Insights on Nefecon®, a Targeted-Release Formulation of Budesonide and Its Selective Immunomodulatory Effects in Patients with IgA Nephropathy.

Immunoglobulin A nephropathy (IgAN) is a chronic, immune-mediated kidney disease characterized by the deposition of galactose-deficient immunoglobulin A1 (Gd-IgA1) in the kidneys. Excess Gd-IgA1 production in patients with IgAN is located within the mucosa-associated lymphoid tissue, particularly within the lamina propria in the distal ileum. Nefecon® is a targeted-release formulation of the corticosteroid budesonide, which became the first treatment approved by the US Food and Drug Administration (FDA; brand name, TARPEYO®) and European Medicines Agency (EMA; KINPEYGO®) for patients with primary IgAN at risk of rapid disease progression, after demonstrating clinically significant reduction of proteinuria in an interim analysis of the Phase III NefIgArd trial. After showing a significant reduction in estimated glomerular filtration rate decline in the full 2-year analysis of the trial, Nefecon was granted full approval by the FDA to reduce the loss of kidney function. Nefecon was specifically designed to deliver budesonide to the distal ileum, selectively targeting excess Gd-IgA1 production in the gut-associated lymphoid tissue. In this review, we describe the properties of Nefecon and the evidence to date that confirms its localized treatment effect. We also present unpublished evidence from Phase I trials investigating the pharmacokinetics and cortisol suppression effects of Nefecon in healthy participants. These studies demonstrated that Nefecon has a distinct pharmacokinetic profile from other budesonide products, allowing for targeted, localized action in the distal ileum. When considered alongside existing clinical trial data showing the effect of Nefecon on gut-associated biomarkers, available evidence indicates that Nefecon has a selective immunomodulatory mechanism of action and a direct disease-modifying effect in patients with IgAN, while having low systemic exposure and adverse effects.

B Cell Epigenetic Modulation of IgA Response by 5-Azacytidine and IgA Nephropathy.

BACKGROUND: IgA nephropathy is an important global cause of kidney failure. Dysregulation of IgA production is thought to play a key role in IgA nephropathy pathogenesis, however, little is known about the epigenetic mechanisms such as RNA 5- methylcytosine (5mC) modification in regulating IgA synthesis. METHODS: To decipher the role of RNA 5mC in regulation of IgA class switch, the miR-23b-/- and LCWE induced Kawasaki disease mice were treated with 5-azacytidine. Trdmt1-/- and double Trdmt1-/-/ miR-23b-/- mice, Aid-/- mice or Aid-/-/ miR-23b-/- mice were also employed. RESULTS: We showed that miR-23b down regulated expression of Transfer RNA Aspartic Acid Methyltransferase 1 (Trdmt1) and consequently reduced 5-methylcytosine (m5C) RNA modification and IgA synthesis in B cells. Inhibition of m5C RNA modification normalised serum IgA levels and ameliorated progression of the IgA nephropathy-like kidney disease in miR-23b-/- and Kawasaki disease mice while mesangial IgA and C3 deposition failed to develop in Trdmt1-/-miR-23b-/- mice. By contrast, increased m5C RNA modification resulted in an exaggerated IgA nephropathy phenotype. miR-23b regulation of serum IgA levels and the development of an IgA nephropathy-like kidney disease in miR-23b-/- and Kawasaki disease mice is likely mediated through TRDMT1 driven 5-methylcytosine RNA modification in B cells, resulting in impaired activation-induced cytidine deaminase activity and IgA class switch recombination. CONCLUSIONS: This study revealed TRDMT1 induced RNA 5mC methylation regulate IgA class switch and inhibition of RNA 5mC by 5-Azacytidine could ameliorate progression of IgA nephropathy.

Accuracy of glomerular filtration rate estimation using creatinine and cystatin C for identifying and monitoring moderate chronic kidney disease: the eGFR-C study.

