Reduction Of Proteinuria Research Articles

#1679 Relationship between initial eGFR DIP with proteinuria after SGLT2i treatment, in patients with IgA nephropathy. A real-world clinical study

Abstract Background and Aims Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are associated with better cardiovascular outcomes and with nephroprotection independent of diabetes status. Recent data suggest that SGLT2i significantly reduce proteinuria in patients with IgA nephropathy (IgAN). However, they often cause an initial decline in estimated glomerular filtration rate (eGFR). The aim of our study was to assess the degree of proteinuria reduction after SGLT2i treatment in IgAN and its possible association with the initial functional dip in eGFR. Method 63 adult patients with biopsy-proven IgA nephropathy, eGFR ≥ 30 mL/min/1.73 m2 (CKD-epi), and total urine protein of >0.5 grams/day at screening were included. Patients with secondary IgAN were excluded. All receiving maximally tolerated RASi for at least 12 weeks. All patients started dapagliflozin 10 mg once per day after baseline data were registered. The total follow-up was 12 months. The main outcome was the decline in eGFR and the reduction in 24-hour proteinuria from SGLT2i initiation to 1,3, 6, 9, 12 months, end-stage renal disease, or kidney or cardiovascular death. Results 55 patients (38/17 M/F), with mean age of 44,2±18,3 years, completed follow up. 8 patients discontinued treatment due to adverse events attributed to dapagliflozin. At baseline eGFR was 66.17±19,7 ml/min/1.73 m2 and Upr: 2356±1023 mg/24H. There was a transient decline in eGFR, 30 days after initiation of dapagliflozin (66.17±19,7 min/1.73 m2 at baseline to 57 ml/min/1.73 m2) but then, there was an improvement at month 3 from baseline. The Upr/24H difference for dapagliflozin was −25.1% (95% CI −27.5, −23.2; p < 0.001) at the end of follow-up (month 12). Proteinuria reduction was similar across all eGFRs. Notably, a significant correlation was found between the initial eGFR dip and percentage proteinuria reduction in the 12th month. (R = –0.23; p = 0.03). Consistent results of dapagliflozin treatment on proteinuria were found in all analysis subgroups including sex, baseline proteinuria, systolic blood pressure, and body mass index. No hypoglycaemic events were reported and no deaths occurred. Conclusion In the present study, the use of SGLT2i was associated with a significant reduction of proteinuria in patients with IgA nephropathy in patients with maximally tolerated RASi. Higher initial eGFR dip after treatment initiation was a predictor of a significantly higher reduction in proteinuria at the end of follow-up. The correlation between eGFR dip and proteinuria reduction perhaps reflects the intraglomerular pressure reduction, mediated by tubuloglomerular feedback, one of the numerous.

#367 PROTECT and NefIgArd two-year proteinuria and eGFR outcomes in adults with IgA nephropathy: matching-adjusted indirect comparison

Abstract Background and Aims Immunoglobulin A (IgA) nephropathy is a rare kidney disorder characterized by deposition of IgA in the glomeruli causing progressive loss of kidney function and increased risk of kidney failure. In the absence of a head-to-head trial, this study used unanchored matching-adjusted indirect comparison (MAIC) of clinical trial data to compare two-year efficacy outcomes between Sparsentan in PROTECT and targeted-release formulation (TRF) budesonide plus real-world optimized and stable renin-angiotensin system inhibition (RASi) standard-of-care (SoC) in NefIgArd. Method We conducted an unanchored MAIC using individual patient level data from the PROTECT trial and aggregate data from the NefIgArd trial. Patients in the sparsentan arm of PROTECT were weighted to match key baseline characteristics of patients in the targeted-release formulation (TRF) budesonide + RASi SoC arm of NefIgArd based on publicly accessible, clinically pertinent baseline characteristics and prognostic factors using the method of moments. After weighting, percentage reduction of urine protein-creatinine ratio (UPCR) relative to baseline and two-year eGFR total slope (based on available data, chronic slope estimates are currently not available from NefIgArd) were estimated. A mixed model for repeated measures (MMRM) was used for UPCR relative percentage reduction and a random effect coefficient model for eGFR total slope. A two-tailed z-test with a pooled standard error was conducted for the indirect comparison. Results After assessing PROTECT and NefIgArd cross-trial characteristics on key outcome definitions, inclusion and exclusion criteria, and patient population, the two trials were considered sufficiently similar for unanchored MAIC. After weighting individual patient data from PROTECT, all matched baseline patient characteristics were well-balanced between arms of the two trials. Comparative results showed patients treated with sparsentan in PROTECT (−43.2% relative reduction in UPCR) exhibited a greater mean percentage reduction in proteinuria at two-years compared to TRF budesonide + RASi SoC (−30.7% relative reduction in UPCR), a relative percentage reduction of 18.1% (p = 0.03; Fig. 1A). For eGFR total slope, patients treated with sparsentan exhibited a slower decline in kidney function compared to TRF budesonide + RASi SoC, a difference of 0.54 ml/min/1.73 m2 per year; however, this difference was not statistically significant (p = 0.35; Fig. 1B). Conclusion Aligned to an earlier analysis of percentage reduction in proteinuria at 9-months (−37%, p < 0.0001 favoring sparsentan), our MAIC results show that sparsentan in PROTECT was associated with a greater relative percentage reduction in proteinuria at two-years compared to TRF budesonide plus real-world optimized and stable RASi SoC in NefIgArd. eGFR total slope for sparsentan in PROTECT was comparable to that reported for TRF budesonide plus real-world optimized and stable RASi SoC in NefIgArd. Results comparing chronic slope may provide a better indication of the long-term nephroprotective value of both therapies.

#468 Voclosporin-based, triple-immunosuppressive therapy vs high-dose glucocorticoid-based dual-immunotherapy for lupus nephritis: a propensity analysis

Abstract Background and Aims Voclosporin is a second generation calcineurin inhibitor (CNI) approved for the treatment of adults with active lupus nephritis (LN) in combination with immunosuppressive therapy. An integrated analysis of the Phase 2 AURA-LV and Phase 3 AURORA 1 studies concluded that combining voclosporin with lower-dose mycophenolate mofetil (MMF, 2 g/day) and low-dose glucocorticoids (GCs) led to significantly greater and earlier reductions in proteinuria when compared to MMF and GCs alone. This is an important finding as early reduction in proteinuria is associated with improved long-term kidney survival and mortality. Yet, dual-immunosuppressive regimens consisting of high-dose glucocorticoids and either intravenous cyclophosphamide (IVC) or higher doses of MMF (>2 g/day) continue to be frequently used for the initial management of active LN despite their association with incomplete efficacy and dose-dependent toxicities. Method All three studies enrolled participants with active LN. In AURA-LV and AURORA 1, participants received voclosporin 23.7 mg BID in combination with MMF (target 2 g/day) and oral GCs (25 mg/day tapered to 2.5 mg/day by Week 16). In ALMS, MMF (target 3 g/day) or IVC (0.5 to 1.0 g/m2/month × 6) was added to oral GCs initiated at a maximum dose of 60 mg/day, tapered every 2 weeks to 10 mg/day. Propensity score methodology was used to generate groups of matched participants (ALMS [MMF and IVC] vs. AURA-LV/AURORA 1 [voclosporin]) based on demographic and disease characteristics. Safety and efficacy were assessed at 3 and 6 months. Results Propensity matching identified 179 pairs of participants with similar demographics and baseline disease characteristics. Mean cumulative exposure to GCs was more than 2-fold higher in the IVC and MMF cohorts of ALMS than AURA-LV/AURORA 1 participants over both 3 and 6 months. The overall incidence of adverse events (AEs) was higher in IVC- and MMF-treated participants of ALMS, although more participants in AURA-LV and AURORA 1 reported hypertension and anemia (Table 1). Due to the known hemodynamic effects of calcineurin inhibition, there was a small decrease in mean eGFR in the AURA-LV/AURORA 1 participants in the first few weeks of treatment after which mean eGFR remained stable; AURA-LV/AURORA 1 participants also had an increased rate of events of GFR decreased. The incidence of serious AEs was similar across treatments. In the first 3 months of treatment, significantly more AURA-LV/AURORA 1 participants achieved a reduction in UPCR >25% from baseline (91.6% vs 69.3%; odds ratio [OR] 4.75, 95% confidence interval [CI] 2.56, 8.84; p < 0.0001). Over six months of treatment, mean (SD) change from baseline in UPCR was −3.1 (2.9) g/g in voclosporin-treated patients in AURA-LV and AURORA 1 compared to −2.4 (3.3) g/g in IVC- or MMF-treated participants in ALMS (Fig. 1). Conclusion Voclosporin-based, triple immunosuppressive therapy was associated with an improved safety profile as well as greater and earlier reductions in proteinuria compared to more conventional dual immunosuppressive regimens. These data support treatment guidelines for active LN that recommend both minimizing patient exposure to GCs and use of a multi-targeted treatment regimen as initial therapy.

