Development and validation of a risk score to prioritize patients for evaluation of access stenosis.

BACKGROUND: Access flow dysfunction, often associated with stenosis, is a common problem in hemodialysis access and may result in progression to thrombosis. Timely identification of accesses in need of evaluation is critical to preserving a functioning access. We hypothesized that a risk score using measurements obtained from the Vasc-Alert surveillance device could be used to predict subsequent interventions. METHODS: Measurement of five factors over the preceding 28 days from 1.46 million hemodialysis treatments (6163 patients) were used to develop a score associated with interventions over the subsequent 60 days. The score was validated in a separate dataset of 298,620 treatments (2641 patients). RESULTS: Interventions in arteriovenous fistulae (AVF; n = 4125) were much more common in those with the highest score (36.2%) than in those with the lowest score (11.0). The score also was strongly associated with interventions in patients with an arteriovenous graft (AVG; n = 2,038; 43.2% vs. 21.1%). There was excellent agreement in the Validation datasets for AVF (OR = 2.67 comparing the highest to lowest score) and good agreement for AVG (OR = 1.92). CONCLUSIONS: This simple risk score based on surveillance data may be useful for prioritizing patients for physical examination and potentially early referral for intervention.

The problem with transferrin saturation as an indicator of iron 'sufficiency' in chronic kidney disease.

After a brief review of physiological iron metabolism, we describe diagnostic tests for iron status and iron deficiency anemia in patients without chronic kidney disease (CKD) or inflammation. Thereafter we review the dysregulation of iron metabolism in CKD. Specific emphasis is placed on the role of the 'inflammatory' state that develops with the progression of CKD. It invokes changes in iron metabolism that are the exact opposite of those occurring during pure iron deficiency. As a result, transferrin saturation (TSAT) becomes a poorer index of iron availability to the bone marrow and serum ferritin no longer represents iron that can be used during erythropoiesis. We argue that serum iron may provide more information to guide iron therapy than TSAT. In other words, the emphasis on TSAT is misplaced. With the development of a number of hypoxia-inducible factor prolyl hydroxylase inhibitors, which restore iron metabolism toward the 'physiologic state', the iron indices indicating sufficient iron availability to avoid functional iron deficiency during therapy of CKD-associated anemia are likely to change. We summarize these changes in the section 'A peek into things to come!', citing the available data.

Roxadustat for anemia in patients with end-stage renal disease incident to dialysis.

BACKGROUND: We evaluated the efficacy and safety of roxadustat versus epoetin alfa for the treatment of chronic kidney disease-related anemia in patients new to dialysis. METHODS: HIMALAYAS was a Phase 3, open-label, epoetin alfa-controlled trial. Eligible adults were incident to hemodialysis/peritoneal dialysis for 2 weeks to ≤4 months prior to randomization and had mean hemoglobin (Hb) ≤10.0 g/dL. Primary endpoints were mean Hb (g/dL) change from baseline averaged over Weeks 28-52 regardless of rescue therapy [non-inferiority criterion: lower limit of 95% confidence interval (CI) for treatment difference >-0.75] and percentage of patients achieving an Hb response between Weeks 1 and 24 censored for rescue therapy (non-inferiority margin for between-group difference -15%). Adverse events were monitored. RESULTS: The intent-to-treat population included patients randomized to roxadustat (n = 522) or epoetin alfa (n = 521). Mean (standard deviation) Hb changes from baseline averaged over Weeks 28-52 were 2.57 (1.27) and 2.36 (1.21) in the roxadustat and epoetin alfa groups. Roxadustat was non-inferior [least squares mean difference: 0.18 (95% CI 0.08, 0.29)] to epoetin alfa. Percentages of patients with an Hb response were 88.2% and 84.4% in the roxadustat and epoetin alfa groups, respectively. Roxadustat was non-inferior to epoetin alfa [treatment-group difference 3.5% (95% CI -0.7%, 7.7%)]. Adverse event rates were comparable between treatment groups. CONCLUSIONS: Roxadustat was efficacious for correcting and maintaining Hb levels compared with epoetin alfa. Roxadustat had an acceptable safety profile.

How arteriovenous grafts could help to optimize vascular access management.