Background: Estimation of glomerular filtration rate using equations based on creatinine is widely used to manage chronic kidney disease. In the UK, the Chronic Kidney Disease Epidemiology Collaboration creatinine equation is recommended. Other published equations using cystatin C, an alternative marker of kidney function, have not gained widespread clinical acceptance. Given higher cost of cystatin C, its clinical utility should be validated before widespread introduction into the NHS. Objectives: Primary objectives were to: (1) compare accuracy of glomerular filtration rate equations at baseline and longitudinally in people with stage 3 chronic kidney disease, and test whether accuracy is affected by ethnicity, diabetes, albuminuria and other characteristics; (2) establish the reference change value for significant glomerular filtration rate changes; (3) model disease progression; and (4) explore comparative cost-effectiveness of kidney disease monitoring strategies. Design: A longitudinal, prospective study was designed to: (1) assess accuracy of glomerular filtration rate equations at baseline (n = 1167) and their ability to detect change over 3 years (n = 875); (2) model disease progression predictors in 278 individuals who received additional measurements; (3) quantify glomerular filtration rate variability components (n = 20); and (4) develop a measurement model analysis to compare different monitoring strategy costs (n = 875). Setting: Primary, secondary and tertiary care. Participants: Adults (≥ 18 years) with stage 3 chronic kidney disease. Interventions: Estimated glomerular filtration rate using the Chronic Kidney Disease Epidemiology Collaboration and Modification of Diet in Renal Disease equations. Main outcome measures: Measured glomerular filtration rate was the reference against which estimating equations were compared with accuracy being expressed as P30 (percentage of values within 30% of reference) and progression (variously defined) studied as sensitivity/specificity. A regression model of disease progression was developed and differences for risk factors estimated. Biological variation components were measured and the reference change value calculated. Comparative costs of monitoring with different estimating equations modelled over 10 years were calculated. Results: Accuracy (P30) of all equations was ≥ 89.5%: the combined creatinine-cystatin equation (94.9%) was superior (p < 0.001) to other equations. Within each equation, no differences in P30 were seen across categories of age, gender, diabetes, albuminuria, body mass index, kidney function level and ethnicity. All equations showed poor (< 63%) sensitivity for detecting patients showing kidney function decline crossing clinically significant thresholds (e.g. a 25% decline in function). Consequently, the additional cost of monitoring kidney function annually using a cystatin C-based equation could not be justified (incremental cost per patient over 10 years = £43.32). Modelling data showed association between higher albuminuria and faster decline in measured and creatinine-estimated glomerular filtration rate. Reference change values for measured glomerular filtration rate (%, positive/negative) were 21.5/-17.7, with lower reference change values for estimated glomerular filtration rate. Limitations: Recruitment of people from South Asian and African-Caribbean backgrounds was below the study target. Future work: Prospective studies of the value of cystatin C as a risk marker in chronic kidney disease should be undertaken. Conclusions: Inclusion of cystatin C in glomerular filtration rate-estimating equations marginally improved accuracy but not detection of disease progression. Our data do not support cystatin C use for monitoring of glomerular filtration rate in stage 3 chronic kidney disease. Trial registration: This trial is registered as ISRCTN42955626. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 11/103/01) and is published in full in Health Technology Assessment; Vol. 28, No. 35. See the NIHR Funding and Awards website for further award information.

Chronic kidney disease, which affects approximately 14% of the adult population, often has no symptoms but, in some people, may later develop into kidney failure. Kidney disease is most often detected using a blood test called creatinine. Creatinine does not identify everyone with kidney disease, or those most likely to develop more serious kidney disease. An alternative blood test called cystatin C may be more accurate, but it is more expensive than the creatinine test. We compared the accuracy of these two tests in more than 1000 people with moderate kidney disease. Participants were tested over 3 years to see if the tests differed in their ability to detect worsening kidney function. We also wanted to identify risk factors associated with loss of kidney function, and how much the tests normally vary to better understand what results mean. We compared the accuracy and costs of monitoring people with the two markers. Cystatin C was found slightly more accurate than the creatinine test at estimating kidney function when comparing the baseline single measurements (95% accurate compared to 90%), but not at detecting worsening function over time. This means that the additional cost of monitoring people over time with cystatin C to detect kidney disease progression could not be justified. Kidney test results could vary by up to 20% between tests without necessarily implying changes in underlying kidney function ­ this is the normal level of individual variation. Cystatin C marginally improved accuracy of kidney function testing but not ability to detect worsening kidney function. Cystatin C improves identification of moderate chronic kidney disease, but our results do not support its use for routine monitoring of kidney function in such patients.

Description and Cross-Sectional Analyses of 25,880 Adults and Children in the UK National Registry of Rare Kidney Diseases Cohort.

