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.

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.

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.

Sodium Zirconium Cyclosilicate among Individuals with Hyperkalemia: A 12-Month Phase 3 Study.

BACKGROUND AND OBJECTIVES: Oral sodium zirconium cyclosilicate (formerly ZS-9) binds and removes potassium via the gastrointestinal tract. Sodium zirconium cyclosilicate-associated restoration and maintenance of normokalemia and adverse events were evaluated in a two-part, open label, phase 3 trial. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In the correction phase, adult outpatients with plasma potassium ≥5.1 mmol/L (i-STAT Point-of-Care) received sodium zirconium cyclosilicate 10 g three times daily for 24-72 hours until normokalemic (potassium =3.5-5.0 mmol/L). Qualifying participants entered the ≤12-month maintenance phase and received sodium zirconium cyclosilicate 5 g once daily titrated to maintain normokalemia without dietary or medication restrictions. Prespecified primary end points were restoration of normal serum potassium values (3.5-5.0 mmol/L) during the correction phase and maintenance of serum potassium ≤5.1 mmol/L during the maintenance phase. Adverse events were assessed throughout. RESULTS: Of 751 participants, 746 (99%) achieved normokalemia during the correction phase (mean serum potassium =4.8 mmol/L; 95% confidence interval, 4.7 to 4.8) and entered the maintenance phase; 466 (63%) participants completed the 12-month trial. Participants were predominantly white, men, and age ≥65 years old; 74% had an eGFR<60 ml/min per 1.73 m2, and 65% used renin-angiotensin-aldosterone system inhibitors. Mean time on sodium zirconium cyclosilicate was 286 days. Mean daily sodium zirconium cyclosilicate dose was 7.2 g (SD=2.6). Over months 3-12, mean serum potassium was 4.7 mmol/L (95% confidence interval, 4.6 to 4.7); mean serum potassium values ≤5.1 and ≤5.5 mmol/L were achieved by 88% and 99% of participants, respectively. Of 483 renin-angiotensin-aldosterone system inhibitor users at baseline, 87% continued or had their dose increased; 11% discontinued. Among 263 renin-angiotensin-aldosterone system inhibitor-naïve participants, 14% initiated renin-angiotensin-aldosterone system inhibitor therapy. Overall, 489 (66%) participants experienced adverse events during the maintenance phase, and 22% experienced a serious adverse event. Of eight (1%) deaths, none were considered related to sodium zirconium cyclosilicate. Nine (1%) and 34 (5%) participants experienced serum potassium <3.0 and 3.0-3.4 mmol/L, respectively. CONCLUSIONS: After achieving normokalemia, individualized once daily sodium zirconium cyclosilicate was associated with maintenance of normokalemia without substantial renin-angiotensin-aldosterone system inhibitor changes for ≤12 months.

Allogeneic Mesenchymal Precursor Cells (MPC) in Diabetic Nephropathy: A Randomized, Placebo-controlled, Dose Escalation Study.

BACKGROUND: Diabetic nephropathy is the most common cause of end stage renal failure. We assessed the safety, tolerability, and explored therapeutic effects of adult allogeneic bone-marrow derived mesenchymal precursor cells (MPC) in patients with moderate to severe diabetic nephropathy. METHODS: Multicenter, randomized, double-blind, dose-escalating, sequential, placebo-controlled trial assessing a single intravenous (IV) infusion of allogeneic MPC (United States adopted name: rexlemestrocel-L) 150×106 (n=10), 300×106 (n=10) or placebo (n=10) in adults with diabetic nephropathy with an estimated glomerular filtration rate (eGFR) 20-50ml/min/1.73m2. Thirty patients at three Australian centers were enrolled between July 2013 and June 2014 and randomized 2:1, in two sequential dose cohorts, to receive rexlemestrocel-L or placebo. Study duration was 60weeks. Primary endpoint was safety and tolerability. Primary exploratory efficacy endpoint was change from baseline in eGFR and directly measured GFR by 99Tc-DTPA plasma clearance (mGFR) at 12weeks post-infusion. The trial was registered on ClinicalTrials.gov (NCT01843387). FINDINGS: All patients completed the study and were included in analyses applied to the intention to treat population. There were no acute adverse events (AEs) associated with infusion and no treatment-related AEs or serious AEs were deemed treatment-related by investigators. No patients developed persistent donor specific anti-HLA antibodies. Relative to placebo, a single IV rexlemestrocel-L infusion showed trends of stabilizing or improving eGFR and mGFR at week 12. The adjusted least squares mean (LSM±SE) differences from placebo in changes from baseline at 12weeks in the rexlemestrocel-L groups were 4.4±2.16 and 1.6±2.15ml/min/1.73m2 for eGFR and 4.1±2.75 and 3.9±2.75 for mGFR for the 150×106 and 300×106 cell groups, respectively. INTERPRETATION: This study demonstrates the safety of rexlemestrocel-L in diabetic nephropathy with suggestive effects on renal function to be confirmed in larger, appropriately powered trials.

