Sparsentan in IgA nephropathy: a plain language summary of publication for the PROTECT study

What is this summary about? Sparsentan (FILSPARI^®) is a once-daily pill for people with Immunoglobulin A (IgA) nephropathy who are at high risk for worsening kidney disease. Early results from a research study (clinical trial) called PROTECT showed that after 9 months of treatment, sparsentan lowered proteinuria more than irbesartan, a blood pressure medication commonly used to treat IgA nephropathy. These results contributed to sparsentan receiving approval in the United States, the European Union, Switzerland, and the United Kingdom in 2024. This is a plain language summary of publication of an original article published in The Lancet (a medical journal) in November 2023, which reported further results from the PROTECT study. The original article reported on how well sparsentan worked to lower proteinuria and slow the worsening of kidney function (measured by estimated glomerular filtration rate (eGFR)) in people with IgA nephropathy compared with the highest possible dose of irbesartan over an approximately 2-year treatment period. The article also described the side effects that people enrolled in this study had with either sparsentan or irbesartan.