Pegcetacoplan is a preparation approved as the first treatment for patients from 12 years of age with C3 glomerulopathy (C3G) or primary immune complex membranoproliferative glomerulonephritis (IC-MPGN). The approval is based on the results of the phase 3 VALIANT trial, in which patients treated with pegcetacoplan achieved a 68% reduction in proteinuria compared to placebo. Treatment stabilized kidney function, as measured by estimated glomerular filtration rate (eGFR), and significantly improved histological findings – 71% of patients achieved complete clearance of C3 deposits in the kidneys. Results were consistent in both adolescents and adults, including kidney transplant patients with relapsed disease. No serious safety issues were reported in the study, and the incidence of adverse events was similar to placebo. Pegcetacoplan is an inhibitor of the complement system that directly affects the underlying mechanism of the disease. This treatment represents a significant advance for patients with these rare kidney diseases.