A one-size-fits-all approach to vascular access for dialysis may be prejudicial. Arteriovenous fistulae (AVF) have high primary failure, failure to mature rate, and late-stage complications making them unsuitable choice for many patients. Aging of population with chronic kidney disease (CKD) coupled with venous injury during CKD stages depletes suitable superficial veins for AVF creation. The National Institutes of Health consortium demonstrated the difficulty in attaining a functional AVF in hemodialysis patients. Recognition of flaws in AVF and the quest to reduce catheter use bring to the fore the benefits of arteriovenous grafts (AVG). Advances in catheter technologies, flow, care, and antibiotic locks have resulted in significant improvement in catheter-related infections. However, widespread recognition of catheter-related complications like central vein stenosis, metastatic infections, and exhaustion of venous access sites preclude their being a viable alternative to AVF, furthering the need to explore AVG as a substitute. Placement of "early cannulation" AVG is a catheter sparing option in patients who are likely to have inadequate fistula maturation. Advances in biohybrid technology and tissue-engineered grafts are providing a robust opportunity to develop biocompatible graft materials with minimal tissue reactivity and thrombogenicity. Xenografts (bovine carotid artery grafts) are proving to be comparable and, in many cases, better than conventional polytetrafluoroethylene material. Older age, dialysis dependence, and smaller vein size are related to the appropriateness of AVG creation. An individualized approach in selecting optimal upper extremity vascular access option using patient-specific factors while incorporating the benefits of an AVG would greatly aid in achieving low catheter usage in the dialysis population.

Phase 2 studies of oral hypoxia-inducible factor prolyl hydroxylase inhibitor FG-4592 for treatment of anemia in China.

BACKGROUND: FG-4592 (roxadustat) is an oral hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitor (HIF-PHI) promoting coordinated erythropoiesis through the transcription factor HIF. Two Phase 2 studies were conducted in China to explore the safety and efficacy of FG-4592 (USAN name: roxadustat, CDAN name: ), a HIF-PHI, in patients with anemia of chronic kidney disease (CKD), both patients who were dialysis-dependent (DD) and patients who were not dialysis-dependent (NDD). METHODS: In the NDD study, 91 participants were randomized to low (1.1-1.75 mg/kg) or high (1.50-2.25 mg/kg) FG-4592 starting doses or to placebo. In the DD study, 87 were enrolled to low (1.1-1.8 mg/kg), medium (1.5-2.3 mg/kg) and high (1.7-2.3 mg/kg) starting FG-4592 doses or to continuation of epoetin alfa. In both studies, only oral iron supplementation was allowed. RESULTS: In the NDD study, hemoglobin (Hb) increase ≥1 g/dL from baseline was achieved in 80.0% of subjects in the low-dose cohort and 87.1% in the high-dose cohort, versus 23.3% in the placebo arm (P < 0.0001, both). In the DD study, 59.1%, 88.9% (P = 0.008) and 100% (P = 0.0003) of the low-, medium- and high-dose subjects maintained their Hb levels after 5- and 6-weeks versus 50% of the epoetin alfa-treated subjects. In both studies, significant reductions in cholesterol were noted in FG-4592-treated subjects, with stability or increases in serum iron, total iron-binding capacity (TIBC) and transferrin (without intravenous iron administration). In the NDD study, hepcidin levels were significantly reduced across all FG-4592-treated arms as compared with no change in the placebo arm. In the DD study, hepcidin levels were also reduced in a statistically significant dose-dependent manner in the highest dose group as compared with the epoetin alfa-treated group. Adverse events were similar for FG-4592-treated and control subjects. CONCLUSIONS: FG-4592 may prove an effective alternative for managing anemia of CKD. It is currently being investigated in a pivotal global Phase 3 program.

Roxadustat (FG-4592): Correction of Anemia in Incident Dialysis Patients.

