Twelve-month real-world outcomes of sparsentan in a multicenter Spanish IgA nephropathy cohort.

Background: Sparsentan has demonstrated significant antiproteinuric effects in randomized trials of IgA nephropathy (IgAN). However, real-world evidence remains scarce and is largely limited to short-term follow-up. Data on the durability of the antiproteinuric response in routine clinical practice are still lacking. Methods: This multicenter retrospective study included patients with biopsy-proven IgAN treated with sparsentan in routine clinical practice across Spanish centers. Patients were eligible if they initiated sparsentan outside a clinical trial and had at least 3 months of follow-up. The primary outcome was the proportion of patients achieving a >50% reduction in proteinuria at 3 months (responders). Secondary outcomes included changes in proteinuria and kidney function at 6 and 12 months, as well as safety. Results: A total of 41 patients were included. The median age was 42 years, with a median baseline estimated glomerular filtration rate (eGFR) of 44 ml/min/1.73 m Conclusions: In this multicenter real-world Spanish cohort, sparsentan was associated with a sustained reduction in proteinuria in patients with biopsy-proven IgAN, maintained up to 12 months, along with preserved kidney function even in those with moderately reduced baseline eGFR, and a favorable safety profile. These findings support the effectiveness of sparsentan on top of contemporary standard of care and provide early evidence of sustained benefit in routine clinical practice.