Ultomiris cuts urinary protein by 43.4%, wins U.S. priority review
Key Facts
AstraZeneca announced on June 15, 2026 that its drug Ultomiris had been granted priority review in the United States to treat adults with immunoglobulin A nephropathy. The action concerns a supplemental licensing application to expand the use of an existing drug with other approved therapeutic indications. An interim analysis of the clinical trial showed a 43.4% reduction in urinary protein compared with placebo at week 34, according to the company. AstraZeneca said Ultomiris, if approved for this use, would become "the first complement component 5 inhibitor available for this rare kidney disease". That potential distinction places the application for expanded use in a specific therapeutic class, while its availability to treat the disease remains subject to regulatory approval.
Detailing the treatment response, AstraZeneca said the reduction in urinary protein began to emerge as early as week 10 of the "I CAN" trial. The placebo-adjusted reduction at week 34 was measured as part of the trial's interim analysis. The reported results thus addressed the onset of response and the size of the difference between the treatment and comparison groups during follow-up. The trial was designed to enroll about 510 participants from 28 countries, according to the company's statement on the results. That figure represents planned enrollment in the trial, which is testing the treatment in adults with immunoglobulin A nephropathy.
Immunoglobulin A nephropathy develops when clusters of antibodies build up in the kidneys, according to the U.S. National Institute of Diabetes and Digestive and Kidney Diseases. These deposits cause inflammation and kidney damage, the disease process targeted by the application to expand the use of Ultomiris. On safety, AstraZeneca reported that the trial identified "no new safety concerns". The drug's prescribing information, issued by the U.S. Food and Drug Administration, warns of an increased risk of serious infections caused by meningococcal bacteria. That warning appears in the prescribing information for Ultomiris as a complement inhibitor, alongside the company's assessment of safety in the trial.
In the treatment landscape for the same disease, Novartis announced on July 16, 2026 that its drug Fabhalta had received traditional U.S. approval. The approval covers slowing the decline in kidney function in adults with primary immunoglobulin A nephropathy who are at risk of disease progression. Longer follow-up in the Ultomiris trial includes a primary endpoint for the final analysis measuring the change in estimated glomerular filtration rate. That change is measured at week 106 against baseline, according to AstraZeneca, addressing the course of kidney function over a longer period than the urinary protein measurement period. On the regulatory front, the company identified the fourth quarter of 2026 as the expected timing for an FDA decision on the application for expanded use.