Voyxact Becomes First Biologic Approved for IgA Nephropathy as Competitors Advance

In a space set to see new competitors soon, Otsuka has come out ahead in the race with the FDA approval of Voyxact (sibeprenlimab-szsi) for reducing proteinuria in adults with primary immunoglobulin A nephropathy (IgAN) at risk of disease progression.

IgAN, also known as “Berger’s disease,” is a chronic kidney disease characterized by abnormal deposition of immunoglobulin A (IgA) antibodies in the glomeruli (the filtering units of the kidney), which triggers kidney inflammation and damage over time. This can lead to protein leaking into the urine (proteinuria) and a gradual decline in kidney function. Eventually, many patients risk progressing to kidney failure.

Voxyact is the first biologic ever approved for IgAN, as all four previous FDA-cleared IgAN therapies have been small molecules.

Until now, treatment options focused on supportive care, including blood pressure control, renin-angiotensin system inhibitors (ACE inhibitors or ARBs) and sometimes with SGLT2 inhibitors or broad immunosuppression. The approval of Voyxact marks the first time a therapy directly targets a key upstream mechanism in IgAN pathogenesis.

Related: Sibeprenlimab Shows 51% Reduction in Proteinuria in Pivotal IgAN Trial

Voyxact is a humanized monoclonal antibody that blocks a cytokine called A proliferation‑inducing ligand (APRIL). By inhibiting APRIL, the drug reduces production of pathogenic, galactose-deficient IgA1m, the abnormal IgA implicated in IgAN.

The approval was based on an interim analysis from the Phase III Visionary study involving adults with biopsy-confirmed IgAN already on stable standard-of-care therapy.

After nine months, patients receiving Voyxact had a 50% reduction in proteinuria (urine protein-to-creatinine ratio from 24h urine collection), compared to a 2% increase in the placebo group.

After one year of treatment, Voyxact achieved a placebo-adjusted 54.3% reduction in proteinuria, according to data presented last week at the American Society of Nephrology’s Kidney Week 2025 and published in The New England Journal of Medicine (NEJM).

Voyxact is administered at 400 mg via subcutaneous injection once every four weeks, a regimen compatible with at-home self-administration.

XTALKS WEBINAR: Why Transmission Electron Microscopy Is Key to Cell Line Characterization

Live and On-Demand: Monday, December 8, 2025, at 10am EST (4pm CET/EU-Central)

Register for this free webinar to learn how transmission electron microscopy (TEM) supports comprehensive cell line characterization strategies aligned with current regulatory expectations.

“The availability of Voxyact represents a novel targeted approach to help manage this complex disease for patients living with IgAN,” said John Kraus, MD, PhD, executive vice president and chief medical officer, Otsuka, in a statement on the approval. “With its targeted mechanism, strong efficacy, safety profile and once-every-four-weeks dosing, Voxyact offers a new option for IgAN patients. We recognize the urgent need for new treatment options for IgAN and are thankful for the patients and healthcare professionals who continue to participate in our clinical trial program.”

The approval is accelerated and based on proteinuria reduction, which is considered a surrogate marker. It has actually not yet been demonstrated whether Voyxact slows long-term decline in kidney function (as measured by estimated glomerular filtration rate, eGFR) or delays progression to kidney failure.

The ongoing Visionary trial will continue to monitor participants, with confirmatory eGFR data expected by 2026. Continued approval may hinge on those results.

Voyxact is the first therapy targeting the APRIL pathway to reach the market, paving the way for a growing pipeline of anti-APRIL candidates.

Several companies, including Vertex, Novartis and Vor Bio, are developing their own APRIL-targeting agents for IgAN and related conditions.

Other companies are advancing BAFF/APRIL dual inhibitors, a class targeting another key pathway in IgAN linked to abnormal protein and autoantibody production.

Vera Therapeutics has submitted a BLA and filed an FDA accelerated approval for atacicept, which cut proteinuria by 42% versus placebo, while Vertex is preparing an accelerated approval submission for povetacicept after reporting 64% proteinuria reductions in a Phase II study. RemeGen, partnered with Vor Bio, has also reported positive Phase III results in China for telitacicept, though its US development path remains uncertain.

According to analysts at Jefferies, IgAN represents a large market worth around $6 billion to $10 billion in potential sales per year. But competition within the APRIL class will be intense, the analysts said, and the space is poised to get crowded fast.