Tenapanor as Therapy for Hyperphosphatemia in Maintenance Dialysis Patients: Results from the OPTIMIZE Study

BACKGROUND

OPTIMIZE was a randomized, open-label study evaluating different tenapanor initiation methods. OPTIMIZE evaluated tenapanor alone and in combination with phosphate binders (PBs) to achieve target serum phosphate (P) ≤5.5 mg/dL.

METHODS

Patients with inadequately controlled P receiving maintenance dialysis from 42 US locations who were taking PBs with baseline P >5.5 mg/dL and ≤10.0 mg/dL, or were PB-naive with baseline P >4.5 mg/dL and ≤10.0 mg/dL, were included in OPTIMIZE. Participants taking PBs at baseline were randomized to switch from PBs to tenapanor (Straight Switch; n = 151) or reduce PB dosage by ≥50% and add tenapanor (Binder Reduction; n = 152); PB-naive patients started tenapanor alone (Binder-Naive; n = 30). Participants received tenapanor 30 mg twice a day for 10 weeks (part A), followed by an elective, 16-week open-label extension (part B). Outcomes included changes from baseline in P, intact fibroblast growth factor 23 (iFGF23), parathyroid hormone (PTH), serum calcium, and medication burden; patient-reported outcomes; and safety.

RESULTS

By part A endpoint, 34.4% (Straight Switch), 38.2% (Binder Reduction), and 63.3% (Binder-Naive) of patients achieved P ≤5.5 mg/dL. Mean P reduction and median pill burden reduction from baseline to part A endpoint were 0.91± 1.7 mg/dL and 4 pills/day for the Straight Switch and 0.99± 1.8 mg/dL and 1 pill/day for the Binder Reduction group. The mean P reduction for Binder-Naive patients was 0.87± 1.5 mg/dL. Among Straight Switch and Binder Reduction patients who completed patient experience questionnaires, 205 of 243 (84.4%) reported an improved phosphate-management routine. Diarrhea was the most common adverse event (133 of 333 [39.9%]).

CONCLUSIONS

Tenapanor as monotherapy or in combination with PBs effectively lowered P toward the target range in patients who were PB naïve or who were not at goal despite PB use.

FUNDING

Ardelyx, Inc.

TRIAL REGISTRATION

NCT04549597.

Difelikefalin in Black/African American Hemodialysis Patients with Moderate-to-Severe Pruritus: Post-hoc Analysis of KALM-1 and KALM-2

Black and African American (AA) people are over-represented in the kidney failure population; therefore, the safety and efficacy of difelikefalin in Black/AA patients was evaluated. This was a post hoc, pooled exploratory subgroup analysis of the Phase 3 KALM-1 and -2 studies. Patients undergoing hemodialysis (HD) who had moderate-to-severe chronic kidney disease-associated pruritus (CKD-aP) at enrollment were stratified into self-reported Black/AA or White subgroups. Patients were randomized (1:1) to receive intravenous (IV) difelikefalin 0.5 µg/kg or placebo for 12 weeks. Difelikefalin efficacy was assessed with validated patient-reported outcome questionnaires: 24-hour Worst Itch Numerical Rating Scale (WI-NRS), 5-D itch, and Skindex 10. There were 249 (29.3%) patients from the KALM studies that self-identified as Black/AA (n=135 difelikefalin; n=114 placebo). Clinically meaningful (≥3-point) reduction in WI-NRS score was achieved by 47.9% of Black/AA patients with difelikefalin versus 24.6% with placebo (P<0.001). More Black/AA patients achieved a ≥5-point 5-D itch total improvement (54.9% vs 35.7%; P=0.013) and a ≥15-point Skindex-10 score improvement with difelikefalin versus placebo (49.0% vs 28.9%; P=0.006) compared with White patients. Incidence of treatment-emergent adverse events (TEAEs) was higher for Black/AA patients (difelikefalin: 78.5%; placebo: 70.8%) versus White patients (difelikefalin: 64.8%; placebo: 61.8%). In this post hoc analysis, difelikefalin was efficacious in the Black/AA population and had an acceptable safety profile.

A phase 3b, multicenter, open-label, single-arm study of roxadustat (ASPEN): Operational learnings within United States dialysis organizations

INTRODUCTION

Roxadustat is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor approved in several regions for the treatment of anemia of chronic kidney disease (CKD). ASPEN evaluated the efficacy, safety, and feasibility of roxadustat in patients with anemia of CKD in US dialysis organizations.

METHODS

This open-label, single-arm study (NCT04484857) comprised a 6-week screening period, followed by 24 weeks of treatment (with optional extension ≤1 year) and a 4-week follow-up. Patients aged ≥18 years, receiving chronic dialysis, with hemoglobin (Hb) 9.0-12.0 g/dL if converting from erythropoiesis-stimulating agents (ESAs), or <10.0 g/dL if receiving ESAs for <6 weeks, received oral roxadustat three times weekly in-center. Primary efficacy endpoints included proportion of patients with mean Hb ≥10 g/dL, averaged over weeks 16-24, and mean Hb change from baseline to the average over weeks 16-24. Safety was also assessed.

FINDINGS

Overall, 283 patients were enrolled and treated, 282 (99.6%) were included in the full analysis set, and 216 (76.3%) continued into the extension period. Most patients enrolled were from DaVita sites (71%), with the rest from US Renal Care sites (29%). Mean (standard deviation [SD]) baseline Hb was 10.6 (0.7) g/dL. Nearly all patients were prior ESA users (n = 274; 97.2%). The proportion of patients with mean Hb ≥10 g/dL during weeks 16-24 was 83.7% (95% confidence interval 78.9-88.6). Mean (SD) Hb increase from baseline to the average over weeks 16-24 was 0.2 (1.0) g/dL. During the treatment period, 82 (29.0%) patients reported treatment-emergent serious adverse events (TESAEs). The most common TESAEs were COVID-19 pneumonia (n = 10; 3.5%), acute respiratory failure (n = 9; 3.2%), COVID-19 (n = 7; 2.5%), acute myocardial infarction (n = 7; 2.5%), and fluid overload (n = 6, 2.1%).

