Three Times Weekly Dosing of Daprodustat versus Conventional Epoetin for Treatment of Anemia in Hemodialysis Patients: ASCEND-TD: A Phase 3 Randomized, Double-Blind, Noninferiority Trial

BACKGROUND AND OBJECTIVES

Daprodustat is a hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI) being investigated for the treatment of anemia of CKD. In this noninferiority trial, we compared daprodustat administered three times weekly with epoetin alfa (epoetin) in patients on prevalent hemodialysis switching from a prior erythropoiesis-stimulating agent (ESA).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Patients on hemodialysis with a baseline hemoglobin of 8-11.5 g/dl receiving an ESA were randomized 2:1 to daprodustat three times weekly (n=270) or conventional epoetin (n=137) for 52 weeks. Dosing algorithms aimed to maintain hemoglobin between 10 and 11 g/dl. The primary end point was mean change in hemoglobin from baseline to the average during the evaluation period (weeks 28-52). The principal secondary end point was average monthly intravenous iron dose. Other secondary end points included BP and hemoglobin variability.

RESULTS

Daprodustat three times weekly was noninferior to epoetin for mean change in hemoglobin (model-adjusted mean treatment difference [daprodustat-epoetin], -0.05; 95% confidence interval, -0.21 to 0.10). During the evaluation period, mean (SD) hemoglobin values were 10.45 (0.55) and 10.51 (0.85) g/dl for daprodustat and epoetin groups, respectively. Responders (defined as mean hemoglobin during the evaluation period in the analysis range of 10 to 11.5 g/dl) were 80% in the daprodustat group versus 64% in the epoetin group. Proportionately fewer participants in the daprodustat group versus the epoetin group had hemoglobin values either below 10 g/dl or above 11.5 g/dl during the evaluation period. Mean monthly intravenous iron use was not significantly lower with daprodustat versus epoetin. The effect on BP was similar between groups. The percentage of treatment-emergent adverse events was similar between daprodustat (75%) and epoetin (79%).

CONCLUSIONS

Daprodustat was noninferior to epoetin in hemoglobin response and was generally well tolerated.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Anemia Studies in Chronic Kidney Disease: Erythropoiesis via a Novel Prolyl Hydroxylase Inhibitor Daprodustat-Three Times Weekly Dosing in Dialysis (ASCEND-TD), NCT03400033.

Serum Phosphorus and Pill Burden Among Hemodialysis Patients Prescribed Sucroferric Oxyhydroxide: One-Year Follow-Up on a Contemporary Cohort

Purpose

In prior analyses of real-world cohorts of hemodialysis patients switched from one phosphate binder (PB) to sucroferric oxyhydroxide (SO), SO therapy has been associated with improvements in serum phosphorus (sP) and reductions in daily PB pill burden. To characterize how SO initiation patterns have changed over time, we examined the long-term effectiveness of SO in a contemporary (2018–2019) cohort.

Patients and Methods

Adult Fresenius Kidney Care hemodialysis patients first prescribed SO monotherapy as part of routine care between May 2018 and May 2019 (N = 1792) were followed for 1 year. All patients received a non-SO PB during a 91-day baseline period before SO prescription. Mean PB pills/day and laboratory parameters were compared before and during SO treatment. Results were divided into consecutive 91-day intervals (Q1–Q4) and analyzed using linear mixed-effects regression and Cochran’s Q test. These results were contrasted with findings from a historical (2014–2015) cohort (N = 530).

Results

The proportion of patients achieving sP ≤5.5 mg/dl increased after switching to SO (from 27.0% at baseline to 37.8%, 45.1%, 44.7%, and 44.0% at Q1, Q2, Q3, and Q4, respectively; P < 0.0001 for all). The mean daily PB pill burden decreased from a baseline of 7.7 to 4.4, 4.6, 4.8, and 4.9, respectively, across quarters (P < 0.0001 for all). Patients in the contemporary cohort had improved sP control (27.0% achieving sP ≤5.5 mg/dl vs 17.7%) and lower daily PB pill burden (mean 7.7 vs 8.5 pills/day) at baseline than those in the historical cohort. Overall use of active vitamin D was similar between cohorts, although higher use of oral active vitamin D (63.9% vs 15.7%) and lower use of IV active vitamin D lower (23.4% vs 74.2%) was observed in the contemporary cohort.

Conclusion

Despite evolving treatment patterns, switching to SO resulted in improved sP control with fewer pills per day in this contemporary hemodialysis cohort.

Groundhog Day: research without old data and old references

BACKGROUND

The use of older data and references is becoming increasingly disfavored for publication. A myopic focus on newer research risks losing sight of important research questions already addressed by now-invisible older studies. This creates a 'Groundhog Day' effect as illustrated by the 1993 movie of this name in which the protagonist has to relive the same day (Groundhog Day) over and over and over within a world with no memory of it. This article examines the consequences of the recent preference for newer data and references in current publication practices and is intended to stimulate new consideration of the utility of selected older data and references for the advancement of scientific knowledge.

METHODS

Examples from the literature are used to exemplify the value of older data and older references. To illustrate the recency of references published in original medical research articles in a selected sample of recent academic medical journals, original research articles were examined in recent issues in selected psychiatry, medicine, and surgery journals.

RESULTS

The literature examined reflected this article's initial assertion that journals are emphasizing the publication of research with newer data and more recent references.

