A new oral medication called iptacopan has shown remarkable promise in slowing kidney function decline for people with IgA nephropathy, a rare autoimmune kidney disease. In a major clinical trial, patients taking iptacopan experienced significantly slower kidney function loss and were 43% less likely to progress to kidney failure requiring dialysis or transplant compared to those receiving a placebo over two years .

What Is IgA Nephropathy and Why Does It Matter?

IgA nephropathy (IgAN) is a chronic kidney disease where the immune system mistakenly attacks the kidneys, causing inflammation and progressive damage to kidney function. Unlike some kidney diseases linked to diabetes or high blood pressure, IgAN occurs when a specific antibody called IgA deposits in the kidney tissue, triggering an inflammatory cascade that gradually destroys the organ's ability to filter waste. For decades, treatment options have been limited, and many patients eventually require dialysis or kidney transplant. This new medication represents a fundamentally different approach to stopping the disease at its source .

How Does Iptacopan Work to Protect Kidneys?

Iptacopan works by blocking a specific part of the immune system called the alternative complement pathway. Think of the complement system as part of your body's defense mechanism, but in IgAN, this system becomes overactive and damages kidney tissue instead of protecting it. By inhibiting this pathway, iptacopan essentially turns down the immune system's attack on the kidneys, allowing them to function better and decline more slowly .

What Did the APPLAUSE-IgAN Trial Show?

The APPLAUSE-IgAN Phase III randomized controlled trial enrolled hundreds of patients with IgA nephropathy and tracked their kidney function over 24 months. Patients taking iptacopan 200 milligrams twice daily experienced significantly slower kidney function decline, losing about 3 milliliters per minute per 1.73 square meters less of estimated glomerular filtration rate (eGFR) per year compared to placebo. eGFR is a standard measure of how well your kidneys are filtering waste from your blood .

Beyond slowing kidney function loss, the medication also improved key markers of disease activity. About 41% of patients treated with iptacopan achieved proteinuria levels below 1,000 milligrams per gram of creatinine by 24 months, compared to only 24% of those receiving placebo. Proteinuria, or protein in the urine, is a sign of kidney damage; lower levels indicate better kidney health. Additionally, the treatment eliminated microscopic blood in the urine for many patients, another important sign of reduced kidney inflammation .

Steps to Understanding Your Kidney Health If You Have IgA Nephropathy

• Know Your eGFR Number: Ask your nephrologist for your estimated glomerular filtration rate, which measures how well your kidneys filter waste. A higher number indicates better kidney function, and tracking this number over time helps you and your doctor assess disease progression.
• Monitor Proteinuria Levels: Request regular urine protein tests to measure how much protein is leaking into your urine. Lower proteinuria levels indicate less kidney damage and better response to treatment.
• Discuss Treatment Options: If you have IgAN, talk with your nephrologist about whether iptacopan or other complement pathway inhibitors might be appropriate for your specific situation, as treatment decisions depend on individual disease severity and kidney function.

The medication was well tolerated, with side effects similar to placebo and no deaths reported during the trial, suggesting it is a safe treatment option for this patient population .

"These results show that iptacopan not only improves markers of disease activity but can also meaningfully slow the loss of kidney function over time," said Brad Rovin, presenter of the study. "For people living with IgA nephropathy, this represents an important step toward changing the long-term course of the disease."

Brad Rovin, Study Presenter

What Happens Next for Patients and Doctors?

The FDA previously granted accelerated approval to iptacopan for IgAN based on interim 9-month data showing a 38.3% reduction in proteinuria compared to placebo. These new 24-month findings provide crucial evidence that the medication not only reduces protein in the urine but also meaningfully slows the decline in kidney function itself, which is the ultimate goal of kidney disease treatment .

However, important questions remain about how iptacopan fits into existing treatment regimens and which patients are most likely to benefit. Doctors will need to determine whether iptacopan works best as a standalone therapy or combined with other kidney-protective medications, and how to identify patients at highest risk of progression who would benefit most from this treatment .

Why This Matters for the Broader Kidney Disease Crisis

Chronic kidney disease (CKD) affects 1 in 7 adults in the United States, yet 90% of those affected are unaware they have the condition. While IgA nephropathy is a relatively rare form of kidney disease, the success of iptacopan demonstrates a new therapeutic approach that could potentially benefit other kidney disease patients. The medication's ability to target the immune system's complement pathway opens doors for treating other immune-mediated kidney diseases .

The findings will be presented at the National Kidney Foundation Spring Clinical Meetings in New Orleans on May 7, 2026, where nephrologists and kidney care professionals from across the country will discuss how to integrate this new treatment into clinical practice and how to best serve patients with this serious kidney disease .