Pharmacodynamics and pharmacokinetics of sodium zirconium cyclosilicate [ZS-9] in the treatment of hyperkalemia.

INTRODUCTION: Hyperkalemia is a common electrolyte disorder that arises from dysfunctional homeostatic mechanisms or as a consequence of decreased renal function. Sodium zirconium cyclosilicate (ZS-9) is a potential new therapy for hyperkalemia in both acute and chronic settings. AREAS COVERED: Here we discuss mechanisms of potassium homeostasis and preclinical and clinical studies that present pharmacokinetics/pharmacodynamics, efficacy and safety profiles of ZS-9. EXPERT OPINION: ZS-9 has a unique mechanism of action consisting of thermodynamically favorable sequestration of potassium ions, enabling rapid trapping and removal of excess potassium. The potassium lowering action of ZS-9 is predictable and rapid, leading to significant reduction of serum potassium within 1 hour of administration by irreversibly eliminating excess potassium rather than acting via intracellular translocation. Its safety profile, including gastrointestinal events, has been generally similar to that of placebo, with the exception of infrequent but manageable events of peripheral edema and transient hypokalemia. ZS-9 has demonstrated potential for enabling renin-angiotensin-aldosterone system inhibitors in mid-term studies, with long-term studies ongoing.

Individual long-term albuminuria exposure during angiotensin receptor blocker therapy is the optimal predictor for renal outcome.

BACKGROUND: Albuminuria reduction due to angiotensin receptor blockers (ARBs) predicts subsequent renoprotection. Relating the initial albuminuria reduction to subsequent renoprotection assumes that the initial ARB-induced albuminuria reduction remains stable during follow-up. The aim of this study was to assess individual albuminuria fluctuations after the initial ARB response and to determine whether taking individual albuminuria fluctuations into account improves renal outcome prediction. METHODS: Patients with diabetes and nephropathy treated with losartan or irbesartan in the RENAAL and IDNT trials were included. Patients with >30% reduction in albuminuria 3 months after ARB initiation were stratified by the subsequent change in albuminuria until Month 12 in enhanced responders (>50% albuminuria reduction), sustained responders (between 20 and 50% reduction), and response escapers (<20% reduction). Predictive performance of the individual albuminuria exposure until Month 3 was compared with the exposure over the first 12 months using receiver operating characteristics (ROC) curves. RESULTS: Following ARB initiation, 388 (36.3%) patients showed an >30% reduction in albuminuria. Among these patients, the albuminuria level further decreased in 174 (44.8%), remained stable in 123 (31.7%), and increased in 91 (23.5%) patients. Similar albuminuria fluctuations were observed in patients with <30% albuminuria reduction. Renal risk prediction improved when using the albuminuria exposure during the first 12 months versus the initial Month 3 change [ROC difference: 0.78 (95% CI 0.75-0.82) versus 0.68 (0.64-0.72); P < 0.0001]. CONCLUSIONS: Following the initial response to ARBs, a large within-patient albuminuria variability is observed. Hence, incorporating multiple albuminuria measurements over time in risk algorithms may be more appropriate to monitor treatment effects and quantify renal risk.

Potential New Agents for the Management of Hyperkalemia.