#1392 MEST-C score correlation with proteinuria reduction after SGLT2i treatment in patients with IgA nephropathy

Abstract Background and Aims Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are associated with better cardiovascular outcomes and with nephroprotection independent of diabetes status. Recent data suggest that SGLT2i significantly reduce proteinuria in patients with IgA nephropathy (IgAN). Data available for the use of the MEST-C score to determine if treatment would benefit IgAN patients is scarce. The aim of our study was to assess the degree of proteinuria reduction after SGLT2i treatment in IgAN and its possible association with the MEST-C score. Method 63 adult patients with biopsy-proven IgA nephropathy, eGFR ≥ 30 mL/min/1.73 m2 (CKD-epi), and total urine protein of >0.5 grams/day at screening were included. Patients with secondary IgAN and crescents were excluded. All receiving maximally tolerated RASi for at least 12 weeks. All patients started dapagliflozin 10 mg once per day after baseline data were registered. The total follow-up was 12 months. The main outcome was the decline in eGFR and the reduction in 24-hour proteinuria from SGLT2i initiation to 1,3, 6, 9, 12 months, end-stage renal disease, or kidney or cardiovascular death. Three repeated measurements of proteinuria (mg/24H) were performed, 90 days before SGLT2i treatment initiation, and only patients with stable proteinuria were enrolled in the study. Results 49 patients (35/14 M/F), with mean age of 41,9 ± 19,6 years, completed follow up. 8 patients discontinued treatment due to adverse events attributed to dapagliflozin. At baseline eGFR was 68.21±18,1 ml/min/1.73 m2 and Upr: 2196±1091 mg/24H. The MEST-C scores were correlated with the serum creatinine level, proteinuria, and hematuria. The mean serum creatinine level was higher in M1, E1, S1, and T1 compared with score “0”. It was statistically significant (p = 0.03) only in the T-score. The mean proteinuria level was again higher in M1, S1, and T1 but reached statistical significance (p = 0.037) in only the T1-score. E1 has higher hematuria. The Upr/24H difference for dapagliflozin was −24.7% (95% CI −27.5, −23.2; p < 0.001) at the end of follow-up (month 12). Proteinuria reduction was similar across all eGFRs, age, and baseline proteinuria. Among MEST-C score parameters, T1 had a negative impact on the antiproteinuric effect of dapagliflozin (p = 0.01) No hypoglycemic events were reported and no deaths occurred. Conclusion In the present study, the use of SGLT2i was associated with a significant reduction of proteinuria in patients with IgA nephropathy and maximally tolerated RASi. We analyzed renal outcomes in association with pathologic features. We established that the presence of the T1 score has a negative impact on proteinuria reduction after SGLT2i treatment. Further studies are needed to investigate the impact of the use of the Oxford Classification score for developing individual treatment therapies.

#145 Subgroup and secondary endpoint evaluation of a phase 2 randomized placebo-controlled trial of ravulizumab in IgA nephropathy

Abstract Background and Aims The pathogenesis of IgA nephropathy (IgAN) involves immune complex deposition and activation of the complement system, causing formation of the terminal pathway components C5a and C5b-9, leading to inflammation and glomerular damage. Elevated levels of activated C3 in plasma are associated with proteinuria and renal function decline in patients with IgAN [1]; mesangial C3 deposition is also associated with progression of disease [2]. Ravulizumab is a humanized monoclonal antibody that immediately and completely inhibits complement component C5. Primary endpoint (week 26) data from the phase 2 randomized controlled trial (RCT) (NCT04564339) were previously reported and demonstrated a 30% and 33% treatment effect of ravulizumab compared to placebo on 24-hour urine protein and 24-hour urine protein-to-creatinine ratio (UPCR) reduction, respectively [3]. This analysis reports prespecified subgroup and secondary endpoints as well as post hoc exploration of treatment response by baseline serum C3 and C4 quartiles through week 26. Method The SANCTUARY RCT evaluated ravulizumab (IV; weight-based dosing Q8W) vs placebo in adults with primary IgA nephropathy. Randomized patients (2:1) were stratified by mean proteinuria (1–2 vs >2 g/day). Patients (18–75 years) with biopsy-confirmed IgA nephropathy, proteinuria ≥1g/day, estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m2, and on stable maximally tolerated renin angiotensin inhibition were enrolled. The primary endpoint was proteinuria reduction at week 26 based on 24-hour urine collection. Secondary endpoints at week 26 included the proportion of patients with >50% reduction in proteinuria (absolute urine protein) and the percentage with <1g/day proteinuria. The percentage change in proteinuria (absolute urine protein) among subgroups of sex, race, duration of disease, baseline proteinuria and eGFR, and baseline serum C3 and C4 levels were also evaluated, as were safety data. Results 66 patients entered the 26-week initial evaluation period (n = 43, ravulizumab arm; n = 23, placebo arm); 71.2% were White and 21.2% were Asian. Overall, 41.5% and 18.2% of ravulizumab- and placebo-treated patients, respectively, achieved >50% proteinuria reduction (Fig. 1). Proteinuria reduction to <1g/day was achieved in 26.8% and 18.2% in the ravulizumab and placebo arms, respectively. Subgroup analysis indicated a treatment effect across subgroups of sex, race, disease duration, and baseline proteinuria and eGFR (Fig. 2). With ravulizumab, there were reductions of 41.9% and 41.0% in proteinuria for those with the lowest quartile of baseline serum C3 and C4, respectively. Similarly, reductions of 40.4% and 40.8% were observed in those with baseline serum C3 and C4 levels above the lowest quartile. In the ravulizumab arm, two patients had low serum C3 at baseline and there were no patients with low serum C4 at baseline; there was no change in mean serum C3 and C4 levels over time. Treatment with ravulizumab was well-tolerated. Conclusion In this phase 2 trial of ravulizumab in IgAN, proteinuria was significantly reduced with ravulizumab vs placebo through week 26. A reduction in proteinuria was also observed across subgroups of patients. As is typical in IgAN, serum C3 and C4 levels at baseline were normal, and there was no difference in proteinuria reduction by baseline serum C3 and C4 levels with ravulizumab through 6 months.

