First Successful Treatment of a Patient with a Primary Immune Complex-Membranoproliferative Glomerulonephritis with Iptacopan: A Case Report

ntroduction:Nowadays, there is insufficient evidence for the recommendation of managementpatients with a primary membranoproliferative glomerulonephritis (MPGN). A better under-standing of the pathogenesis has led to the reclassification of primary MPGN and distinction intothe two main entities of either primary immune complex-MPGN or C3 glomerulopathy. Bothentities share overlapping pathophysiological features with complement alternative pathway (AP)dysregulation. Iptacopan is an oral inhibitor of the complement factor B that effectively blocks thecomplement AP.Case Presentation:We report thefirst successful treatment of a 47-year-oldman suffering from a primary immune complex-MPGN with iptacopan. So far establishedimmunosuppressive therapies with prednisone and mycophenolate mofetil failed to controlthe currentflare of the disease, mainly presenting with impaired kidney function andproteinuria within the nephrotic range. However, 3 months after starting the treatment withiptacopan urine protein-creatinine ratio decreased impressively to a level of 100-150 mg/mmol.Thereafter, low-level proteinuria and kidney function remained stable during follow-up. Do date,the treatment with iptacopan is continued as a monotherapy and is well tolerated.Conclusion:Tothe best of our knowledge, this is thefirst case report which suggests that iptacopan may be aninteresting treatment option for primary immune complex-MPGN.(c) 2024 The Author(s).Published by S. Karger AG, Basel