Otsuka’s Voyxact (sibeprenlimab) just did something no IgA nephropathy drug has done in a phase 3 trial: it stabilized kidney function decline to the rate seen in healthy adults. Two-year data from the VISIONARY trial showed an annualized eGFR slope of positive 0.3 mL/min/1.73m², against negative 4.2 for placebo. That matches the under-1 mL/min/1.73m² benchmark KDIGO’s 2025 guideline sets for normal age-related decline.
Voyxact already has skin in the game: it grabbed FDA accelerated approval in November 2025 on a 51% proteinuria reduction, and Otsuka is now filing the two-year eGFR data to convert that to full approval. First-half 2026 sales hit 17.1 billion yen ($110 million), and Otsuka more than doubled its full-year forecast to 60 billion yen while pulling its 100 billion-yen target forward a year, to 2027.
The 12-month interim data disappointed industry watchers last year, showing a 3 mL/min/1.73m² loss and anti-drug antibodies in 34% of patients. This readout answers both worries at once: the slope flipped positive by month 24, and only 8% of patients developed neutralizing antibodies. That’s the kind of durability signal accelerated-approval sponsors need before FDA lets them drop the “accelerated.”
It also reframes the APRIL/BAFF race. Vera’s dual-target Trutakna cleared FDA in July with a 96-week eGFR slope of negative 0.6, worse than Voyxact’s single-target result. If APRIL inhibition alone beats a BAFF/APRIL combo on the metric nephrologists actually care about, the dual-target thesis gets a lot harder to sell. Vera’s own phase 3 eGFR readout lands in Q3.
Rebecca Lauren