Safety and Efficacy of Vadadustat for Anemia in Patients Undergoing Dialysis.

BACKGROUND: Vadadustat is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor, a class of compounds that stimulate endogenous erythropoietin production. METHODS: We conducted two randomized, open-label, noninferiority phase 3 trials to evaluate the safety and efficacy of vadadustat, as compared with darbepoetin alfa, in patients with anemia and incident or prevalent dialysis-dependent chronic kidney disease (DD-CKD). The primary safety end point, assessed in a time-to-event analysis, was the first occurrence of a major adverse cardiovascular event (MACE, a composite of death from any cause, a nonfatal myocardial infarction, or a nonfatal stroke), pooled across the trials (noninferiority margin, 1.25). A key secondary safety end point was the first occurrence of a MACE plus hospitalization for either heart failure or a thromboembolic event. The primary and key secondary efficacy end points were the mean change in hemoglobin from baseline to weeks 24 to 36 and from baseline to weeks 40 to 52, respectively, in each trial (noninferiority margin, -0.75 g per deciliter). RESULTS: A total of 3923 patients were randomly assigned in a 1:1 ratio to receive vadadustat or darbepoetin alfa: 369 in the incident DD-CKD trial and 3554 in the prevalent DD-CKD trial. In the pooled analysis, a first MACE occurred in 355 patients (18.2%) in the vadadustat group and in 377 patients (19.3%) in the darbepoetin alfa group (hazard ratio, 0.96; 95% confidence interval [CI], 0.83 to 1.11). The mean differences between the groups in the change in hemoglobin concentration were -0.31 g per deciliter (95% CI, -0.53 to -0.10) at weeks 24 to 36 and -0.07 g per deciliter (95% CI, -0.34 to 0.19) at weeks 40 to 52 in the incident DD-CKD trial and -0.17 g per deciliter (95% CI, -0.23 to -0.10) and -0.18 g per deciliter (95% CI, -0.25 to -0.12), respectively, in the prevalent DD-CKD trial. The incidence of serious adverse events in the vadadustat group was 49.7% in the incident DD-CKD trial and 55.0% in the prevalent DD-CKD trial, and the incidences in the darbepoetin alfa group were 56.5% and 58.3%, respectively. CONCLUSIONS: Among patients with anemia and CKD who were undergoing dialysis, vadadustat was noninferior to darbepoetin alfa with respect to cardiovascular safety and correction and maintenance of hemoglobin concentrations. (Funded by Akebia Therapeutics and Otsuka Pharmaceutical; INNO2VATE ClinicalTrials.gov numbers, NCT02865850 and NCT02892149.).

Vadadustat in Patients with Anemia and Non-Dialysis-Dependent CKD.

BACKGROUND: Vadadustat is an oral hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitor, a class of drugs that stabilize HIF and stimulate erythropoietin and red-cell production. METHODS: In two phase 3, randomized, open-label, active-controlled, noninferiority trials, we compared vadadustat with the erythropoiesis-stimulating agent (ESA) darbepoetin alfa in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) not previously treated with an ESA who had a hemoglobin concentration of less than 10 g per deciliter and in patients with ESA-treated NDD-CKD and a hemoglobin concentration of 8 to 11 g per deciliter (in the United States) or 9 to 12 g per deciliter (in other countries). The primary safety end point, assessed in a time-to-event analysis, was the first major adverse cardiovascular event (MACE; a composite of death from any cause, nonfatal myocardial infarction, or nonfatal stroke), pooled across the two trials. Secondary safety end points included expanded MACE (MACE plus hospitalization for either heart failure or a thromboembolic event). The primary and key secondary efficacy end points in each trial were the mean change in hemoglobin concentration from baseline during two evaluation periods: weeks 24 through 36 and weeks 40 through 52. RESULTS: A total of 1751 patients with ESA-untreated NDD-CKD and 1725 with ESA-treated NDD-CKD underwent randomization in the two trials. In the pooled analysis, in which 1739 patients received vadadustat and 1732 received darbepoetin alfa, the hazard ratio for MACE was 1.17 (95% confidence interval [CI], 1.01 to 1.36), which did not meet the prespecified noninferiority margin of 1.25. The mean between-group differences in the change in the hemoglobin concentration at weeks 24 through 36 were 0.05 g per deciliter (95% CI, -0.04 to 0.15) in the trial involving ESA-untreated patients and -0.01 g per deciliter (95% CI, -0.09 to 0.07) in the trial involving ESA-treated patients, which met the prespecified noninferiority margin of -0.75 g per deciliter. CONCLUSIONS: Vadadustat, as compared with darbepoetin alfa, met the prespecified noninferiority criterion for hematologic efficacy but not the prespecified noninferiority criterion for cardiovascular safety in patients with NDD-CKD. (Funded by Akebia Therapeutics and Otsuka Pharmaceutical; PRO2TECT ClinicalTrials.gov numbers, NCT02648347 and NCT02680574.).