CONCLUSIONS

The current valuation of newer data above older data fails to appreciate the fact that new data eventually become old, and that old data were once new. The bias demonstrated in arbitrary policies pertaining to older data and older references can be addressed by instituting comparable treatment of older and newer data and references.

Sucroferric oxyhydroxide for hyperphosphatemia: a review of real-world evidence

Hyperphosphatemia is a common complication in dialysis-dependent patients with chronic kidney disease. Most dialysis-dependent patients need oral phosphate binder therapy to control serum phosphorus concentrations. Most phosphate binders have a high daily pill burden, which may reduce treatment adherence and impair phosphorus control. Sucroferric oxyhydroxide is a potent iron-based phosphate binder approved for use in dialysis-dependent patients in 2013. A randomized controlled trial of sucroferric oxyhydroxide demonstrated its efficacy for reduction of serum phosphorus with a lower pill burden than sevelamer carbonate. Clinical trials carefully select patients, monitor adherence, and routinely titrate medications to a protocol-defined goal. Consequently, trials may not reflect real-world use of medications. Since its approval, we and others have performed retrospective and prospective analyses of sucroferric oxyhydroxide in real-world clinical practice in > 6400 hemodialysis and approximately 500 peritoneal dialysis patients in the USA and Europe. Consistent with the clinical trial data, real-world observational studies have demonstrated that sucroferric oxyhydroxide can effectively reduce serum phosphorus with a lower daily pill burden than most other phosphate binders. These studies have also shown sucroferric oxyhydroxide provides effective serum phosphorus control in different treatment settings, including as monotherapy in phosphate binder-naïve patients, in patients switching from other phosphate binders, or when used in combination with other phosphate binders. These observational studies indicate a favorable safety and tolerability profile, and minimal, if any, systemic iron absorption. This article reviews the key results from these observational studies of sucroferric oxyhydroxide and evaluates its role in the management of hyperphosphatemia in clinical practice.

Phosphate Balance and CKD-Mineral Bone Disease

Chronic kidney disease–mineral bone disorder (CKD-MBD) is a common comorbidity in patients with CKD. Characterized by laboratory abnormalities, bone abnormality, and vascular calcification, CKD-MBD encompasses a group of mineral and hormone disturbances that are strongly associated with increased cardiovascular (CV) morbidity and mortality. Abnormal serum phosphate concentrations are an independent risk factor for CV morbidity and mortality, and overall mortality. Phosphate retention plays a central role in initiating and driving many other disturbances in CKD-MBD (e.g., increased parathyroid hormone and fibroblast growth factor 23 concentrations, hypocalcemia, low vitamin D) that are also linked to increased CV risk. Thus, effective phosphate control is a logical therapeutic target for CKD-MBD treatment. Current phosphate management strategies (dietary restrictions, dialysis, phosphate binders) are insufficient to consistently achieve and maintain target phosphate concentrations in patients on dialysis. Phosphate binders reduce available phosphate for intestinal absorption but do not impair the dominant phosphate absorption pathway. Novel therapies that consider new mechanistic understandings of intestinal phosphate absorption are needed. One such therapy is tenapanor, a targeted sodium-hydrogen exchanger isoform 3 inhibitor that has been shown to reduce serum phosphate concentrations in multiple clinical trials. Tenapanor has a novel mechanism of action that reduces intestinal phosphate absorption in the primary paracellular phosphate absorption pathway.

Roxadustat for CKD-related Anemia in Non-dialysis Patients

Introduction

Roxadustat is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor that stimulates erythropoiesis and improves iron metabolism. We assessed the efficacy and tolerability of roxadustat in patients with chronic kidney disease (CKD)-related anemia not on dialysis.

Methods

ANDES was a global Phase 3 randomized study in which adults with stage 3–5 CKD not on dialysis received roxadustat or placebo. Patients were initially dosed thrice weekly; dose was titrated to achieve a hemoglobin level ≥11.0 g/dl, followed by titration for maintenance. The primary endpoints were change in hemoglobin (weeks 28–52) and proportion of patients achieving a hemoglobin response (hemoglobin ≥11.0 g/dl and increase ≥1.0 g/dl [baseline >8.0 g/dl], or increase ≥2.0 g/dl [baseline ≤8.0 g/dl]) (week 24). Treatment-emergent adverse events (TEAEs) and serious adverse events (TESAEs) were recorded.

Results

In roxadustat (n = 616) and placebo (n = 306) groups, hemoglobin mean (SD) change from baseline over weeks 28–52 was significantly larger for roxadustat (2.00 [0.95]) versus placebo (0.16 [0.90]), corresponding to least-squares mean difference of 1.85 g/dl (95% confidence interval [CI] 1.74–1.97; P < 0.0001). The proportion of patients achieving a response at week 24 was larger for roxadustat (86.0%; 95% CI 83.0%–88.7%) versus placebo (6.6%; 95% CI 4.1%–9.9%; P < 0.0001). The proportion of patients receiving rescue therapy at week 52 was smaller for roxadustat (8.9%) versus placebo (28.9%); hazard ratio, 0.19 (95% CI 0.14–0.28; P < .0001). The incidences of TEAEs and TESAEs were comparable.

Conclusion

This study showed that roxadustat corrected and maintained hemoglobin and was well tolerated in patients with CKD-related anemia not on dialysis (ClinicalTrials.gov NCT01750190).

