Background: Among patients with focal segmental glomerulosclerosis (FSGS), proteinuria and kidney function decline may be associated with increased economic burden. This study aimed to provide current information on the epidemiology and economic burden of FSGS in the United States. Methods: Descriptive, non-interventional, retrospective cohort study. Overall, 9899 patients were identified between January 2016 and December 2020 in Optum® de-identified Market Clarity Data based on International Classification of Diseases code or Optum® proprietary Natural Language Processing data. Descriptive statistics were reported for categorical and continuous variables. Prevalence estimates were standardized to the age, gender, and race/ethnicity distribution of the general United States population using direct methods and data from the 2021 United States Census Bureau. Per-patient-per-month healthcare resource utilization and associated costs, in 2020 United States dollars were reported by proteinuria (≤ 1.5 g/g vs. >1.5 g/g or < 3.5 g/g vs. ≥3.5 g/g) and chronic kidney disease stage (stage 1–5/kidney failure). The Fisher's Exact Test was used for categorical healthcare resource utilization outcomes, and linear regression (mean) and the Jonckheere-Terpstra Test (medians) were used for continuous healthcare resource utilization and cost outcomes. Results Estimated annual United States prevalence (average for 2016–2020) was 212.6 per 1 000 000. There was a consistent trend toward higher healthcare resource utilization and total costs with both chronic kidney disease progression (stage 1–5/kidney failure) and higher levels of proteinuria (≤ 1.5 g/g vs. >1.5 g/g or < 3.5 g/g vs. ≥3.5 g/g). Conclusions The observed prevalence of FSGS increased in the US and was highest among African Americans. Both more advanced chronic kidney disease and higher levels of proteinuria were associated with higher healthcare resource utilization and costs. Treatments which reduce proteinuria and slow kidney function decline have potential to reduce the economic burden associated with FSGS.

BACKGROUND:Focal segmental glomerulosclerosis (FSGS) leads to proteinuria and progressive decline in glomerular filtration rate which correlates with kidney failure and increased cardiovascular risk. The purpose of this study was to estimate the effects of proteinuria on kidney failure status/all-cause mortality and cardiovascular disease events/all-cause mortality, as well as the relationship between progression to kidney failure and occurrence of cardiovascular disease/mortality events among adult patients (≥18 years old) with FSGS.METHODS:This was an observational, retrospective cohort study utilizing Optum® de-identified Market Clarity Data and proprietary Natural Language Processing (NLP) data. The study period was from January 1, 2007 through March 31, 2021, with patients in the overall cohort being identified from July 1, 2007 through March 31, 2021. The index date was the first FSGS ICD-10 diagnosis code or FSGS-related NLP term within the identification period.RESULTS:Elevated proteinuria >1.5 g/g and ≥3.5 g/g increased risk for kidney failure/all-cause mortality (adjusted hazard ratio [95% CI]: 2.34 [1.99-2.74] and 2.44 [2.09-2.84], respectively) and cardiovascular disease/all-cause mortality (adjusted hazard ratio [95% CI]: 2.11 [1.38-3.22] and 2.27 [1.44-3.58], respectively). Progression to kidney failure was also associated with a higher risk of cardiovascular disease/all-cause mortality (adjusted hazard ratio [95% CI]: 3.04 [2.66-3.48].CONCLUSIONS:A significant proportion of FSGS patients experience kidney failure and cardiovascular disease events. Elevated proteinuria and progression to kidney failure were associated with a higher risk of cardiovascular disease/all-cause mortality events, and, elevated pre-kidney failure proteinuria was associated with progression to kidney failure/all-cause mortality events. Treatments that meaningfully reduce proteinuria and slow the decline in glomerular filtration rate have the potential to reduce the risk of cardiovascular disease, kidney failure and early mortality in patients with FSGS.