Potassium responses to sodium zirconium cyclosilicate in hyperkalemic hemodialysis patients: post-hoc analysis of DIALIZE.

BACKGROUND: Sodium zirconium cyclosilicate (SZC) is an effective and well-tolerated treatment for hyperkalemia in maintenance hemodialysis patients. In post-hoc analyses of the phase 3b DIALIZE study, we examined the spectrum of potassium responses to SZC. METHODS: Post-hoc analyses with SZC and placebo included: the number of long interdialytic interval (LIDI) visits during the 4-week evaluation period where patients attained pre-dialysis serum potassium (sK+) concentrations of 4.0-5.0 and 4.0-5.5 mmol/L; potassium gradient (the difference between pre-dialysis sK+ and dialysate potassium) at days 36, 43, 50, and 57, and change from baseline to the end of treatment (EOT) using categories of potassium gradient (1 to < 2, 2 to < 3, 3 to < 4, and ≥ 4 mmol/L). RESULTS: A greater proportion of patients achieved the ranges of pre-dialysis sK+ concentration with SZC versus placebo for ≥1, ≥ 2, ≥ 3, and 4 LIDI visits over 4 weeks; 23.7 and 48.5% of patients in the SZC group achieved pre-dialysis sK+ concentrations of 4.0-5.0 and 4.0-5.5 mmol/L, respectively, at all 4 LIDI visits. Baseline mean potassium gradient was similar with SZC and placebo. At day 57, mean (standard deviation) potassium gradient was 2.78 (0.08) mmol/L with SZC and 3.52 (0.08) mmol/L with placebo; mean difference (95% confidence interval) was - 0.74 mmol/L (- 0.97 to - 0.52). A greater reduction in potassium gradient category from baseline towards lower-risk categories at EOT was observed with SZC versus placebo. CONCLUSIONS: These analyses expand our knowledge of the spectrum of potassium responses with SZC in hyperkalemic hemodialysis patients. TRIAL REGISTRATION: NCT03303521 .

Consensus-Based Recommendations for the Management of Hyperkalemia in the Hemodialysis Setting.

Hyperkalemia (serum K+ >5.0 mmol/L) is commonly observed among patients receiving maintenance hemodialysis and associated with increased risk of cardiac arrhythmias. Current international guidelines may not reflect the latest evidence on managing hyperkalemia in patients undergoing hemodialysis, and there is a lack of high-quality published studies in this area. This consensus guideline aims to provide recommendations in relation to clinical practice. Available published evidence was evaluated through a systematic literature review, and the nominal group technique was used to develop consensus recommendations from a panel of experienced nephrologists, covering monitoring, dietary restrictions, prescription of K+ binders, and concomitant prescription of renin-angiotensin-aldosterone system inhibitors. Recent studies have shown that K+ binders reduce the incidence of hyperkalemia, but further evidence is needed in areas including whether reduced-K+ diets or treatment with K+ binders improve patient-centered outcomes. Treatment of hyperkalemia in the hemodialysis setting is complex, and decisions need to be tailored for individual patients.

Hypoxia-Inducible Factor Stabilization as an Emerging Therapy for CKD-Related Anemia: Report From a Scientific Workshop Sponsored by the National Kidney Foundation.

