FDA Approves Voyxact, First Targeted Therapy for IgA Nephropathy
The Food and Drug Administration has granted accelerated approval to Voyxact (sibeprenlimab-szsi), developed by Otsuka, marking a significant breakthrough in the treatment of primary immunoglobulin A nephropathy (IgAN), a progressive kidney disease. This approval, based on interim analysis from the phase 3 VISIONARY trial, offers a new hope for adults at risk of disease progression, providing the first therapy specifically designed to target the underlying cause of IgAN.
Understanding IgA Nephropathy
Also known as Berger disease, IgAN is characterized by the buildup of immunoglobulin A (IgA) in the kidneys, hindering their ability to filter blood effectively. This leads to a cascade of potential complications, including blood in the urine, declining kidney function, and ultimately, kidney failure. Currently, there is no cure for IgAN, and treatment options have been limited to managing symptoms and slowing disease progression.
“Voyxact is the first approved treatment for adults with primary IgAN at risk for disease progression that blocks the activity of APRIL,” stated Dana Rizk, MD, professor of medicine at the University of Alabama at Birmingham and a principal investigator in the VISIONARY study. “I’m encouraged by its potential to help improve the outlook for IgAN patients.”
Clinical Trial Results Demonstrate Significant Proteinuria Reduction
Data from the VISIONARY trial revealed a substantial reduction in proteinuria – a key indicator of kidney damage – in patients treated with Voyxact. After nine months, individuals receiving Voyxact experienced a 50% reduction in proteinuria compared to just 2% in those receiving a placebo. The placebo-adjusted treatment effect was a remarkable 51% (P < .0001).
The VISIONARY trial enrolled 510 participants, all with biopsy-confirmed IgAN, and all were receiving standard-of-care treatment, including maximally tolerated angiotensin-converting enzyme inhibitors and/or angiotensin receptor blockers, with or without a sodium-glucose cotransporter 2 inhibitor. Sibeprenlimab was administered via a prefilled syringe for subcutaneous self-injection every four weeks. An interim analysis presented at the European Renal Association Congress in June further confirmed a 51.2% reduction (P < .0001) in proteinuria after nine months of treatment.
Safety Profile and Adverse Events
The safety profile of Voyxact appears favorable. A slightly lower percentage of patients treated with Voyxact (76.3%) experienced any treatment-emergent adverse event (AE) compared to those receiving the placebo (84.5%). Serious AE rates were also lower in the Voyxact group (3.9%) versus the placebo group (5.4%). The most common adverse reactions observed in the trial were infections and injection site reactions, occurring at slightly higher rates in the Voyxact group (49% vs 45% and 24% vs 23%, respectively).
How Voyxact Works
Voyxact is a monoclonal antibody that works by inhibiting the activity of APRIL (A PRoliferation-Inducing Ligand). By blocking APRIL, the therapy aims to reduce levels of both total IgA and pathogenic galactose-deficient IgA, which are believed to play a central role in the development of IgAN. It is the first and only therapy to target this specific pathway.
According to John Krause, MD, PhD, executive vice president and chief medical officer at Otsuka Pharmaceutical Development & Commercialization, “If approved, sibeprenlimab would enable individuals living with IgA nephropathy to self-inject once every 4 weeks. We are thankful to share a potential treatment that could offer important clinical benefits and convenience to those living with this disease.”
Prior Designations and Further Research
Sibeprenlimab previously received both a priority review and a breakthrough therapy designation from the FDA, based on data from the VISIONARY and phase 2 ENVISION trials. The ENVISION trial, a multicenter, double-blind, placebo-controlled study, evaluated different intravenous doses of sibeprenlimab (2mg, 4mg, and 8mg) against a placebo. Results showed the 8-mg dose achieved the greatest reduction in protein-to-creatinine ratio (62.0%), while the placebo group experienced a 20.0% reduction. .
While this approval represents a major step forward, a confirmatory trial is ongoing to assess whether Voyxact can slow the long-term decline in kidney function. Updated data from this trial are expected in early 2026 and will be crucial for securing full FDA approval.