Rationale & Objective: Few data are available regarding histological features at the time of focal segmental glomerulosclerosis (FSGS) diagnosis among diverse real-world populations. This study describes clinical and histological characteristics and correlates of histological disease severity in adults with FSGS who underwent a clinical kidney biopsy. Study Design: Real-world cohort study with data derived from health records. Setting & Participants: Adults with FSGS by kidney biopsies from Arkana Laboratories from January 1, 2016 to May 31, 2020. Exposure: Race, chronic kidney disease stage, nephrotic proteinuria, age, sex, and hypertension. Outcomes: Severe histological disease, defined as global glomerulosclerosis in >50% of glomeruli and >25% interstitial fibrosis and tubular atrophy (IFTA). Analytical Approach: Demographic, clinical, and histological characteristics were compared between race groups. Correlates of severe disease were analyzed using multiple logistic regression. Results: Among 2,011 patients with FSGS, 40.6% were White, and 23.6% Black. White patients were older (52.8 vs 45.5 years, P < 0.001) with a higher estimated glomerular filtration rate (eGFR) than Black patients (53.5 vs 43.1 mL/min/1.73 m2, P < 0.001). A higher proportion of Black patients had global glomerulosclerosis ≥50% (32.1% vs 14.6%, P < 0.001) or IFTA >50% (34.6% vs 14.7%, P < 0.001). Severe histological disease was more likely in Black patients (OR, 2.46; 95% CI, 1.59-3.79; P < 0.001). A higher proportion of patients with nephrotic than nonnephrotic proteinuria exhibited diffuse foot process effacement. Limitations: Unequal representation across United States regions, missing demographic and clinical data, and lack of data on primary versus secondary FSGS, treatments, or outcomes. Conclusions: Black patients were more frequently diagnosed at younger age with lower eGFR and more severe histological disease compared with White patients. Timelier identification of FSGS could increase the opportunity for therapeutic intervention, especially for high-risk patients, to mitigate disease progression and complications. Plain-Language Summary: Focal segmental glomerulosclerosis (FSGS) accounts for around one-quarter of diagnoses derived from clinical kidney biopsies in the United States. Limited data are available regarding the classes and distribution of histological features at FSGS diagnosis among diverse real-world populations. Analyzing data from US patients who underwent kidney biopsy and were diagnosed with FSGS, we showed that up to half of patients had features of severe histological disease. Of this overall population, Black patients were more frequently diagnosed at a younger age but with more severe histological disease than White patients. The work highlights the need for timelier diagnosis of FSGS to enable intervention at an earlier disease stage.

Background IgA nephropathy can progress to kidney failure, and risk assessment soon after diagnosis has advantages both for clinical management and the development of new therapeutics. We present relationships among proteinuria, eGFR slope, and lifetime risks for kidney failure. Methods The IgA nephropathy cohort (2299 adults and 140 children) of the UK National Registry of Rare Kidney Diseases (RaDaR) was analyzed. Patients enrolled had a biopsy-proven diagnosis of IgA nephropathy plus proteinuria >0.5 g/d or eGFR <60 ml/min per 1.73 m 2 . Incident and prevalent populations and a population representative of a typical phase 3 clinical trial cohort were studied. Analyses of kidney survival were conducted using Kaplan–Meier and Cox regression. eGFR slope was estimated using linear mixed models with random intercept and slope. Results The median (Q1, Q3) follow-up was 5.9 (3.0, 10.5) years; 50% of patients reached kidney failure or died in the study period. The median (95% confidence interval [CI]) kidney survival was 11.4 (10.5 to 12.5) years; the mean age at kidney failure/death was 48 years, and most patients progressed to kidney failure within 10–15 years. On the basis of eGFR and age at diagnosis, almost all patients were at risk of progression to kidney failure within their expected lifetime unless a rate of eGFR loss ≤1 ml/min per 1.73 m 2 per year was maintained. Time-averaged proteinuria was significantly associated with worse kidney survival and more rapid eGFR loss in incident, prevalent, and clinical trial populations. Thirty percent of patients with time-averaged proteinuria of 0.44 to <0.88 g/g and approximately 20% of patients with time-averaged proteinuria <0.44 g/g developed kidney failure within 10 years. In the clinical trial population, each 10% decrease in time-averaged proteinuria from baseline was associated with a hazard ratio (95% CI) for kidney failure/death of 0.89 (0.87 to 0.92). Conclusions Outcomes in this large IgA nephropathy cohort are generally poor with few patients expected to avoid kidney failure in their lifetime. Significantly, patients traditionally regarded as being low risk, with proteinuria <0.88 g/g (<100 mg/mmol), had high rates of kidney failure within 10 years.