The National Kidney Foundation convened an interdisciplinary international workshop in March 2019 to discuss the potential role of a new class of agents for the treatment of anemia in patients with chronic kidney disease (CKD): the hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs). International experts with expertise in physiology, biochemistry, structural chemistry, translational medicine, and clinical management of anemia participated. Participants reviewed the unmet needs of current anemia treatment, the biology of hypoxia-inducible factor, the pharmacology of prolyl hydroxylase inhibitors, and the results of phase 2 clinical trials of HIF-PHIs among patients with CKD, both those treated by dialysis and those not receiving kidney replacement therapy. The results of key phase 3 clinical trials of HIF-PHIs available as of the time of writing are also included in this report, although they appeared after the workshop was completed. Participants in the workshop developed a number of recommendations for further examination of HIF-PHIs, which are summarized in this report and include long-term safety issues, potential benefits, and practical considerations for implementation including patient and provider education.

Long-term safety and efficacy of sodium zirconium cyclosilicate for hyperkalaemia in patients with mild/moderate versus severe/end-stage chronic kidney disease: comparative results from an open-label, Phase 3 study.

BACKGROUND: Sodium zirconium cyclosilicate (SZC; formerly ZS-9) is a selective potassium (K+) binder for the treatment of adults with hyperkalaemia. This post hoc analysis of an open-label, single-arm trial (NCT02163499) compared SZC efficacy and safety >12 months among outpatients with hyperkalaemia and Stages 4 and 5 chronic kidney disease (CKD) versus those with Stages 1-3 CKD. METHODS: Adults with serum K+ ≥5.1 mmol/L (measured by point-of-care i-STAT device) received SZC 10 g three times daily for 24-72 h until normokalaemia (i-STAT K+ 3.5-5.0 mmol/L) was achieved [correction phase (CP)], followed by once daily SZC 5 g for ≤12 months [maintenance phase (MP)]. Here, patients were stratified by baseline estimated glomerular filtration rate (eGFR <30 or ≥30 mL/min/1.73 m2). Study endpoints included percent achieving normokalaemia during CP and MP, mean serum K+ and bicarbonate during MP, and adverse events (AEs). RESULTS: Of 751 patients enrolled, 289 (39%), 453 (60%) and 9 (1%) had baseline eGFR values of <30, ≥30 mL/min/1.73 m2 or missing, respectively. During the CP, 82% of patients achieved normokalaemia in both eGFR subgroups within 24 h, and 100 and 95% with baseline eGFR <30 and ≥30 mL/min/1.73 m2, respectively, within 72 h. Corresponding proportions with normokalaemia during the MP were 82 and 90% at Day 365, respectively. Mean serum K+ reduction from baseline during the CP was sustained throughout the MP and serum bicarbonate increased. AEs during the MP were more common in the eGFR <30 ≥30 mL/min/1.73 m2 subgroup. CONCLUSIONS: SZC corrects hyperkalaemia and maintains normokalaemia among outpatients regardless of the CKD stage.

Sodium zirconium cyclosilicate increases serum bicarbonate concentrations among patients with hyperkalaemia: exploratory analyses from three randomized, multi-dose, placebo-controlled trials.

BACKGROUND: Sodium zirconium cyclosilicate (SZC) binds potassium and ammonium in the gastrointestinal tract. In addition to serum potassium reduction, Phase 2 trial data have shown increased serum bicarbonate with SZC, which may be clinically beneficial because maintaining serum bicarbonate ≥22 mmol/L preserves kidney function. This exploratory analysis examined serum bicarbonate and urea, and urine pH data from three SZC randomized, placebo-controlled Phase 3 studies among patients with hyperkalaemia [ZS-003 (n = 753), HARMONIZE (n = 258) and HARMONIZE-Global (n = 267)]. METHODS: In all studies, patients received ≤10 g SZC 3 times daily (TID) for 48 h to correct hyperkalaemia, followed by randomization to maintenance therapy with SZC once daily (QD) versus placebo for ≤29 days among those achieving normokalaemia. RESULTS: Significant dose-dependent mean serum bicarbonate increases from baseline of 0.3 to 1.5 mmol/L occurred within 48 h of SZC TID in ZS-003 (all P < 0.05), which occurred regardless of chronic kidney disease (CKD) stage. Similar acute increases in HARMONIZE and HARMONIZE-Global were maintained over 29 days. With highest SZC maintenance doses, patient proportions with serum bicarbonate <22 mmol/L fell from 39.4% at baseline to 4.9% at 29 days (P = 0.005) in HARMONIZE and from 87.9% to 70.1%, (P = 0.006) in HARMONIZE-Global. Path analyses demonstrated that serum urea decreases (but not serum potassium or urine pH changes) were associated with SZC effects on serum bicarbonate. CONCLUSIONS: SZC increased serum bicarbonate concentrations and reduced patient proportions with serum bicarbonate <22 mmol/L, likely due to SZC-binding of gastrointestinal ammonium. These SZC-induced serum bicarbonate increases occurred regardless of CKD stage and were sustained during ongoing maintenance therapy.