#2549 Real world data of dapagliflozin effect on proteinuria in primary glomerulopathies in Croatia

Abstract Background and Aims SGLT2 inhibitors, namely dapagliflozin, proved to slow progression of kidney disease in randomized clinical trials. Our aim was to assess real world efficacy of dapagliflozin on proteinuria level in primary glomerulopathies (GN). Method adult patients with biopsy proven glomerulonephritis from all university hospitals in Croatia who started dapagliflozin as a standard of care were enrolled. Data were analyzed if patients had at least six months of follow up. None of the patients were on immunosuppression. Data are shown as N (%) or median with interquartile range (IQR) and accompanied p levels. Results Overall 118 patients, predominantly male 84 (71.8%) of average age of 52 years (min–max 20–76), were enrolled. Most of the patients had IgA nephropathy (IgAN) (N = 55;46.6%), followed by membranous nephropathy (N = 27;22.9%), FSGS (N = 19;16.1%), membranoproliferative GN (N = 8;6.8%), Alport syndrome (N = 8;6.8%). 95.8% of patients were on ACE inhibitors or angiotensin receptor blockers and 10.7% were on mineralocorticoid receptor inhibitors and RAAS blockage was not significantly upscaled during follow up. During the median follow up of 12.2 (7.5-18.6) months, proteinuria was significantly reduced from 1139 (534–2265) to 701 (305-1543) mg/dU; p < 0.001. When divided by glomerulonephritis type, statistically significant reduction of proteinuria was observed in patients with IgAN and Alport syndrome, while trend of reduction of proteinuria was observed in all types of GN. There was a slight reduction in eGFR levels (54 (43-78) vs. 52 (39–73) ml/min/1,73 m²; p < 0.001) and rise in creatinine values (122 (89–149) vs. 128 (91–159) μmol/l; p < 0.001). There was a significant reduction in systolic (130 (120-140) vs.125 (115-134) mmHg; p < 0.001) and diastolic blood pressure (80 (75-90) vs. 80 (70-85) mmHg; p < 0.001). Reduction of uric acid level was noticed (377 (313–460) vs.343 (294–422); p < 0.001), while there was no effect on LDL levels (2.6 (2.12–3.53) vs.2.3 (1.9–3.30); p = 0.073). Dapagliflozin was well tolerated, one patient discontinued the therapy due to intolerance, one due to urinary infection and two due to relapse of GN which needed immunosuppressive therapy. One patient was excluded from analysis due to non-adherence. Conclusion SGLT2 inhibitor dapagliflozin has significant effect on reduction of proteinuria in patients with primary glomerulonephritis. Our data support a growing body of evidence that SGLT2 inhibitors should be used as a standard of care in patients with glomerular kidney diseases, especially IgAN. Future research should address earlier use of SGLT2 inhibitors during the treatment of glomerulonephritis alongside immunosuppressive therapy as well as look into the effect of SGLT2 inhibitors on mesangial cells.

#1166 ACTION3 pivotal Phase 3 & open-label extension study assessing DMX-200 in adult & paediatric patients with focal segmental glomerulosclerosis (FSGS)

Abstract Background and Aims Focal segmental glomerulosclerosis (FSGS) is a major cause of glomerular disease that affects both adults and children. FSGS can rapidly progress to end-stage kidney disease. Lack of safe and effective treatment represents a significant unmet need for patients with FSGS. Development of treatments has been hampered by complexities including the rare nature of the disease, varying drivers of pathogenesis, and the evolving diagnostic and clinical trial designs, necessitating innovative research approaches. DMX-200 (repagermanium) is a C-C motif chemokine receptor 2 (CCR2) pathway inhibitor. Activation of the angiotensin II type 1 receptor (AT1R) and CCR2 have been independently implicated in the pathogenesis and progression of FSGS. These receptors form a functional complex so inhibition of both receptors may provide an efficient approach to FSGS treatment. In vivo data shows co-administration of DMX-200 and the angiotensin receptor blocker (ARB) irbesartan demonstrated a synergistic reduction in proteinuria, macrophage infiltration, and podocyte loss compared with vehicle or either antagonist alone. A subsequent Phase 2a cross-over study (NCT03649152) in N = 8 patients with biopsy-proven primary FSGS showed that the combination of DMX-200 and irbesartan (compared to placebo) was well tolerated with most patients experiencing a reduction in proteinuria. Based on these data, the global Phase 3 study (ACTION3) was initiated to confirm the proteinuria lowering effects of DMX-200 and assess effects on eGFR decline. ACTION3 is a randomised, placebo-controlled, double-blind, long-duration study of FSGS patients and on completion will provide a resource for the wider nephrology community and advocacy groups on the natural history of FSGS patients and the effects of a CCR2-inhibitor on the background of an ARB. Here we present the baseline data from the first 90 patients enrolled in ACTION3 at 12th January 2024. Method The ACTION3 (NCT05183646) study is a pivotal Phase 3, multicentre study of the efficacy and safety of DMX-200, 120 mg twice daily compared with placebo in adult patients with biopsy-proven FSGS receiving maximal tolerated ARB, with persistent proteinuria >1.5g/ day and eGFR >25 ml/min/1.73 m2. The study plans to enroll approximately 286 patients with primary FSGS, genetic FSGS and FSGS of undetermined cause with the primary objective of evaluating the efficacy of DMX-200 in percent change in 24-hour urine PCR and eGFR slope. The initial 104-week randomized period will be extended in a 2-year open label extension study. A futility analysis by an Independent Data Monitoring Committee following the first 72 patients completing 35 weeks of treatment confirm that continuation of the study is non-futile. Results The study is actively recruiting at 71 sites in 11 countries listed in Table 1. Demographic data of randomised patients is listed in Table 2. Patients are predominantly male (65%), with an average age of 46.6 yrs. and mean eGFR 56.3 ± 27.6 (ml/min/1.73 m2). The study is expanding recruitment into additional countries in the Asia Pacific, Europe, and Latin American regions. Further, the study protocol has sought and received regulatory approval to enroll adolescent patients aged 12-18 in Argentina, Mexico, UK and the US. Conclusion DMX-200 (repagermanium) has shown encouraging signs of safety and efficacy in combination with an ARB for the treatment of FSGS. The contributing countries and baseline characteristics of the patients enrolled in ACTION3 are similar to the populations studied in other recent FSGS trials. No clinically significant safety concerns have been observed in patients enrolled to date in the ACTION3 Phase 3 study.