Hyperkalemia is a common electrolyte disturbance with multiple potential etiologies. It is usually observed in the setting of reduced renal function. Mild to moderate hyperkalemia is usually asymptomatic, but is associated with poor prognosis. When severe, hyperkalemia may cause serious acute cardiac arrhythmias and conduction abnormalities, and may result in sudden death. The rising prevalence of conditions associated with hyperkalemia (heart failure, chronic kidney disease, and diabetes) and broad use of renin-angiotensin-aldosterone system (RAAS) inhibitors and mineralocorticoid receptor antagonists (MRAs), which improve patient outcomes but increase the risk of hyperkalemia, have led to a significant rise in hyperkalemia-related hospitalizations and deaths. Current non-invasive therapies for hyperkalemia either do not remove excess potassium or have poor efficacy and tolerability. There is a clear need for safer, more effective potassium-lowering therapies suitable for both acute and chronic settings. Patiromer sorbitex calcium and sodium zirconium cyclosilicate (ZS-9) are two new potassium-lowering compounds currently in development. Although they have not yet been approved by the US FDA, both have demonstrated efficacy and safety in recent trials. Patiromer sorbitex calcium is a polymer resin and sorbitol complex that binds potassium in exchange for calcium; ZS-9, a non-absorbed, highly selective inorganic cation exchanger, traps potassium in exchange for sodium and hydrogen. This review discusses the merits of both novel drugs and how they may help optimize the future management of patients with hyperkalemia.

Sodium zirconium cyclosilicate in hyperkalemia.

BACKGROUND: Hyperkalemia (serum potassium level, >5.0 mmol per liter) is associated with increased mortality among patients with heart failure, chronic kidney disease, or diabetes. We investigated whether sodium zirconium cyclosilicate (ZS-9), a novel selective cation exchanger, could lower serum potassium levels in patients with hyperkalemia. METHODS: In this multicenter, two-stage, double-blind, phase 3 trial, we randomly assigned 753 patients with hyperkalemia to receive either ZS-9 (at a dose of 1.25 g, 2.5 g, 5 g, or 10 g) or placebo three times daily for 48 hours. Patients with normokalemia (serum potassium level, 3.5 to 4.9 mmol per liter) at 48 hours were randomly assigned to receive either ZS-9 or placebo once daily on days 3 to 14 (maintenance phase). The primary end point was the exponential rate of change in the mean serum potassium level at 48 hours. RESULTS: At 48 hours, the mean serum potassium level had decreased from 5.3 mmol per liter at baseline to 4.9 mmol per liter in the group of patients who received 2.5 g of ZS-9, 4.8 mmol per liter in the 5-g group, and 4.6 mmol per liter in the 10-g group, for mean reductions of 0.5, 0.5, and 0.7 mmol per liter, respectively (P<0.001 for all comparisons) and to 5.1 mmol per liter in the 1.25-g group and the placebo group (mean reduction, 0.3 mmol per liter). In patients who received 5 g of ZS-9 and those who received 10 g of ZS-9, serum potassium levels were maintained at 4.7 mmol per liter and 4.5 mmol per liter, respectively, during the maintenance phase, as compared with a level of more than 5.0 mmol per liter in the placebo group (P<0.01 for all comparisons). Rates of adverse events were similar in the ZS-9 group and the placebo group (12.9% and 10.8%, respectively, in the initial phase; 25.1% and 24.5%, respectively, in the maintenance phase). Diarrhea was the most common complication in the two study groups. CONCLUSIONS: Patients with hyperkalemia who received ZS-9, as compared with those who received placebo, had a significant reduction in potassium levels at 48 hours, with normokalemia maintained during 12 days of maintenance therapy. (Funded by ZS Pharma; ClinicalTrials.gov number, NCT01737697.).

Pyridoxamine dihydrochloride in diabetic nephropathy (PIONEER-CSG-17): lessons learned from a pilot study.