Impact of chronic kidney disease and anemia on health-related quality of life and work productivity: analysis of multinational real-world data.

BACKGROUND: Reductions in health-related quality of life (HRQoL) in patients with chronic kidney disease (CKD) are thought to be exacerbated by the low hemoglobin (Hb) levels that define anemia, a common complication of CKD. The current analysis evaluated the impact of anemia on HRQoL and work productivity in patients with non-dialysis dependent and dialysis-dependent CKD using real-world data. METHODS: Data were collected in France, Germany, Italy, Spain, the UK, the USA and China in 2012-2018 in the Adelphi Real World Disease Specific Programme™ for CKD, a large, cross-sectional, survey of physicians and their patients. Patients completed three patient-reported outcomes (PRO) instruments: the EuroQol 5-Dimension 3-level (EQ-5D-3 L), the Kidney Disease Quality of Life (KDQOL-36) instrument and the Work Productivity and Activity Impairment questionnaire. PROs were assessed by CKD stage and Hb levels, and regression analyses were performed with CKD stage and Hb level as independent variables and PROs as outcome variables, while adjusting for age, sex, CKD stage, comorbidities and cardiovascular risk. RESULTS: Overall, 5276 patients participated in the survey, including 28% stage 4 and 36% dialysis patients. Patients with lower Hb levels more often reported problems/issues on all EQ-5D-3 L domains (p < 0.0001). Regression analyses showed significant associations between lower Hb levels and the probability of low (< 0.8) EQ-5D-3 L utility scores (p < 0.0001) and low visual analog scale scores (p < 0.05), indicating poorer health status. Associations were seen even when adjusting for CKD stage and other potential confounding factors. Significant associations were observed between Hb level and the 12-Item Short-Form Health Survey (SF-12) Physical Component Summary, SF-12 Mental Component Summary and the three KDQOL-36 subscales (all p < 0.0001), and were confirmed using linear regression analyses adjusting for CKD stage and other potential confounders. Numerically greater work productivity losses and greater activity impairment were observed with lower Hb levels. CONCLUSIONS: Lower Hb levels worsen the impact of CKD on HRQoL, and are associated with lower work productivity in patients with CKD. Assessment and treatment of anemia should be recognized as a key component of integral CKD management throughout all stages of the disease.

A Phase 3b, Randomized, Double-Blind, Placebo-Controlled Study of Sodium Zirconium Cyclosilicate for Reducing the Incidence of Predialysis Hyperkalemia.

BACKGROUND: Patients with ESRD have minimal renal potassium excretion and, despite hemodialysis, often have persistent predialysis hyperkalemia. The DIALIZE study (NCT03303521) evaluated sodium zirconium cyclosilicate (SZC) in the management of hyperkalemia in hemodialysis patients. METHODS: In the DIALIZE study, a double-blind, placebo-controlled, phase 3b multicenter study, we randomized adults with ESRD who were managed by three-times weekly hemodialysis and had predialysis hyperkalemia to receive placebo or SZC 5 g once daily on non-dialysis days, and titrated towards maintaining normokalemia over 4 weeks, in 5 g increments to a maximum of 15 g. The primary efficacy outcome was proportion of patients during the 4-week stable-dose evaluation period who maintained predialysis serum potassium of 4.0-5.0 mmol/L during at least three of four hemodialysis treatments after the long interdialytic interval and did not require urgent rescue therapy to reduce serum potassium. RESULTS: In total, 196 patients (mean [standard deviation (SD)] age =58.1 [13.7] years old) were randomized to sodium zirconium cyclosilicate or placebo. Of 97 patients receiving sodium zirconium cyclosilicate, 41.2% met the primary end point and were deemed treatment responders compared with 1.0% of 99 patients receiving placebo (P<0.001). Rescue therapy to reduce serum potassium during the treatment period was required by 2.1% of patients taking sodium zirconium cyclosilicate versus 5.1% taking placebo. Serious adverse events occurred in 7% and 8% of patients in sodium zirconium cyclosilicate and placebo groups, respectively. The two groups displayed comparable interdialytic weight gain. There were few episodes of hypokalemia. CONCLUSIONS: Sodium zirconium cyclosilicate is an effective and well-tolerated treatment for predialysis hyperkalemia in patients with ESRD undergoing adequate hemodialysis.