#1917 SGLT2-Inhibition in patients with Alport syndrome – an international, retrospective and in parts prospective observational large cohort study

Abstract Background and Aims Large-scale trials showed positive outcomes of SGLT2-inhibitors (SGLT2i) in elderly patients with CKD. Patients with Alport syndrome, a type IV collagen disease, develop CKD early in life. Whether the use of SGLT2i is safe and effective in patients with the type IV collagen disease Alport syndrome (and thus a different pathogenesis) has not yet been investigated specifically besides case reports. Method For the first time, this observational, multicenter, international study (NCT02378805) assessed 112 patients with AS from nine countries and 21 trial sites after start of SGLT2i at early stages of their chronic kidney disease (CKD). The study's primary endpoint was change of albuminuria in albumin/g creatinine after start of therapy with SGLT2i. Results Compared to the large randomized trials investigating the effect of SGLT2i in CKD, the adult patients in this trial were much younger (38 ± 14 years; n = 101), had a better eGFR (63 ± 35 ml/min/1.73m2; n = 98) and had a higher albuminuria (1699 ± 1472 mg/g creatinine; n = 51). At a mean time on SGLT2i-therapy of 6 ± 1 months, albuminuria decreased significantly (1727 ± 1564 vs. 1203 ± 1165 mg/g creatinine; n = 33; p = 0.01). Compared to baseline, at the first three follow-up visits after initiation of SGLT2i-therapy, a significant reduction of albuminuria >30% was observed. Mean loss of eGFR was 9 ± 12 ml/min/1.73 m² almost one year after initiation of SGLT2i-therapy (n = 35). At a mean follow up of 12 ± 2 month after initiation of SGLT2i-therapy, serum-albumin increased significantly from 3.7 ± 0.7 to 4.0 ± 0.4 g/dL (n = 18; p = 0.019). At a total of 68 patient-years at risk, adverse events occurred in 11/85 patients (13%). Two very serious adverse events (acute necrotizing pancreatitis and Fournier's gangrene) occurred. Conclusion This study demonstrated that SGLT2i, when added to RASi, have the potential to reduce the rate of albuminuria in adult patients with Alport Syndrome. The study will be continued to provide valuable data on the long-term course of CKD under SGLT2i-therapy in AS to investigate if the promising reduction of albuminuria results in a clinical relevant delay in renal failure. This observational study successfully formed the scientific basis for the current randomized controlled trial with SGLT2i in children and young adults with AS Double Protect Alport.

#2308 The effect of Dapagliflozin on albuminuria and biomarkers associated with renal function in patients with β-thalassemia and/or sickle-cell disease

Abstract Background and Aims Patients with β-thalassemia present already from the 1st year of life with serious anemia thus needing regular blood transfusions in order to attain normal hemoglobin levels. Chronic anemia, iron overload and the use of iron chelating agents have been associated with renal dysfunction. In sickle-cell syndromes, which include sickle-cell anemia and sickle-cell trait, patients present with typical kidney functional and structural defects, resulting in urinary concentrating defects, distal nephron dysfunction and albuminuria. Sodium–glucose cotransporter-2 inhibitors (SGLT-2i) have shown beneficial effects on renal outcomes in large clinical trials with the added benefit of a substantial decrease in albuminuria. The aim of this prospective, non randomized open label study is to investigate the effect of Dapagliflozin at a dose of 10 mg daily on albuminuria and the overall progression of CKD in patients with β-thalassemia and/or sickle-cell disease undergoing regular blood transfusions. Method In this study we included adult patients undergoing regular blood transfusions with a baseline albuminuria of ACR>30 mg/gCr (assessed with a spot urine sample) who received treatment with Dapagliflozin, a second group with no albuminuria that did not receive treatment and a group of adults with no kidney disease (Controls). In all patients renal function biomarkers were measured in urine and serum with commercial ELISA kits (NGAL and uPAR in serum, MMP9 and KIM-1 in urine), while in patients that received Dapagliflozin additional measurements of ACR and eGFR (CKD-EPI formula) were performed after 3 months of treatment initiation. Results In this study we included 16 patients (7 males) with β-thalassemia and/or sickle-cell disease with ACR>30 mg/gCr, 35 patients (17 males) with β-thalassemia and/or sickle-cell disease without albuminuria and 20 controls (13 males). Patients that received Dapagliflozin showed a significant reduction in albuminuria three months post-initiation of treatment (ACR: 0.52 ± 1.2 vs. 0.3 ± 0.68 mg/g, p=0.006) while kidney function showed a slight non-significant reduction (eGFR: 99.3 ± 21.7 vs. 94.7 ± 28.9 ml/min/1.73m2, p=0.36). Concerning the urine and serum biomarkers of tubular dysfunction, inflammation and kidney disease progression, all were significantly increased in patients with β-thalassemia and/or sickle-cell disease in comparison to controls (Table 1). In patients that received treatment with Dapagliflozin, NGAL, MMP-9 and suPAR at 3 months post-treatment initiation did not show any significant reduction (Table 2). Conclusion Patients with β-thalassemia and/or sickle-cell disease show increased urine and serum levels of kidney damage biomarkers in comparison to healthy controls. Treatment of these patients with Dapagliflozin for 3 months has a significant effect in albuminuria reduction while it does not alter urine and serum levels of these biomarkers.

#3033 IgA vasculitis: a unexpected diagnosis of pulmonary renal syndrome

Abstract Background IgA vasculitis is an inflammatory condition affecting blood vessels that poses a significant diagnostic and therapeutic challenge in clinical practice. Characterized by the deposition of immunoglobulin A (IgA) on vessel walls, this pathology can manifest in various ways, presenting a broad and sometimes complex clinical spectrum. Ninety percent of cases occur in the pediatric age group. Severe lung involvement, such as pulmonary hemorrhage, is rare in patients with IgAV. We present a case of a 33-year-old patient with pulmonary renal syndrome and without purpura, an atypical presentation of IgA vasculitis. Case Report We describe the case of a 33-year-old patient with no relevant medical history or regular medication, who presented to the emergency department in November 2022 with symptoms of hemoptysis, fatigue, myalgias, and pallor. On physical examination, the patient was conscious, cooperative, normotensive, tachycardic, afebrile, with bilateral axillary adenopathies, and scattered crackles on lung auscultation. Laboratory tests revealed anemia with a hemoglobin level of 5.8 g/dL, non-oliguric acute kidney injury with a creatinine level of 2.25 mg/dL, microscopic hematuria (>50/hpf), and proteinuria (UPCR of 2.8 mg/mg and UACR of 1.6 mg/mg). A chest CT scan showed bilateral and scattered ground-glass opacities consistent with alveolar hemorrhage. The patient was admitted to the Nephrology service, underwent 3 sessions of plasma exchange, and started therapy with methylprednisolone 1000 mg for 3 days. A renal biopsy revealed 24 glomeruli, with 3 showing segmental sclerosis and 1 with fibrocellular crescents, mild interstitial nephritis; immunofluorescence showed IgA+++, C3++, IgM, and IgG+- Oxford Classification: M1 E0 S1 T0 C1. Bronchofibroscopy showed a rosy bronchoalveolar lavage and macrophages with hemosiderin pigment deposition. The patient continued with prednisolone at 1 mg/kg. In January 2023 (after two months), there was a >25% reduction in albuminuria with resolution of acute kidney injury. A gradual reduction of prednisolone was initiated, and it was definitively discontinued in October 2023. In the last outpatient visit in January 2024, the patient maintained normal renal function, with no hematuria, UPCR of 100 mg/g, UACR of 70 mg/g, and no further episodes of alveolar hemorrhage. Conclusion This case stands out for its atypical presentation: an adult with alveolar hemorrhage and without other more classical manifestations of IgA vasculitis, such as purpura. This is yet another case that emphasizes the importance of the broad spectrum of diagnoses that a nephrologist should consider in the face of acute kidney injury.