Introduction: The National Registry of Rare Kidney Diseases (RaDaR) collects data from people living with rare kidney diseases across the UK, and is the world's largest, rare kidney disease registry. We present the clinical demographics and renal function of 25,880 prevalent patients and sought evidence of bias in recruitment to RaDaR. Methods: RaDaR is linked with the UK Renal Registry (UKRR, with which all UK patients receiving kidney replacement therapy [KRT] are registered). We assessed ethnicity and socioeconomic status in the following: (i) prevalent RaDaR patients receiving KRT compared with patients with eligible rare disease diagnoses receiving KRT in the UKRR, (ii) patients recruited to RaDaR compared with all eligible unrecruited patients at 2 renal centers, and (iii) the age-stratified ethnicity distribution of RaDaR patients with autosomal dominant polycystic kidney disease (ADPKD) was compared to that of the English census. Results: We found evidence of disparities in ethnicity and social deprivation in recruitment to RaDaR; however, these were not consistent across comparisons. Compared with either adults recruited to RaDaR or the English population, children recruited to RaDaR were more likely to be of Asian ethnicity (17.3% vs. 7.5%, P-value < 0.0001) and live in more socially deprived areas (30.3% vs. 17.3% in the most deprived Index of Multiple Deprivation (IMD) quintile, P-value < 0.0001). Conclusion: We observed no evidence of systematic biases in recruitment of patients into RaDaR; however, the data provide empirical evidence of negative economic and social consequences (across all ethnicities) experienced by families with children affected by rare kidney diseases.

The role of complement in kidney disease: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference.

Uncontrolled complement activation can cause or contribute to glomerular injury in multiple kidney diseases. Although complement activation plays a causal role in atypical hemolytic uremic syndrome and C3 glomerulopathy, over the past decade, a rapidly accumulating body of evidence has shown a role for complement activation in multiple other kidney diseases, including diabetic nephropathy and several glomerulonephritides. The number of available complement inhibitor therapies has also increased during the same period. In 2022, Kidney Diseases: Improving Global Outcomes (KDIGO) convened a Controversies Conference, "The Role of Complement in Kidney Disease," to address the expanding role of complement dysregulation in the pathophysiology, diagnosis, and management of various glomerular diseases, diabetic nephropathy, and other forms of hemolytic uremic syndrome. Conference participants reviewed the evidence for complement playing a primary causal or secondary role in progression for several disease states and considered how evidence of complement involvement might inform management. Participating patients with various complement-mediated diseases and caregivers described concerns related to life planning, implications surrounding genetic testing, and the need for inclusive implementation of effective novel therapies into clinical practice. The value of biomarkers in monitoring disease course and the role of the glomerular microenvironment in complement response were examined, and key gaps in knowledge and research priorities were identified.

Core needs and diverse opportunity: A survey of academic clinical lecturers and the effects of the COVID-19 pandemic.

During a clinical lecturer role, parallel clinical and academic training is undertaken. The anticipation is that a lectureship represents an exciting and expansive time. However, a national crisis has been declared at the clinical lecturer level with a leaky pipeline of clinical academics resulting in dwindling numbers. Clinical lecturers are infrequently represented as a group partly due to their distributed nature and diverse job plans. We conducted a survey of clinical lecturers in the UK. Responses (n = 107) revealed a motivated but divided workforce. A content analysis revealed core elements that sculpt an individual's success or failure, but these were variably present. COVID-19 had a negative effect on many with various strategies reported to try and reset academic trajectories. Feelings of isolation and anxiety about a viable future in academia were significant findings. This echoes calls for a greater number of secure longer-term grants to ensure that clinical academics and their skills are retained within the research workforce. A continued effort to analytically appraise whether supportive elements are in place for all lecturers will help focus initiatives to foster excellence in clinical academic training for everyone.

Focal Segmental Glomerulosclerosis Patient Baseline Characteristics in the Sparsentan Phase 3 DUPLEX Study.

