Ultomiris earns FDA accelerated approval for IgA nephropathy after cutting proteinuria by 43%

A complement inhibitor is making waves in kidney disease treatment. Ravulizumab-cwvz (Ultomiris, Alexion/AstraZeneca) — a terminal C5 complement inhibitor — significantly reduced proteinuria compared to placebo in adults with IgA nephropathy (IgAN), a progressive kidney disease driven by immune-mediated glomerular injury. The results, presented at ASN Kidney Week and published in the New England Journal of Medicine, supported the FDA's accelerated approval of Ultomiris for proteinuria reduction in adults with primary IgAN at risk for disease progression.

In the phase 3 I CAN trial, 352 adults were randomized to weight-based IV ravulizumab-cwvz or placebo every 8 weeks. Proteinuria reduction was evident as early as week 10 and sustained through week 34, with consistent results across all patient subgroups, including those with hematuria at baseline.

By the Numbers:

• 43.4% reduction in proteinuria (UPCR) vs. placebo at week 34
• 37.7% vs. 12.1% of patients achieved ≥50% proteinuria remission
• 42.4% vs. 11.1% achieved hematuria resolution
• Serious adverse events: 4.6% (ravulizumab) vs. 9% (placebo); no deaths in either group

Why it matters: IgAN is a leading cause of kidney failure with limited treatment options. Ultomiris's accelerated approval gives clinicians a new complement-targeting tool, though traditional approval hinges on a final 2-year analysis assessing kidney function preservation (eGFR) as the primary endpoint.