with active treatment, the non-inferiority of IBPBs in reducing serum phosphate and iPTH was demonstrated. FC significantly improved serum hemoglobin and iron-related parameters and decreased the use of intravenous iron and erythropoiesis-stimulating agent, whereas PA21 did not increase serum hemoglobin level. The incidences of infection and hospitalization were similar between the two groups, with FC having a higher risk of diarrhea than the placebo and active treatments.

CONCLUSION

FC was associated with the control of hyperphosphatemia and the improvement of anemia. However, PA21 did not show superiority for alleviating anemia compared with the active treatment. Other IBPBs, such as fermagate and SBR759, remained poorly understood due to the limited number of studies. Further trials are required to assess the effect of IBPBs on the risk of cardiovascular events and all-cause mortality.

Clinical Evaluation of the Safety, Efficacy and Tolerability of Lanthanum Carbonate in the Management of Hyperphosphatemia in Patients with End-Stage Renal Disease

Patients with progressive chronic kidney disease (CKD) commonly develop mineral and bone abnormalities and extraskeletal calcifications with following increased cardiovascular risk. A key pathophysiological role is played by hyperphosphatemia. Since diet and dialysis are often insufficient to control serum phosphorus levels, many patients require treatment with phosphate binders. Among them is lanthanum carbonate, an aluminum-free non-calcium-based compound. The present review summarizes the most recent literature data concerning the safety, efficacy and tolerability of lanthanum carbonate in patients with end-stage renal disease and hyperphosphatemia. The drug is taken orally as chewable tablets or powder with only minimal gastrointestinal absorption and resulting reduced risk of tissue deposition and systemic drug interactions. The dissociation of the drug in the acid environment of the upper gastrointestinal tract induces the release of lanthanum ions, which bind to dietary phosphate forming insoluble complexes then excreted in the feces. Even though there is no clear evidence that lowering serum phosphorus levels can improve patient-centered outcomes, a mortality benefit with all phosphate binders, especially non-calcium containing ones, is not excluded. Lanthanum carbonate has been suggested to decrease all-cause mortality but not cardiovascular event rate compared to other phosphate binders. It induces a lower suppression of bone turnover than calcium carbonate and calcium acetate and may improve systolic function and cardiac dimension compared to calcium carbonate. Moreover, the use of lanthanum carbonate has been associated with better nutritional status compared to other phosphate binders, lower risk for hypercalcemia than calcium-containing binders, and amelioration of mild metabolic acidosis contrary to sevelamer hydrochloride. Main adverse effects include nausea, alkaline gastric reflux, gastric deposition of lanthanum, gastrointestinal obstruction, subileus, ileus, perforation, fecal impaction, and reduction of gastrointestinal absorption of some drugs including statins, angiotensin-converting enzyme inhibitors and some antibiotics such as fluoroquinolones or tetracyclines.

Erythropoiesis stimulating agents are associated with serum fibroblast growth factor 23 metabolism in patients on hemodialysis

Background

This study aimed to determine associations among short- and long-acting erythropoiesis stimulating agents (ESAs), changes in serum fibroblast growth factor 23 (FGF23) and biomarkers of iron metabolism.

Methods

Among 108 patients on hemodialysis (HD), 44 received every 2 weeks or monthly doses of continuous erythropoiesis receptor activator (CERA), 31 received weekly doses of darbepoetin-α, 24 received three doses per week of epoetin-β and 9 were not treated with an ESA. Intact and C-terminal FGF23 and transferrin saturation (TSAT), ferritin, erythroferrone and hepcidin 25 were measured in blood samples collected before the HD session at the end of the dialysis week (baseline, Day 0) and on Days 3, 5, 7 and 14 thereafter.

Results

Levels of ferritin, hepcidin 25 and erythroferrone as well as TSAT were significantly decreased or elevated in patients treated with CERA compared with other types of ESAs. Levels of C-terminal FGF23 increased in all groups during the observation period. Levels of intact FGF23 and ratios of intact FGF23 to C-terminal FGF23 gradually decreased between Days 3 and 7 in the CERA but not in the other groups. Multivariate models associated changes in hepcidin 25 and phosphate with those of intact FGF23.

Conclusion

The long-acting ESA CERA might influence levels of intact FGF23 by increasing FGF23 cleavage in patients on HD in association with prolonged hepcidin 25 suppression.

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.

Strategies for Phosphate Control in Patients With CKD

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