Effect of bardoxolone methyl on the urine albumin-to-creatinine ratio in patients with type 2 diabetes and stage 4 chronic kidney disease.

Bardoxolone methyl attenuates inflammation by inducing nuclear factor erythroid-derived 2-related factor 2 and suppressing nuclear factor κB. The Bardoxolone Methyl Evaluation in Patients With Chronic Kidney Disease and Type 2 Diabetes (BEACON) trial was a phase 3 placebo-controlled, randomized, double-blind, parallel-group, international, multicenter trial in 2185 patients with type 2 diabetes mellitus and stage 4 chronic kidney disease. BEACON was terminated because of safety concerns, largely related to a significant increase in early heart failure events in patients randomized to bardoxolone methyl. Bardoxolone methyl resulted in increased estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio. Herein, we present post hoc analyses characterizing the relation between the urine albumin-to-creatinine ratio and eGFR. The urine albumin-to-creatinine ratio and eGFR were assessed every four weeks through Week 12, followed by assessments every eight weeks thereafter, and 4 weeks after the last dose of bardoxolone methyl was administered. The initial increases in urine albumin-to-creatinine ratio observed in patients randomized to bardoxolone methyl were attenuated after six months. Multivariable regression analysis identified baseline eGFR and eGFR over time as the dominant factors associated with change in the urine albumin-to-creatinine ratio. Relative to placebo, bardoxolone methyl resulted in a significant decrease in albuminuria when indexed to eGFR (least-squared means: -0.035 [95% confidence interval -0.031 to -0.039]). Thus, among patients with type 2 diabetes mellitus and stage 4 chronic kidney disease treated with bardoxolone methyl, changes in albuminuria are directly related to changes in eGFR, challenging the conventional construct that increases in albuminuria universally reflect kidney injury and denote harm.

Efficacy and Safety of Sodium Zirconium Cyclosilicate for Treatment of Hyperkalemia: An 11-Month Open-Label Extension of HARMONIZE.

BACKGROUND: Sodium zirconium cyclosilicate (SZC; formerly ZS-9) is a selective potassium (K+) binder for treatment of hyperkalemia. An open-label extension (OLE) of the -HARMONIZE study evaluated efficacy and safety of SZC for ≤11 months. METHODS: Patients from HARMONIZE with point-of-care device i-STAT K+ 3.5-6.2 mmol/L received once-daily SZC 5-10 g for ≤337 days. End points included achievement of mean serum K+ ≤5.1 mmol/L (primary) or ≤5.5 mmol/L (secondary). RESULTS: Of 123 patients who entered the extension (mean serum K+ 4.8 mmol/L), 79 (64.2%) completed the study. The median daily dose of SZC was 10 g (range 2.5-15 g). The primary end point was achieved by 88.3% of patients, and 100% achieved the secondary end point. SZC was well tolerated with no new safety concerns. CONCLUSION: In the HARMONIZE OLE, most patients maintained mean serum K+ within the normokalemic range for ≤11 months during ongoing SZC treatment.

Effects of sucroferric oxyhydroxide and sevelamer carbonate on chronic kidney disease-mineral bone disorder parameters in dialysis patients.