Hyperleptinemia in Patients with End-Stage Renal Disease Undergoing Continuous Ambulatory Peritoneal Dialysis

Objective

To determine whether the increased plasma leptin levels reported in hemodialyzed patients is a feature of end-stage renal disease or an artifact of hemodialysis, we studied plasma levels in patients treated exclusively by continuous ambulatory peritoneal dialysis (CAPD).

Design

Prospective comparison of end points in CAPD patients and matched healthy subjects.

Setting

Tertiary care institutional dialysis center.

Participants

Fifty-six healthy subjects, age 50.8 ± 2.3 years, body mass index (BMI) 27.7 ± 1.3 kg/m2, recruited through public announcement, and 36 patients with end-stage renal disease, age 51.0 ± 2.4 yr, BM128.2 ± 1.3 kg/m2, enrolled in a CAPD treatment program.

Intervention

Four exchanges of CAPD per day, using 2.0, 2.5, or 3.0 L of dialysate over a period of 1 -96 months (median 22 mth).

Main Outcome Measures

The primary outcome measure was plasma leptin concentration. Secondary measures included plasma glucose, insulin, C-peptide, and cortisol concentrations; and residual renal function and dialysis adequacy (Kt/V).

Results

Plasma leptin levels in CAPD patients were 27.1 -490 ng/mL(women)and 1.3 -355 ng/mL(men); the levels in healthy subjects were 2.0 84.7 ng/mL (women) and 1.8 -55.4 ng/mL (men). The mean leptin levels were 5-fold higher among CAPD-treated men than control men (49.9 ± 18.4 vs 9.8 ± 2.5 ng/mL, p < 0.001) and 7.5-fold higher among CAPD-treated women than control women (220 ± 28.1 vs 29.3 ± 3.7 ng/mL, p < 0.0001). Female gender and BMI were the strongest predictors of hyperleptinemia in CAPD patients.

Conclusion

These results indicate that hyperleptinemia is a feature of terminal renal failure, not an artifact of hemodialysis.

Sotatercept Safety and Effects on Hemoglobin, Bone, and Vascular Calcification

INTRODUCTION

Patients with end-stage kidney disease (ESKD) exhibit anemia, chronic kidney disease‒mineral bone disorder (CKD-MBD), and cardiovascular disease. The REN-001 and REN-002 phase II, multicenter, randomized studies examined safety, tolerability, and effects of sotatercept, an ActRIIA-IgG1 fusion protein trap, on hemoglobin concentration; REN-001 also explored effects on bone mineral density (BMD) and abdominal aortic vascular calcification.

METHODS

Forty-three patients were treated in REN-001 (dose range: sotatercept 0.3‒0.7 mg/kg or placebo subcutaneously [s.c.] for 200 days) and 50 in REN-002 (dose range: 0.1‒0.4 mg/kg i.v. and 0.13‒0.5 mg/kg s.c. for 99 days).

RESULTS

In REN-001, frequency of achieving target hemoglobin response (>10 g/dl [6.21 mmol/l]) with sotatercept was dose-related and greater than placebo (0.3 mg/kg: 33.3%; 0.5 mg/kg: 62.5%; 0.7 mg/kg: 77.8%; 0.7 mg/kg [doses 1 and 2]/0.4 mg/kg [doses 3‒15]: 33.3%; placebo: 27.3%). REN-002 hemoglobin findings were similar (i.v.: 16.7%-57.1%; s.c.: 11.1%‒42.9%). Dose-related achievement of ≥2% increase in femoral neck cortical BMD was seen among only REN-001 patients receiving sotatercept (0.3‒0.7 mg/kg: 20.0%‒57.1%; placebo: 0.0%). Abdominal aortic vascular calcification was slowed in a dose-related manner, with a ≤15% increase in Agatston score achieved by more REN-001 sotatercept versus placebo patients (60%‒100% vs. 16.7%). The most common adverse events during treatment were hypertension, muscle spasm, headache, arteriovenous fistula site complication, and influenza observed in both treatment and placebo groups.

CONCLUSION

In patients with ESKD, sotatercept exhibited a favorable safety profile and was associated with trends in dose-related slowing of vascular calcification. Less-consistent trends in improved hemoglobin concentration and BMD were observed.

Changes in serum albumin and other nutritional markers when using sucroferric oxyhydroxide as phosphate binder among hemodialysis patients: a historical cohort study

Background

Elevated serum phosphorus concentrations are common among maintenance hemodialysis patients. Protein is a major source of dietary phosphate, but restriction of protein intake can result in hypoalbuminemia and protein-energy wasting. We hypothesized that sucroferric oxyhydroxide (SO), a potent phosphate binder with a low pill burden, may reduce serum phosphorus levels in hemodialysis patients with hypoalbuminemia without adversely impacting albumin levels or dietary intake of protein.

Methods

We retrospectively examined de-identified data from 79 adult, in-center hemodialysis patients with baseline hypoalbuminemia (≤ 3.5 g/dL) switched to SO as part of routine clinical care for at least 1 year. Temporal changes (3-month intervals from baseline through Q4) in phosphate binder pill burden, serum phosphorous levels, nutritional markers, and equilibrated Kt/V were analyzed. Data from a matched reference group of non-hypoalbuminemic patients (N = 79) switched to SO were also examined.