DISCUSSION

Roxadustat was effective in maintaining Hb in patients with anemia of CKD on dialysis in large, community-based dialysis organizations.

Evaluation of the effect of sodium zirconium cyclosilicate on arrhythmia-related cardiovascular outcomes in patients receiving chronic haemodialysis with hyperkalaemia: protocol for the multicentre, randomised, controlled DIALIZE-Outcomes study

INTRODUCTION

Patients with kidney failure receiving chronic haemodialysis have elevated risk of arrhythmias potentially increasing the likelihood of sudden cardiac death, stroke and hospitalisation. The DIALIZE study (NCT03303521) demonstrated that sodium zirconium cyclosilicate (SZC) was an efficacious and well-tolerated treatment for predialysis hyperkalaemia in patients undergoing haemodialysis. The DIALIZE-Outcomes study evaluates the effect of SZC on sudden cardiac death and arrhythmia-related cardiovascular outcomes in patients receiving chronic haemodialysis with recurrent hyperkalaemia.

METHODS AND ANALYSIS

International, multicentre, randomised, double-blind, placebo-controlled study conducted at 357 study sites across 25 countries. Adults (≥18 years) receiving chronic haemodialysis three times per week with recurrent predialysis serum potassium (K+) ≥5.5 mmol/L post long interdialytic interval (LIDI) are eligible. Patients (~2800) will be randomised 1:1 to SZC or placebo, starting at 5 g orally once daily on non-dialysis days and titrated weekly in 5 g increments (maximum 15 g) to target predialysis serum K+ 4.0-5.0 mmol/L post LIDI. The primary objective is to evaluate efficacy of SZC versus placebo in reducing occurrence of the primary composite endpoint of sudden cardiac death, stroke or arrhythmia-related hospitalisation, intervention or emergency department visit. Secondary endpoints include efficacy of SZC versus placebo in maintaining normokalaemia (serum K+ 4.0-5.5 mmol/L post LIDI) at the 12-month visit, preventing severe hyperkalaemia (serum K+ ≥6.5 mmol/L post LIDI) at the 12-month visit and reducing the incidence of individual cardiovascular outcomes. Safety of SZC will be evaluated. The study is event driven, with participants remaining in the study until 770 primary endpoint events have occurred. Average time in the study is expected to be ~25 months.

ETHICS AND DISSEMINATION

Approval was obtained from the relevant institutional review board/independent ethics committee from each participating site (approving bodies in supplementary information). The results will be submitted to a peer-reviewed journal.

TRIAL REGISTRATION NUMBERS

EudraCT 2020-005561-14 and clinicaltrials.gov identifier NCT04847232.

Difelikefalin for the treatment of moderate-to-severe pruritus associated with chronic kidney disease on hemodialysis

INTRODUCTION

Chronic kidney disease-associated pruritus (CKD-aP) is often experienced by patients with CKD receiving dialysis. Approximately 40% of hemodialysis patients are "moderately" to "extremely bothered" by itching, associated with reduced quality of life, poor sleep quality, and depression as well as worse clinical outcomes, including increased medication use, infections, hospitalizations, and mortality.

AREAS COVERED

This review covers the pathophysiology and treatment landscape of CKD-aP, and the development, clinical efficacy, and safety profile of difelikefalin. We summarize the existing evidence, and discuss both the position of difelikefalin in the treatment pathway and potential future developments.

EXPERT OPINION

Difelikefalin is a kappa opioid receptor agonist, with a primary mode of action that is outside of the central nervous system and provides an improved safety profile compared with other opioid agonists, with limited potential for abuse and dependency. Difelikefalin has demonstrated efficacy, tolerability, and safety profile in several large-scale clinical trials in more than 1,400 hemodialysis patients with CKD-aP treated for up to 64 weeks. Difelikefalin is the only approved treatment for CKD-aP in the USA and Europe; other treatments are used off-label, have limited proof of efficacy in large-scale clinical trials in this patient population, and may present an increased risk of toxicity in patients with CKD.

Hypoxia-inducible factor stabilizers: 27,228 patients studied, yet a role still undefined

With the emergence of Hypoxia Inducible Factor- Prolyl Hydroxylase Inhibitors (HIF-PHIs), came the hope that using these oral drugs could improve the treatment of the anemia of kidney disease. In this editorial we discuss the accumulated knowledge on these agents and the clinical context for use.

Changes in Iron Availability with Roxadustat in Nondialysis- and Dialysis-Dependent Patients with Anemia of CKD

Background

Roxadustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor, increases hemoglobin by stimulating erythropoietin synthesis and improving iron availability through facilitation of iron uptake and/or release from stores. In this exploratory analysis, we assessed the effect of roxadustat treatment on laboratory parameters related to iron metabolism in patients with anemia of chronic kidney disease (CKD).

Methods

Data were pooled from pivotal, randomized, phase 3 roxadustat trials: three placebo-controlled, double-blind trials in nondialysis-dependent (NDD) CKD and three open-label, active-comparator (epoetin alfa) trials in dialysis-dependent (DD) CKD. In this exploratory analysis, mean changes from baseline in hemoglobin, iron parameters, and hepcidin, and intravenous (iv) iron use were evaluated. Pooled results in NDD CKD and DD CKD patients are reported.

Results

Overall, 4277 patients with NDD CKD and 3890 patients with DD CKD were evaluated. Hemoglobin increases with roxadustat treatment were accompanied by increases in serum iron and total iron-binding capacity (TIBC) and decreases in serum ferritin and hepcidin from baseline through week 52. With epoetin alfa, the hemoglobin increase was accompanied by decreases in serum ferritin and hepcidin, but serum iron decreased, and there was no change in TIBC. With placebo, there were no changes in hemoglobin, iron parameters, or hepcidin. During treatment, iv iron use was reduced with roxadustat versus placebo and epoetin alfa.

Conclusions

In patients with NDD CKD and DD CKD, roxadustat treatment is associated with increases in serum iron and TIBC, accompanied by reduced hepcidin and indicative of improved iron kinetics. Patients treated with roxadustat achieved target hemoglobin levels with less iv iron use versus comparators. Practitioners treating patients with anemia of CKD with roxadustat should consider its unique effects when interpreting iron parameters.