BACKGROUND: Treatment of hyperphosphataemia is the primary goal of chronic kidney disease-mineral and bone disorder (CKD-MBD) management. This post hoc analysis of a randomized, Phase 3 study evaluated the effects of 1-year treatment with the phosphate binders sucroferric oxyhydroxide or sevelamer carbonate ('sevelamer') on CKD-MBD indices among dialysis patients with hyperphosphataemia. METHODS: After a 2- to 4-week washout from previous phosphate binders, 1059 patients were randomized 2:1 to sucroferric oxyhydroxide 1.0-3.0 g/day (n = 710) or sevelamer 2.4-14.4 g/day (n = 349) for up to 24 weeks. Eligible patients enrolled in a 28-week extension. This post hoc analysis was performed for patients who completed ≥1 year of continuous treatment (n = 549). As the treatment groups showed similar CKD-MBD outcomes, the data were pooled for this analysis. RESULTS: Phosphate-binder therapy was associated with significant and sustained 30% reductions in serum phosphorus (P < 0.001). Median intact fibroblast growth factor-23 (FGF-23) also significantly decreased (P < 0.001) by 64% over 1 year. Intact parathyroid hormone decreased significantly after 24 weeks (P < 0.001), but levels returned to near baseline values by Week 52; minimal changes in serum calcium were observed. Of the bone resorption markers evaluated, tartrate-resistant acid phosphatase 5b (TRAP5b) decreased significantly (P < 0.001), whereas CTx increased transiently but returned to baseline levels by Week 52. The bone formation markers bone-specific alkaline phosphatase and osteocalcin both increased over 1 year of treatment. CONCLUSIONS: Overall, 1 year of sucroferric oxyhydroxide or sevelamer treatment significantly reduced serum FGF-23, which has been associated with clinical benefit in patients with CKD. The trend towards increased bone formation marker levels indicates a beneficial effect on bone metabolism.

Update on Anemia in ESRD and Earlier Stages of CKD: Core Curriculum 2018.

Anemia is a frequent complication during the later stages of chronic kidney disease. When present, it may cause symptoms such as fatigue and shortness of breath. The pathogenesis of anemia in chronic kidney disease is complex, but a central feature is a relative deficit of erythropoietin. New information has elucidated the critical role of the hypoxia-sensing system in mediating erythropoietin synthesis and release. Iron deficiency is a second important factor in the anemia of chronic kidney disease. New insights into the dynamics of iron metabolism have clarified the role of chronic inflammation and hepcidin as key mediators of impaired iron utilization. In this article, we review the epidemiology, pathobiology, clinical evaluation, and treatment of anemia in chronic kidney disease.

One-year efficacy and safety of the iron-based phosphate binder sucroferric oxyhydroxide in patients on peritoneal dialysis.

BACKGROUND: Sucroferric oxyhydroxide is a noncalcium, iron-based phosphate binder that demonstrated sustained serum phosphorus control, good tolerability and lower pill burden compared with sevelamer carbonate (sevelamer) in a Phase 3 study conducted in dialysis patients. This subanalysis examines the efficacy and tolerability of sucroferric oxyhydroxide and sevelamer in the peritoneal dialysis (PD) patient population. METHODS: The initial study (NCT01324128) and its extension (NCT01464190) were multicenter, Phase 3, open-label, randomized (2:1), active-controlled trials comparing sucroferric oxyhydroxide (1.0-3.0 g/day) with sevelamer (2.4-14.4 g/day) in dialysis patients over 52 weeks in total. RESULTS: In the overall study, 84/1055 (8.1%) patients received PD and were eligible for efficacy analysis (sucroferric oxyhydroxide, n = 56; sevelamer, n = 28). The two groups were broadly comparable to each other and to the overall study population. Serum phosphorus concentrations decreased comparably with both phosphate binders by week 12 (mean change from baseline - 0.6 mmol/L). Over 52 weeks, sucroferric oxyhydroxide effectively reduced serum phosphorus concentrations to a similar extent as sevelamer; 62.5% and 64.3% of patients, respectively, were below the Kidney Disease Outcomes Quality Initiative target range (≤1.78 mmol/L). This was achieved with a lower pill burden (3.4 ± 1.3 versus 8.1 ± 3.7 tablets/day) with sucroferric oxyhydroxide compared with sevelamer. Treatment adherence rates were 91.2% with sucroferric oxyhydroxide and 79.3% with sevelamer. The proportion of patients reporting at least one treatment-emergent adverse event was 86.0% with sucroferric oxyhydroxide and 93.1% with sevelamer. The most common adverse events with both treatments were gastrointestinal: diarrhea and discolored feces with sucroferric oxyhydroxide and nausea, vomiting and constipation with sevelamer. CONCLUSIONS: Sucroferric oxyhydroxide is noninferior to sevelamer for controlling serum phosphorus in patients undergoing PD, while providing a relatively low pill burden and a high rate of adherence.

Vadadustat, a novel oral HIF stabilizer, provides effective anemia treatment in nondialysis-dependent chronic kidney disease.