BACKGROUND/AIMS: Pyridoxamine dihydrochloride (Pyridorin™) blocks pathogenic oxidative pathways in the progression of diabetic nephropathy. The pyridoxamine pilot study was designed to test entry criteria and outcomes. Subjects had SCr 1.3-3.5 mg/dl, protein-to-creatinine ≥1,200 mg/g and used a surrogate outcome of ΔSCr over 52 weeks. Subjects had to be on a maximally tolerated dose of ACE/ARB for 3 months; stable other antihypertensive doses for 2 months; stable diuretic dose for 2 weeks, and BP ≤160/90 mm Hg; or enter a Pharmaco-Stabilization Phase (PSP). This pilot failed to detect an effect on ΔSCr in intent-to-treat analysis. METHODS: We queried the locked clinical trial database for subgroups in which there was a treatment effect. RESULTS: Subjects not requiring PSP and those with entry SCr <2.0 mg/dl had a treatment effect. Subjects entering PSP required more changes in antihypertensive medications and experienced larger ΔSCr over 52 weeks. PSP subjects with BP >140/90 mm Hg had no treatment effect, but those ≤140/90 mm Hg did. CONCLUSION: Time required for acute effects of ACE/ARB to stabilize is unknown, but these data suggest >3 months. Thus, subjects in the pivotal trial must be on ACE/ARB for 6 months. Frequent antihypertensive adjustment could engender SCr changes unrelated to CKD progression. Thus, we will require subjects to have BP ≤150/90 mm Hg and on stable antihypertensives for 26 weeks, or ≤140/90 mm Hg and on stable antihypertensives for 13 weeks. Since ΔSCr over 52 weeks is limited as a surrogate outcome, the pivotal trial uses a time-to-event analysis of baseline SCr to at least a 50% increase in SCr or ESRD as the primary outcome. This substantial ΔSCr is protected from noise and is clinically relevant. The pyridoxamine pilot provided critical information to inform the design of PIONEER-CSG-17, which we conducted under the SPA agreement with FDA.

Effect of sodium zirconium cyclosilicate on potassium lowering for 28 days among outpatients with hyperkalemia: the HARMONIZE randomized clinical trial.

IMPORTANCE: Hyperkalemia is a common electrolyte abnormality that may be difficult to manage because of a lack of effective therapies. Sodium zirconium cyclosilicate is a nonabsorbed cation exchanger that selectively binds potassium in the intestine. OBJECTIVE: To evaluate the efficacy and safety of zirconium cyclosilicate for 28 days in patients with hyperkalemia. DESIGN, SETTING, AND PARTICIPANTS: HARMONIZE was a phase 3, multicenter, randomized, double-blind, placebo-controlled trial evaluating zirconium cyclosilicate in outpatients with hyperkalemia (serum potassium ≥5.1 mEq/L) recruited from 44 sites in the United States, Australia, and South Africa (March-August 2014). INTERVENTIONS: Patients (n = 258) received 10 g of zirconium cyclosilicate 3 times daily in the initial 48-hour open-label phase. Patients (n = 237) achieving normokalemia (3.5-5.0 mEq/L) were then randomized to receive zirconium cyclosilicate, 5 g (n = 45 patients), 10 g (n = 51), or 15 g (n = 56), or placebo (n = 85) daily for 28 days. MAIN OUTCOMES AND MEASURES: The primary end point was mean serum potassium level in each zirconium cyclosilicate group vs placebo during days 8-29 of the randomized phase. RESULTS: In the open-label phase, serum potassium levels declined from 5.6 mEq/L at baseline to 4.5 mEq/L at 48 hours. Median time to normalization was 2.2 hours, with 84% of patients (95% CI, 79%-88%) achieving normokalemia by 24 hours and 98% (95% CI, 96%-99%) by 48 hours. In the randomized phase, serum potassium was significantly lower during days 8-29 with all 3 zirconium cyclosilicate doses vs placebo (4.8 mEq/L [95% CI, 4.6-4.9], 4.5 mEq/L [95% CI, 4.4-4.6], and 4.4 mEq/L [95% CI, 4.3-4.5] for 5 g, 10 g, and 15 g; 5.1 mEq/L [95% CI, 5.0-5.2] for placebo; P < .001 for all comparisons). The proportion of patients with mean potassium <5.1 mEq/L during days 8-29 was significantly higher in all zirconium cyclosilicate groups vs placebo (36/45 [80%], 45/50 [90%], and 51/54 [94%] for the 5-g, 10-g, and 15-g groups, vs 38/82 [46%] with placebo; P < .001 for each dose vs placebo). Adverse events were comparable between zirconium cyclosilicate and placebo, although edema was more common in the 15-g group (edema incidence: 2/85 [2%], 1/45 [2%], 3/51 [6%], and 8/56 [14%] patients in the placebo, 5-g, 10-g, and 15-g groups). Hypokalemia developed in 5/51 (10%) and 6/56 patients (11%) in the 10-g and 15-g zirconium cyclosilicate groups, vs none in the 5-g or placebo groups. CONCLUSIONS AND RELEVANCE: Among outpatients with hyperkalemia, open-label sodium zirconium cyclosilicate reduced serum potassium to normal levels within 48 hours; compared with placebo, all 3 doses of zirconium cyclosilicate resulted in lower potassium levels and a higher proportion of patients with normal potassium levels for up to 28 days. Further studies are needed to evaluate the efficacy and safety of zirconium cyclosilicate beyond 4 weeks and to assess long-term clinical outcomes. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT02088073.