#362 Dosing low, winning high: unlocking the promise of endothelin antagonism for the treatment of CKD in the zibotentan/dapagliflozin ZENITH trials

Abstract Background and Aims The Phase 2b ZENITH-CKD trial demonstrated that combined treatment with the endothelin A receptor (ETAR) antagonist zibotentan and the sodium-glucose co-transporter-2 inhibitor (SGLT2i) dapagliflozin yields a robust and significant reduction in albuminuria in individuals with chronic kidney disease (CKD), compared to dapagliflozin treatment alone [1]. This is hypothesized to translate into a significant reduction of kidney function decline and may further confer cardiometabolic benefits including reducing blood pressure, LDL cholesterol and (in type 2 diabetes) HbA1c in the ongoing Phase 3 ZENITH High Proteinuria trial. The usage of ETAR antagonists has until now been limited by the class effect of fluid retention, which is associated with an increased risk of heart failure in the at-risk CKD population. Zibotentan has previously been investigated at 10 mg per day in Phase 3 for the treatment of prostate cancer. Method Model-Informed Drug Development (MIDD) was integrated with clinical pharmacology data to develop the dose strategy for both ZENITH trials. A low-dose strategy was selected considering the increased plasma exposure of zibotentan in kidney impairment. The Phase 2b dose steps were selected based on an exposure response model for the efficacy marker urinary albumin to creatinine ratio (uACR) and were supported using clinical trial simulations. The dose strategy for Phase 3 was defined based on a combined analysis of ZENITH-CKD results for both efficacy and tolerability: efficacy (uACR reduction on top of dapagliflozin) was analysed with a Dose-Response Mixed Model for Repeated Measures, and tolerability (fluid retention events, defined as a combination of specified body weight and BNP increase) was evaluated with Kaplan Meier analyses. Results Zibotentan doses of 0.25 mg and 1.5 mg (in a first, discontinued study part also 5 mg), in combination with dapagliflozin 10 mg, were selected for ZENITH-CKD. Clinical trial simulations indicated that inclusion of the low dose of 0.25 mg was crucial to characterise the dose-response relationship. Dose-uACR response modelling of ZENITH-CKD data predicted a zibotentan dose of 0.75 mg to result in a mean uACR reduction of around 25% in addition to the reduction with dapagliflozin. A post-hoc regression analysis of uACR mean changes from baseline, stratified by dose, showed a trend towards lower uACR reduction with higher eGFR levels. Kaplan-Meier analyses of the fluid retention risk in different eGFR subgroups indicated that the fluid retention risk increased with increasing zibotentan dose for eGFR levels <45 mL/min/1.73 m2, while for higher eGFR levels, no differences were observed between treatments with dapagliflozin alone and added zibotentan 0.25 mg or 1.5 mg. Therefore, a kidney-function based zibotentan dose strategy was selected for the ZENITH High Proteinuria trial: Combined zibotentan/dapagliflozin is being compared against dapagliflozin alone; within the combination treatment arm, 0.25 mg zibotentan is selected for participants with baseline eGFR levels <45 mL/min/1.73 m2, and 0.75 mg is selected for higher eGFR level, with a tolerance eGFR window for participants whose eGFR declines below this cut-off, and with the possibility to reduce the dose to 0.25 mg in case of tolerability findings. Conclusion The favourable benefit/risk profile that was demonstrated for combined zibotentan/dapagliflozin in ZENITH-CKD was enabled by the zibotentan low-dose strategy. The wide dose ranging and MIDD further enabled selection of a kidney-function based zibotentan dosing strategy for ZENITH High Proteinuria which is designed to further balance benefit/risk. The low-dose zibotentan strategy and the combination with dapagliflozin opened for the first time a therapeutic window for ETAR antagonists, with the potential to redefine their value for the treatment of CKD. This work was sponsored by AstraZeneca.

#2043 Telitacicept in patients with IgA nephropathy

Abstract Background and Aims IgA nephropathy (IgAN) is typified by the renal deposition of IgA immune complexes. Advancements in understanding the pathogenesis of this disease have paved the way for innovative therapeutic approaches. Telitacicept is a fusion protein composed of transmembrane activator and calcium-modulating cyclophilin ligand interactor and fragment crystallizable portion of immunoglobulin G (IgG), which neutralizes the B lymphocyte stimulator and a proliferation-inducing ligand. We presented our single-center experience of treating IgAN with Telitacicept. Method Six patients with IgAN who received Telitacicept at the First affiliated hospital of Xi'an Jiaotong university between January 2023 and July 2023 were included in this retrospective study. All the patients had proteinuria ≥ 1.0 g/d despite optimal supportive therapy and received subcutaneous telitacicept 160 mg weekly. Clinical and laboratory parameters were evaluated before and after telitacicept treatment. Results Of all patients, there were 4 men and mean age was 35.2 ± 7.9 years. Table 1 shows baseline demographic characteristics of these patients. Before telitacicept administration, the mean serum creatinine was 133.2 ± 40.6 umol/L, median protein excretion was 2.23 (IQR, 2.05–3.54) g/d, and MAP was 97.9 ± 17.5 mmHg. After a median follow-up of 151 ± 91 days after telitacicept therapy, the mean proteinuria reduction percentage was 51.1% from baseline. The eGFR remained stable over time. The detailed laboratory parameters were shown in Table 2. No adverse events were observed during the follow-up. Conclusion Telitacicept treatment led to a clinically meaningful reduction in proteinuria in patients with IgAN. Larger prospective studies are needed to confirm these findings.

#851 Effects of gliflozins on endothelial cells: in vitro and clinical evidence

Abstract Background and Aims Gliflozins are a class drugs widely used in diabetes as they act as sodium-glucose co-transporter type 2 inhibitors (SGLT2i). Irrespective from glycaemic control, SGLT2i are known to possess kidney and heart protective effects. The kidney- and heart-protective effects of gliflozins (SGLT2i) have received different explanations because of their efficacy in non-diabetic patients. Indeed, the non-glycemic effects of SGLT2i are puzzling because SGLT2, the molecular target of gliflozins, is mainly expressed in proximal tubule cells, with very low expression levels in other cell types. Though SGLT2 inhibitors might be nephroprotective because of a reduction of eGFR, this mechanism seems insufficient to explain heart protection. Emerging evidence suggests that SGLT2i have off-target effects in endothelial cells. In this study, we analyze this assumption by testing the effects of gliflozins on endothelial cells in vitro and verifying a differential effect of gliflozins on glomerular diseases involving primarily the endothelial compartment vs those involving podocytes or both. Methods In vitro studies have been conducted on EA.hy926 cells. A dose-response curve of gliflozins on mitochondrial activity and cell viability has been obtained using MTT staining. Morphological parameters were obtained using phase contrast microscopy, and the details of the plasma membranes were studied using Atomic Force microscopy. Patients with IgA nephropathy, minimal change disease or Focal Segmental Glomerulo Sclerosis FSGS, and with diabetic nephropathy (n = 12 per group). were studied for the percent change in albuminuria and creatinine four months after gliflozin treatment (empagliflozin or dapagliflozin). Three additional control groups (IgA, podocytopathies, diabetes) without gliflozin treatment (n = 12 per group) were also included. Results Gliflozin treatment induced a dose-response improvement in EA.hy926 cells' survival and restoration of cell-cell borders in AFM images. In patients, the albuminuria was reduced by a similar extent (−38 ± 6%) in all groups when treated with gliflozins. However, in diabetic patients and podocytopathies, this was associated with decreased eGFR (−6% and −8%), whereas in IgA nephropathy, the eGFR levels were increased after treatment (+3.8%). Conclusion In vitro, gliflozins show a direct endothelial protection effect. In vivo, part of the effects on proteinuria may be explained by a hemodynamic effect on the glomerular filtration rate in diseases affecting podocytes (diabetes, MCD, FSGS), as shown by the increase in creatinine. However, for diseases involving the endothelium (IgA nephropathy), the endothelial protection effect of gliflozins is demonstrated by the reduction in proteinuria and the protective effect on creatinine levels.

