A Phase III trial published in the New England Journal of Medicine showed pegcetacoplan, a C3 complement inhibitor, produced substantial reductions in proteinuria and stabilized kidney function in patients with C3 glomerulopathy (C3G) and immune‑complex MPGN. The multicenter, randomized study reported up to 68% reduction in urine protein and high remission rates in pediatric patients, leading to recent FDA approval for patients 12 and older. Investigators from the University of Iowa and 122 centers worldwide detailed histologic and clinical remission rates, marking a mechanistic advance by directly targeting complement dysregulation at the root of disease.