Erythropoietic effects of vadadustat in patients with anemia associated with chronic kidney disease

Patients with chronic kidney disease (CKD) develop anemia largely because of inappropriately low erythropoietin (EPO) production and insufficient iron available to erythroid precursors. In four phase 3, randomized, open-label, clinical trials in dialysis-dependent and non-dialysis-dependent patients with CKD and anemia, the hypoxia-inducible factor prolyl hydroxylase inhibitor, vadadustat, was noninferior to the erythropoiesis-stimulating agent, darbepoetin alfa, in increasing and maintaining target hemoglobin concentrations. In these trials, vadadustat increased the concentrations of serum EPO, the numbers of circulating erythrocytes, and the numbers of circulating reticulocytes. Achieved hemoglobin concentrations were similar in patients treated with either vadadustat or darbepoetin alfa, but compared with patients receiving darbepoetin alfa, those receiving vadadustat had erythrocytes with increased mean corpuscular volume and mean corpuscular hemoglobin, while the red cell distribution width was decreased. Increased serum transferrin concentrations, as measured by total iron-binding capacity, combined with stable serum iron concentrations, resulted in decreased transferrin saturation in patients randomized to vadadustat compared with patients randomized to darbepoetin alfa. The decreases in transferrin saturation were associated with relatively greater declines in serum hepcidin and ferritin in patients receiving vadadustat compared with those receiving darbepoetin alfa. These results for serum transferrin saturation, hepcidin, ferritin, and erythrocyte indices were consistent with improved iron availability in the patients receiving vadadustat. Thus, overall, vadadustat had beneficial effects on three aspects of erythropoiesis in patients with anemia associated with CKD: increased endogenous EPO production, improved iron availability to erythroid cells, and increased reticulocytes in the circulation.

Ferric pyrophosphate citrate for parenteral administration of maintenance iron: structure, mechanism of action, clinical efficacy and safety

Anemia is a common complication in patients with hemodialysis-dependent chronic kidney disease (HDD-CKD). Anemia is principally the result of erythropoietin deficiency, inflammation, and iron deficiency. High molecular weight iron oxide nanoparticles (IONP) are routinely administered intravenously to replace iron losses and, although effective, there are lingering concerns about possible safety issues. Ferric pyrophosphate citrate (FPC, Triferic, Triferic AVNU [Triferic and Triferic AVNU are the proprietary name for ferric pyrophosphate citrate. Triferic and Triferic AVNU are registered trademarks of Rockwell medical Inc.]) is a complex iron salt that donates iron directly to plasma transferrin. FPC is devoid of any carbohydrate moiety and is administered via the dialysate or intravenously during each hemodialysis session to replace iron and maintain hemoglobin. Controlled clinical trials of up to 48 weeks in duration have demonstrated the efficacy of regular administration of dialysate FPC for maintaining hemoglobin levels and iron balance in HDD-CKD patients. Clinical data also suggest that dialysate FPC may reduce the dose requirements for and use of erythropoiesis-stimulating agents and IONPs in HDD-CKD patients. Safety data from clinical studies and post-marketing surveillance show that FPC is well tolerated and not associated with an increased risk of infection, inflammation, iron overload, or serious hypersensitivity reactions. FPC represents an effective and well-tolerated choice for iron replacement and maintenance of hemoglobin in the long-term management of HDD-CKD patients.

Safety and Tolerability of Difelikefalin for the Treatment of Moderate to Severe Pruritus in Hemodialysis Patients: Pooled Analysis From the Phase 3 Clinical Trial Program

Rationale & Objective

We report a pooled safety analysis of intravenous difelikefalin in participants with moderate to severe chronic kidney disease–associated pruritus (CKD-aP) treated by hemodialysis in 4 phase 3 clinical studies.

Study Design

KALM-1 and KALM-2 were randomized, double-blind, placebo-controlled, pivotal phase 3 studies; CLIN3101 (52 weeks) and CLIN3105 (12 weeks) were open-label studies.

Setting & Participants

Adults with moderate to severe CKD-aP treated by hemodialysis in North America, Europe, and the Asia-Pacific region.

Intervention

At least 1 intravenous placebo or difelikefalin dose of 0.5 mcg/kg for up to 64 weeks.

Outcomes

Safety.

Results

Safety analyses were conducted with 848 participants in the placebo-controlled cohort (424 participants each in the difelikefalin and placebo groups) and in 1,306 participants in the all-difelikefalin-exposure cohort. In the placebo-controlled cohort, the most commonly reported treatment-emergent adverse events (TEAEs), occurring in ≥2% of participants receiving difelikefalin and with a ≥1% higher incidence than placebo, were diarrhea (9.0% and 5.7%, respectively); dizziness (6.8% and 3.8%, respectively); nausea (6.6% and 4.5%, respectively); gait disturbances, including falls (6.6% and 5.4%, respectively), hyperkalemia (4.7% and 3.5%, respectively); headache (4.5% and 2.6%, respectively); somnolence (4.2% and 2.4%, respectively); and mental status changes (3.3% and 1.4%, respectively). These were mostly mild or moderate, with few leading to discontinuation. Incidence rates of TEAEs, serious TEAEs, and discontinuations because of TEAEs did not increase with long-term exposure. Three participants (0.7%) in the difelikefalin group and 5 participants (1.2%) in the placebo group died during the study.

Limitations

Pooled data from studies with different designs.

Conclusions

Intravenous difelikefalin demonstrated an acceptable safety profile, was generally well tolerated with long-term use, and may address the unmet treatment need for patients with CKD-aP treated by hemodialysis.

Funding

Cara Therapeutics, Inc.

Trial Registration

KALM-1 is registered as NCT03422653, KALM-2 as NCT03636269, CLIN3101 as NCT03281538, and CLIN3105 as NCT03998163.

Improving Detection and Management of Anemia in CKD

At the end of the activity, participants will be able to:Describe approaches to improve recognition of chronic kidney disease (CKD) and anemia in primary care. Explain the importance of early management of anemia in CKD to reduce adverse outcomes and improve symptoms. Prescribe evidence-based treatment for patients with anemia in CKD who can be managed in the primary care setting. Discuss emerging evidence for new agents being studied for treating anemia in CKD.

