BOSTON, US | June 15, 2026
Alexion, AstraZeneca Rare Disease announced that the U.S. Food and Drug Administration (FDA) has accepted and granted Priority Review to the supplemental Biologics License Application (sBLA) for Ultomiris (ravulizumab) as a treatment for adults with immunoglobulin A nephropathy (IgAN). The regulatory milestone highlights the therapy’s potential to become the first C5 complement inhibitor approved for this rare kidney disease, where significant unmet medical need remains despite currently available therapies. The FDA has assigned a Prescription Drug User Fee Act (PDUFA) target action date during the fourth quarter of 2026, reflecting the agency’s recognition that the application could provide a meaningful advancement in treatment options. IgAN is a progressive inflammatory kidney disease caused by abnormal IgA immune complex deposition, triggering terminal complement-driven inflammation that damages the kidney’s filtering units and may ultimately lead to chronic kidney disease (CKD) and end-stage kidney disease (ESKD). More than 217,000 people have been diagnosed with the disease in the United States, underscoring the importance of innovative therapies capable of slowing disease progression and preserving kidney function.
Phase III Trial Shows Significant Proteinuria Reduction
The FDA submission is supported by findings from the Phase III I CAN clinical trial, where Ultomiris achieved a 43.4% placebo-adjusted reduction in proteinuria after 34 weeks of treatment, meeting the study’s prespecified interim efficacy endpoint with high statistical significance (p<0.0001). Patients receiving Ultomiris experienced a 46.6% reduction in 24-hour urine protein creatinine ratio (UPCR) from baseline compared with only 5.6% in the placebo group. Investigators also observed a rapid treatment response beginning as early as week 10, when proteinuria declined by 36.7%, with benefits remaining consistent through week 34. Importantly, the positive outcomes were observed across multiple patient populations regardless of demographic characteristics, disease severity, or baseline clinical factors, reinforcing the therapy’s broad clinical potential. The study continues to evaluate the important kidney function endpoint of estimated glomerular filtration rate (eGFR) through 106 weeks, which will determine whether early proteinuria improvements translate into long-term preservation of renal function.
Safety Profile Supports Regulatory Advancement
According to the interim analysis, Ultomiris maintained a safety profile consistent with previous clinical experience, with no new safety concerns identified during the study. The therapy was generally well tolerated while delivering sustained inhibition of the terminal complement pathway, an important mechanism involved in the inflammatory damage associated with IgAN. As the longest-acting C5 complement inhibitor, Ultomiris is administered following an initial loading dose and then every eight weeks in adults, providing durable complement blockade with fewer infusions compared with shorter-acting therapies. Company leadership emphasized that the regulatory progress reflects years of investment in complement science and strengthens the possibility of introducing a disease-modifying option capable of targeting the underlying inflammatory process responsible for kidney injury rather than simply managing disease symptoms. If approved, the medicine could significantly expand treatment options for nephrologists managing patients at risk of irreversible kidney damage and eventual kidney failure.
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Alexion Expands Rare Disease Leadership
The latest regulatory achievement further strengthens Alexion’s leadership in rare disease therapeutics while expanding the clinical potential of Ultomiris, which is already approved across multiple global markets for paroxysmal nocturnal haemoglobinuria (PNH), atypical haemolytic uraemic syndrome (aHUS), generalised myasthenia gravis (gMG) and neuromyelitis optica spectrum disorder (NMOSD). The company continues to evaluate the therapy across additional indications as part of its broader development strategy focused on complement-mediated diseases. As a subsidiary of AstraZeneca, Alexion remains committed to developing innovative therapies addressing serious rare diseases with limited treatment options. A successful FDA approval later this year would not only establish Ultomiris as the first approved C5 complement inhibitor for IgAN, but could also reshape the treatment landscape by introducing a targeted biological therapy designed to slow disease progression and improve long-term outcomes for adults living with this challenging kidney disorder.
Source: AstraZeneca press release