#277 Update to the long-term safety and efficacy of iptacopan in C3G: 33-month extension study data from patients enrolled in a phase 2 study

Abstract Background and Aims Complement 3 glomerulopathy (C3G), due to dysregulation of the alternative complement pathway (AP), is an ultra-rare primary glomerulonephritis. Iptacopan (LNP023) is an oral, proximal complement inhibitor that specifically binds factor B and inhibits the AP. We previously reported the primary endpoint data from the Phase (Ph) 2 extension study (NCT03955445), showing proteinuria reduction (57% [p < 0.0001]) and estimated glomerular filtration rate (eGFR) improvement (by +6.83 mL/min/1.73 m2 [p = 0.0174]) from baseline, following 12 months (M) of treatment with iptacopan in patients with C3G. Here we present further long-term efficacy and safety data from patients with C3G and recurrent C3G (post-kidney transplantation), who completed 33M of treatment with iptacopan (NCT03955445). Method Adults with C3G disease (Cohort A) or C3G recurrence post-transplantation (Cohort B) received iptacopan 200 mg twice-daily (bid) for at least 12 weeks in the Ph2 study (NCT03832114) before entering the open label extension study (NCT03955445). Long-term efficacy was assessed by a number of renal endpoints, including a 2-component composite renal endpoint (eGFR stability [≤10% reduction] and ≥50% proteinuria reduction). Long-term safety and tolerability of iptacopan was continually monitored. Results Of 27 patients completing the Ph2 study (NCT03832114), 26 (16 Cohort A, 10 Cohort B) entered the extension study treatment with iptacopan 200 mg bid; 22 patients (14 Cohort A, 8 Cohort B) completed the 33M visit (i.e., 3M in the Ph2 study and 30M in the extension study). In Cohort A, 42.9% of patients met the 2-component composite renal endpoint criteria at 33M. Proteinuria (first morning void [FMV] urine protein–creatinine ratio [UPCR]) was reduced by 41% (p = 0.0097) compared to baseline. eGFR stabilized or improved in most patients (13/16) over time and change from baseline at the 33M time-point was −3.18 mL/min/1.73 m2 (p = 0.3512). C3 levels increased by 275% (p < 0.0001) from baseline. In Cohort B, eGFR change from baseline at the 33M time-point was −6.34 mL/min/1.73 m2 (p = 0.0571), and C3 levels increased by 102%. Baseline proteinuria values (FMV UPCR) were within the normal range for most participants in Cohort B and remained so during iptacopan treatment. Iptacopan was generally well-tolerated, and most adverse events were of mild severity in both cohorts. Biomarkers demonstrated substantial AP inhibition. Conclusion Long-term treatment with iptacopan was associated with sustained reduction in proteinuria in patients with C3G (Cohort A), and preservation of eGFR. These improvements in kidney function were associated with substantial inhibition of the AP leading to normalization of serum C3. Iptacopan was well-tolerated with no new safety findings in the long term, in patients with C3G, including those with recurrence post-transplantation on top of broad triple immunosuppression. The ongoing Ph3 APPEAR-C3G study (NCT04817618) is evaluating the efficacy and safety of iptacopan in patients with C3G.

#2457 Effect of belimumab in renal function and proteinuria in patients with lupus nephritis (LN): our experience

Abstract Background and Aims Belimumab was approved for systemic lupus erythematosus (SLE) after demonstrating its security and effectiveness in patients without renal activity. Recently it has been approved to treat LN [1, 2]. In this study, we analyse the experience of our centre with patients treated with Belimumab with any of the indications and renal SLE affectation. Method We retrospectively reviewed the clinical and analytical presentations and outcomes in patients diagnosed with SLE and treated with belimumab in our centre no matter the indication of the latest. We collected clinical, analytical, therapeutic and histological data of patients diagnosed with biopsy-proven LN and at least 6 months of follow-up and analyzed the evolution after belimumab was initiated. We excluded hemodialysis patients when analyzed renal function. We also reviewed clinical histories seeking potential complications related to belimumab. Results Our cohort includes 14 patients, 71% women, 71% Caucasian, 64% presented HTA and 14% were diabetic. Belimumab was initiated because of extrarenal manifestations in 43% of patients. The mean age at SLE and LN diagnosis was 31 and 36 years respectively, with a mean treatment length of 2.3 years; 71% of patients had class III or IV LN, 14% had V LN and 14% had III+V LN. Before its initiation, our cohort presented a mean SCr 0.8 mg/dL, 2g/g proteinuria, anti-DNA 172 UI/mL, C3 91 mg/dL, C4 21 mg/dL, mean SLEDAI 28.3. Of patients, 71% were under chloroquine, 93% under oral steroids (mean dose 10 mg/day), 93% under MPA (mean dose 1004 mg/day) and 43% under calcineurin inhibitors (CNI). After 6 months mean creatinine was 0.7 mg/dL, proteinuria diminished to 1.5 g/g (p < 0.025), anti-dsDNA were 87UI/mL, C3 was 88.5 and C4 32.7 mg/dL respectively; and after 12 months, creatinine was 0.87 mg/dL, proteinuria was 1.44g/g, anti-dsDNA were 148UI/mL, C3 was 99 and C4 24.7 mg/dL respectively and mean SLEDAI score was 7.1. After one year 66.67% of patients were under chloroquine, 88.89% under corticosteroids (mean dose 6 mg/day), 77.8% under MPA and 33.3% under CNI. After follow up we had 1 death with no secondary effects related to belimumab and reduction in proteinuria kept a trend but was no longer significative (p = 0.052). Belimumab was stopped in 5 patients, 2 of them before their inclusion in a CAR-T programme, 2 of them temporally when diagnosed with endocarditis and 1 of them after the finish of the protocol. Conclusion Our study has several limitations, mostly its reduced sample size. In our cohort, belimumab initiation is related only to a reduction of proteinuria after 6 months, but the most important aspect of this analysis may be that it proved to be safe and allowed clinicians to withdraw or reduce other immunosuppressive drugs to avoid their chronic toxicity with no undesirable side effects.

#2284 Clinical characteristics and renal survival of patients with monoclonal gammopathy of renal significance (MGRS)