Living Well With Kidney Disease and Effective Symptom Management: Consensus Conference Proceedings

Chronic kidney disease (CKD) confers a high burden of uremic symptoms that may be underrecognized, underdiagnosed, and undertreated. Unpleasant symptoms, such as CKD-associated pruritus and emotional/psychological distress, often occur within symptom clusters, and treating 1 symptom may potentially alleviate other symptoms in that cluster. The Living Well with Kidney Disease and Effective Symptom Management Consensus Conference convened health experts and leaders of kidney advocacy groups and kidney networks worldwide to discuss the effects of unpleasant symptoms related to CKD on the health and well-being of those affected, and to consider strategies for optimal symptom management. Optimizing symptom management is a cornerstone of conservative and preservative management which aim to prevent or delay dialysis initiation. In persons with kidney dysfunction requiring dialysis (KDRD), incremental transition to dialysis and home dialysis modalities offer personalized approaches. KDRD is proposed as the preferred term given the negative connotations of "failure" as a kidney descriptor, and the success stories in CKD journeys. Engaging persons with CKD to identify and prioritize their personal values and individual needs must be central to ensure their active participation in CKD management, including KDRD. Person-centered communication and care are required to ensure diversity, equity, and inclusion; education/awareness that considers the health literacy of persons with CKD; and shared decision-making among the person with CKD, care partners, and providers. By putting the needs of people with CKD, including effective symptom management, at the center of their treatment, CKD can be optimally treated in a way that aligns with their goals.

MO424: Relationship Between Itch Intensity and Patient-Reported Disease Improvement in Patients With Chronic Kidney Disease-Associated Pruritus Treated With Difelikefalin

BACKGROUND AND AIMS

Chronic kidney disease-associated pruritus (CKD-aP) is a common condition in patients with CKD undergoing haemodialysis (HD), leading to poor sleep quality, reduced quality of life and depression. Difelikefalin is a selective kappa opioid receptor agonist approved in the United States for the treatment of moderate-to-severe pruritus in adults undergoing HD, which significantly reduced itch intensity in HD patients with CKD-aP in the Phase 3 KALM-1 and KALM-2 multicentre, placebo-controlled trials. The KALM trials used the Worst-Itching Numerical Rating Scale (WI-NRS) to assess itch-intensity [range from 0 (no itching) to 10 (worst itching imaginable)] and the Patient Global Impression of Change (PGIC) to assess the patient's overall perception of change in itch (range from ‘very much improved’ to ‘very much worse’) relative to the start of the study. The aim of this post hoc analysis was to establish how the WI-NRS score relates to the PGIC and to assess a clinically relevant change in WI-NRS.

METHOD

A post hoc analysis of data from KALM-1 and KALM-2 was performed. Studies enrolled maintenance HD patients with mean baseline 24-h WI-NRS score &gt; 4 in KALM-1 or ≥ 5 in KALM-2. Patients were randomized 1:1 to intravenous difelikefalin 0.5 mcg/kg or placebo three times/week for 12 weeks. Patients completed the PGIC at the end of the 12-week, double-blind treatment period, as well as completing the WI-NRS daily. Cumulative distribution function (CDF) analyses were performed at Week 12. Results are reported for 50% CDF at week 12.

RESULTS

For the overall population, ‘very much improved’ corresponded to a 5-to-6-point WI-NRS reduction; ‘much improved’ corresponded to a 3-to-4-point WI-NRS reduction; and ‘minimally improved’ corresponded to a 1-to-2-point WI-NRS reduction (Figure 1).

CONCLUSION

There is a clear relationship between the PGIC and the WI-NRS, with greater reductions in itch severity corresponding to perceptions of better overall improvement in itch following treatment with difelikefalin. A 3-point reduction in WI-NRS can be considered clinically relevant, since it was perceived by patients as equivalent to their itch being ‘much improved’. This analysis further corroborates similar clinically meaningful changes in pruritus, previously reported in patients with CKD-aP, as ≥ 3-points [1, 2].

Roxadustat Versus Epoetin Alfa for Treating Anemia in Patients with Chronic Kidney Disease on Dialysis: Results from the Randomized Phase 3 ROCKIES Study

Background

Concerns regarding cardiovascular safety with current treatments for anemia in patients with dialysis-dependent (DD)-CKD have encouraged the development of alternatives. Roxadustat, an oral hypoxia-inducible factor prolyl hydroxylase inhibitor, stimulates erythropoiesis by increasing endogenous erythropoietin and iron availability.

Methods

In this open-label phase 3 study, patients with DD-CKD and anemia were randomized 1:1 to oral roxadustat three times weekly or parenteral epoetin alfa per local clinic practice. Initial roxadustat dose depended on erythropoiesis-stimulating agent dose at screening for patients already on them and was weight-based for those not on them. The primary efficacy end point was mean hemoglobin change from baseline averaged over weeks 28‒52 for roxadustat versus epoetin alfa, regardless of rescue therapy use, tested for noninferiority (margin, −0.75 g/dl). Adverse events (AEs) were assessed.

Results

Among 2133 patients randomized (n=1068 roxadustat, n=1065 epoetin alfa), mean age was 54.0 years, and 89.1% and 10.8% were on hemodialysis and peritoneal dialysis, respectively. Mean (95% confidence interval) hemoglobin change from baseline was 0.77 (0.69 to 0.85) g/dl with roxadustat and 0.68 (0.60 to 0.76) g/dl with epoetin alfa, demonstrating noninferiority (least squares mean difference [95% CI], 0.09 [0.01 to 0.18]; P<0.001). The proportion of patients experiencing ≥1 AE and ≥1 serious AE was 85.0% and 57.6% with roxadustat and 84.5% and 57.5% with epoetin alfa, respectively.

Conclusions

Roxadustat effectively increased hemoglobin in patients with DD-CKD, with an AE profile comparable to epoetin alfa.

Clinical Trial registry name and registration number:

Safety and Efficacy Study of Roxadustat to Treat Anemia in Patients With Chronic Kidney Disease, on Dialysis. ClinicalTrials.gov Identifier: NCT02174731.

