By inhibiting the APRIL cascade, Otsuka Pharmaceuticals’ Voyxact slowed kidney function decline in patients with IgAN, opening up a potential path for full approval while also reading through to Vertex and others with similar assets.
Otsuka Pharmaceuticals’ APRIL inhibitor Voyxact stabilized kidney function decline in a late-stage IgA nephropathy study—findings analysts say could have broader implications across the drug class, with readthrough to companies like Vertex Pharmaceuticals and Vera Therapeutics.
The FDA granted Voyxact accelerated approval in November 2025 for the reduction of proteinuria in adults with primary IgAN who are at risk for disease progression. The new data, interim findings from the Phase 3 VISIONARY trial released Thursday, could help the company support the asset’s conversion to full approval. Indeed, Otsuka has now started a rolling biologics application.
The study showed that at 12 months, patients on Voyxact saw a 0.7 mL/min/1.73 m2 increase in estimated glomerular filtration rate (eGFR), an indicator of kidney function. This result, according to Otsuka, meets the professional standard to slow kidney function decline “to the normal physiological rate.” Meanwhile, in placebo comparators, eGFT declined by 4.8 mL/min/1.73 m2.
In addition to supporting Otsuka’s regulatory filing, the data potentially validate the APRIL pathway for treating IgAN, according to RBC Capital Markets. “We believe there had been good evidence already suggesting that proteinuria reductions [are] seen with” APRIL inhibitors, the analysts wrote to investors on Thursday, such as Vertex’s povetacicept.
Still, “this is the first time we have seen this [kidney benefit] shown clearly in a placebo-controlled study of a global population,” the analysts added.
RBC believes Otsuka’s data could have “positive readthroughs” to Vertex, which is racing toward a November 30 decision date for povetacicept. Like Voyxact, povetacicept blocks APRIL, but also inhibits BAFF, a protein that plays a role in B cell activity and is known to drive IgAN pathology.
“We believe this reinforcement of the proteinuria-eGFR link in IgAN should solidify the accelerated approval path for VRTX and minimizes risk that pove will not also demonstrate similar eGFR benefits or perhaps even better,” RBC argued.
Otsuka’s data could also have some readthrough to Vera and its IgAN candidate atacicept, which like Vertex’s povetacicept targets both the BAFF and APRIL pathways. Otsuka’s readout “highlights that not all B-cell modulating drugs w/in the BAFF/APRIL class are equivalent,” Jefferies said in a note on Thursday evening, noting that Voyxact “fell short of true stabilization of kidney function.”
Atacicept has previously demonstrated “greater eGFR slope preservation,” in turn “matching the natural aging decline in healthy adults,” the analysts continued. This suggests better long-term kidney outcomes for patients on atacicept.
Still, Jefferies concedes that the “mechanism debate is not yet settled” and that it “remains an open question whether dual BAFF/APRIL inhibition is superior to [an] APRIL-only” approach. Otsuka’s data remain incomplete for such a conclusion, they said, and efficacy comparisons are confounded by differences in population characteristics.
