A shot every four weeks kept kidneys steady for two years in IgA nephropathy

If you or someone you love has IgA nephropathy, there is real good news. A new shot given every four weeks kept kidney function steady for two years, while kidney function in people on placebo kept sliding.

The drug is called sibeprenlimab. In the study, almost nobody who took it had their kidneys worsen or fail. That is the outcome people with IgA nephropathy most want to avoid.

How the study worked

Researchers followed 510 adults with IgA nephropathy for 24 months. By chance, some got a 400 mg shot under the skin every four weeks, and the others got a placebo shot on the same schedule. It was a large phase 3 trial, the final step before a drug goes to regulators. It was funded by the drug maker, Otsuka, and it ran for two years. It was published on Oct. 22, 2026, in the New England Journal of Medicine.

What they found

The main measure was eGFR, a number that shows how well your kidneys filter your blood. A falling eGFR means the kidneys are wearing down.

In the sibeprenlimab group, eGFR held level at +0.3 units per year. In the placebo group, it fell 4.2 units per year. After 24 months, the gap between the two groups was 9.2 units in favor of the shot.

The researchers also counted people whose kidney function dropped or whose kidneys failed. Only 1 person on sibeprenlimab had that happen, which is 0.4%. On placebo, 28 people did, which is 11.2%.

Safety looked good, too. Serious side effects were less common with the shot (8.1%) than with placebo (12.7%). The same was true for serious infections (1.9% versus 4.0%). Side effects of any kind were about equal in both groups, and no one died during the study.

What is IgA nephropathy?

It is one of the most common kidney diseases in the world, and it often starts in young adulthood. Abnormal IgA antibodies form clumps that lodge in the kidneys’ tiny filters. That causes inflammation, blood and protein in the urine, and a slow loss of kidney function. Over time, many people need dialysis or a transplant.

Sibeprenlimab works earlier in that chain. It blocks a signal called APRIL, which drives the making of the abnormal IgA. Less of the faulty antibody means less clogging of the filters.

What you can do today

Get your own numbers in one place. If you have IgA nephropathy, write down your latest eGFR and urine protein results with their dates. You can find them on your lab report or in your patient portal. Bring the list to your next visit with your kidney doctor, so you can see your trend and ask about newer treatments that target the cause of the disease. Keep up your blood pressure care, too.