Introduction: The phase 3 DUPLEX trial is evaluating sparsentan, a novel, nonimmunosuppressive, single-molecule dual endothelin angiotensin receptor antagonist, in patients with focal segmental glomerulosclerosis (FSGS). Methods: DUPLEX (NCT03493685) is a global, multicenter, randomized, double-blind, parallel-group, active-controlled study evaluating the efficacy and safety of sparsentan 800 mg once daily versus irbesartan 300 mg once daily in patients aged 8 to 75 years (USA/UK) and 18 to 75 years (ex-USA/UK) weighing ≥20 kg with biopsy-proven FSGS or documented genetic mutation in a podocyte protein associated with FSGS, and urine protein-to-creatinine ratio (UP/C) ≥1.5 g/g. Baseline characteristics blinded to treatment allocation are reported descriptively. Results: The primary analysis population includes 371 patients (336 adult, 35 pediatric [<18 years]) who were randomized and received study drug (median age, 42 years). Patients were White (73.0%), Asian (13.2%), Black/African American (6.7%), or Other race (7.0%); and from North America (38.8%), Europe (36.1%), South America (12.7%), or Asia Pacific (12.4%). Baseline median UP/C was 3.0 g/g; 42.6% in nephrotic-range (UP/C >3.5 g/g [adults]; >2.0 g/g [pediatrics]). Patients were evenly distributed across estimated glomerular filtration rate (eGFR) categories corresponding to chronic kidney disease (CKD) stages 1 to 3b. Thirty-three patients (9.4% of 352 evaluable samples) had pathogenic or likely pathogenic (P/LP) variants of genes essential to podocyte structural integrity and function, 27 (7.7%) had P/LP collagen gene (COL4A3/4/5) variants, and 14 (4.0%) had high-risk APOL1 genotypes. Conclusions: Patient enrollment in DUPLEX, the largest interventional study in FSGS to date, will enable important characterization of the treatment effect of sparsentan in a geographically broad and clinically diverse FSGS population.

Hypoxia-inducible factor prolyl hydroxylase inhibitors for anaemia in chronic kidney disease: a document by the European Renal Best Practice board of the European Renal Association.

Anaemia is a common complication of chronic kidney disease (CKD) and is associated with poor long-term outcomes and quality of life. The use of supplemental iron, erythropoiesis stimulating agents (ESAs) and blood transfusions has been the mainstay of treatment of anaemia in CKD for more than three decades. Despite available treatments, CKD patients with anaemia are undertreated and moderate-to-severe anaemia remains prevalent in the CKD population. Anaemia has consistently been associated with greater mortality, hospitalisation, cardiovascular events, and CKD progression in patients with CKD, and the risk increases with anaemia severity. Hypoxia-inducible factor (HIF) prolyl hydroxylase (PH) inhibitors have a novel mechanism of action by mimicking the body's response to hypoxia and have emerged as an alternative to ESAs for the treatment of anaemia in CKD. Their efficacy in correcting and maintaining haemoglobin has been demonstrated in over 30 phase 3 clinical trials. Additionally, HIF activation results in various pleiotropic effects beyond erythropoiesis with cholesterol reduction and improved iron homeostasis and potential anti-inflammatory effects. The long-term safety of these agents, particularly with respect to cardiovascular and thromboembolic events, and their possible effect on tumor growth requires to be fully elucidated. This document presents in detail the effects of HIF-PH inhibitors, describes their mechanisms of action and pharmacologic properties, and discusses their place in the treatment of anaemia in CKD according to the available evidence.

Examining the association between serum galactose-deficient IgA1 and primary IgA nephropathy: a systematic review and meta-analysis.

BACKGROUND: IgA nephropathy (IgAN) is a common primary glomerular disease. The O-glycosylation status of IgA1 plays a crucial role in disease pathophysiology. The level of poorly-O-galactosylated IgA1, or galactose-deficient IgA1 (Gd-IgA1), has also been identified as a potential biomarker in IgAN. We sought to examine the value of serum Gd-IgA1 as a biomarker in IgAN, by investigating its association with clinical, laboratory, and histopathological features of IgAN. METHODS: The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations and was registered in PROSPERO (CRD42021287423). The literature search was conducted in PubMed, Web of Science, Cochrane, and Scopus, and the selected articles were evaluated for eligibility based on predefined criteria. The methodological quality of the studies was assessed using the Newcastle-Ottawa Scale. Statistical analysis was performed to calculate effect sizes and assess heterogeneity among the studies. RESULTS: This review analyzed 29 out of 1,986 studies, conducted between 2005 and 2022, with participants from multiple countries. Gd-IgA1 levels were not associated with age and gender, while associations with hypertension, hematuria, and proteinuria were inconsistent. In the meta-analyses, a correlation between serum Gd-IgA1 and estimated glomerular filtration rate was identified, however, the relationships between Gd-IgA1 levels and chronic kidney disease (CKD) stage and progression to kidney failure were inconsistent. CONCLUSIONS: Serum Gd-IgA1 levels were not associated with validated prognostic risk factors, but were negatively correlated with kidney function. Further research in larger studies using standardized assays are needed to establish the value of Gd-IgA1 as a prognostic risk factor in IgAN.

