FDA approves Ultomiris for IgA nephropathy

Overview

Updated 1 hour ago

The US Food and Drug Administration (FDA) cleared AstraZeneca's Ultomiris on Thursday as the first complement inhibitor approved to cut proteinuria — excess protein in the urine — in adults with primary immunoglobulin A nephropathy (IgAN). The approval is accelerated, so AstraZeneca still must show the drug preserves kidney function or risk losing the indication.

IgAN is a rare inflammatory kidney disease that can progress to kidney failure within a decade for roughly half of patients with elevated urine protein or reduced kidney function. The nod rests on an interim trial showing Ultomiris reduced proteinuria by 43.4% versus placebo at 34 weeks. A confirmatory trial measuring kidney function change at week 106 will decide whether the drug earns full approval.

Why it matters

Ultomiris is the first C5 complement inhibitor for IgA nephropathy, giving patients a targeted option in a disease that often ends in kidney failure.

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Key Indicators

43.4%

Proteinuria reduction vs placebo at 34 weeks

Placebo-adjusted reduction from the I CAN Phase III interim analysis.

46.6%

24-hour urine protein reduction from baseline

For Ultomiris patients at week 34, versus 5.6% for placebo.

US indications for Ultomiris

IgA nephropathy is the fifth rare disease indication for the drug.

200,000+

People in the US with IgAN

AstraZeneca's estimate of Americans living with the disease.

Voices

Curated perspectives — historical figures and your fellow readers.

Ever wondered what historical figures would say about today's headlines?

People Involved

Marc Dunoyer

Chief Executive Officer, Alexion (AstraZeneca Rare Disease)

Leading Alexion as Ultomiris wins its fifth US indication

Organizations Involved

AstraZeneca

Pharmaceutical company

Holds FDA accelerated approval for Ultomiris in IgAN

British-Swedish drugmaker whose rare-disease unit Alexion developed Ultomiris.

U.S. Food and Drug Administration

Federal Regulatory Agency

Granted accelerated approval for Ultomiris in IgAN

The agency that approves and regulates drugs in the United States.

Timeline

April 2026 October 2026

2 events Latest: Today

October 2026
FDA grants accelerated approval for Ultomiris in IgAN
Today Regulatory approval

The FDA approves Ultomiris to reduce proteinuria in adults with primary IgAN at risk of progression, the first C5 inhibitor cleared for the indication.
Today
April 2026
I CAN interim analysis shows proteinuria reduction
Clinical trial results

AstraZeneca reports Ultomiris cut urine protein by 43.4% versus placebo at 34 weeks in the Phase III I CAN trial.
April 21st, 2026

Scenarios

I CAN trial confirms eGFR benefit, Ultomiris wins full approval

Likely Resolves by End of 2027

Discussed by: AstraZeneca, which says the ongoing I CAN trial is intended to support traditional approval

The I CAN trial's primary endpoint at week 106 is change in estimated glomerular filtration rate (eGFR), a direct measure of kidney function. If the final analysis shows Ultomiris slows eGFR decline, the FDA can convert the accelerated approval to traditional approval, giving the drug an unqualified claim to preserve kidney function.

I CAN misses eGFR endpoint, FDA weighs indication withdrawal

Possible Resolves by End of 2027

Discussed by: AstraZeneca's own label, which states continued approval depends on confirming clinical benefit

Accelerated approvals carry confirmatory obligations. If the week-106 eGFR endpoint fails to show meaningful kidney function preservation, the FDA could begin withdrawal proceedings for the IgAN indication, despite the proteinuria improvement.

Rival complement drugs win IgAN approval before Ultomiris's confirmatory data

Uncertain Resolves by End of 2027

Discussed by: Fierce Pharma, which notes Ultomiris enters a market with Tarpeyo, Filspari and Fabhalta

Novartis's Fabhalta targets complement Factor B, an earlier step in the same pathway. If Fabhalta or other candidates win IgAN approval with full kidney-function data before Ultomiris's confirmatory results land, the market could favor drugs with unqualified label claims, pressuring Ultomiris's commercial position.

Historical Context

2 moments from history that rhyme with this story — and how they unfolded.

2007

Soliris and the birth of C5 inhibition (2007)

Soliris (eculizumab), Alexion's first C5 complement inhibitor, won FDA approval in 2007 for paroxysmal nocturnal hemoglobinuria, a rare blood disease. It was the first drug of its class and opened complement inhibition as a treatment field.

Then

Soliris became the standard for a handful of rare complement-mediated diseases and made Alexion a rare-disease pioneer.

Now

The C5 mechanism became a platform, with Ultomiris engineered as a longer-acting successor that requires dosing every eight weeks instead of every two.

Why this matters now

Ultomiris extends the same C5 mechanism Alexion pioneered with Soliris into kidney disease, a new organ system for the class.

2021-2023

Proteinuria-based accelerated approvals in IgAN (2021-2023)

Tarpeyo (budesonide) and Filspari (sparsentan) won FDA approval for IgAN under the accelerated pathway, using urine protein reduction as a surrogate for kidney function. They were the first treatments specifically cleared for the disease.

Then

Proteinuria became the accepted surrogate endpoint for IgAN drug trials.

Now

Later IgAN drugs, including Ultomiris, carry confirmatory obligations to prove they preserve kidney function.

Why this matters now

Ultomiris is the latest drug to ride this regulatory path, with its fate tied to the same confirmatory-testing standard the earlier approvals faced.