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 both non-dialysis dependent and dialysis-dependent CKD. The results of key phase 3 clinical trials of HIF-PHIs in the public domain as of this writing are also presented in this article 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 article and include long-term safety issues, potential benefits, and practical considerations for implementation including patient and provider education.

Acute kidney injury in pediatric patients hospitalized with acute COVID-19 and multisystem inflammatory syndrome in children associated with COVID-19

This study describes the incidence, associated clinical characteristics and outcomes of acute kidney injury in a pediatric cohort with COVID-19 and Multisystem Inflammatory Syndrome in Children (MIS-C). We performed a retrospective study of patients 18 years of age and under admitted to four New York hospitals in the Northwell Health System interned during the height of the COVID-19 pandemic, between March 9 and August 13, 2020. Acute kidney injury was defined and staged according to Kidney Disease: Improving Global Outcomes criteria. The cohort included 152 patients; 97 acute-COVID-19 and 55 with MIS-C associated with COVID-19. Acute kidney injury occurred in 8 with acute-COVID-19 and in 10 with MIS-C. Acute kidney injury, in unadjusted models, was associated with a lower serum albumin level (odds ratio 0.17; 95% confidence interval 0.07, 0.39) and higher white blood cell counts (odds ratio 1.11; 95% confidence interval 1.04, 1.2). Patients with MIS-C and acute kidney injury had significantly greater rates of systolic dysfunction, compared to those without (80% vs 49%). In unadjusted models, patients with acute kidney injury had 8.4 days longer hospitalizations compared to patients without acute kidney injury (95% confidence interval, 4.4-6.7). Acute kidney injury in acute-COVID-19 and MIS-C may be related to inflammation and/or dehydration. Further research in larger pediatric cohorts is needed to better characterize risk factors for acute kidney injury in acute-COVID-19 and with MIS-C consequent to COVID-19.

MO539HEMATOLOGIC EFFICACY OF VADADUSTAT FOR ANEMIA IN PATIENTS WITH KIDNEY FAILURE ON DIALYSIS

Background and Aims

Vadadustat is a small-molecule inhibitor of hypoxia-inducible factor prolyl hydroxylase being developed for treatment of anemia associated with chronic kidney disease (CKD). The vadadustat phase 3 program includes four efficacy and cardiovascular safety outcome trials of vadadustat versus the erythropoiesis-stimulating agent (ESA) darbepoetin alfa. Here we describe detailed results on hematologic efficacy in two of the four phase 3, randomized, open-label, sponsor-blind trials (the INNO2VATE trials) in adult patients with dialysis-dependent (DD) CKD and anemia, where vadadustat met prespecified noninferiority criteria compared with darbepoetin alfa with respect to cardiovascular safety and correction/maintenance of hemoglobin (Hb) target concentrations.

Method

The mean screening Hb range for the incident DD-CKD trial (NCT02865850) was 8.0-11.0 g/dL; for the prevalent DD-CKD trial (NCT02892149), it was 8.0-11.0 g/dL in the United States (US) and 9.0-12.0 g/dL for non-US. Patients in the incident and prevalent DD-CKD trials had initiated dialysis within &lt;16 weeks with limited or no prior ESA exposure and &gt;12 weeks with established ESA treatment prior to screening, respectively. Vadadustat starting dose was 300 mg/day for all patients, whereas initial darbepoetin alfa dose depended on each patient’s prior dose or product label. Both vadadustat and darbepoetin alfa doses were titrated according to prespecified dosing algorithms to achieve target Hb concentrations (US: 10-11 g/dL; non-US: 10-12 g/dL) during the primary evaluation period (PEP; weeks 24-36) and the secondary evaluation period (SEP; weeks 40-52). Herein, we present topline results from PEP and SEP endpoints, as well as other, more detailed hematologic erythrocyte parameters.

Results

A total of 3923 patients (369 with incident DD-CKD and 3554 with prevalent DD-CKD) were randomized 1:1 to vadadustat or darbepoetin alfa. Vadadustat was noninferior to darbepoetin alfa in achieving target-range Hb concentrations (primary efficacy endpoint) among patients who were new to, or established on, dialysis. The respective proportions of patients (vadadustat vs. darbepoetin alfa) with an average Hb value within the geography-specific target range in the PEP and SEP were 43.6% versus 56.9% and 39.8% versus 41.0% in the incident trial and 49.2% versus 53.2% and 44.3% versus 50.9% in the prevalent dialysis trial. The proportion of patients who achieved an Hb increase &gt;1.0 g/dL from baseline to week 52 was assessed only for the incident trial and was 84.0% (95% CI: 77.8%, 89.0%) for vadadustat versus 89.9% (95% CI: 84.7%, 93.8%) for darbepoetin alfa.

Hematologic erythrocyte parameters at time points within the PEP and SEP are presented in Table 1. In the incident trial, reticulocyte count was slightly increased from baseline at 28 and 52 weeks for vadadustat, whereas for darbepoetin alfa, reticulocyte count was slightly decreased or unchanged in both trials. Erythrocyte mean corpuscular volume and erythrocyte mean corpuscular Hb showed increases by week 52 for both groups.

Conclusion

Vadadustat demonstrated similar profiles across erythrocyte parameters compared with darbepoetin alfa in the treatment of anemia associated with CKD in adults in both incident dialysis and prevalent dialysis settings.

FC 077LONG-TERM SAFETY OF TENAPANOR FOR THE CONTROL OF SERUM PHOSPHORUS IN PATIENTS WITH CKD ON DIALYSIS

Background and Aims

Tenapanor, a first-in-class, phosphate absorption inhibitor blocks the paracellular absorption of phosphate in the GI tract by local inhibition of the sodium-hydrogen exchanger (NHE3). It therefore provides a novel, non-binder approach for managing hyperphosphatemia. Tenapanor is dosed as one small pill twice daily. In three pivotal trials, tenapanor met its primary phosphorus-lowering outcome. This report evaluates long-term safety data from the longest of these trials.

