The U.S. Food and Drug Administration granted accelerated approval to Otsuka’s sibeprenlimab (Voyxact) for adults with primary IgA nephropathy after a late-stage trial showed a large reduction in proteinuria. Otsuka presented interim Visionary trial data demonstrating a 51% reduction in 24-hour urine protein-to-creatinine ratio at nine months and a 56.6% reduction at 12 months versus placebo. The approval, announced ahead of the original PDUFA date, makes Voyxact the first APRIL-targeting therapy available for IgAN and positions Otsuka to commercialize an oral/SC product in a disease with limited options. Voyxact is a subcutaneously administered monoclonal antibody designed to block A proliferation inducing ligand (APRIL), a cytokine implicated in pathogenic immunoglobulin A production. Regulators based their decision on consistent reductions in proteinuria and a favorable safety profile from the randomized Visionary trial; longer-term effects on renal function (eGFR) remain under follow-up with data expected in 2026. Analysts estimate a multi-billion dollar peak market opportunity, drawing attention from larger nephrology-focused programs with overlapping mechanisms. Clinicians and payors will watch for the ongoing 12‑ to 24‑month data that regulators cited as confirmatory; the drug’s label and uptake may hinge on whether durable eGFR preservation is demonstrated. For developers, the approval underscores the FDA’s willingness to reward targeted biologics in rare renal diseases based on robust proteinuria endpoints, while leaving endpoints tied to long-term organ function to confirmatory studies.