Current treatment of anemia in chronic kidney disease (CKD) with erythropoiesis-stimulating agents can lead to substantial hemoglobin oscillations above target range and high levels of circulating erythropoietin. Vadadustat (AKB-6548), a novel, titratable, oral hypoxia-inducible factor prolyl hydroxylase inhibitor induces endogenous erythropoietin synthesis and enhances iron mobilization. In this 20-week, double-blind, randomized, placebo-controlled, phase 2b study, we evaluated the efficacy and safety of once-daily vadadustat in patients with stages 3a to 5 non-dialysis-dependent CKD. The primary endpoint was the percentage of patients who, during the last 2 weeks of treatment, achieved or maintained either a mean hemoglobin level of 11.0 g/dl or more or a mean increase in hemoglobin of 1.2 g/dl or more over the predose average. Significantly, the primary endpoint was met in 54.9% of patients on vadadustat and 10.3% of patients on placebo. Significant increases in both reticulocytes and total iron-binding capacity and significant decreases in both serum hepcidin and ferritin levels were observed in patients on vadadustat compared with placebo. The overall incidence of adverse events was comparable between the 2 groups. Serious adverse events occurred in 23.9% and 15.3% of the vadadustat- and placebo-treated patients, respectively. Three deaths occurred in the vadadustat arm. Thus, this phase 2b study demonstrated that vadadustat raised and maintained hemoglobin levels in a predictable and controlled manner while enhancing iron mobilization in patients with nondialysis-dependent CKD.

Peginesatide for anemia in patients with chronic kidney disease not receiving dialysis.

BACKGROUND: Peginesatide is a peptide-based erythropoiesis-stimulating agent (ESA) that may have therapeutic potential for anemia in patients with advanced chronic kidney disease. We evaluated the safety and efficacy of peginesatide, as compared with another ESA, darbepoetin, in 983 such patients who were not undergoing dialysis. METHODS: In two randomized, controlled, open-label studies (PEARL 1 and 2), patients received peginesatide once a month, at a starting dose of 0.025 mg or 0.04 mg per kilogram of body weight, or darbepoetin once every 2 weeks, at a starting dose of 0.75 µg per kilogram. Doses of both drugs were adjusted to achieve and maintain hemoglobin levels between 11.0 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 97.5% confidence interval was -1.0 g per deciliter or higher. Cardiovascular safety was evaluated on the basis of an adjudicated composite end point. RESULTS: In both studies and at both starting doses, peginesatide was noninferior to darbepoetin in increasing and maintaining hemoglobin levels. The mean differences in the hemoglobin level with peginesatide as compared with darbepoetin in PEARL 1 were 0.03 g per deciliter (97.5% confidence interval [CI], -0.19 to 0.26) for the lower starting dose of peginesatide and 0.26 g per deciliter (97.5% CI, 0.04 to 0.48) for the higher starting dose, and in PEARL 2 they were 0.14 g per deciliter (97.5% CI, -0.09 to 0.36) and 0.31 g per deciliter (97.5% CI, 0.08 to 0.54), respectively. The hazard ratio for the cardiovascular safety end point was 1.32 (95% CI, 0.97 to 1.81) for peginesatide relative to darbepoetin, with higher incidences of death, unstable angina, and arrhythmia with peginesatide. CONCLUSIONS: The efficacy of peginesatide (administered monthly) was similar to that of darbepoetin (administered every 2 weeks) in increasing and maintaining hemoglobin levels. However, cardiovascular events and mortality were increased with peginesatide in patients with chronic kidney disease who were not undergoing dialysis. (Funded by Affymax and Takeda Pharmaceutical; ClinicalTrials.gov numbers, NCT00598273 [PEARL 1], NCT00598442 [PEARL 2], NCT00597753 [EMERALD 1], and NCT00597584 [EMERALD 2].).

Hypoxia-Inducible Factor Stabilizers: a New Avenue for Reducing BP While Helping Hemoglobin?

