Otsuka's Voyxact Shows Statistically Significant Kidney Function Improvement in 24-Month IgAN Study

New 24-month data from the VISIONARY trial for Otsuka's Voyxact (sibeprenlimab) showed a statistically significant improvement in kidney function for patients with IgA nephropathy (IgAN). The late-breaking results, presented at the GlomCon conference in August, were reviewed by analysts at BTIG and reinforce the drug's efficacy profile over an extended period.

Key Trial Results

The primary measure of kidney function, the estimated glomerular filtration rate (eGFR), showed sustained positive changes for patients treated with Voyxact. The data demonstrated a clear and statistically significant benefit compared to placebo over the two-year study.

• Annualized eGFR Slope: Voyxact-treated patients showed an improvement of +0.3 mL/min/1.73m² per year, a stark contrast to the -4.2 mL/min/1.73m² per year decline seen in the placebo group.
• Treatment Effect: This represents a net treatment benefit of +4.5 mL/min/1.73m² per year (p<0.0001), meeting the KDIGO therapeutic goal of limiting kidney function decline to less than 1 mL/min/1.73 m² annually.
• Change from Baseline: The least squares mean change in eGFR from the study's start showed a +1.3 mL/min/1.73m² improvement for Voyxact, versus a -7.9 mL/min/1.73m² decline for placebo, for a total treatment effect of +9.2 mL/min/1.73m² (p<0.0001).

Commercial Performance and Outlook

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Following its accelerated FDA approval in November 2025, Voyxact has shown strong initial market uptake. Otsuka reported second-quarter 2026 revenue for the drug of approximately $78 million, suggesting an annual run-rate of about $312 million. The company has initiated a rolling supplemental Biologics License Application based on the latest data.

As of June 30, 2026, more than 2,000 new patients have started treatment since the launch. Based on this momentum, Otsuka projects full-year 2026 revenue for Voyxact to reach approximately $375 million.

Context for Investors

IgA nephropathy is a chronic autoimmune disease that affects the kidneys and typically requires lifelong therapy, with diagnoses often occurring between the ages of 16 and 35. The positive 24-month data is crucial as it demonstrates a sustained, long-term benefit in preserving kidney function, a key consideration for physicians and patients managing this progressive condition. The strong sales figures and patient adoption rates indicate a successful commercial launch in a market with significant unmet needs.