Otsuka Gains FDA Accelerated Approval for VOYXACT in IgAN on Surrogate Endpoint Strategy

Proteinuria reduction as a surrogate endpoint has now anchored an accelerated approval for a biologic in IgAN, a precedent that regulatory affairs and QA teams should log carefully. Otsuka Pharmaceutical's VOYXACT (sibeprenlimab-szsi), an APRIL blocker administered subcutaneously every four weeks, received FDA accelerated approval on November 25, 2025, for reducing proteinuria in adults with primary immunoglobulin A nephropathy at risk of disease progression.

The approval rested on a single pivotal trial, VISIONARY (NCT05248646), a randomized, double-blind, placebo-controlled, multicenter study conducted across 242 sites in 31 countries. The efficacy determination drew from an interim analysis of 320 patients who reached Month 9, with the primary endpoint defined as relative change from baseline in urine protein-to-creatinine ratio (UPCR) from 24-hour urine collections. Of those 320 patients, only 33 were enrolled at US sites, a demographic detail relevant to post-approval diversity and representativeness considerations under current FDA expectations.

Enrollment criteria required biopsy-proven IgAN, an eGFR of at least 30 mL/min/1.73 m², and total urine protein of 1.0 g/day or greater, with patients on maximally tolerated stable doses of a renin-angiotensin system (RAS) inhibitor, with or without an SGLT2 inhibitor. The safety dataset was broader, covering 510 patients who received at least one dose, a distinction RA teams should note when cross-referencing the prescribing information against the trial's interim efficacy cut.

For regulatory affairs leads, the structural question is straightforward: accelerated approval via surrogate endpoint obligates a confirmatory trial demonstrating clinical benefit, and the VISIONARY trial design appears to serve dual purpose for both efficacy and safety assessment. How FDA handles the confirmatory milestone for VOYXACT will inform submission strategies for other biologics targeting kidney disease endpoints where hard outcomes trials run long.

The approval also reinforces the agency's willingness to accept UPCR-based endpoints in nephrology under 21 CFR Part 314 Subpart H and its biologics equivalent, a regulatory pathway that competing programs in IgAN and related glomerulopathies are already tracking.

The confirmatory trial outcome and any label updates tied to full approval will be the next measurable checkpoint for teams monitoring VOYXACT's regulatory trajectory.

Source: FDA Drug Trials Snapshots via FDA.gov, July 8, 2026.