Safety concerns with erythropoietin analogues and intravenous (IV) iron for treatment of anemia in CKD necessitate development of safer therapies. Roxadustat (FG-4592) is an orally bioavailable hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitor that promotes coordinated erythropoiesis through HIF-mediated transcription. We performed an open-label, randomized hemoglobin (Hb) correction study in anemic (Hb≤10.0 g/dl) patients incident to hemodialysis (HD) or peritoneal dialysis (PD). Sixty patients received no iron, oral iron, or IV iron while treated with roxadustat for 12 weeks. Mean±SD baseline Hb was 8.3±1.0 g/dl in enrolled patients. Roxadustat at titrated doses increased mean Hb by ≥2.0 g/dl within 7 weeks regardless of baseline iron repletion status, C-reactive protein level, iron regimen, or dialysis modality. Mean±SEM maximal change in Hb from baseline (ΔHb(max)), the primary endpoint, was 3.1±0.2 g/dl over 12 weeks in efficacy-evaluable patients (n=55). In groups receiving oral or IV iron, ΔHb(max) was similar and larger than in the no-iron group. Hb response (increase in Hb of ≥1.0 g/dl from baseline) was achieved in 96% of efficacy-evaluable patients. Mean serum hepcidin decreased significantly 4 weeks into study: by 80% in HD patients receiving no iron (n=22), 52% in HD and PD patients receiving oral iron (n=21), and 41% in HD patients receiving IV iron (n=9). In summary, roxadustat was well tolerated and corrected anemia in incident HD and PD patients, regardless of baseline iron repletion status or C-reactive protein level and with oral or IV iron supplementation; it also reduced serum hepcidin levels.

Peginesatide in patients with anemia undergoing hemodialysis.

BACKGROUND: Peginesatide, a synthetic peptide-based erythropoiesis-stimulating agent (ESA), is a potential therapy for anemia in patients with advanced chronic kidney disease. METHODS: We conducted two randomized, controlled, open-label studies (EMERALD 1 and EMERALD 2) involving patients undergoing hemodialysis. Cardiovascular safety was evaluated by analysis of an adjudicated composite safety end point--death from any cause, stroke, myocardial infarction, or serious adverse events of congestive heart failure, unstable angina, or arrhythmia--with the use of pooled data from the two EMERALD studies and two studies involving patients not undergoing dialysis. In the EMERALD studies, 1608 patients received peginesatide once monthly or continued to receive epoetin one to three times a week, with the doses adjusted as necessary to maintain a hemoglobin level between 10.0 and 12.0 g per deciliter for 52 weeks or more. The primary efficacy end point was the mean change from the baseline hemoglobin level to the mean level during the evaluation period; noninferiority was established if the lower limit of the two-sided 95% confidence interval was -1.0 g per deciliter or higher in the comparison of peginesatide with epoetin. The aim of evaluating the composite safety end point in the pooled cohort was to exclude a hazard ratio with peginesatide relative to the comparator ESA of more than 1.3. RESULTS: In an analysis involving 693 patients from EMERALD 1 and 725 from EMERALD 2, peginesatide was noninferior to epoetin in maintaining hemoglobin levels (mean between-group difference, -0.15 g per deciliter; 95% confidence interval [CI], -0.30 to -0.01 in EMERALD 1; and 0.10 g per deciliter; 95% CI, -0.05 to 0.26 in EMERALD 2). The hazard ratio for the composite safety end point was 1.06 (95% CI, 0.89 to 1.26) with peginesatide relative to the comparator ESA in the four pooled studies (2591 patients) and 0.95 (95% CI, 0.77 to 1.17) in the EMERALD studies. The proportions of patients with adverse and serious adverse events were similar in the treatment groups in the EMERALD studies. The cardiovascular safety of peginesatide was similar to that of the comparator ESA in the pooled cohort. CONCLUSIONS: Peginesatide, administered monthly, was as effective as epoetin, administered one to three times per week, in maintaining hemoglobin levels in patients undergoing hemodialysis. (Funded by Affymax and Takeda Pharmaceutical; ClinicalTrials.gov numbers, NCT00597753 [EMERALD 1], NCT00597584 [EMERALD 2], NCT00598273 [PEARL 1], and NCT00598442 [PEARL 2].).

Roxadustat (FG-4592) Versus Epoetin Alfa for Anemia in Patients Receiving Maintenance Hemodialysis: A Phase 2, Randomized, 6- to 19-Week, Open-Label, Active-Comparator, Dose-Ranging, Safety and Exploratory Efficacy Study.