Method

This 52-week study consisted of a 26-week, open-label, randomized treatment period with a 12-week placebo-controlled randomized withdrawal period, followed by a 14-week open label safety extension period. Maintenance dialysis patients with serum phosphorus ≥ 6.0 mg/dL and a 1.5 mg/dL increase in serum phosphorus following phosphate binder washout were randomized 3:1 to receive tenapanor 30 mg twice daily or sevelamer carbonate, dosed per package insert. At end of the randomized treatment period all patients in the tenapanor arm were re-randomized 1:1 to either tenapanor or placebo for the randomized withdrawal period followed by tenapanor for the safety extension period. Sevelamer was used as a safety control for comparisons of serious adverse events/hospitalizations to tenapanor.

Results

Tenapanor was generally well tolerated, with diarrhea the only adverse event reported by &gt;5% of patients during the randomized treatment period. Diarrhea was typically mild-to-moderate in severity, transient, and occurred more commonly during the randomized treatment period than the randomized withdrawal or safety extension periods. Rates of serious adverse events leading to hospitalization were higher in patients treated with sevelamer than tenapanor (35.8% vs 24.6%). The highest reported percentages of serious adverse events were infections and infestations (16.1% vs 9.3%) cardiac disorders (8.0% vs 5.7%), respiratory, thoracic and mediastinal disorders (8.8% vs 5.5%), and metabolism and nutritional disorders (7.3% vs 3.6%) for sevelamer and tenapanor, respectively. Adverse events leading to death were higher in patients treated with sevelamer than tenapanor (3.6% vs 2.9%).

Conclusion

Among maintenance dialysis patients with hyperphosphatemia, tenapanor, a novel, non-binder, phosphate absorption inhibitor that blocks paracellular absorption of phosphorus with a one tablet twice daily dose, has an acceptable safety profile, and, if approved, may offer a new approach to the treatment of hyperphosphatemia.

MO214EVALUATION OF THE EFFECT OF A POTASSIUM BINDER ON ARRHYTHMIA-RELATED CARDIOVASCULAR OUTCOMES IN PATIENTS ON CHRONIC HAEMODIALYSIS WITH RECURRENT HYPERKALAEMIA: DESIGN AND RATIONALE FOR THE SODIUM ZIRCONIUM CYCLOSILICATE DIALIZE-OUTCOMES STUDY

Background and Aims

Patients with end-stage renal disease (ESRD) on chronic haemodialysis are at an elevated risk of arrhythmias that can increase the risk of sudden cardiac death (SCD) and stroke, along with the need for hospitalisation and interventions. These arrhythmias may be exacerbated by pre-dialysis hyperkalaemia and rapid serum potassium (sK+) shifts that occur during and after haemodialysis sessions. The DIALIZE study (NCT03303521) demonstrated that sodium zirconium cyclosilicate (SZC) was an effective and well-tolerated treatment for pre-dialysis hyperkalaemia, when administered once-daily on non-dialysis days for 8 weeks in patients with ESRD undergoing chronic haemodialysis. The DIALIZE-Outcomes study (EudraCT 2020-005561-14) will evaluate the effect of SZC treatment on arrhythmia-related cardiovascular (CV) outcomes in patients with ESRD on chronic haemodialysis with recurrent hyperkalaemia.

Method

The DIALIZE-Outcomes study is an international, multicentre, randomised, double-blind, parallel-group, placebo-controlled study, to be conducted at ∼300 study sites across ∼20 countries. Adults (≥18 years of age) with ESRD on haemodialysis three times weekly and with recurrent pre-dialysis sK+ ≥5.5 mmol/L after the long interdialytic interval (LIDI) will be eligible for enrolment. Approximately 2300 patients will be randomised 1:1 to SZC or placebo (Figure), starting at 5 g orally once daily on non-dialysis days (4 days/week) and uptitrated weekly in 5 g increments (maximum 15 g) to achieve pre-dialysis sK+ 4.0–5.0 mmol/L after the LIDI. Dose adjustments after the uptitration phase will be guided by sK+ monitoring, as per clinical practice. The primary objective is to evaluate the efficacy of SZC versus placebo in reducing the incidence of the primary composite endpoint of time to first occurrence of SCD, stroke or hospitalisation/intervention/emergency department visit due to arrhythmias (atrial fibrillation, bradycardia, asystole, ventricular tachyarrhythmia). Secondary endpoints include the efficacy of SZC versus placebo in maintaining normokalaemia (sK+ 4.0–5.5 mmol/L after the LIDI) and preventing severe hyperkalaemia (sK+ ≥6.5 mmol/L after the LIDI) at 1 year (assessed through measurement of sK+ at the 12-month study visit), and time to occurrence of CV outcomes. Safety and tolerability of SZC versus placebo will also be evaluated. The study is event-driven, with patients remaining on study treatment until a pre-specified number of primary endpoint events (770) has occurred. The anticipated average treatment period is ∼25 months.

Conclusion

The DIALIZE-Outcomes study is the first evaluation of a K+ binder in improving CV outcomes in patients with ESRD on chronic haemodialysis and with recurrent hyperkalaemia. The study findings will provide valuable information that may help to further our understanding of the relationship between hyperkalaemia and CV morbidity and mortality in patients on chronic haemodialysis, and to optimise treatment regimens in this high CV and SCD risk population.

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.).

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.

Methods and rationale of the DISCOVER CKD global observational study

Background

Real-world data for patients with chronic kidney disease (CKD), specifically pertaining to clinical management, metabolic control, treatment patterns, quality of life (QoL) and dietary patterns, are limited. Understanding these gaps using real-world, routine care data will improve our understanding of the challenges and consequences faced by patients with CKD, and will facilitate the long-term goal of improving their management and prognosis.

Methods

DISCOVER CKD follows an enriched hybrid study design, with both retrospective and prospective patient cohorts, integrating primary and secondary data from patients with CKD from China, Italy, Japan, Sweden, the UK and the USA. Data will be prospectively captured over a 3-year period from >1000 patients with CKD who will be followed up for at least 1 year via electronic case report form entry during routine clinical visits and also via a mobile/tablet-based application, enabling the capture of patient-reported outcomes (PROs). In-depth interviews will be conducted in a subset of ∼100 patients. Separately, secondary data will be retrospectively captured from >2 000 000 patients with CKD, extracted from existing datasets and registries.