Abstract Background and Aims Monoclonal gammopathy of renal significance (MGRS) comprises a diverse group of renal disorders related to a nephrotoxic monoclonal immunoglobulin. Due to the rarity of the disease and the recent definition of MGRS-associated kidney lesions, data about long-term clinical outcomes remain limited. Method A single-center, retrospective cohort study was conducted including data of all patients with biopsy-proven MGRS who were followed at our center between 2005 and 2023. We examined the clinicopathologic characteristics and renal survival of the patients. Disease progression was defined as an eGFR decline >30% or end-stage kidney disease (ESKD). Univariate Cox regression analysis was used to assess the relationship between clinical features and disease progression. Results A total of 23 adults (males 43.5%) with a median age of 65 years (IQR 55-70) were included in our study. At presentation, median eGFR was 51 ml/min/1.73 m2 (IQR 40-80) and proteinuria 3.94 g/24 h (IQR 2.00-6.26). Serum or urine monoclonal protein was not detected in 4 patients (18.2%). MGRS-associated renal lesions included Ig-related amyloidosis (n = 8), monoclonal immunoglobulin deposition disease (n = 7), cryoglobulinemic glomerulonephritis (n = 2), C3 glomerulopathy (n = 2), proliferative glomerulonephritis with monoclonal IgG deposits (n = 1), immunotactoid glomerulopathy (n = 1) and miscellaneous (n = 2). Most patients were treated with a plasma cell-directed regimen (77.3%) and the rest with B-cell-directed (13.6%) or conservative therapy (9.1%). Median follow-up for the cohort was 45 months (IQR 27-67). Thirteen patients responded to treatment (52.1%), achieving a reduction in proteinuria (0.44 vs 3.94 g/24 h, p:001) and maintenance of eGFR (60 vs 56 ml/min, p:0.363) at the last follow-up visit. All responders had received clone-directed therapy. Disease progression occurred in 8 patients (34.8%), three of whom reached ESKD (13.0%). Renal survival, defined as survival without ESKD, was 84.6% at 48 months (CI 73.3-101.7). Factors that were associated with disease progression were Ig-related amyloidosis (HR: 6.94, CI: 1.30-36.84, p:0.023) and eGFR < 45 ml/min at diagnosis (HR: 14.73, CI: 1.62-132.95, p:0.017). Conclusion MGRS is a heterogeneous clinical entity manifesting with varying degrees of proteinuria and kidney injury. Impaired kidney function at diagnosis and Ig-related amyloidosis correlated with worse renal prognosis in our cohort. Early identification and clone-directed treatment of MGRS may improve long-term renal survival.

#388 IONIS-FB-LRx, an antisense oligonucleotide to complement factor B for treatment of IgA nephropathy

Abstract Background and Aims Pathogenesis of IgA nephropathy (IgAN) is known to be dependent upon multiple factors, one being the complement system. Since overactivity of the complement Alternative Pathway (AP) has been proposed to contribute to pathogenesis of IgAN, it has been hypothesized that a reduction of AP activity would improve proteinuria. IONIS-FB-LRx, (ISIS696844, RO7434656), is an investigational antisense oligonucleotide targeting complement factor B (CFB) mRNA and reduces CFB production in the liver. We have previously demonstrated that administration of IONIS-FB-LRx lowered the production of CFB, a required component of the AP, and led to reduction of AP and reduction in proteinuria in IgAN patients (2023 ASN Abstract#SA-PO926, N = 13 patients). Current abstract provides an update to our previous report extending results to 19 patients treated with IONIS-FB-LRx. Method An exploratory, single-arm, multi-national open-label Ph2 study (NCT04014335) recruited patients with biopsy-confirmed IgAN, proteinuria >1.5 g/d, eGFR >40 mL/min/1.73 m2, and hematuria despite maximum tolerated RAAS blockade and/or stable dose of SGLT-2 inhibitor for a minimum of 6 months. Study drug was administered at Weeks 1, 3, and 5, and then every 4 weeks through Week 25 (Cohort A) and at Week 1 and then every 4 weeks through Week 25 (Cohort B). Primary outcome was change in 24-hr proteinuria at Week 29 (4 weeks after last dose) compared to baseline (BL). Results 19 patients have completed study to date (13Nov2023), 25-62 yr, 42% Female, 11 Asian, and 8 White. Median 24-hr UPCR at BL was 1.56 g/g (IQR 1.23, 2.33 g/g). At Week 29, a 45% geometric mean ratio reduction was observed. There was little change in eGFR at Week 29 compared to BL (mean ± SD; BL 72 ± 22; Week 29 74.6 ± 20 mL/min/1.73 m2). The drug demonstrated an acceptable safety profile with no Treatment Emergent SAEs; the only clinically meaningful laboratory finding was reversible and transient ALT elevation without a change in bilirubin. All patients completed the study and one patient discontinued study drug after 4 months to initiate SGLT-2 inhibitors. That patient experienced a 38% reduction in 24-hr UPCR collected 3 weeks (Week 27) after the last dose of IONIS-FB-LRx, but prior to use of SGLT-2 inhibitors. Conclusion This Ph2 open-label study provides continuing clinical evidence that IONIS-FB-LRx reduces complement levels and proteinuria in patients with IgAN, supporting Ph3 development (NCT05797610) to determine the potential of IONIS-FB-LRx to reduce the progression of IgAN.

#425 Felzartamab (anti-CD38) in patients with IgA Nephropathy—interim results from the IGNAZ study

Abstract Background and Aims Most patients with IgA nephropathy (IgAN) will progress to kidney failure within 10-15 years of diagnosis. Sustained proteinuria is the best predictor of adverse long-term kidney outcomes and is a surrogate marker for efficacy. CD38+ plasma cells are likely the main source of pathogenic Gd-IgA1, and the related autoantibodies in IgAN. Felzartamab (felza; HIB202) is a recombinant purified human immunoglobulin G1 (IgG1) monoclonal antibody (mAb) that binds to CD38 on plasma cells and is being studied across immune-mediated kidney diseases such as IgAN, Primary Membranous Nephropathy, Lupus Nephritis, and Antibody Mediated Rejection. The primary aims of the IGNAZ study were to assess: 1) efficacy of felza compared to placebo on urine protein:creatinine ratio (UPCR) and estimated glomerular filtration rate (eGFR) change from baseline, and 2) the relationship between exposure, safety, and efficacy in each of 3 dose groups vs. placebo. Interim results with 15 months of follow-up from this 24-month trial are presented. Method In Part 1, 48 IgAN subjects were randomized in a 1:1:1:1 ratio across a placebo and 3 active arms in this multicenter, double-blind placebo-controlled, phase IIa trial. The M1, M2, and M3 active arms received 2 doses in 15 days, 5 doses in 2 months, and 9 doses in 5 months, respectively. In Part 2, 6 Japanese subjects received the M3 regimen, open-label, and have been followed for 9 months. Key inclusion criteria included ages 18-80 years, biopsy confirmed diagnosis of IgAN within the past 8 years, proteinuria at screening ≥1.0 g/d, eGFR ≥30 ml/min/1.73 m2 (by CKD-EPI), and background stable and maximally tolerated renin angiotensin system inhibitors. Results 48 randomized subjects were enrolled at 28 sites in the US and in 14 different countries in Europe and in Asia, of which 46 completed the treatment phase. Mean (SD) baseline characteristics (Parts 1 and 2 combined): age 41.6 (12.3) yrs, UPCR 1.67 (1.0) g/g, eGFR 74.6 (30.3) ml/min/1.73 m2. 67% of subjects were male. Intention-to-treat with felza demonstrated rapid, clinically meaningful reductions in UPCR with the maximal treatment effect being observed in the M3 9-dose regimen. In Part 1, percentage change from baseline in UPCR was −14% for placebo and −25% for M3 9-dose arm at month 3, and +9% for placebo and −35% for M3 at month 6 (Fig. A). Reductions in proteinuria observed at month 6 persisted until Month 15, 10 months after the last dose: +6% and −38% mean UPCR change from baseline for placebo and the M3 9-dose arm, respectively (Fig. B). Relatively stable eGFR values were observed for the felza arms compared to loss of eGFR in the placebo arm. Rapid, durable reductions in IgA and Gd-IgA1 levels were seen across the dosing arms, with reductions lasting 10 months after the last dose (Fig. C). IgG recovery occurred faster off-treatment than IgA. Results in the Part 2 subjects were similar to the Part 1 M3 cohort through 9 months. There were no apparent dose-dependent adverse events and no exposure-safety relationship. Treatment-emergent adverse events (TEAEs) were generally of mild or moderate intensity or toxicity grade. The most common TEAE assessed as related by study investigator was infusion related reactions (IRR), most of which occurred on the first infusion. There was one treatment-related serious AE due to an IRR. Five subjects discontinued treatment due to IRRs or drug hypersensitivity; for four of the five subjects, the infusion rate was higher than protocol-specified or had an error in pre-medication. TEAE infections were comparable between placebo and felza arms: Placebo (33.3%), M1 (33.3%), M2 (36.4%), M3 (38.5%), Part 2 (50.0%); all were Grades 1 or 2, and non-serious. Conclusion This proof-of-concept study highlights the potential for disease modification in IgAN with the anti-CD38 mAb felza and supports continued research as a potential treatment for high-risk IgAN patients. Felza treatment resulted in clinically meaningful, prolonged UPCR reductions and eGFR stabilization sustained ≥10 months after dosing was completed. Felza was generally well tolerated with rapid recovery of IgG with durable reductions in IgA and pathogenic Gd-IgA1 levels.