BACKGROUND: Roxadustat (FG-4592) is an oral hypoxia-inducible factor prolyl-hydroxylase inhibitor that promotes erythropoiesis through increasing endogenous erythropoietin, improving iron regulation, and reducing hepcidin. STUDY DESIGN: Phase 2, randomized (3:1), open-label, active-comparator, safety and efficacy study. SETTING & PARTICIPANTS: Patients with stable end-stage renal disease treated with hemodialysis who previously had hemoglobin (Hb) levels maintained with epoetin alfa. INTERVENTION: Part 1: 6-week dose-ranging study in 54 individuals of thrice-weekly oral roxadustat doses versus continuation of intravenous epoetin alfa. Part 2: 19-week treatment in 90 individuals in 6 cohorts with various starting doses and adjustment rules (1.0-2.0mg/kg or tiered weight based) in individuals with a range of epoetin alfa responsiveness. Intravenous iron was prohibited. OUTCOMES: Primary end point was Hb level response, defined as end-of-treatment Hb level change (ΔHb) of -0.5g/dL or greater from baseline (part 1) and as mean Hb level ≥ 11.0g/dL during the last 4 treatment weeks (part 2). MEASUREMENTS: Hepcidin, iron parameters, cholesterol, and plasma erythropoietin (the latter in a subset). RESULTS: Baseline epoetin alfa doses were 138.3±51.3 (SD) and 136.3±47.7U/kg/wk in part 1 and 152.8±80.6 and 173.4±83.7U/kg/wk in part 2, in individuals randomly assigned to roxadustat and epoetin alfa, respectively. Hb level responder rates in part 1 were 79% in pooled roxadustat 1.5 to 2.0mg/kg compared to 33% in the epoetin alfa control arm (P=0.03). Hepcidin level reduction was greater at roxadustat 2.0mg/kg versus epoetin alfa (P<0.05). In part 2, the average roxadustat dose requirement for Hb level maintenance was ∼1.7mg/kg. The least-squares-mean ΔHb in roxadustat-treated individuals was comparable to that in epoetin alfa-treated individuals (about -0.5g/dL) and the least-squares-mean difference in ΔHb between both treatment arms was -0.03 (95% CI, -0.39 to 0.33) g/dL (mixed effect model-repeated measure). Roxadustat significantly reduced mean total cholesterol levels, not observed with epoetin alfa. No safety concerns were raised. LIMITATIONS: Short treatment duration and small sample size. CONCLUSIONS: In this phase 2 study of anemia therapy in patients with end-stage renal disease on maintenance hemodialysis therapy, roxadustat was well tolerated and effectively maintained Hb levels.

Ferric pyrophosphate citrate administered via dialysate reduces erythropoiesis-stimulating agent use and maintains hemoglobin in hemodialysis patients.

Ferric pyrophosphate citrate (FPC) is a water-soluble iron salt administered via dialysate to supply iron directly to transferrin. The PRIME study tested whether treatment with FPC could reduce prescribed erythropoiesis-stimulating agent (ESA) use and maintain hemoglobin in hemodialysis patients. This 9-month, randomized, placebo-controlled, double-blind, multicenter clinical study included 103 patients undergoing hemodialysis 3-4 times weekly. The FPC group received dialysate containing 2 µmol/l of iron. The placebo group received standard dialysate. A blinded central anemia management group facilitated ESA dose adjustments. Intravenous iron was administered according to the approved indication when ferritin levels fell below 200 µg/l. The primary end point was the percentage change from baseline in prescribed ESA dose at end of treatment. Secondary end points included intravenous iron use and safety. At the end of treatment, there was a significant 35% reduction in prescribed ESA dose in FPC-treated patients compared with placebo. The FPC patients used 51% less intravenous iron than placebo. Adverse and serious adverse events were similar in both groups. Thus, FPC delivered via dialysate significantly reduces the prescribed ESA dose and the amount of intravenous iron needed to maintain hemoglobin in chronic hemodialysis patients.

Randomized placebo-controlled dose-ranging and pharmacodynamics study of roxadustat (FG-4592) to treat anemia in nondialysis-dependent chronic kidney disease (NDD-CKD) patients.