Results

The DISCOVER CKD program captures and will report on patient demographics, biomarker and laboratory measurements, medical histories, clinical outcomes, healthcare resource utilization, medications, dietary patterns, physical activity and PROs (including QoL and qualitative interviews).

Conclusions

The DISCOVER CKD program will provide contemporary real-world insight to inform clinical practice and improve our understanding of the epidemiology and clinical and economic burden of CKD, as well as determinants of clinical outcomes and PROs from a range of geographical regions in a real-world CKD setting.

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.

Roxadustat for Treating Anemia in Patients with CKD Not on Dialysis: Results from a Randomized Phase 3 Study

BACKGROUND

Current anemia therapies for patients with non-dialysis-dependent CKD may require injection and medical visits. Roxadustat, an oral hypoxia-inducible factor prolyl hydroxylase inhibitor, stimulates erythropoiesis and improves iron homeostasis.

METHODS

In this double-blind phase 3 study, we randomized patients with non-dialysis-dependent CKD stages 3-5 and hemoglobin <10.0 g/dl (1:1) to thrice-weekly 70-mg oral roxadustat or placebo. Doses were titrated throughout the study based on hemoglobin levels. The primary efficacy end point was mean change from baseline in hemoglobin averaged over weeks 28-52 versus placebo, irrespective of rescue therapy use. We assessed patients for adverse events.

RESULTS

The study included 2781 patients, 1393 who received roxadustat and 1388 who received placebo. Mean baseline hemoglobin was 9.1 g/dl for both groups. The mean change in hemoglobin from baseline was 1.75 g/dl (95% confidence interval [95% CI], 1.68 to 1.81) with roxadustat versus 0.40 g/dl (95% CI, 0.33 to 0.47) with placebo, (P<0.001). Among 411 patients with baseline elevated high-sensitivity C-reactive protein, mean change in hemoglobin from baseline was 1.75 g/dl (95% CI, 1.58 to 1.92) with roxadustat versus 0.62 g/dl (95% CI, 0.44 to 0.80) with placebo, (P<0.001). Roxadustat reduced the risk of red blood cell transfusion by 63% (hazard ratio, 0.37; 95% CI, 0.30 to 0.44). The most common adverse events with roxadustat and placebo, respectively, were ESKD (21.0% versus 20.5%), urinary tract infection (12.8% versus 8.0%), pneumonia (11.9% versus 9.4%), and hypertension (11.5% versus 9.1%).

CONCLUSIONS

Roxadustat effectively increased hemoglobin in patients with non-dialysis-dependent CKD and reduced the need for red blood cell transfusion, with an adverse event profile comparable to that of placebo.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Safety and Efficacy Study of Roxadustat to Treat Anemia in Patients With CKD, Not on Dialysis, NCT02174627.

Clinical Management of Hyperkalemia

Hyperkalemia is an electrolyte abnormality with potentially life-threatening consequences. Despite various guidelines, no universally accepted consensus exists on best practices for hyperkalemia monitoring, with variations in precise potassium (K⁺) concentration thresholds or for the management of acute or chronic hyperkalemia. Based on the available evidence, this review identifies several critical issues and unmet needs with regard to the management of hyperkalemia. Real-world studies are needed for a better understanding of the prevalence of hyperkalemia outside the clinical trial setting. There is a need to improve effective management of hyperkalemia, including classification and K⁺ monitoring, when to reinitiate previously discontinued renin-angiotensin-aldosterone system inhibitor (RAASi) therapy, and when to use oral K⁺-binding agents. Monitoring serum K⁺ should be individualized; however, increased frequency of monitoring should be considered for patients with chronic kidney disease, diabetes, heart failure, or a history of hyperkalemia and for those receiving RAASi therapy. Recent clinical studies suggest that the newer K⁺ binders (patiromer sorbitex calcium and sodium zirconium cyclosilicate) may facilitate optimization of RAASi therapy. Enhancing the knowledge of primary care physicians and internists with respect to the safety profiles of these newer K⁺ binders may increase confidence in managing patients with hyperkalemia. Lastly, the availability of newer K⁺-binding agents requires further study to establish whether stringent dietary K⁺ restrictions are needed in patients receiving K⁺-binder therapy. Individualized monitoring of serum K⁺ among patients with an increased risk of hyperkalemia and the use of newer K⁺-binding agents may allow for optimization of RAASi therapy and more effective management of hyperkalemia.

Outcomes Among Patients Hospitalized With COVID-19 and Acute Kidney Injury

RATIONALE & OBJECTIVE

Outcomes of patients hospitalized with coronavirus disease 2019 (COVID-19) and acute kidney injury (AKI) are not well understood. The goal of this study was to investigate the survival and kidney outcomes of these patients.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Patients (aged≥18 years) hospitalized with COVID-19 at 13 hospitals in metropolitan New York between March 1, 2020, and April 27, 2020, followed up until hospital discharge.

EXPOSURE

AKI.

OUTCOMES

Primary outcome: in-hospital death.

SECONDARY OUTCOMES

requiring dialysis at discharge, recovery of kidney function.

ANALYTICAL APPROACH

Univariable and multivariable time-to-event analysis and logistic regression.

RESULTS

Among 9,657 patients admitted with COVID-19, the AKI incidence rate was 38.4/1,000 patient-days. Incidence rates of in-hospital death among patients without AKI, with AKI not requiring dialysis (AKI stages 1-3), and with AKI receiving dialysis (AKI 3D) were 10.8, 31.1, and 37.5/1,000 patient-days, respectively. Taking those without AKI as the reference group, we observed greater risks for in-hospital death for patients with AKI 1-3 and AKI 3D (HRs of 5.6 [95% CI, 5.0-6.3] and 11.3 [95% CI, 9.6-13.1], respectively). After adjusting for demographics, comorbid conditions, and illness severity, the risk for death remained higher among those with AKI 1-3 (adjusted HR, 3.4 [95% CI, 3.0-3.9]) and AKI 3D (adjusted HR, 6.4 [95% CI, 5.5-7.6]) compared with those without AKI. Among patients with AKI 1-3 who survived, 74.1% achieved kidney recovery by the time of discharge. Among those with AKI 3D who survived, 30.6% remained on dialysis at discharge, and prehospitalization chronic kidney disease was the only independent risk factor associated with needing dialysis at discharge (adjusted OR, 9.3 [95% CI, 2.3-37.8]).