#1021 A phase 3 randomized controlled trial of ravulizumab in adult patients with IgA nephropathy

Abstract Background and Aims The pathogenesis of IgA nephropathy (IgAN) includes the deposition of immune complexes in the kidney and activation of the complement system. Complement components, including C5a (anaphylatoxin) and C5b-9 (membrane attack complex), are generated leading to mesangial inflammation and glomerular injury [1]. Ravulizumab, a humanized monoclonal antibody, is a long-acting complement C5 inhibitor that provides immediate, complete, and sustained inhibition of the terminal complement pathway, thereby targeting a key component of the pathophysiology of IgAN. A phase 2 study of ravulizumab (NCT04564339) demonstrated a rapid effect and significant reduction in proteinuria compared with placebo at week 26 (change from baseline in 24-hour urine protein to creatinine ratio [UPCR] –40.3% vs –10.9%), and treatment was well-tolerated [2]. This abstract describes the study design of the planned phase 3 trial of ravulizumab in adult patients with IgAN. Method This phase 3, randomized, double-blind, placebo-controlled trial (I CAN) will evaluate the efficacy and safety of ravulizumab (IV; weight-based dosing Q8W) in adults with IgAN. Eligibility criteria include a diagnosis of primary IgAN based on kidney biopsy at any point, estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m2 at screening, and UPCR ≥0.75 g/g or urine protein ≥1.0 g/day (Table 1). The study consists of a 6-week screening period, followed by randomization (1:1) of participants to ravulizumab or placebo and a 2-year blinded treatment period (Fig. 1); all patients receive a stable and maximally tolerated dose of renin-angiotensin system inhibitor therapy. Approximately 450 patients will be randomized, stratified by proteinuria (<2 g/g vs ≥2 g/g), eGFR (<45 vs ≥45 mL/min/1.73 m2), and SGLT2i use (yes/no). The co-primary endpoints are change from baseline to week 34 in 24-hour UPCR evaluated on the log scale and the annualized total eGFR slope over 106 weeks. The sample size for the proteinuria endpoint of n = 204 will provide ∼90% power to detect a 35% relative treatment effect in UPCR at week 34 at a one-sided significance level of 0.005. The total sample size of n = 450 for the eGFR endpoint will provide ∼90% power to detect a difference in total annualized eGFR slope of 2.2 mL/min/1.73 m2 at week 106 at a one-sided significance level of 0.025. An open-label exploratory cohort (n = 20) with eGFR 20-29 mL/min/1.73 m2 and with kidney biopsy within 6 months of or during screening will be enrolled and analyzed separately from the main cohort. At completion of the blinded treatment period, all study participants will have the option to enter an open-label ravulizumab access period for up to 2 years. Results The co-primary endpoints are the change in 24-hour UPCR at week 34 and the annualized total eGFR slope over 106 wks. Secondary and exploratory endpoints include change in 24-hour UPCR at weeks 10, 26, 50, and 106, a composite kidney failure endpoint over 106 weeks, reduction in 24-hour UPCR ≥50% from baseline, time to UPCR <1 g/g and <0.3 g/g, and patient reported outcomes on fatigue, quality of life, and work-related productivity. Safety, tolerability, immunogenicity, pharmacokinetics, and pharmacodynamics will be evaluated. Conclusion Through immediate, complete, and sustained inhibition of C5, ravulizumab targets the pathophysiology of IgAN and has the potential to provide a disease modifying treatment option. This pivotal phase 3 study (I CAN) will evaluate the efficacy of ravulizumab in patients with IgAN who are at high risk of disease progression. The trial will evaluate effects on proteinuria and eGFR that may translate to long term kidney function preservation and provide a rapidly acting treatment option for patients living with IgAN.

#1324 The antiproteinuric effect of Gliflozins is associated with the mitochondrial density of endothelial cells in diabetic patients

Abstract Background and Aims The sodium-glucose co-transporter type 2 inhibitors (SGLT2i) such as dapagliflozin and empagliflozin, are a new class of nephro- and cardio-protective drugs in diabetic and non-diabetic patients. SGLT2 is greatly expressed in the proximal tubule cells, and therefore the protective effects of gliflozins are thought to be mediated by a hemodynamic mechanism on glomerular hyperfiltration. However, they could be acting also in other cell types, particularly in diabetic patients, because hyperglycemia induces the expression of SGLT2 in endothelial cells, mesangial cells, cardiomyocytes, etc. Because SGLT2 changes the intracellular concentration of sodium and glucose, gliflozins may indirectly change mitochondrial swelling and activity. In this study, we have tested the hypothesis that gliflozins act on mitochondria in patients suffering from diabetes. Method We have analyzed kidney biopsies from diabetic patients in treatment with a gliflozin (n = 10) or without gliflozin treatment (n = 10) stained with fuchsin red, which gives a color intensity proportional to mitochondrial content. Clinical variables (albumin-creatinine ratio (ACR), blood pressure, eGFR, glycated albumin) have been measured before and after 4 months of treatment. Images have been acquired using a Zeiss Axioscope with 100x objective and analyzed using ImageJ software to quantify staining intensity (expressed as optical density) after background subtraction. Two different cell types have been considered: proximal tubule cells and endothelial cells in glomeruli. Only non-sclerotic glomeruli have been considered. Results The systolic blood pressure was linearly correlated to the intensity of staining of mitochondria in the proximal tubule cells in all patients irrespective of gliflozin treatment. In non-treated diabetic patients, the mitochondrial content of endothelial cells was not related to the extent of ACR reduction over time. In diabetic patients treated with gliflozins, the extent of ACR reduction after treatment was correlated with the intensity of mitochondrial staining in glomerular endothelial cells. This correlation was not present in proximal tubule cells. Gliflozin treatment may induce a change in the mitochondrial content of endothelial cells, particularly in patients responding with a reduction in proteinuria. Conclusion Proteinuria in diabetic patients depends on damage in both the endothelial and podocyte compartments. Gliflozins may improve proteinuria by a hemodynamic mechanism; however, our data suggest an effect of gliflozins specific on mitochondria of the endothelial cells in the glomeruli, which is proportional to their anti-proteinuric effect. Though we do not analyze the mechanism of gliflozins on mitochondria, it is possible to speculate that the changes of intracellular sodium-induced by gliflozins may induce an altered mitochondrial activity.