Results

SO therapy was associated with a mean reduction of 45.7 and 45.1% in daily phosphate binder pill burden, and a mean reduction of 0.4 mg/dL and 0.51 mg/dL in serum phosphorus levels for the hypoalbuminemic and non-hypoalbuminemic patients, respectively. Hypoalbuminemic patients demonstrated significant increases in mean serum albumin levels from 3.50 mg/dL at baseline to 3.69, 3.74, 3.70, and 3.69 mg/dL during Q1 through Q4, respectively (P < 0.0001), whereas serum albumin levels remained unchanged in the non-hypoalbuminemic group.

Conclusions

Both hypoalbuminemic and non-hypoalbuminemic patients switching to SO exhibited significant reductions in serum phosphorus concentrations and daily phosphate binder pill burden. Among hypoalbuminemic patients, the initiation of SO therapy was also associated with increases in serum albumin, suggesting therapy may have allowed patients to increase their dietary intake of protein.

Effects of bardoxolone methyl on body weight, waist circumference and glycemic control in obese patients with type 2 diabetes mellitus and stage 4 chronic kidney disease

AIMS

Obesity is associated with progression of chronic kidney disease (CKD). Treatment with bardoxolone methyl in a multinational phase 3 trial, Bardoxolone Methyl Evaluation in Patients with Chronic Kidney Disease and Type 2 Diabetes (BEACON), resulted in increases in estimated glomerular filtration rate (eGFR) with concurrent reductions in body weight. We performed post-hoc analyses to further characterize reductions in body weight with bardoxolone methyl.

METHODS

Eligible patients with type 2 diabetes (T2DM) and CKD stage 4 (eGFR 15 to <30 mL/min/1.73 m²) were randomized 1:1 to receive once-daily oral dose of bardoxolone methyl (20 mg) or placebo.

RESULTS

BEACON enrolled 2185 patients. Patients randomized to bardoxolone methyl experienced significant reductions in body weight from baseline relative to patients randomized to placebo (-5.7 kg; 95% CI: -6.0 to -5.3 kg; p < 0.001). In patients randomized to bardoxolone methyl, rate and magnitude of body weight loss were proportional to baseline BMI. Bardoxolone methyl resulted in significant reductions in waist circumference and improved glycemic control.

CONCLUSIONS

Bardoxolone methyl resulted in significant weight loss in a generally obese patient population with T2DM and stage 4 CKD, with the magnitude and rate dependent on baseline BMI.

Real-World Scenario Improvements in Serum Phosphorus Levels and Pill Burden in Peritoneal Dialysis Patients Treated with Sucroferric Oxyhydroxide

BACKGROUND

A database analysis was conducted to assess the effectiveness of sucroferric oxyhydroxide (SO) on lowering serum phosphorus and phosphate binder (PB) pill burden among adult peritoneal dialysis (PD) patients prescribed SO as part of routine care.

METHODS

Adult PD patients (n = 258) prescribed SO through a renal pharmacy service were analyzed. Baseline was 3 months before SO prescription. SO-treated follow-up was for 6 months or until either a new PB was prescribed, SO was not refilled, PD modality changed, or patient was discharged. In-range serum phosphorus was defined as ≤5.5 mg/dL.

RESULTS

At baseline, mean serum phosphorus was 6.59 mg/dL with 10 prescribed PB pills/day. The proportion of patients achieving in-range serum phosphorus increased by 72% from baseline to month 6. Prescribed PB pills/day decreased by 57% (10 at baseline to 4.3 at SO follow-up, p < 0.0001). The mean length of SO follow-up was 5.1 months; SO follow-up ended for 38, 27, and 50 patients at months 4, 5, and 6, respectively, due to no further PB fills, and for 10, 11, and 4 patients at months 4, 5, and 6, respectively, due to another PB prescribed. In patients with baseline serum phosphorus >5.5 mg/dL who achieved in-range serum phosphorus during SO follow-up for ≥1 quarter, a notable improvement in serum phosphorus (6.54 to 5.10 mg/dL, p < 0.0001) was observed, and there was a 53% reduction in PB pill burden (9.9 to 4.7, p < 0.0001).

CONCLUSION

Among PD patients prescribed SO as part of routine care, improvements in serum phosphorus control and >50% reduction in PB pills/day were observed.

Iron Treatment Strategies in Dialysis-Dependent CKD

Iron deficiency is common in patients on chronic dialysis, and most require iron-replacement therapy. In addition to absolute iron deficiency, many patients have functional iron deficiency as shown by a suboptimal response to the use of erythropoietin-stimulating agents. Both absolute and functional iron-deficiency anemia have been shown to respond to intravenous (IV) iron replacement. Although parenteral iron is an efficacious method and superior to standard doses of oral iron in patients on hemodialysis, there are ongoing safety concerns about repeated exposure potentially enhancing infection risk and cardiovascular disease. Each IV iron product is composed of an iron core with a carbohydrate shell. The avidity of iron binding and the type of carbohydrate shell play roles in the safe maximal dose and the frequency and severity of acute infusion reactions. All IV iron products are taken up into the reticuloendothelial system where the shell is metabolized and the iron is stored within tissue ferritin or exported to circulating transferrin. IV iron can be given as large intermittent doses (loading therapy) or in smaller doses at frequent intervals (maintenance dosing regimen). Limited trial data and observational data suggest that a maintenance dosing regimen is more efficacious and possibly safer than loading therapy. There is no consensus regarding the preferred method of iron repletion in patients on peritoneal dialysis, although small studies comparing oral and parenteral iron regimens in these patients have shown the latter to be more efficacious. Use of IV iron in virtually all hemodialysis and many peritoneal dialysis patients remains the standard of care.