Introduction: Focal segmental glomerulosclerosis (FSGS) is a rare glomerular disease with high unmet clinical need. Interest in proteinuria as a surrogate end point for regulatory approval of novel treatments has increased. We assessed the relationship between achieving complete remission (CR) of proteinuria at least once during follow-up and long-term kidney outcomes. Methods: This post hoc analysis included all patients enrolled in the DUET trial of sparsentan in FSGS and the open-label extension (OLE). Evaluations occurred every 12 weeks, including blood pressure (BP), edema, proteinuria, and kidney function. CR was defined as a urine protein/creatinine ratio #0.3g/g in a first morning urine sample. Results: A total of 108 patients who received >= 1 sparsentan dose were included in this study. During a median follow-up of 47.0 months, 46 patients (43%) experienced >= 1 CR, 61% occurring within 12 months of starting sparsentan. There was an increased likelihood of CR with a higher sparsentan dose or baseline subnephrotic-range proteinuria. Achieving >= 1 CR was associated with significantly slower rate of estimated glomerular filtration rate (eGFR) decline versus non-CR patients (P < 0.05). Use of immunosup-pressive agents was more frequent in patients who achieved a CR. However, the antiproteinuric effect of sparsentan was additive to that achieved with concomitant immunosuppressive treatment. No unantici-pated adverse events occurred. Conclusion: We conclude that sparsentan can be safely administered for extended periods and exerts a sustained antiproteinuric effect. Achievement of CR at any time during follow-up, even if it is not sustained, may be an indicator of a favorable response to treatment and a predictor of improved kidney function outcomes.

[This corrects the article DOI: 10.1016/j.ekir.2023.06.016.].

Background:In patients with severe symptomatic aortic stenosis at low surgical risk, transfemoral transcatheter aortic valve replacement (TAVR) with the SAPIEN 3 valve has been shown to reduce the composite of death, stroke, or rehospitalization at 2-year follow-up compared with surgical aortic valve replacement (SAVR). Whether TAVR is cost-effective compared with SAVR for low-risk patients remains uncertain. Methods:Between 2016 and 2017, 1000 low-risk patients with aortic stenosis were randomly assigned to TAVR with the SAPIEN 3 valve or SAVR in the PARTNER 3 trial (Placement of Aortic Transcatheter Valves). Of these patients, 929 underwent valve replacement, were enrolled in the United States, and were included in the economic substudy. Procedural costs were estimated using measured resource use. Other costs were determined by linkage with Medicare claims or by regression models when linkage was not feasible. Health utilities were estimated using the EuroQOL 5-item questionnaire. With the use of a Markov model informed by in-trial data, lifetime cost-effectiveness from the perspective of the US health care system was estimated in terms of cost per quality-adjusted life-year gained. Results:Although procedural costs were nearly $19 000 higher with TAVR, total index hospitalization costs were only $591 more with TAVR compared with SAVR. Follow-up costs were lower with TAVR such that TAVR led to 2-year cost savings of $2030/patient compared with SAVR (95% CI, -$6222 to $1816) and a gain of 0.05 quality-adjusted life-years (95% CI, -0.003 to 0.102). In our base-case analysis, TAVR was projected to be an economically dominant strategy with a 95% probability that the incremental cost-effectiveness ratio for TAVR would be <$50 000/quality-adjusted life-year gained (consistent with high economic value from a US health care perspective). These findings were sensitive to differences in long-term survival, however, such that a modest long-term survival advantage with SAVR would render SAVR cost-effective (although not cost saving) compared with TAVR. Conclusions:For patients with severe aortic stenosis and low surgical risk similar to those enrolled in the PARTNER 3 trial, transfemoral TAVR with the SAPIEN 3 valve is cost saving compared with SAVR at 2 years and is projected to be economically attractive in the long run as long as there are no substantial differences in late death between the 2 strategies. Long-term follow-up will be critical to ultimately determine the preferred treatment strategy for low-risk patients from both a clinical and economic perspective.

