Mechanistic Evaluation of Atrasentan in Patients With IgA Nephropathy (IgAN)

This multicenter, single-arm, open-label Phase 4 pilot study evaluates the effects of atrasentan added to optimized supportive care on kidney structure and function in adults with biopsy-confirmed IgA nephropathy. Approximately 20 participants will receive atrasentan 0.75 mg orally once daily for 52 weeks. Kidney multiparametric MRI is performed at baseline, 6 months, and 12 months, with blood and urine biomarker assessments throughout treatment. An optional nested cohort of up to 5 participants undergoes native kidney biopsy at baseline and 12 months.