Otsuka said VOYXACT cut the two-year risk of kidney decline or failure by 97.1% in a 510-patient phase 3 trial. It completed a staged U.S. filing for full approval after accelerated approval in November 2025, and kept its 2026 forecast unchanged.
Key facts
Otsuka’s sibeprenlimab cut the risk of a composite kidney event, defined as declining kidney function or kidney failure, by 97.1% versus placebo in the final analysis of the phase 3 VISIONARY trial.
| Measure | Sibeprenlimab group | Placebo group |
|---|---|---|
| Composite kidney events | 1 (0.4%) | 28 (11.2%) |
| Sustained eGFR decline of 40% or more | 1 | 28 |
| Sustained doubling of serum creatinine | 0 | 13 |
| Sustained eGFR decline to below 15 | 1 | 10 |
| Initiation of kidney replacement therapy | 0 | 5 |
The randomized trial enrolled 510 adults with primary IgA nephropathy and assessed them over 24 months. Only one patient in the drug group had a composite event, and the group also had fewer events than placebo across the individual measures of kidney decline and failure.
The strong suppression of kidney-function decline provides important clinical evidence for patients at risk of progressing to kidney failure. However, there were 29 composite events across both groups, making longer-term data an important focus in evaluating the treatment’s effects.
The trial also found that kidney function was maintained over 24 months. The annual eGFR slope was plus 0.3 in the sibeprenlimab group and minus 4.2 mL/min/1.73m² per year in the placebo group, a between-group difference of plus 4.5.
Otsuka said the trial was the first phase 3 study in IgA nephropathy to meet the KDIGO 2025 treatment target of limiting annual kidney-function decline to less than the normal rate of 1 mL/min/1.73m². The results add to evidence that the drug can preserve kidney function over time, alongside improvements in proteinuria, and may slow disease progression.
The safety profile over 24 months was comparable with placebo, with no new safety concerns identified. Serious infections were less frequent in the drug group.
| Adverse event | Sibeprenlimab group | Placebo group |
|---|---|---|
| Any adverse event | 90.7% | 90.0% |
| Infections and infestations | 51.4% | 51.0% |
| Injection-site reactions | 35.1% | 32.3% |
| Serious infections | 1.9% | 4.0% |
The two-year data on both efficacy and safety will inform the drug’s assessment as a treatment option. Because the drug affects the immune system, longer-term safety and the durability of its effects will remain key areas to monitor.
VOYXACT received accelerated approval from the U.S. Food and Drug Administration in November 2025 to reduce proteinuria in adults with IgA nephropathy who are at risk of disease progression. Otsuka completed the staged submission of a supplemental Biologics License Application (sBLA) for full approval on Oct. 6, U.S. time.
The trial results provide important support for seeking full approval following accelerated approval. Otsuka sees VOYXACT as one of the products that will drive future growth, but the announcement has not changed its earnings forecast for the current fiscal year.
Analyst take
The substantial reduction in composite events involving kidney-function decline or kidney failure, together with the eGFR and safety findings, strengthens the clinical case for full approval. The drug currently has accelerated approval in the U.S., so full approval and further long-term data are the next milestones. The key question is whether clinical progress can translate into business growth.