New options for the anemia of chronic kidney disease

Anemia is a common complication of chronic kidney disease. Use of erythropoiesis-stimulating agents (ESA) has been a mainstay of treatment since 1990. A series of large trials demonstrated that ESAs have serious safety problems, including increasing cardiovascular and thrombotic events, and death. Analyses suggest high pharmacologic doses of ESAs, rather than the highly achieved hemoglobin, may mediate harm. Hypoxia-inducible factor (HIF) activators stimulate endogenous erythropoietin production and enhance iron availability. In early clinical trials, these oral agents appear to be capable of replacing ESA therapy and minimizing the need for i.v. iron therapy for chronic kidney disease–related anemia, while having other potentially advantageous actions. Large phase 3 trials are underway with several HIF activators. This commentary reviews trends in anemia management, the safety issues related to our present therapies, the role of HIF in regulating erythropoiesis, and the diverse actions of HIF activators.

Use of 2MD, a Novel Oral Calcitriol Analog, in Hemodialysis Patients with Secondary Hyperparathyroidism

BACKGROUND

Use of existing therapies for secondary hyperparathyroidism (SHPT), such as calcitriol or paricalcitol, is frequently limited by the development of hypercalcemia. 2-Methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D3 (2MD; DP001) is a novel and a more potent vitamin D receptor activator (VDRA) that more selectively localizes in the parathyroid gland, and has a wider therapeutic margin in the uremic rat model than calcitriol and paricalcitol.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Hemodialysis patients were enrolled and dosed with 110, 220, 330, 440, or 550 ng of 2MD orally thrice weekly for 4 weeks. Responders were defined as patients having a ≥30% reduction in parathyroid hormone (PTH) from baseline, and were assessed at weeks 2 and 4.

RESULTS

Of 31 patients recruited, 24 completed the 4-week treatment. There was little or no reduction in PTH in the 110 and 220 ng dose cohorts. Higher dose cohorts had greater PTH suppression with more than half the patients in the 440 and 550 ng dose cohorts considered responders (≥30% PTH reduction from baseline). None had oversuppression of PTH or hypercalcemia (corrected serum calcium >10.6 mg/dl). Plasma drug concentration increased with increasing dose, and all responders achieved a 2MD concentration of ≥1.5 pg/ml. All dose levels of 2MD were well tolerated without safety concerns.

CONCLUSIONS

In hemodialysis patients with SHPT, 2MD, at thrice weekly oral doses of 440 and 550 ng, is well tolerated and effectively suppresses PTH without hypercalcemia. Future studies are needed to study the long-term implications of treating ESRD patients with this novel VDRA.

A randomized, open-label trial of iron isomaltoside 1000 (Monofer®) compared with iron sucrose (Venofer®) as maintenance therapy in haemodialysis patients

BACKGROUND

Iron deficiency anaemia is common in patients with chronic kidney disease, and intravenous iron is the preferred treatment for those on haemodialysis. The aim of this trial was to compare the efficacy and safety of iron isomaltoside 1000 (Monofer®) with iron sucrose (Venofer®) in haemodialysis patients.

METHODS

This was an open-label, randomized, multicentre, non-inferiority trial conducted in 351 haemodialysis subjects randomized 2:1 to either iron isomaltoside 1000 (Group A) or iron sucrose (Group B). Subjects in Group A were equally divided into A1 (500 mg single bolus injection) and A2 (500 mg split dose). Group B were also treated with 500 mg split dose. The primary end point was the proportion of subjects with haemoglobin (Hb) in the target range 9.5-12.5 g/dL at 6 weeks. Secondary outcome measures included haematology parameters and safety parameters.

RESULTS

A total of 351 subjects were enrolled. Both treatments showed similar efficacy with >82% of subjects with Hb in the target range (non-inferiority, P = 0.01). Similar results were found when comparing subgroups A1 and A2 with Group B. No statistical significant change in Hb concentration was found between any of the groups. There was a significant increase in ferritin from baseline to Weeks 1, 2 and 4 in Group A compared with Group B (Weeks 1 and 2: P < 0.001; Week 4: P = 0.002). There was a significant higher increase in reticulocyte count in Group A compared with Group B at Week 1 (P < 0.001). The frequency, type and severity of adverse events were similar.

CONCLUSIONS

Iron isomaltoside 1000 and iron sucrose have comparative efficacy in maintaining Hb concentrations in haemodialysis subjects and both preparations were well tolerated with a similar short-term safety profile.

A randomized trial of iron isomaltoside 1000 versus oral iron in non-dialysis-dependent chronic kidney disease patients with anaemia

Background

Iron deficiency anaemia is common in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) and is often treated with oral or intravenous (IV) iron therapy. This trial compared the efficacy and safety of IV iron isomaltoside 1000 (Monofer®) and oral iron in NDD-CKD patients with renal-related anaemia.