Charting new frontiers in IgA nephropathy: a paradigm shift toward precision medicine and early intervention?

Advancements in glomerular transcriptomics offer a promising avenue toward precision medicine in IgA nephropathy. Traditional prognostic biomarkers, including proteinuria, blood pressure, and histomorphometry, fall short at capturing the complexity of IgA nephropathy and can only crudely guide therapeutic decisions. This issue needs to be addressed urgently as pathway-specific treatments become available. Glomerular transcriptomics, although technically challenging, offers an opportunity to refine prognostic precision and identify therapeutic targets, even when apparent risk of disease progression is low.

A phase 2b, randomized, double-blind, placebo-controlled, clinical trial of atacicept for treatment of IgA nephropathy.

Atacicept is a first-in-class, dual anti-B-cell Activation Factor-A Proliferation-Inducing Ligand fusion protein in clinical evaluation for treatment of IgA nephropathy. To compare efficacy and safety of atacicept versus placebo in patients with IgAN, this randomized, double-blind, placebo-controlled phase 2b clinical trial ORIGIN enrolled 116 individuals with biopsy-proven IgA nephropathy. Participants were randomized to atacicept 150, 75, or 25 mg versus placebo once weekly for up to 36 weeks. Primary and key secondary endpoints were changes in urine protein creatinine ratio based on 24-hour urine collection at weeks 24 and 36, respectively, in the combined atacicept 150 mg and 75 mg group versus placebo. The primary endpoint was met at week 24 as the mean urine protein creatinine ratio was reduced from baseline by 31% in the combined atacicept group versus 8% with placebo, resulting in a significant 25% reduction with atacicept versus placebo. At week 36, the key secondary endpoint was met as the mean urine protein creatinine ratio reduced from baseline by 34% in the combined atacicept group versus a 2% increase with placebo, resulting in a significant 35% reduction with atacicept versus placebo. The reduction in proteinuria was accompanied by stabilization in endpoint eGFR with atacicept compared to a decline with placebo at week 36, resulting in significant between-group geometric mean difference of 11%, approximating an absolute difference of 5.7 mL/min/1.73m2. Endpoint galactose deficient IgA1 levels significantly decreased from baseline by 60% versus placebo. The safety profile of atacicept was like placebo. Thus, our results provide evidence to support a pivotal, phase 3 study of atacicept in IgA nephropathy.

Effects of rare kidney diseases on kidney failure: a longitudinal analysis of the UK National Registry of Rare Kidney Diseases (RaDaR) cohort.

BACKGROUND: Individuals with rare kidney diseases account for 5-10% of people with chronic kidney disease, but constitute more than 25% of patients receiving kidney replacement therapy. The National Registry of Rare Kidney Diseases (RaDaR) gathers longitudinal data from patients with these conditions, which we used to study disease progression and outcomes of death and kidney failure. METHODS: People aged 0-96 years living with 28 types of rare kidney diseases were recruited from 108 UK renal care facilities. The primary outcomes were cumulative incidence of mortality and kidney failure in individuals with rare kidney diseases, which were calculated and compared with that of unselected patients with chronic kidney disease. Cumulative incidence and Kaplan-Meier survival estimates were calculated for the following outcomes: median age at kidney failure; median age at death; time from start of dialysis to death; and time from diagnosis to estimated glomerular filtration rate (eGFR) thresholds, allowing calculation of time from last eGFR of 75 mL/min per 1·73 m2 or more to first eGFR of less than 30 mL/min per 1·73 m2 (the therapeutic trial window). FINDINGS: Between Jan 18, 2010, and July 25, 2022, 27 285 participants were recruited to RaDaR. Median follow-up time from diagnosis was 9·6 years (IQR 5·9-16·7). RaDaR participants had significantly higher 5-year cumulative incidence of kidney failure than 2·81 million UK patients with all-cause chronic kidney disease (28% vs 1%; p<0·0001), but better survival rates (standardised mortality ratio 0·42 [95% CI 0·32-0·52]; p<0·0001). Median age at kidney failure, median age at death, time from start of dialysis to death, time from diagnosis to eGFR thresholds, and therapeutic trial window all varied substantially between rare diseases. INTERPRETATION: Patients with rare kidney diseases differ from the general population of individuals with chronic kidney disease: they have higher 5-year rates of kidney failure but higher survival than other patients with chronic kidney disease stages 3-5, and so are over-represented in the cohort of patients requiring kidney replacement therapy. Addressing unmet therapeutic need for patients with rare kidney diseases could have a large beneficial effect on long-term kidney replacement therapy demand. FUNDING: RaDaR is funded by the Medical Research Council, Kidney Research UK, Kidney Care UK, and the Polycystic Kidney Disease Charity.

