Kidney Week

Abstract: TH-PO0497

Early Real-World Experience with Sibeprenlimab in IgAN

Session Information

• Glomerular Diseases: Clinical, Outcomes, and Therapeutics Research - IgAN
  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

• Efe, Orhan, Massachusetts General Hospital, Boston, Massachusetts, United States

Orhan Efe, MD

• Seethapathy, Harish Shanthanu, Massachusetts General Hospital, Boston, Massachusetts, United States

Harish Shanthanu Seethapathy, MD, MBBS

• Chadha, Ashima, Massachusetts General Hospital, Boston, Massachusetts, United States

Ashima Chadha, MD

• Aaron, Sydney, Massachusetts General Hospital, Boston, Massachusetts, United States

Sydney Aaron

• Laliberte, Karen A., Massachusetts General Hospital, Boston, Massachusetts, United States

Karen A. Laliberte, RN

• Niles, John L., Massachusetts General Hospital, Boston, Massachusetts, United States

John L. Niles, MD

• Al Jurdi, Ayman, Massachusetts General Hospital, Boston, Massachusetts, United States

Ayman Al Jurdi, MD, MPH, FASN

Background

Sibeprenlimab has received accelerated approval by the FDA for IgA nephropathy (IgAN) patients who are at risk for progression. Real-world experience regarding its use in IgAN is not available.

Methods

This is a case series of IgAN patients who started sibeprenlimab from November 2025 to May 2026 at Mass General Brigham Vasculitis and Glomerulonephritis Center, Boston. Baseline patient characteristics were collected, and efficacy and safety outcomes are currently being monitored. IgAN patients, including those who have Henoch-Schonlein Purpura (HSP), with any eGFR and UPCR were included.

Results

A total of 21 patients were started on sibeprenlimab, including 2 patients with HSP. Median age was 44 (IQR 35 – 59) years, and 29% (6/21) were female. Baseline median creatinine and eGFR were 1.84 (IQR 1.46 – 2.86) mg/dL and 41 (21 – 55) ml/min/1.73 m², and UPCR was 1.22 (0.79 – 1.52) g/g. 48% (10/21) had eGFR <30 ml/min/1.73m² and 48% (10/21) had UPCR <1 g/g at baseline. Hematuria of 1+ or higher was present 57% (12/21). Baseline MEST-C scores based on the most recent kidney biopsy comprised M1 in 78%, E1 in 58%, S1 in 85%, T1-2 in 61%, and C1-2 in 52%. In 29% (6/21), sibeprenlimab was combined with other immunosuppressive agents, including iptacopan (n=3), steroid taper (n=2), and steroid taper and mycophenolate mofetil (n=1). 86% (18/21) were exposed to other disease-modifying therapies before sibeprenlimab. All but one patient were on angiotensin receptor blockers and/or SGLT-2 inhibitors, and 24% (5/21) were on an endothelin receptor antagonist at the time of sibeprenlimab initiation. Adverse events, immunoglobulin levels, eGFR, proteinuria, and hematuria are currently being monitored and will be reported at ASN Kidney Week.

Conclusion

This study will show the real-world efficacy and safety of sibeprenlimab as a mono- and combination therapy in IgAN, including patients with features that were excluded from clinical trials.