ERA 2025: Sibeprenlimab Halves Proteinuria in IgAN in Phase 3 VISIONARY Trial

Interim Phase 3 VISIONARY trial data presented at ERA 2025 showed Otsuka Pharmaceutical's sibeprenlimab resulted in a 51.2% reduction in proteinuria at 9 months compared to placebo in IgA nephropathy patients. The study, involving 320 patients, supports the BLA filing for sibeprenlimab, which has received priority review with a target action date of November 28, 2025. Safety data was reassuring, with fewer treatment-emergent adverse events in the sibeprenlimab group.

Analysis

Interim data from the Phase 3 VISIONARY trial, presented at the ERA 2025 Congress, demonstrated that Otsuka Pharmaceutical's sibeprenlimab achieved a statistically significant 51.2% placebo-adjusted reduction in proteinuria at 9 months among 320 patients with IgA nephropathy (IgAN). This robust efficacy, observed in what is reported as the largest Phase 3 IgAN trial to date (total enrollment 530 patients), supports the company's Biologics License Application (BLA) filed in October 2024. The FDA has subsequently accepted this BLA, granted it priority review, and set a target action date of November 28, 2025. Notably, proteinuria reduction, a key predictor for long-term prognosis in IgAN, was observed as early as 4 weeks with sibeprenlimab. The safety profile appears favorable, with treatment-emergent adverse events (TEAEs) occurring in 76.3% of sibeprenlimab-treated patients versus 84.5% in the placebo group, and serious TEAEs reported in 3.9% versus 5.4%, respectively. These findings are particularly encouraging as sibeprenlimab offers a novel mechanism targeting APRIL, potentially addressing the immunologic pathogenesis of IgAN. The full trial results, including the key secondary endpoint of annualized eGFR slope over 24 months, are anticipated in 2026.

Key Decisions for Investors

• Investors should view the positive interim Phase 3 data for sibeprenlimab as a significant clinical validation and a potential catalyst for Otsuka Pharmaceutical, reinforcing the drug's prospects in the IgA nephropathy market.
• The FDA's priority review and the November 28, 2025 target action date are key milestones to monitor; successful approval could lead to a new therapeutic option for IgAN patients and a new revenue stream for the company.
• Consider the favorable safety profile and the novel mechanism of action as potential differentiating factors for sibeprenlimab, but also await the full eGFR data expected in 2026 for a more complete understanding of its long-term renal protective effects.