# IgA nephropathy clinical trial developments > Live situation record from CLSTR: https://clstr.news/situations/iga-nephropathy-clinical-trial-developments > Updated: 2026-10-27T13:48:00.000Z. Sources: 9. Developments: 2. Recent clinical trial results have demonstrated progress in treating IgA nephropathy (IgAN) through different therapeutic approaches. In the phase 3 RAINIER trial, the investigational dual inhibitor povetacicept showed a significant reduction in proteinuria. Interim results indicated that participants receiving 80 mg every four weeks achieved a 52.0% reduction in the 24-hour urine protein-to-creatinine ratio at week 36, compared to a 4.3% reduction in the placebo group. The study also noted a reduction in galactose-deficient IgA1 levels and the resolution of hematuria in 85% of applicable participants. Separately, final 24-month results from Otsuka Pharmaceutical’s phase 3 Visionary study regarding sibeprenlimab reported a 97.1% reduction in the risk of composite renal outcomes, such as renal function decline or failure, compared to a placebo. This study is noted as the first phase 3 IgAN trial to meet the KDIGO 2025 therapeutic goal of slowing renal function decline to near-physiological levels. ## Timeline ### 2026-10-27: Otsuka Pharmaceutical reports kidney function preservation in IgAN study Otsuka Pharmaceutical's phase 3 Visionary study shows sibeprenlimab reduces the risk of composite renal outcomes by 97.1% in adults with primary IgA nephropathy. 5 sources. https://clstr.news/cluster/otsuka-pharmaceutical-reports-kidney-function-preservation-in-igan-study ### 2026-10-25: Povetacicept shows significant proteinuria reduction in IgA nephropathy trial Phase 3 RAINIER trial interim data shows povetacicept reduced proteinuria by 52% in adults with IgA nephropathy at week 36, significantly outperforming the placebo group. 3 sources. https://clstr.news/cluster/povetacicept-shows-significant-proteinuria-reduction-in-iga-nephropathy-trial --- Cite as: IgA nephropathy clinical trial developments. CLSTR, https://clstr.news/situations/iga-nephropathy-clinical-trial-developments