Methods

The trial was a Phase III open-label, comparative, multicentre, non-inferiority trial conducted in 351 iron-deficient NDD-CKD patients, randomized 2:1 to either iron isomaltoside 1000 (Group A) or iron sulphate administered as 100 mg elemental oral iron twice daily (200 mg daily) for 8 weeks (Group B). The patients in Group A were randomized into A1 (infusion of max. 1000 mg single doses over 15 min) and A2 (bolus injections of 500 mg over 2 min). A modified Ganzoni formula was used to calculate IV iron need. The primary end point was change in haemoglobin concentrations from baseline to Week 4.

Results

Iron isomaltoside 1000 was both non-inferior to oral iron at Week 4 (P < 0.001) and sustained a superior increase in haemoglobin from Week 3 until the end of the study at Week 8 (P = 0.009 at Week 3). The haemoglobin response was more pronounced with iron isomaltoside 1000 doses ≥1000 mg (P < 0.05). Serum-ferritin and transferrin saturation concentrations were also significantly increased with IV iron. Adverse drug reactions were observed in 10.5% in the iron isomaltoside 1000 group and 10.3% in the oral iron group. More patients treated with oral iron sulphate withdrew from the study due to adverse events (4.3 versus 0.9%, P = 0.2).

Conclusions

Iron isomaltoside 1000 was more efficacious than oral iron for increase in haemoglobin and proved to be well tolerated at the tested dose levels in NDD-CKD patients.

Considerations and challenges in defining optimal iron utilization in hemodialysis

Trials raising concerns about erythropoiesis-stimulating agents, revisions to their labeling, and changes to practice guidelines and dialysis payment systems have provided strong stimuli to decrease erythropoiesis-stimulating agent use and increase intravenous iron administration in recent years. These factors have been associated with a rise in iron utilization, particularly among hemodialysis patients, and an unprecedented increase in serum ferritin concentrations. The mean serum ferritin concentration among United States dialysis patients in 2013 exceeded 800 ng/ml, with 18% of patients exceeding 1200 ng/ml. Although these changes are broad based, the wisdom of these practices is uncertain. Herein, we examine influences on and trends in intravenous iron utilization and assess the clinical trial, epidemiologic, and experimental evidence relevant to its safety and efficacy in the setting of maintenance dialysis. These data suggest a potential for harm from increasing use of parenteral iron in dialysis-dependent patients. In the absence of well powered, randomized clinical trials, available evidence will remain inadequate for making reliable conclusions about the effect of a ubiquitous therapy on mortality or other outcomes of importance to dialysis patients. Nephrology stakeholders have an urgent obligation to initiate well designed investigations of intravenous iron in order to ensure the safety of the dialysis population.

A randomized multicenter trial of paricalcitol versus calcitriol for secondary hyperparathyroidism in stages 3-4 CKD

BACKGROUND AND OBJECTIVES

Calcitriol is used to treat secondary hyperparathyroidism in patients with CKD. Paricalcitol is less calcemic and phosphatemic in preclinical studies and in some trials in dialysis patients, but head-to-head comparisons in nondialysis patients are lacking. A large meta-analysis of trials concluded that these agents did not consistently reduce parathyroid hormone (PTH) and increased the risk of hypercalcemia and hyperphosphatemia. Therefore, the objective of this multicenter trial was to compare the rate of hypercalcemia between calcitriol and paricalcitol, while suppressing PTH 40%-60%.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Patients with stages 3-4 CKD (n=110) with a PTH level >120 pg/ml were recruited and randomized to 0.25 μg/d of calcitriol or 1 μg/d of paricalcitol between April 2009 and July 2011. Subsequent dose adjustments were by protocol to achieve 40%-60% PTH suppression below baseline. The primary endpoint was the rate of confirmed hypercalcemia of >10.5 mg/dl between groups.

RESULTS

Forty-five patients in each group completed the 24 weeks of treatment. Both agents suppressed PTH effectively (-52% with paricalcitol and -46% with calcitriol; P=0.17), although the paricalcitol group reached a 40% reduction in PTH sooner at a median 8 weeks (interquartile range [IQR], 4, 12) versus 12 weeks (IQR, 8, 18; P=0.02) and had a lower pill burden of 240 (IQR, 180, 298) versus 292 (IQR, 231, 405; P=0.01). Confirmed hypercalcemia was very low in both groups (three with paricalcitol and one with calcitriol) and was not significantly different (P=0.36). Both groups had small increases in calcium and phosphorus levels (0.3-0.4 mg/dl in each electrolyte) and significant decreases in alkaline phosphatase, a marker of high bone turnover, with no significant differences between groups.

CONCLUSIONS

These results show that both calcitriol and paricalcitol achieved sustained PTH and alkaline phosphatase suppression in stages 3-4 CKD, with small effects on serum calcium and phosphorus and a low incidence of hypercalcemia.

Relationship of 1,25 dihydroxy Vitamin D Levels to Clinical Outcomes in Critically Ill Patients with Acute Kidney Injury

BACKGROUND

Calcitriol [1,25(OH)₂D] plays a central role in endocrine regulation of bone and mineral metabolism. Low 1,25(OH)₂D levels in chronic kidney disease (CKD) are associated with increased cardiovascular morbidity and mortality. However, the role of 1,25(OH)₂D in acute kidney injury (AKI) is unclear, with very limited data. This pilot study examined the relationship between 1,25(OH)₂D levels in critically ill patients with AKI and clinical outcomes.

