Otsuka’s Voyxact Shows Promising Kidney Protection in IgA Nephropathy Patients

New Phase 3 Data Highlights Potential Long-Term Benefits

Otsuka Pharmaceutical Co., Ltd. has shared encouraging new data for Voyxact (sibeprenlimab), an investigational treatment for adults living with primary IgA nephropathy (IgAN) who are at risk of disease progression.

The latest results come from a pre-specified interim analysis of the Phase 3 VISIONARY trial and were presented at the European Renal Association (ERA) Congress in Glasgow, United Kingdom.

The findings suggest that Voyxact may help preserve kidney function over time, an important goal for people living with IgA nephropathy.

Understanding IgA Nephropathy

If you are not familiar with IgA nephropathy, it is a chronic kidney disease caused by the buildup of abnormal IgA antibodies in the kidneys. Over time, this can lead to inflammation, kidney damage, and a gradual loss of kidney function.

For many patients, the biggest concern is slowing down the decline in kidney function to avoid serious complications such as kidney failure, dialysis, or kidney transplantation.

That is why new treatment options that can protect kidney function are receiving a lot of attention from doctors and researchers.

What the New Study Found

The Phase 3 VISIONARY trial evaluated 320 patients with primary IgA nephropathy.

Among them:

• 152 patients received Voyxact (sibeprenlimab)

• 168 patients received placebo

Researchers measured kidney function using estimated glomerular filtration rate (eGFR), which is one of the most important indicators of how well the kidneys are working.

After 12 months of treatment, patients receiving Voyxact showed a mean increase in eGFR from baseline of +0.7 mL/min/1.73 m².

In comparison, patients receiving placebo experienced a decline of -4.8 mL/min/1.73 m².

This resulted in an overall treatment benefit of 5.5 mL/min/1.73 m² in favor of Voyxact.

The results suggest that the treatment may help stabilize kidney function rather than allowing it to continue declining.

Meeting an Important Treatment Goal

One of the most notable findings from the study is that patients receiving Voyxact achieved a rate of kidney function decline that aligns with treatment goals established by the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines.

These guidelines recommend reducing annual kidney function decline to less than 1 mL/min/1.73 m² per year whenever possible.

According to the study results, the average kidney function decline seen with Voyxact was within this target range, which is considered close to the normal physiological rate of kidney aging.

This finding gives researchers confidence that the treatment could potentially improve long-term outcomes for patients.

Additional Evidence from eGFR Slope Analysis

Researchers also looked at the annualized eGFR slope, another important measure used to evaluate how quickly kidney function declines over time.

The results showed:

• Voyxact group: -3.0 mL/min/1.73 m² per year

• Placebo group: -7.6 mL/min/1.73 m² per year

This represents a treatment benefit of 4.6 mL/min/1.73 m² per year for patients receiving Voyxact.

These findings further support the idea that the treatment may slow disease progression and help preserve kidney function for longer periods.

Why These Results Matter

According to Professor Vlado Perkovic from the University of New South Wales, preserving kidney function is one of the most important goals when treating IgA nephropathy.

He explained that slowing kidney damage can reduce the risk of kidney failure and help patients avoid dialysis or transplantation later in life.

The study findings suggest that selectively targeting APRIL, a protein involved in the disease process, may help achieve that goal.

Professor Perkovic described the data as encouraging and said they support the idea that APRIL inhibition could become an important approach for protecting kidney health in IgA nephropathy patients.

How Voyxact Works

Voyxact works through selective inhibition of APRIL (A Proliferation-Inducing Ligand).

APRIL plays a key role in B-cell activity and the production of abnormal IgA antibodies that contribute to kidney damage in IgA nephropathy.

By targeting APRIL, Voyxact aims to reduce the production of disease-causing IgA without completely depleting B-cells.

This targeted approach may allow the treatment to address the underlying disease process while maintaining a favorable safety profile.

Researchers believe this mechanism differentiates Voyxact from other treatment strategies currently available.

Safety Profile Remains Encouraging

The study also showed positive safety results.

According to Otsuka, the overall safety profile of Voyxact was comparable to placebo.

The most commonly reported side effects included:

• Infections

• Injection site reactions

Researchers reported that treatment-emergent adverse events were generally similar in type and frequency between the Voyxact and placebo groups.

No new safety concerns were identified during the interim analysis.

These findings are consistent with previously reported clinical data.

Building on Earlier Success

The new kidney function data add to previously reported benefits seen with Voyxact.

Earlier analyses demonstrated reductions in several key disease markers, including:

• Galactose-deficient IgA1 (Gd-IgA1)

• Proteinuria

• Hematuria

Together with the latest eGFR findings, these results strengthen the overall evidence supporting the treatment's potential clinical benefits.

According to John Kraus, Executive Vice President and Chief Medical Officer at Otsuka, the growing body of evidence suggests that Voyxact could meaningfully improve outcomes for adults with primary IgA nephropathy who face a risk of disease progression.

What Happens Next?

While the current findings are based on a pre-specified interim analysis, the Phase 3 VISIONARY study is still ongoing.

Researchers will continue collecting long-term data to further evaluate the treatment's effectiveness and safety.

Otsuka has stated that full results from the final study analysis will be presented at a future medical conference.

Those results will provide a clearer picture of the long-term impact of Voyxact on kidney function and disease progression.

Looking Ahead

The latest VISIONARY trial results represent another positive step forward in the treatment of IgA nephropathy.

Patients treated with Voyxact showed preserved kidney function over 12 months, slower rates of kidney decline, and a safety profile comparable to placebo.

Combined with previous reductions in disease-related biomarkers, these findings strengthen the case for selective APRIL inhibition as a targeted treatment strategy for IgA nephropathy.

As the Phase 3 study continues, the medical community will be watching closely to see whether these promising early results translate into long-term benefits for patients living with this progressive kidney disease.