Sibeprenlimab is a new biological drug that targets the cytokine APRIL and is intended for the treatment of IgA nephropathy, the most common primary glomerulonephritis in the world.[4][9] An interim analysis of a phase 3 trial demonstrated that sibeprenlimab achieved a significant reduction in pathological IgA and proteinuria in patients with this disease.[4] IgA nephropathy is a chronic disease that leads to the deposition of immunoglobulin A in the kidneys and is one of the leading causes of end-stage renal failure.[9] The treatment with sibeprenlimab represents a new approach in the treatment of this disease, since there is no optimal therapy so far and mainly ACE inhibitors and corticosteroids are used.[3] Clinical studies III. phases of this drug aim to comprehensively evaluate its safety and efficacy in a wider patient population.[6] Results from a preliminary analysis suggest the potential of sibeprenlimab as an effective drug to slow the progression of this serious kidney disease.