BACKGROUND: Roxadustat (FG-4592) is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor that stimulates erythropoiesis. This Phase 2a study tested efficacy (Hb response) and safety of roxadustat in anemic nondialysis-dependent chronic kidney disease (NDD-CKD) subjects. METHODS: NDD-CKD subjects with hemoglobin (Hb) ≤11.0 g/dL were sequentially enrolled into four dose cohorts and randomized to roxadustat or placebo two times weekly (BIW) or three times weekly (TIW) for 4 weeks, in an approximate roxadustat:placebo ratio of 3:1. Efficacy was assessed by (i) mean Hb change (ΔHb) from baseline (BL) and (ii) proportion of Hb responders (ΔHb ≥ 1.0 g/dL). Pharmacodynamic evaluation was performed in a subset of subjects. Safety was evaluated by adverse event frequency/severity. RESULTS: Of 116 subjects receiving treatment, 104 completed 4 weeks of dosing and 96 were evaluable for efficacy. BL characteristics for roxadustat and placebo groups were comparable. In roxadustat-treated subjects, Hb levels increased from BL in a dose-related manner in the 0.7, 1.0, 1.5 and 2.0 mg/kg groups. Maximum ΔHb within the first 6 weeks was significantly higher in the 1.5 and 2.0 mg/kg groups than in the placebo subjects. Hb responder rates were dose dependent and ranged from 30% in the 0.7 mg/kg BIW group to 100% in the 2.0 mg/kg BIW and TIW groups versus 13% in placebo. CONCLUSIONS: Roxadustat transiently and moderately increased endogenous erythropoietin and reduced hepcidin. Adverse events were similar in the roxadustat and placebo groups. Roxadustat produced dose-dependent increases in blood Hb among anemic NDD-CKD patients in a placebo-controlled trial. CLINICAL TRIALS REGISTRATION: Clintrials.gov #NCT00761657.

Vascular access cannulation practices and outcomes.

Vascular access cannulation practices such as the dialysis prescription for blood pump flow and dialysis duration vary significantly among countries. Choice of needle gauge and cannulation practice with the needle in terms of direction relative to the flow stream and rotation after insertion are dictated in part by practicalities but appear to be mostly the result of 'cultural' practices within dialysis centers. Prospective studies of cannulation are needed to improve access outcomes.

Iron repletion is associated with reduction in platelet counts in non-dialysis chronic kidney disease patients independent of erythropoiesis-stimulating agent use: a retrospective cohort study.

BACKGROUND: Iron deficiency is common in non-dialysis chronic kidney disease (ND-CKD) patients and, on occasion, requires parenteral iron therapy. We investigated the effect of intravenous iron repletion on platelet counts in ND-CKD patients with and without concomitant darbepoetin administration. METHODS: We conducted a retrospective analysis of ND-CKD patients with iron deficiency anemia treated with low molecular weight iron dextran (LMWID) between 2005 and 2009 at our CKD clinic. The primary end-point was change in platelet count 60 days post infusion of LMWID in those with and without concomitant darbepoetin administration. Secondary end-points were the correlations between changes in platelet count and iron indices. RESULTS: A total of 108 patients met inclusion and exclusion criteria. The decrease in platelet counts in response to iron repletion was statistically significant (305.72 ± 108.86 vs 255.58 ± 78.97, P = < .0001). The decrease in platelet count was independent of concomitant darbepoetin use. Bivariate regression analysis between baseline platelet count and transferrin saturation by iron (TSAT) showed a negative association (ßTSAT = -5.82, P = .0007) and moderate correlation (R = 0.32). Following iron treatment, the within individual changes in platelet count in 60 days were not related to changes in TSAT (ßΔTSAT = -0.41, P = .399) and demonstrated a poor correlation (R = 0.10). CONCLUSIONS: Parenteral iron treatment by LMWID is associated with reduction in platelet counts in iron deficient anemic ND-CKD patients. However, ESA use in the majority of patients prior to intravenous iron administration could have altered platelet production through bone marrow competition.

An open-label, sequential, dose-finding study of peginesatide for the maintenance treatment of anemia in chronic hemodialysis patients.