LIMITATIONS

Observational retrospective study, limited to the NY metropolitan area during the peak of the COVID-19 pandemic.

CONCLUSIONS

AKI in hospitalized patients with COVID-19 was associated with significant risk for death.

Ziltivekimab for Treatment of Anemia of Inflammation in Patients on Hemodialysis: Results from a Phase 1/2 Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Patients with CKD who are on hemodialysis are hyporesponsive to erythropoiesis-stimulating agents (ESAs) because of anemia of inflammation. Interleukin-6 (IL-6) induced hepcidin expression is a key mediator of such inflammation.

METHODS

This phase 1/2, placebo-controlled trial assessed effects of ziltivekimab, a novel anti-IL-6 ligand antibody, in patients on hemodialysis with rs855791, a single nucleotide polymorphism of the TMPRSS6 gene that is hypothesized to heighten susceptibility to IL-6-mediated inflammatory effects. After a screening period documenting stable ESA and iron dosing, we randomized 61 patients with elevated IL-6 (≥4 pg/ml) to receive placebo or ziltivekimab (doses of 2, 6, or 20 mg), administered intravenously every 2 weeks for 12 weeks during hemodialysis. ESA dose adjustments were allowed after 4 weeks. We analyzed safety and effects on inflammation, iron metabolism, serum albumin, and anti-drug antibodies.

RESULTS

No patient experienced dose-limiting toxicity. Four patients (two each in the 6- and 20-mg cohorts) died of a treatment-emergent adverse event. Compared with patients receiving placebo, those receiving ziltivekimab experienced significantly greater reductions of high-sensitivity C-reactive protein, serum amyloid A, and fibrinogen from baseline to end of treatment. Median ESA usage decreased by 15,000, 15,000, or 33,000 IU/wk per patient in the 2-, 6-, and 20-mg ziltivekimab cohorts, respectively, compared with no change in the placebo group. We also noted significant dose responses for decreased ESA resistance index and increased serum iron, total iron binding capacity, transferrin saturation, and serum albumin.

CONCLUSIONS

Ziltivekimab significantly improved markers of inflammation, reduced ESA requirements, and increased serum albumin in patients on hemodialysis with inflammation and hyporesponsiveness to ESA therapy.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Study to Assess the Safety, Pharmacokinetics, and Pharmacodynamics of Multiple Doses of COR-001, NCT02868229.

Pooled Analysis of Roxadustat for Anemia in Patients With Kidney Failure Incident to Dialysis

Introduction

Erythropoiesis-stimulating agents are associated with increased cardiovascular risk when higher doses are used toward higher hematocrit targets. Patients new to dialysis are at higher risk for morbidity and mortality. Systematic evaluation of this population was predefined in the roxadustat clinical development program. Roxadustat is a hypoxia-inducible prolyl hydroxylase inhibitor.

Methods

Data were pooled from 3 phase 3, randomized, open-label, active-controlled trials. Eligible adults had kidney failure and initiated dialysis for 2 weeks to ≤ 4 months prior to randomization to roxadustat or epoetin alfa. Efficacy was assessed as mean change in hemoglobin from baseline averaged over weeks 28 to 52, regardless of rescue therapy. Key cardiovascular safety endpoints were major adverse cardiovascular events (MACE; all-cause mortality [ACM], myocardial infarction, and stroke), and MACE+ (MACE plus unstable angina or congestive heart failure requiring hospitalization), and ACM.

Results

This study included 1530 patients with kidney failure incident to dialysis. Mean (SD) changes in hemoglobin from baseline averaged over weeks 28 to 52, regardless of rescue therapy, were 2.12 (1.45) versus 1.91 (1.42) g/dl in the roxadustat and epoetin alfa groups (least-squares mean difference: 0.22; 95% CI, 0.05 to 0.40; P = 0.0130). Risks of MACE and MACE+ were lower in the roxadustat group (hazard ratio [HR], 0.70; 95% CI, 0.51 to 0.96) than the epoetin alfa group (HR, 0.66; 95% CI, 0.50 to 0.89); the HR for ACM was 0.76 (95% CI, 0.52 to 1.11).

Conclusion

Roxadustat was at least as efficacious as epoetin alfa. Roxadustat had a lower risk of MACE/MACE+ in patients new to dialysis.

Outcomes of patients with end-stage kidney disease hospitalized with COVID-19

Given the high risk of infection-related mortality, patients with end-stage kidney disease (ESKD) may be at increased risk with COVID-19. To assess this, we compared outcomes of patients with and without ESKD, hospitalized with COVID-19. This was a retrospective study of patients admitted with COVID-19 from 13 New York hospitals from March 1, 2020, to April 27, 2020, and followed through May 27, 2020. We measured primary outcome (in-hospital death), and secondary outcomes (mechanical ventilation and length of stay). Of 10,482 patients with COVID-19, 419 had ESKD. Patients with ESKD were older, had a greater percentage self-identified as Black, and more comorbid conditions. Patients with ESKD had a higher rate of in-hospital death than those without (31.7% vs 25.4%, odds ratio 1.38, 95% confidence interval 1.12 - 1.70). This increase rate remained after adjusting for demographic and comorbid conditions (adjusted odds ratio 1.37, 1.09 - 1.73). The odds of length of stay of seven or more days was higher in the group with compared to the group without ESKD in both the crude and adjusted analysis (1.62, 1.27 - 2.06; vs 1.57, 1.22 - 2.02, respectively). There was no difference in the odds of mechanical ventilation between the groups. Independent risk factors for in-hospital death for patients with ESKD were increased age, being on a ventilator, lymphopenia, blood urea nitrogen and serum ferritin. Black race was associated with a lower risk of death. Thus, among patients hospitalized with COVID-19, those with ESKD had a higher rate of in-hospital death compared to those without ESKD.