Effectiveness and Safety of Nefecon in Primary IgA Nephropathy Across Different Baseline Proteinuria Levels: A Real-World Study.

INTRODUCTION: IgA nephropathy (IgAN) is a chronic autoimmune kidney disease characterized by the deposition of immune complexes containing galactose-deficient IgA1 (Gd-IgA1) in the glomerulus. Nefecon is a targeted-release formulation of the budesonide that reduces excess production of Gd-IgA1. This study aimed to evaluate the real-world effectiveness and safety of nefecon across different baseline proteinuria levels in this disease population. METHODS: In this retrospective real-world study, 28 patients with IgAN who received nefecon for more than 9 months were consecutively included between September 2024 and March 2025. Data on demographics and clinical characteristics, outcomes, and safety were collected and analyzed. RESULTS: After 9 months of nefecon treatment, proteinuria reduced from 1.7 ± 1.2 to 0.6 ± 0.5 g/day (55.8% reduction), while estimated glomerular filtration rate improved from 80.3 ± 24.6 to 86.2 ± 25.4 mL/min/1.73 m2 (5.0% increase). Nefecon appeared to preserve renal function across patients with varying baseline proteinuria levels, with signals of greater benefit when initiated earlier in the disease course. Seventeen patients (60.7%) experienced adverse events (AEs), with the most common events being acne (21.4%). No severe AEs or treatment-related deaths were observed. CONCLUSION: In the real-world practice, nefecon was associated with favorable antiproteinuric and renal benefits with acceptable safety in patients with IgAN, including those with relatively low baseline proteinuria. This study suggests a potential benefit of early intervention following diagnosis.