BACKGROUND: Peginesatide is a peptide-based erythropoiesis-stimulating agent that was designed and engineered to stimulate specifically the erythropoietin receptor dimer that governs erythropoiesis. The primary objective of this phase 2 dose-finding study was to determine the once-monthly peginesatide dosing strategy that would maintain hemoglobin within ±1.0 g/dL of baseline values after conversion from epoetin alfa; the safety of peginesatide was evaluated concurrently. METHODS: Chronic hemodialysis patients on stable regimens of epoetin alfa were sequentially assigned to cohorts that differed on (1) how the peginesatide starting dose was determined (using a single epoetin alfa-to-peginesatide dose conversion ratio or a tiered, weight-based or absolute-dose conversion table) and on (2) whether or not a 1-week erythropoiesis-stimulating agent-free interval was used. Peginesatide doses were titrated to maintain hemoglobin levels within ±1.0 g/dL from baseline. RESULTS: A total of 164 patients were enrolled and received intravenous peginesatide every 4 weeks for up to 6 doses; the duration of the study including follow-up was ≤29 weeks. Overall, the proportion of patients with hemoglobin levels within ±1.0 g/dL of baseline increased over the course of the study from 39% (Weeks 2-13) to 54% (Weeks 18-25). Cohorts that used tiered dose conversion tables trended towards having more stable peginesatide doses than did those cohorts that used a single dose conversion ratio. Moreover, cohorts that used an erythropoiesis-stimulating agent-free interval did not have the substantial initial increase in hemoglobin levels that was seen in those cohorts that did not use such an interval. In this study, the safety profile of peginesatide was consistent with those of marketed erythropoiesis-stimulating agents. CONCLUSIONS: The results of this study were used to guide the dosing regimens used subsequently in phase 3 studies. Once-monthly peginesatide is feasible in hemodialysis patients. TRIAL REGISTRATION: ClinicalTrials.gov registration: NCT00228449.

Association of risk stratification score with dialysis vascular access stenosis.

BACKGROUNDS: Clinical monitoring is the recommended standard for identifying dialysis access dysfunction; however, clinical monitoring requires skill and training, which is challenging for understaffed clinics and overburdened healthcare personnel. A vascular access risk stratification score was recently proposed to assist in detecting dialysis access dysfunction. PURPOSE: Our objective was to evaluate the utility of using vascular access risk scores to assess venous stenosis in hemodialysis vascular accesses. METHODS: We prospectively enrolled adult patients who were receiving hemodialysis through an arteriovenous access and who had a risk score ⩽3 (low-risk) or ⩾8 (high-risk). We compared the occurrence of access stenosis (>50% on ultrasonography or angiography) between low-risk and high-risk groups and assessed clinical monitoring results for each group. RESULTS: Of the 38 patients analyzed (18 low-risk; 20 high-risk), 16 (42%) had significant stenosis. Clinical monitoring results were positive in 39% of the low-risk and 60% of the high-risk group (p = 0.19). The high-risk group had significantly higher occurrence of stenosis than the low-risk group (65% vs 17%; p = 0.003). Sensitivity and specificity of a high score for identifying stenosis were 81% and 68%, respectively. The positive predictive value of a high-risk score was 65%, and the negative predictive value was 80%. Only 11 (58%) of 19 subjects with positive clinical monitoring had significant stenosis. In a multivariable model, the high-risk group had seven-fold higher odds of stenosis than the low-risk group (aOR = 7.38; 95% CI, 1.44-37.82; p = 0.02). Positive clinical monitoring results and previous stenotic history were not associated with stenosis. Every unit increase in the score was associated with 34% higher odds of stenosis (aOR = 1.34; 95% CI, 1.05-1.70; p = 0.02). CONCLUSIONS: A calculated risk score may help predict the development of hemodialysis vascular access stenosis and may provide a simple and reliable objective measure for risk stratification.

Candidate biomarkers for erythropoietin response in end-stage renal disease.

Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) is important clinically and economically. Escalation of dose may produce harm. Post hoc analyses of clinical trials showed that responsiveness could be predicted by hemoglobin response to a fixed dose escalation. This maneuver requires weeks to months. The study by Merchant et al. offers promise that peptidomic analyses of patient sera and mass spectrometry can identify biomarkers of both responsiveness and resistance to ESAs.

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).

Maintenance treatment of renal anaemia in haemodialysis patients with methoxy polyethylene glycol-epoetin beta versus darbepoetin alfa administered monthly: a randomized comparative trial.