Anemia of chronic kidney disease (CKD) is common and is associated with diminished quality of life, cognitive impairment, cardiovascular morbidity, hospitalizations, and mortality. As the prevalence of end-stage renal disease continues to rise, the management of anemia represents a growing economic burden. Erythropoiesis-stimulating agents (ESA) are the mainstay of anemia management but their use is limited due to the associated cardiovascular adverse events. Prolyl hydroxylase domain enzyme (PHD) inhibitors are a new class of drugs that stabilize the hypoxia-inducible factors and are under clinical investigation for the treatment of renal anemia. The advantages of PHD inhibitors include the oral route of administration, improved iron profile, restoration of diurnal rhythm of erythropoietin secretion, and endogenous erythropoietin production near physiological range. Emerging but limited data indicates a small blood pressure lowering effect of PHD inhibitors. The effect of PHD inhibitors on cardiovascular endpoints and the potential risks of CKD progression and pulmonary hypertension remains to be addressed in the ongoing clinical trials.

Novel Agents for the Prevention and Management of Hyperkalemia.

Hyperkalemia is defined as serum potassium concentrations elevated above the upper limit of normal (> 5.0 mEq/L). It has become more common in cardiovascular practice due to the growing population of patients with chronic kidney disease and the broad application of drugs that modulate renal elimination of potassium by reducing production of angiotensin II (angiotensin-converting enzyme inhibitors, direct renin inhibitors, ß-adrenergic receptor antagonists), blocking angiotensin II receptors (angiotensin receptor blockers), or antagonizing the action of aldosterone on mineralocorticoid receptors (mineralocorticoid receptor antagonists). The risk of hyperkalemia is a major limiting factor for the use of these disease-modifying drugs in both acute and chronic cardiorenal syndromes. Thus, agents to control the plasma concentration of potassium are needed in the multidrug treatment of cardiorenal disease, including chronic kidney disease, heart failure, and acute kidney injury. Novel oral therapies in development for both acute and extended use in the management of hyperkalemia include patiromer sorbitex calcium and sodium zirconium cyclosilicate. Important biochemical differences between these compounds result in unique product profiles and electrolyte outcomes in patients treated for hyperkalemia. This review highlights the major mechanisms of hyperkalemia and key results from randomized trials in a range of clinical scenarios in patients with, and at risk for, hyperkalemia.

Long-term effects of the iron-based phosphate binder, sucroferric oxyhydroxide, in dialysis patients.

BACKGROUND: Hyperphosphatemia necessitates the use of phosphate binders in most dialysis patients. Long-term efficacy and tolerability of the iron-based phosphate binder, sucroferric oxyhydroxide (previously known as PA21), was compared with that of sevelamer carbonate (sevelamer) in an open-label Phase III extension study. METHODS: In the initial Phase III study, hemo- or peritoneal dialysis patients with hyperphosphatemia were randomized 2:1 to receive sucroferric oxyhydroxide 1.0-3.0 g/day (2-6 tablets/day; n = 710) or sevelamer 2.4-14.4 g/day (3-18 tablets/day; n = 349) for 24 weeks. Eligible patients could enter the 28-week extension study, continuing the same treatment and dose they were receiving at the end of the initial study. RESULTS: Overall, 644 patients were available for efficacy analysis (n = 384 sucroferric oxyhydroxide; n = 260 sevelamer). Serum phosphorus concentrations were maintained during the extension study. Mean ± standard deviation (SD) change in serum phosphorus concentrations from extension study baseline to Week 52 end point was 0.02 ± 0.52 mmol/L with sucroferric oxyhydroxide and 0.09 ± 0.58 mmol/L with sevelamer. Mean serum phosphorus concentrations remained within Kidney Disease Outcomes Quality Initiative target range (1.13-1.78 mmol/L) for both treatment groups. Mean (SD) daily tablet number over the 28-week extension study was lower for sucroferric oxyhydroxide (4.0 ± 1.5) versus sevelamer (10.1 ± 6.6). Patient adherence was 86.2% with sucroferric oxyhydroxide versus 76.9% with sevelamer. Mean serum ferritin concentrations increased over the extension study in both treatment groups, but transferrin saturation (TSAT), iron and hemoglobin concentrations were generally stable. Gastrointestinal-related adverse events were similar and occurred early with both treatments, but decreased over time. CONCLUSIONS: The serum phosphorus-lowering effect of sucroferric oxyhydroxide was maintained over 1 year and associated with a lower pill burden, compared with sevelamer. Sucroferric oxyhydroxide was generally well tolerated long-term and there was no evidence of iron accumulation.