Kidney Week

Abstract: SA-OR047

Duration of Absolute Proteinuria Response with Nefecon in Patients with Primary IgAN: Results from the Two-Year NefIgArd Trial

Session Information

• Glomerular Targeted Therapies: The New Era
  November 08, 2025 | Location: Room 310A, Convention Center
  Abstract Time: 04:40 PM - 04:50 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Rovin, Brad, Division of Nephrology, The Ohio State University Wexner Medical Center, Columbus, Ohio, United States

Brad Rovin, FASN

• Reich, Heather N., Division of Nephrology, University Health Network, Department of Medicine, University of Toronto, Toronto, Ontario, Canada

Heather N. Reich, MD, PhD

• Lafayette, Richard A., Division of Nephrology, Department of Medicine, Stanford University, Stanford, California, United States

Richard A. Lafayette, MD

• Jones, Russell, Calliditas Therapeutics AB, Stockholm, Sweden

Russell Jones, MSc

• Barratt, Jonathan, College of Life Sciences, University of Leicester, Leicester, United Kingdom

Jonathan Barratt, MBChB, PhD

Background

Proteinuria reduction is a surrogate marker of improved kidney outcomes in immunoglobulin A nephropathy (IgAN), and the Kidney Disease: Improving Global Outcomes (KDIGO) 2021 guidelines consider an absolute reduction to <1 g/day a “reasonable treatment target.” Data from the 2-year placebo-controlled NefIgArd trial have shown sustained relative reductions in the urine protein–creatinine ratio (UPCR) from baseline with nefecon, a targeted-release budesonide formulation, in patients with IgAN (Barratt J, et al. ERA 2025 [abstract]). Here, we present NefIgArd data evaluating the effect of nefecon versus placebo on sustained absolute proteinuria response.

Methods

In this Phase 3 trial, adults with IgAN, estimated glomerular filtration rate (eGFR) 35–90 mL/min/1.73 m², and UPCR ≥0.8 g/gram despite optimized renin–angiotensin system inhibition (RASi), were randomized to receive nefecon 16 mg/day or placebo for 9 months, followed by 15 months off treatment. Optimized RASi was maintained throughout. Proportions of patients maintaining an absolute UPCR response, defined as UPCR ≤1 g/gram, for ≥6, ≥9, ≥12, and ≥18 months were determined.

Results

Among nefecon-treated patients, 72% maintained an absolute UPCR response for ≥9 months, compared with 38% of patients in the placebo group (Table). Furthermore, 46% of patients receiving nefecon maintained an absolute UPCR response for ≥18 months compared with 21% of patients receiving placebo.

Conclusion

Almost three-quarters of nefecon-treated patients maintained UPCR at or below the 1 g/gram threshold for at least 9 months, and almost half for at least 18 months. These data show that nefecon treatment enables a substantial proportion of patients to achieve absolute target proteinuria levels for sustained periods and experience improved kidney outcomes.

Proportion of patients experiencing an absolute UPCR response (defined as UPCR ≤1 g/gram) for at least 6, 9, 12, and 18 months

Funding

• Commercial Support – Calliditas Therapeutics

Digital Object Identifier (DOI)

• doi: 10.1681/ASN.2025e6h5trrj