Alexion, AstraZeneca Rare Disease, said the FDA has accepted and granted Priority Review to its supplemental Biologics License Application for Ultomiris (ravulizumab) to treat adults with immunoglobulin A nephropathy (IgAN). If approved, Ultomiris would become the first C5 complement inhibitor available for this rare kidney disease. The FDA has set a target action date in the fourth quarter of 2026 under the Prescription Drug User Fee Act timeline.
IgAN is a rare, inflammatory kidney disease driven by abnormal IgA proteins that form immune complexes and deposit in the kidneys, activating the complement system and causing terminal complement–mediated inflammation and progressive damage to glomerular structures. Over time, this process impairs kidney function and can lead to chronic kidney disease and end-stage kidney disease, with more than 217,000 people diagnosed with IgAN in the US. Alexion’s CEO Marc Dunoyer said many patients still progress to kidney failure despite available treatments, underscoring the need for new disease-modifying approaches targeting complement biology.
The Priority Review is supported by a prespecified interim analysis from a Phase III study in adults with IgAN, recently presented at the 2026 European Renal Association Congress. In that analysis, Ultomiris led to a 46.6% reduction in 24-hour urine protein creatinine ratio from baseline at week 34, compared with a 5.6% reduction for placebo, yielding a placebo-adjusted treatment effect of 43.4% (p<0.0001). The reduction in proteinuria emerged rapidly by week 10—36.7% with Ultomiris versus 8.5% with placebo—and was sustained through week 34, with consistent effects across subgroups defined by baseline demographics, clinical characteristics and disease severity.
The trial’s primary endpoint, change from baseline in estimated glomerular filtration rate at week 106, will be assessed after longer-term follow-up to better characterize the impact on kidney function. Safety findings in the study were in line with the known profile of Ultomiris, and the drug was generally well tolerated with no new safety concerns identified. Alexion said the Priority Review highlights both the strength of the interim proteinuria data and the potential of Ultomiris as a first-in-class C5 complement inhibitor to address terminal complement–driven inflammation in IgAN.
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