First-in-class treatment delivers major advance for incurable kidney disease

The latest findings from the PROTECT phase III trial show sparsentan - a novel treatment for IgA nephropathy - significantly reduces proteinuria, or abnormal protein levels in the urine, compared to standard treatment irbesartan.

The interim analysis of data from the PROTECT trial was published today in The Lancet and simultaneously presented at the World Congress of Nephrology in Bangkok, Thailand.

IgA nephropathy, also known as Berger’s disease, is a condition where the antibody immunoglobulin A (IgA) builds up in the kidneys, causing inflammation and scarring. In healthy people, IgA is produced by the body to fight infection, but in patients with IgA nephropathy it affects kidney function and progresses to end-stage kidney disease in a quarter of cases over ten years1.

Lead author Professor Hiddo Lambers Heerspink, Clinical Pharmacologist at the University Medical Center Groningen, Netherlands, and Director, Better Treatments Program at The George Institute for Global Health said, “IgA nephropathy is a chronic kidney disease with no cure, so optimising supportive care to slow further kidney damage by reducing proteinuria is vital. This data shows sparsentan was responsible for a rapid and sustained reduction in proteinuria, and this has the potential to prevent progressive kidney function loss in patients with the disease”.

PROTECT is a multicentre, randomised double-blind active-controlled trial, assessing sparsentan versus the active comparator irbesartan in patients with IgA nephropathy. 280 patients were assessed in a prespecified interim analysis at 36 weeks for the primary endpoint of change in urine protein/creatinine (UP/C) ratio from baseline, a measure of proteinuria.

Among patients treated with sparsentan, the mean percentage reduction in UP/C from baseline was 49.8%, versus a 15.1% reduction with irbesartan, a relative reduction in UP/C with sparsentan of 41%. Sparsentan showed a favourable safety profile comparable to irbesartan. Changes in body weight, which acts as a proxy measure of fluid retention, and reductions in blood pressure were also comparable between the two treatment arms.

Professor Vlado Perkovic, Dean of Medicine and Health at UNSW, Sydney, and Professorial Fellow at The George Institute for Global Health said, “Sparsentan represents a new class of drug that promises great benefit for patients with IgA nephropathy. With its recent approval in the US and anticipated approval in other countries, I look forward to seeing the difference this treatment could make for those living with IgA nephropathy.”

The PROTECT trial will continue for another 110 weeks, to validate the finding that sparsentan compared to irbesartan not only reduces proteinuria, but also slows the decline of estimated glomerular filtration rate (eGFR) - another measure of kidney function.

With around 10% of the world’s population being affected by chronic kidney disease, The George Institute for Global Health is committed to addressing the challenges faced by this patient population through improvements to treatment and care.



  1. Storrar J et al. The epidemiology and evolution of IgA nephropathy over two decades: A single centre experience. PLOS One. September 1, 2022.