METHODS

Plasma 1,25(OH)₂D, intact parathyroid hormone (iPTH), 25-OH Vitamin D (VitD), calcium and phosphorus were measured in 34 patients with AKI without pre-existing chronic kidney disease and 12 healthy controls.

RESULTS

The mean 1,25(OH)₂D levels were significantly lower in patients with AKI compared to controls, (42±5.6 pg/mL vs. 76.1±5.3 pg/mL, P <0.0001). The mortality in patients with AKI was 30%. 1,25(OH)₂D levels were higher in non-survivors than survivors (62±41.4 pg/mL vs. 33.7±24.2 pg/mL respectively, P = 0.046) and serum phosphorus was also higher in non-survivors (6.2±2.1 mg/dL vs. 4.6±1.6 mg/dL, P = 0.019). However, on multivariate regression analysis, accounting for age and APACHE II score, higher levels of 1,25(OH)₂D was not associated with mortality in critically ill patients with AKI.

CONCLUSION

Mineral metabolism is dysregulated within days of acute renal injury in critically ill patients. On univariate analysis, high levels of calcitriol were associated with adverse clinical outcome in AKI. This association was not apparent after adjusting for age and APACHE II. Large controlled studies are needed to confirm these results, and determine if higher 1,25(OH)₂D mediates worse outcomes in AKI.

Effects of paricalcitol on calcium and phosphate metabolism and markers of bone health in patients with diabetic nephropathy: results of the VITAL study

Background

Chronic kidney disease (CKD) is associated with elevations in serum phosphate, calcium–phosphorus product and bone-specific alkaline phosphatase (BAP), with attendant risks of cardiovascular and bone disorders. Active vitamin D can suppress parathyroid hormone (PTH), but may raise serum calcium and phosphate concentrations. Paricalcitol, a selective vitamin D activator, suppressed PTH in CKD patients (stages 3 and 4) with secondary hyperparathyroidism (SHPT) with minimal changes in calcium and phosphate metabolism.

Methods

The VITAL study enrolled patients with CKD stages 2–4. We examined the effect and relationship of paricalcitol to calcium and phosphate metabolism and bone markers in a post hoc analysis of VITAL. The study comprised patients with diabetic nephropathy enrolled in a double-blind, placebo-controlled, randomized trial of paricalcitol (1 or 2 μg/day). Urinary and serum calcium and phosphate, serum BAP, and intact PTH (iPTH) concentrations were measured throughout the study.

Results

Baseline demographics and calcium, phosphate, PTH (49% with iPTH <70 pg/mL), and BAP concentrations were similar between groups. A transient, modest yet significant increase in phosphate was observed for paricalcitol 2 μg/day (+0.29 mg/dL; P < 0.001). Dose-dependent increases in serum and urinary calcium were observed; however, there were few cases of hypercalcemia: one in the 1-μg/day group (1.1%) and three in the 2-μg/day group (3.2%). Significant reductions in BAP were observed that persisted for 60 days after paricalcitol discontinuation (P < 0.001 for combined paricalcitol groups versus placebo). Paricalcitol dose-dependent reductions in iPTH were observed. Paricalcitol in CKD patients (±SHPT) was associated with modest increases in calcium and phosphate.

Conclusion

Paricalcitol reduces BAP levels, which may be beneficial for reducing vascular calcification.

Trial registration

Trial is registered with ClinicalTrials.gov, number NCT00421733.

Understanding and exploiting hepcidin as an indicator of anemia due to chronic kidney disease

Hepcidin, produced by the liver, is the master regulator of iron balance. Serum hepcidin is increased by high iron stores, blocks intestinal iron absorption, and impairs storage iron release. Conversely, iron deficiency lowers hepcidin levels and enhances intestinal iron absorption and the release of storage iron. As with ferritin, hepcidin is an acute phase reactant. Consequently, inflammation increases hepcidin and leads to impaired iron absorption, lowers serum iron and transferrin saturation, and contributes to the anemia of chronic kidney disease (CKD). We review the physiology of iron absorption, its relationship to hepcidin and the transmembrane iron transporter ferroportin, the role of hepcidin in CKD related anemia, and the possible diagnostic implications and limitations of using hepcidin as a marker of iron status.

Bioavailable vitamin D in chronic kidney disease

Most of the major vitamin D metabolites 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D circulates in a tightly bound state to vitamin D-binding protein (DBP), rendering this fraction unavailable for biological action. A smaller fraction, loosely bound to albumin or circulating freely, is bioavailable, and hence bioactive. This Commentary discusses the free hormone hypothesis and the role of DBP in vitamin D metabolism.

The health-related quality of life was not improved by targeting higher hemoglobin in the Normal Hematocrit Trial