Mechanisms contributing to adverse cardiovascular events in patients with type 2 diabetes mellitus and stage 4 chronic kidney disease treated with bardoxolone methyl.

BACKGROUND: Bardoxolone methyl, an Nrf2-activating and nuclear factor-κB-inhibiting semisynthetic oleanane triterpenoid compound, was evaluated in a phase 3 trial (BEACON) in patients with type 2 diabetes mellitus (T2DM) and stage 4 chronic kidney disease (CKD). The trial was terminated because of an increase in heart failure events in the bardoxolone methyl group, many of which appeared related to fluid retention. Thus, additional analyses were conducted to explain these serious adverse events. METHODS: Patients (n = 2,185) were randomized to receive once-daily bardoxolone methyl (20 mg) or placebo. Twenty-four-hour urine collections were analyzed in a subset of the BEACON population and from a separate, open-label pharmacology study in patients with stage 3b/4 CKD and T2DM administered 20 mg bardoxolone methyl once daily for 56 consecutive days. RESULTS: Bardoxolone-methyl-treated patients in the BEACON substudy had a clinically meaningful reduction in urine volume and sodium excretion at week 4 relative to baseline (p < 0.05), and a separate study revealed that decreased sodium excretion and urine output occurred in some patients with stage 4 CKD but not those with stage 3b CKD. The clinical phenotype of fluid overload and heart failure in BEACON was similar to that observed with endothelin receptor antagonists in advanced CKD patients, and preclinical data demonstrate that bardoxolone methyl modifies endothelin signaling. CONCLUSIONS: The totality of the evidence suggests that through modulation of the endothelin pathway, bardoxolone methyl may pharmacologically promote acute sodium and volume retention and increase blood pressure in patients with more advanced CKD.

Residual proteinuria and eGFR predict progression of renal impairment within 2 years in type 2 diabetic patients with nephropathy who are receiving optimal treatment with angiotensin receptor blockers.

AIM: Proteinuria and estimated glomerular filtration rate (eGFR) predict progression of renal impairment in type 2 diabetic nephropathy (DN) but are they still predictive when these patients are treated with angiotensin receptor blockers (ARB)? We investigated whether residual (after ≥3 months of ARB treatment) urinary protein/creatinine ratio (rPCR) or urinary albumin/creatinine ratio (rACR) and residual eGFR (reGFR), predict subsequent progression. METHODS: One thousand, two hundred and forty-five patients with type 2 DN from two international multi-center studies were analysed. Cross classification of rPCR, rACR with reGFR (rPCR: <1000, 1000-<2000 and ≥2000 mg/g; rACR: <666.7, 666.7-<1333.3 and ≥1333.3 mg/g; reGFR: 15-29, 30-44 and 45-59 mL/min per 1.73 m2). Progression of renal disease exhibited as: end stage renal failure, doubling of serum creatinine, or serum creatinine ≥6 mg/dL. RESULTS: Increasing rPCR or rACR, and decreasing reGFR were strongly associated with increasing risk of renal disease progression, with no evidence of interaction between rPCR and reGFR, or rACR and reGFR. The estimated 24-month risk was low (<8%) for patients with rPCR <1000 mg/g regardless of reGFR, for patients with reGFR ≥45 mL/min per 1.73 m2 regardless of rPCR, or with rPCR between 1000-<2000 mg/g and reGFR ≥30 mL/min per 1.73 m2 . However, the risk rose steeply (to 39.4%) for reGFR <30 mL/min per 1.73 m2 and rPCR ≥2000 mg/g. CONCLUSION: Despite DN patients being treated with ARB, renal disease progression risk over 2 years increases with increasing proteinuria, albuminuria and decreasing eGFR. Recognition of these risk factors' impact is important in patient management and future clinical trial design.

