Abstract: TH-PO0522
Real-World Use of Iptacopan in Treatment-Resistant Crescentic IgAN
Session Information
- Glomerular Diseases: IgAN, IgA Vasculitis, and More
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Parkinson, William M., Brooke Army Medical Center, Joint Base San Antonio Fort Sam Houston, Texas, United States
- Nassar, Tareq Issa, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States
- Kanduri, Swetha Rani, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States
Introduction
IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide and may progress to kidney failure in up to 30-40% of patients. Crescentic IgAN is associated with rapidly progressive kidney dysfunction and is associated with limited treatment options when refractory to corticosteroids and conventional immunosuppressive therapy. We report successful use of iptacopan, a factor B inhibitor targeting the alternative complement pathway in steroid resistant crescentic IgAN.
Case Description
A 25-year-old woman presented for a second opinion for progressive biopsy-proven crescentic IgAN refractory to multiple therapies. Serum creatinine rapidly increased from 2.3 to 3.1 mg/dL with proteinuria of 650 mg/mg and BUN 54 mg/dL. Kidney biopsy demonstrated crescentic IgAN with Oxford classification score M2E0S1T1C1, including 19/45 globally sclerosed glomeruli, marked mesangial hypercellularity, one cellular crescent and moderate interstitial fibrosis/tubular atrophy. Immunofluorescence showed 3+ IgA and 3+ C3 staining with mesangial and capillary loop deposits, suggesting significant complement activation. The patient was initially treated with high dose corticosteroids followed by budesonide without meaningful improvement. Rituximab, mycophenolate mofetil and tacrolimus were subsequently attempted with minimal benefit. Cyclophosphamide was discussed but declined because of fertility concerns. Given progressive disease and significant complement staining on biopsy, iptacopan was initiated. After 5 months of therapy, proteinuria and renal function improved, with serum creatinine decreasing to 1.8 mg/dL.
Discussion
Refractory crescentic IgAN remains difficult to treat. Increasing evidence supports a central role for alternative complement pathway activation in IgAN pathogenesis. Iptacopan selectively inhibits factor B, blocking amplification of the alternative complement cascade. This case highlights the potential role of complement targeted therapy in treatment resistant crescentic IgAN, particularly in patients with prominent C3 deposition and failure of conventional immunosuppressive therapy.