BACKGROUND: Several studies with erythropoiesis-stimulating agents claim that maintenance therapy of renal anaemia may be possible at extended dosing intervals; however, few studies were randomized, results varied, and comparisons between agents were absent. We report results of a multi-national, randomized, prospective trial comparing haemoglobin maintenance with methoxy polyethylene glycol-epoetin beta and darbepoetin alfa administered once monthly. METHODS: Haemodialysis patients (n = 490) on stable once-weekly intravenous darbepoetin alfa were randomized to methoxy polyethylene glycol-epoetin beta once monthly or darbepoetin alfa every 2 weeks for 26 weeks, with dose adjustment for individual haemoglobin target (11-13 g/dL; maximum decrease from baseline 1 g/dL). Subsequently, patients entered a second 26-week period of once-monthly methoxy polyethylene glycol-epoetin beta and darbepoetin alfa. The primary endpoint was the proportion of patients who maintained average haemoglobin ≥10.5 g/dL, with a decrease from baseline ≤1 g/dL, in Weeks 50-53; the secondary endpoint was dose change over time. The trial is registered at www.ClinicalTrials.gov, number NCT00394953. RESULTS: Baseline characteristics were similar between groups. One hundred and fifty-seven of 245 patients treated with methoxy polyethylene glycol-epoetin beta and 99 of 245 patients with darbepoetin alfa met the response definition (64.1% and 40.4%; P < 0.0001). Doses increased by 6.8% with methoxy polyethylene glycol-epoetin beta and 58.8% with darbepoetin alfa during once-monthly treatment. Death rates were equal between treatments (5.7%). Most common adverse events included hypertension, procedural hypotension, nasopharyngitis and muscle spasms, with no differences between groups. CONCLUSIONS: Methoxy polyethylene glycol-epoetin beta maintained target haemoglobin more successfully than darbepoetin alfa at once-monthly dosing intervals despite dose increases with darbepoetin alfa.

Automated intravascular access pressure surveillance reduces thrombosis rates.

Although monitoring of vascular accesses by physical examination is nearly as sensitive as surveillance measurements by vascular access pressure when performed by examiners, the frequency of examinations is limited by time. We developed intravascular access pressure surveillance as a surrogate to physical examination. Using real-time data from hemodialysis machines, we derived intravascular access pressure ratios for each dialytic procedure. An automated, noninvasive surveillance algorithm that generated a "warning" list of patients at risk for thrombosis was formulated. We hypothesized that this algorithm would reduce access thrombosis frequency. We designed a study comparing thrombosis rates during a baseline 6-month interval to three subsequent 6-month periods of active surveillance. Referrals for interventions during this 18-month period were based on persistently abnormal elevated vascular access pressure ratio tests (VAPRT) >0.55. Thrombosis rates declined progressively for arteriovenous grafts (AVG) during the intervention period compared with the baseline period. Arteriovenous fistula (AVF) thrombosis rates decreased during postintervention months 13-18 during employment of the VAPRT. We conclude that use of VAPRT can reduce thrombosis rates in vascular accesses, and the magnitude of the effect is larger and more consistent in arteriovenous grafts (AVGs) than autologous AVFs.

Iron metabolism, iron deficiency, thrombocytosis, and the cardiorenal anemia syndrome.

In treating moderate to severe anemia of chronic kidney disease (CKD), oral iron is effective only in a minority of nondialysis patients. Intravenous iron is more effective and can raise levels of hemoglobin even without the use of erythropoiesis-stimulating agents (ESAs). Unfortunately, the current assays of iron status that are presently widely available are not especially helpful in predicting response. In patients on dialysis, i.v. iron is effective over a wide range of serum ferritin from <100 ng/ml to 800 ng/ml. None of the three available randomized controlled trials comparing oral with i.v. iron showed evidence of nephrotoxicity caused by i.v. iron. Iron deficiency is a risk factor for thrombocytosis and should, wherever possible, be avoided. Optimal coadministration of iron may reduce the risk for ESA-driven cardiovascular events. Increased total body iron stores (imperfectly reflected by serum ferritin levels in CKD) do not appear to be related to such events or hospitalization in CKD; it is unclear what other risk factors and mechanisms need to be considered. In the appreciable proportion of patients with both renal and cardiac dysfunction, management is further complicated by a vicious circle (which can be characterized as cardiorenal anemia syndrome) in which CKD, heart failure, and anemia exacerbate each other. In such patients, correction of anemia appears to improve cardiac function and quality of life without a greater risk for adverse events.