An Update on Current Therapeutic Options in IgA Nephropathy.

Immunoglobulin A nephropathy (IgAN) remains the leading cause of primary glomerular disease worldwide. Outcomes are poor with high rates of progressive chronic kidney disease and kidney failure, which contributes to global healthcare costs. Although this disease entity has been described, there were no disease-specific treatments until recently, with the current standard of care focusing on optimal supportive measures including lifestyle modifications and optimization of the renin-angiotensin-aldosterone blockade. However, with significant advances in the understanding of the pathogenesis of IgAN in the past decade, and the acceptance of surrogate outcomes for accelerated drug approval, there have been many new investigational agents tested to target this disease. As these agents become available, we envision a multi-pronged treatment strategy that simultaneously targets the consequences of ongoing nephron loss, stopping any glomerular inflammation, inhibiting pro-fibrotic signals in the glomerulus and tubulo-interstitium, and inhibiting the production of pathogenic IgA molecules. This review is an update on a previous review published in 2021, and we aim to summarize the developments and updates in therapeutic strategies in IgAN and highlight the promising discoveries that are likely to add to our armamentarium.

Risk Factors for Thromboembolic Events in Patients With Dialysis-Dependent CKD: Pooled Analysis of Phase 3 Roxadustat Trials in Japan.

INTRODUCTION: Thromboembolic events have occurred in clinical trials of roxadustat. This post hoc analysis explored potential factors related to thromboembolic events in dialysis-dependent patients treated with roxadustat in four phase 3 clinical trials in Japan. METHODS: Thromboembolic events with onset before and after week 12 were evaluated. Baseline risk factors for thromboembolic events were investigated by Cox regression analyses. Nested case-control analyses using conditional logistic models with matched pairs of case-control data explored relationships between thromboembolic events and laboratory parameters. RESULTS: Of the 444 patients, 56 thromboembolic events were observed in 44 patients during ≤ 52 weeks of treatment. The proportion of venous and arterial thromboembolic events gradually increased after week 12. Baseline risk factors included hemodialysis (vs peritoneal dialysis), advanced age (≥ 65 years), shorter dialysis vintage (< 4 months), and history of thromboembolism. The absence of concomitant intravenous or oral iron therapy (including ferric citrate) was associated with thromboembolic events before week 12 (hazard ratio 11.25; 95% confidence interval [CI] 3.36-37.71; vs presence). Case-control analysis revealed that low average transferrin saturation (< 10%; unadjusted odds ratio [OR] 6.25; 95% CI 1.52-25.62; vs ≥ 20%), high average transferrin level (≥ 2.5 g/L; unadjusted OR 4.36; 95% CI 1.23-15.39; vs < 2.0 g/L), and high average roxadustat dose (≥ 150 mg; unadjusted OR 5.95; 95% CI 1.07-33.16; vs < 50 mg) over the previous 8 weeks before the event onset were associated with thromboembolic events after week 12. However, adjustment for iron status extinguished the significant relationship between roxadustat dose and events. Multivariate case-control analysis showed that increased transferrin from baseline (≥ 1.0 g/L; adjusted OR 7.85; 95% CI 1.82-33.90; vs < 0.5 g/dL) and decreased mean corpuscular volume (< - 2 fL; adjusted OR 5.55; 95% CI 1.73-17.83; vs ≥ 0 fL) were associated with increased risk of thromboembolic events. CONCLUSION: In addition to established risk factors, iron deficiency may be related to thromboembolic events. Graphical Abstract available for this article. TRIAL REGISTRATION: NCT02780726, NCT02952092, NCT02780141, NCT02779764.