The Normal Hematocrit Trial (NHT) was the largest trial of epoetin randomizing 1265 hemodialysis patients with cardiac disease to lower (9-11 g/dl) or higher (13-15 g/dl) hemoglobin (Hgb), hypothesizing that higher Hgb would reduce mortality, and improve survival and quality of life. The trial was terminated early, and a 1998 publication reported that targeting higher hematocrit levels led to an insignificant increase in the primary end points (death or myocardial infarct), or risk ratio 1.3, 95% confidence interval (CI), 0.9-1.90, but the P-value was not given, and all-cause death risk was not reported. A higher target reportedly did not increase hospitalization rates, but did significantly improve the 'physical function' domain of quality of life. Comparing the 1996 Food and Drug Administration (FDA)-filed clinical trial report to the 1998 publication, however, found several discrepancies. Among these, the 1998 article reported interim trial results with only the adjusted CI but did not state that the unadjusted CIs were 99.912th percentile, and despite being a secondary end point, reported only the association of achieved Hgb with higher quality of life score. Randomization to the higher target had actually increased the risk for the primary end point (risk ratio 1.28, 95% CI=1.06-1.56; P=0.0112; 99.92% CI=0.92-1.78), the risk of death (risk ratio 1.27, 95% CI=1.04-1.54), non-access thrombotic events (P=0.041), and hospitalization rate (P=0.04), while 'physical function' did not improve (P=0.88). Hence, disclosure of these results in the 1998 publication or access to the FDA-filed report on the NHT in the late 1990s would likely have led to earlier concerns about epoetin safety and greater doubts about its benefits.

Very Low Density Lipoprotein Metabolism in Patients with Chronic Kidney Disease

BACKGROUND: Hypertriglyceridemia is a common metabolic complication of chronic kidney disease (CKD) and an important risk factor for coronary heart disease in this patient population. The mechanisms responsible for the development of hypertriglyceridemia in subjects with CKD are not clear. METHODS: We studied very low density lipoprotein triglyceride (VLDL-TG) and VLDL-apolipoprotein B-100 (VLDL-apoB-100) kinetics in vivo in 6 subjects with non-dialysis-dependent CKD (CKD-ND), 6 subjects with CKD treated with peritoneal dialysis (CKD-PD) and 24 sex-, age- and body mass index-matched control subjects with normal renal function (12 control subjects each matched with the CKD-ND and CKD-PD group, respectively). RESULTS: The secretion rates of VLDL-TG and VLDL-apoB-100 into plasma were not different between CKD-ND or CKD-PD and their respective control groups. The mean residence times of VLDL-TG and VLDL-apoB-100 in plasma, which represents the time VLDL-TG and VLDL-apoB-100 spend in the circulation after secretion by the liver, tended to be greater in subjects with CKD-ND than in control subjects (222 ± 38 vs. 143 ± 21 min, p = 0.07, and 352 ± 102 vs. 200 ± 20 min, p = 0.06, respectively) and were about two-fold greater in subjects with CKD-PD compared with their control group (248 ± 51 vs. 143 ± 21 min and 526 ± 116 vs. 182 ± 16 min, respectively; both p ≤ 0.01). CONCLUSION: Impaired plasma clearance of VLDL-TG and VLDL-apoB-100 is the major abnormality associated with hypertriglyceridemia in patients with either CKD-ND or CKD-PD.

The future of intravenous iron in nephrology

Management of anaemia in chronic kidney disease (CKD) patients can be difficult and expensive. The recently completed Trial to Reduce Cardiovascular Events with Aranesp Therapy (TREAT), the largest double-blinded trial of erythropoiesis-stimulating agents (ESA) treatment in CKD to date, provides us with a wealth of new information on the natural history of anaemia in Stage 3 and 4 CKD and the risks and benefits of use of ESAs. This section will discuss some of the TREAT trial results in the context of other recent studies of ESAs and intravenous iron in CKD patients. It will also review applying those results when choosing anaemia goals for an individual, and determining if iron therapy might improve anaemia.

A crossover intervention trial evaluating the efficacy of a chlorhexidine-impregnated sponge in reducing catheter-related bloodstream infections among patients undergoing hemodialysis

BACKGROUND

Catheter-related bloodstream infections (CRBSIs) account for the majority of hemodialysis-related infections. There are no published data on the efficacy of the chlorhexidine-impregnated foam dressing at reducing the rate of CRBSI among patients undergoing hemodialysis.

DESIGN

A prospective, nonblinded, crossover intervention trial to determine the efficacy of a chlorhexidine-impregnated foam dressing to reduce the rate of CRBSI among patients undergoing hemodialysis.

SETTING

Two outpatient dialysis centers.

PATIENTS

A total of 121 patients who underwent dialysis through tunneled central venous catheters received the intervention during the trial.

METHODS

The primary outcome of interest was the incidence of CRBSI. A nested cohort study of all patients who received the chlorhexidine-impregnated foam dressing was also conducted. Backward stepwise logistic regression analysis was used to determine independent risk factors for development of CRBSI.

RESULTS

Thirty-seven CRBSIs occurred in the intervention group, for an incidence of 6.3 CRBSIs per 1,000 dialysis sessions, and 30 CRBSIs occurred in the control group, an incidence of 5.2 CRBSIs per 1,000 dialysis sessions (risk ratio, 1.22 [95% confidence interval {CI}, 0.75-1.97]; P = .46). The chlorhexidine-impregnated foam dressing was well tolerated, with only 2 patients (<2%) experiencing dermatitis that led to its discontinuation. The only independent risk factor for development of CRBSI was dialysis treatment at one dialysis center (adjusted odds ratio, 4.4 [95% CI, 1.77-13.65]; P = .002). Age of at least 60 years (adjusted odds ratio, 0.28 [95% CI, 0.09-0.82]; P = .02) was associated with lower risk of CRBSI.

CONCLUSIONS

The use of a chlorhexidine-impregnated foam dressing did not decrease the incidence of CRBSI among patients with tunneled central venous catheters who were undergoing hemodialysis.