Otsuka's Voyxact Stabilizes Kidney Function Decline in Landmark Two-Year Phase 3 IgA Nephropathy Trial

Otsuka's Voyxact Stabilizes Kidney Function Decline in Landmark Two-Year Phase 3 IgA Nephropathy Trial

Otsuka Pharmaceutical announced unprecedented two-year (24-month) results from its Phase 3 VISIONARY trial of Voyxact (sibeprenlimab-szsi), a selective anti-APRIL monoclonal antibody, in adults with primary IgA nephropathy (IgAN) at risk of disease progression. The trial successfully met its key secondary endpoint, demonstrating that Voyxact effectively halts the progressive decline of kidney function, bringing it back to a normal baseline physiologic rate. This represents a monumental shift in the therapeutic landscape for IgAN, where existing therapies have primarily focused on symptom management (such as proteinuria reduction) rather than reversing or stabilizing the underlying decline in estimated glomerular filtration rate (eGFR).

According to the data presented at the GlomCon Hawaii 2026 conference, patients treated with Voyxact achieved an annualized estimated eGFR slope of +0.3 mL/min/1.73 m²/year over two years, compared to a decline of -4.2 mL/min/1.73 m²/year for those on placebo. This represents a statistically significant treatment effect of +4.5 mL/min/1.73 m²/year (p<0.0001). Under the KDIGO 2025 Clinical Practice Guidelines, reducing kidney function decline to less than 1 mL/min/1.73 m²/year is the gold-standard therapeutic goal, making Voyxact the first IgAN treatment to achieve this milestone over a two-year period with a safety profile comparable to placebo.

Otsuka has initiated a rolling submission of a supplemental Biologics License Application (sBLA) to the FDA to convert Voyxact’s accelerated approval (granted in 2025 based on 9-month proteinuria reduction) to traditional full approval¹.²

"Phase 3 VISIONARY study met its key secondary endpoint, showing an annualized estimated eGFR slope of +0.3 (95% CI, -0.4 to 0.9) mL/min/1.73 m²/year with sibeprenlimab versus -4.2 (95% CI, -4.9 to -3.6) mL/min/1.73 m²/year with placebo... VOYXACT is the first-and-only U.S. FDA-approved IgAN treatment to show stabilization of kidney function, with evidence of improvement, and a safety profile consistent with placebo over two years" — Otsuka Press Release / Business Wire

"Results from the phase 3 Visionary trial showed that Voyxact (sibeprenlimab) achieved an annualized estimated glomerular filtration rate (eGFR) slope of a 0.3 mL/min/1.73m² gain over two years, suggesting an improvement in kidney function. The rate matches the normal age-related decline of less than 1 mL/min/1.73m² per year, as laid out in the KDIGO 2025 Clinical Practice Guideline for IgAN." — Fierce Pharma