Roxadustat is an oral medicine that treats anemia in patients with chronic kidney disease (CKD). Thromboembolic events, or blood vessels blocked by a blood clot, have occurred in clinical trials of roxadustat. This study explored potential factors that may be related to thromboembolic events in roxadustat-treated patients with anemia of CKD on dialysis before and after week 12. This study found that hemodialysis (vs peritoneal dialysis), advanced age (older than 65 years), short amount of time on dialysis (less than 4 months), previous history of thromboembolic events, and not receiving iron therapy were risk factors for thromboembolic events before week 12. Iron deficiency and high roxadustat dose were risk factors for thromboembolic events after week 12. When iron status was also considered, we did not find that roxadustat dose was related to thromboembolic events. A different model found that increased levels of transferrin, a protein that transports iron, from baseline and decreased mean corpuscular volume, or smaller red blood cells, increased the risk of thromboembolic events. Patients with anemia of CKD on dialysis may benefit from more intentional monitoring and management of iron while receiving roxadustat.

Risk Factors for Thromboembolic Events in Patients With Dialysis-Dependent CKD: Pooled Analysis of Four Global Roxadustat Phase 3 Trials.

INTRODUCTION: Risk factors for thromboembolic events in patients with dialysis-dependent chronic kidney disease (CKD) receiving roxadustat are unknown. Iron deficiency has been reported as a risk factor for thrombosis in the general population. METHODS: Thromboembolic events with onset before and after week 12 in patients receiving roxadustat were evaluated in this pooled analysis of four global phase 3 trials, PYRENEES, SIERRAS, HIMALAYAS, and ROCKIES. Baseline risk factors for thromboembolic events were investigated by Cox regression analyses. Nested case-control analyses with matched pairs of case-control data explored the relationship between thromboembolic events and last known laboratory parameters before event onset. RESULTS: Of 2354 patients, 1026 thromboembolic events were observed in 568 patients. Baseline risk factors found included hemodialysis (vs peritoneal dialysis), advanced age (≥ 65 years), Black race, high high-sensitivity C-reactive protein, and history of thromboembolism, cardiovascular disease, or diabetes. Univariate case-control analyses revealed that high hemoglobin rate of rise (≥ 0.5 g/dL/week; odds ratio [OR] 2.09; 95% confidence interval [CI] 0.98-4.46) showed a trend towards increased risk of thromboembolic events before week 12, and high rate of hemoglobin decline was associated with events after week 12 (< - 0.5 g/dL/week; OR 3.73; 95% CI 1.68-8.27) as compared to stable hemoglobin levels (≥ - 0.1 to < 0.1 g/dL/week). Multivariate case-control analyses showed that low last known hemoglobin level (< 10 g/dL: adjusted OR 1.91; 95% CI 1.04-3.50; vs ≥ 12 g/dL) and low last known transferrin saturation (TSAT < 10%: adjusted OR 3.78; 95% CI 1.71-8.39; vs ≥ 30%) before event onset were associated with events after week 12. In patients with last known TSAT < 30%, higher roxadustat dose was associated with thromboembolic events; however, no association was observed in those with TSAT ≥ 30%. CONCLUSIONS: Among various risk factors for thromboembolic events, it is reasonable to avoid a rapid increase and decline in hemoglobin levels as well as ensure TSAT ≥ 30%, rather than increasing the roxadustat dose. Graphical Abstract available for this article. TRIAL REGISTRATION: NCT02278341, NCT02273726, NCT02052310, NCT02174731.

Roxadustat is an oral treatment for patients with anemia, or low hemoglobin levels, due to chronic kidney disease. Thromboembolic events are caused by a blood clot blocking blood vessels, and they have occurred in clinical trials of roxadustat. This analysis evaluated risk factors for thromboembolic events in patients receiving roxadustat to treat anemia of chronic kidney disease who are on dialysis. Two different statistical approaches were used to investigate risk factors for thromboembolic events that occurred before and after 12 weeks of roxadustat treatment. We found that rapid improvement of anemia after starting roxadustat treatment may be associated with an increased risk of thromboembolic events occurring in the first 12 weeks of treatment. In contrast, severe anemia or worsening of anemia was associated with an increased risk of thromboembolic events after week 12. Low iron levels in the blood or greater decline of available iron in the blood from baseline were also detected as risk factors for the events after week 12, suggesting that iron supplementation is important in patients who are iron-deficient. Moreover, thromboembolic events were also associated with older age (≥ 65 years), Black race, high levels of inflammation, and having had a previous thromboembolic event or having a history of cardiovascular disease or diabetes. Some risk factors, such as iron status and hemoglobin levels, can be changed after beginning roxadustat treatment and should be monitored and modified, as needed.