WCN26-3819 UPDATE TO THE LONG-TERM EFFICACY AND SAFETY OF IPTACOPAN IN C3 GLOMERULOPATHY: 39-MONTH PHASE 2 EXTENSION STUDY DATA

associated IgAN were observed (eGFR 74.2 27.5 vs 80.0 21.4 mL/ min/1.73m 2 , p=0.44; proteinuria 0.76 [0.46-1.70]vs 0.72 [0.50-1.08]g/gCr, p=0.62).The IBD group had a higher proportion of males (93%, p<0.001) and higher serum IgA levels (587 [435-632] mg/dL, p<0.001).Treatment frequencies were comparable for RAS inhibitors (96.0% vs. 86.7%,p=0.17), corticosteroids (74.3% vs. 80.0%, p=0.76), and tonsillectomies (80.2% vs. 60.0%,p=0.10).No differences were observed in the Oxford MEST-C scores.Among patients with IBDassociated IgAN, Crohn's disease and ulcerative colitis accounted for 73.3% and 26.7%, respectively.At the time of renal diagnosis, 86.7% of the patients had inactive IBD.At 2 years, the reduction rate in proteinuria was similar (-77.6%[-87.1 to -57.8] vs -85.2% [-95 to -50], p=0.36), and no difference was observed in the eGFR slope (-2.54 [-5.25 to 1.36] vs -1.03 [-6.52 to -0.54] mL/min/1.73m 2 / year, p=0.93).In multivariate analysis, the eGFR slope was independently associated with: baseline eGFR (=-0.49,p<0.001), baseline proteinuria (=-0.20,p=0.049), tonsillectomy (=0.32,p=0.02), segmental sclerosis (S lesions; =-0.21,p=0.048), but was not associated with IBD status (=0.13,p=0.23).Urinary protein remission rates based on the Oxford classification did not differ between MEST-C classifications.Cox regression analysis revealed no association between IBD and cumulative urinary protein remission rates (Hazard ratio, 1.14; 95% confidence interval, 0.53-2.45;p=0.7).Conclusion: In this Japanese cohort, patients with IBD-associated IgAN showed clinical features, treatment responses, and renal outcomes comparable to those without IBD.These findings suggest that the coexistence of IBD does not adversely affect renal prognosis if intestinal inflammation is adequately controlled and evidence-based IgAN therapy is administered.I have no potential conflict of interest to disclose.I did not use generative AI and AI-assisted technologies in the writing process.