Vitamin D reduces left atrial volume in patients with left ventricular hypertrophy and chronic kidney disease.

BACKGROUND: Left atrial enlargement, a sensitive integrator of left ventricular diastolic function, is associated with increased cardiovascular morbidity and mortality. Vitamin D is linked to lower cardiovascular morbidity, possibly modifying cardiac structure and function; however, firm evidence is lacking. We assessed the effect of an activated vitamin D analog on left atrial volume index (LAVi) in a post hoc analysis of the PRIMO trial (clinicaltrials.gov: NCT00497146). METHODS AND RESULTS: One hundred ninety-six patients with chronic kidney disease (estimated glomerular filtration rate 15-60 mL/min per 1.73 m(2)), mild to moderate left ventricular hypertrophy, and preserved ejection fraction were randomly assigned to 2 µg of oral paricalcitol or matching placebo for 48 weeks. Two-dimensional echocardiography was obtained at baseline and at 24 and 48 weeks after initiation of therapy. Over the study period, there was a significant decrease in LAVi (-2.79 mL/m(2), 95% CI -4.00 to -1.59 mL/m(2)) in the paricalcitol group compared with the placebo group (-0.70 mL/m(2) [95% CI -1.93 to 0.53 mL/m(2)], P = .002). Paricalcitol also attenuated the rise in levels of brain natriuretic peptide (10.8% in paricalcitol vs 21.3% in placebo, P = .02). For the entire population, the change in brain natriuretic peptide correlated with change in LAVi (r = 0.17, P = .03). CONCLUSIONS: Forty-eight weeks of therapy with an active vitamin D analog reduces LAVi and attenuates the rise of BNP. In a population where only few therapies alter cardiovascular related morbidity and mortality, these post hoc results warrant further confirmation.

Vitamin D therapy and cardiac structure and function in patients with chronic kidney disease: the PRIMO randomized controlled trial.

CONTEXT: Vitamin D is associated with decreased cardiovascular-related morbidity and mortality, possibly by modifying cardiac structure and function, yet firm evidence for either remains lacking. OBJECTIVE: To determine the effects of an active vitamin D compound, paricalcitol, on left ventricular mass over 48 weeks in patients with an estimated glomerular filtration rate of 15 to 60 mL/min/1.73 m(2). DESIGN, SETTING, AND PARTICIPANTS: Multinational, double-blind, randomized placebo-controlled trial among 227 patients with chronic kidney disease, mild to moderate left ventricular hypertrophy, and preserved left ventricular ejection fraction, conducted in 11 countries from July 2008 through September 2010. INTERVENTION: Participants were randomly assigned to receive oral paricalcitol, 2 µg/d (n =115), or matching placebo (n = 112). MAIN OUTCOME MEASURES: Change in left ventricular mass index over 48 weeks by cardiovascular magnetic resonance imaging. Secondary end points included echocardiographic changes in left ventricular diastolic function. RESULTS: Treatment with paricalcitol reduced parathyroid hormone levels within 4 weeks and maintained levels within the normal range throughout the study duration. At 48 weeks, the change in left ventricular mass index did not differ between treatment groups (paricalcitol group, 0.34 g/m(2.7) [95% CI, -0.14 to 0.83 g/m(2.7)] vs placebo group, -0.07 g/m(2.7) [95% CI, -0.55 to 0.42 g/m(2.7)]). Doppler measures of diastolic function including peak early diastolic lateral mitral annular tissue velocity (paricalcitol group, -0.01 cm/s [95% CI, -0.63 to 0.60 cm/s] vs placebo group, -0.30 cm/s [95% CI, -0.93 to 0.34 cm/s]) also did not differ. Episodes of hypercalcemia were more frequent in the paricalcitol group compared with the placebo group. CONCLUSION: Forty-eight week therapy with paricalcitol did not alter left ventricular mass index or improve certain measures of diastolic dysfunction in patients with chronic kidney disease. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00497146.