Introduction: IgA nephropathy (IgAN) is a progressive autoimmune kidney disease and a leading cause of glomerular disease that can result in kidney failure (KF). The median age at diagnosis is 35 to 37 years and approximately 50% of patients will progress to KF within 20 years. We aimed to enhance the understanding of renal histology and chronic kidney disease (CKD) stage at the time of IgAN diagnosis using a large real-world biopsy cohort.Methods: This retrospective cohort study evaluated biopsy data and clinical characteristics from adult patients within the US who were diagnosed with IgAN between January 1, 2016 to May 31, 2020. Descriptive statistics were summarized and relationship(s) between each Oxford Classification (MEST-C) component score with 24-hour proteinuria or CKD stage were examined using regression analysis.Results: A total of 4375 patients (mean age 47.7 years, 62.7% male) met eligibility criteria. Mild to moderate mesangial hypercellularity (47.3%), segmental sclerosis (65.0%), tubular atrophy >= 25% (57.4%), and crescents (18.5%) were identified; and 74.6% of patients were at CKD stage >= 3. Proteinuria >= 1 g/d was associated with higher MEST-C scores, and the odds of mesangial hypercellularity, segmental sclerosis, tubular atrophy, and crescents increased with CKD stage.Conclusion: Most patients with IgAN in our US cohort were diagnosed at CKD stage >= 3 and had high MEST-C scores and proteinuria that are suggestive of significant disease burden at the time of kidney biopsy. Strategies are required to raise awareness and promote earlier detection of asymptomatic urinary abnormalities before extensive irreversible kidney damage has occurred.

Rationale & Objective: Among patients with IgA nephropathy (IgAN), proteinuria and decline in kidney function may be associated with increased economic burden. This study aimed to provide current information on the epidemiology and economic burden of IgAN in the United States.Study Design: Retrospective cohort study.Setting & Study Population: Overall, 9,984 patients in the Optum's Market Clarity database identified by the presence of at least 2 natural language processing-derived IgAN signs and disease and symptoms terms; 813 with linked claims data included in a health care resource utilization/cost subcohort.Predictor: High-risk proteinuria (=1 g/d), chronic kidney disease (CKD) stage.Outcomes: Standardized prevalence, health care resource utilization, costs.Analytical Approach: Descriptive statistics for categorical and continuous variables. Direct standardization for prevalence estimation. Generalized linear models for health care resource utilization/ costs, reported as per-patient-per-month (PPPM) costs in 2020 US dollars.Results: The estimated standardized US prevalence of IgAN (2016-2020) was 329.0 per1,000,000 persons. High-risk proteinuria (=1 vs <1 g/d) was associated with a higher mean PPPM number of outpatient visits (3.49 vs 1.74; P = 0.01) and pharmacy claims (3.79 vs 2.41; P = 0.01), contributing to higher mean total costs PPPM ($3,732 vs $1,457; P = 0.01). Furthermore, higher CKD stage was also associated with higher health care resource utilization (number of outpatient visits PPPM, number of pharmacy claims PPPM, proportion of patients with inpatient visits and emergency department visits; P < 0.001) and mean total cost PPPM (from $2,111 CKD stage 1 to $10,703 CKD stage 5/kidney failure; P < 0.001).Limitations: Generalizability outside of the catchment group for the database, missing data/errors inherent in retrospective database studies, relatively small sample size, use of Optum Market Clarity standardized pricing algorithms, exclusion of out-of-pocket costs.Conclusions: Health care resource utilization and costs were higher for IgAN patients with high-risk proteinuria and worsening kidney function. Treatments that reduce proteinuria and slow CKD disease progression may reduce the economic burden associated with IgAN.

Characterized by increased production of inflammatory cytokines that damage the glomerular filtration barrier resulting in proteinuria and hematuria, immunoglobulin A nephropathy (IgAN) leads to end-stage kidney disease (ESKD). This study describes epidemiology, treatment modalities, resource burden, and mortality of ESKD attributed to IgAN in the United States (US).