The VALIANT study was a double-blind, placebo-controlled, phase 3 clinical trial that investigated the efficacy and safety of pegcetacoplan, a C3 and C3b inhibitor, in adolescents and adults with C3 glomerulopathy or primary immune complex membranoproliferative glomerulonephritis (MPGN), including both native and transplant patients.[2] Patients were randomly assigned 1:1 to pegcetacoplan or placebo.[2] The primary endpoint was the log-transformed ratio of urinary protein to creatinine at week 26 versus baseline.[2] Pegcetacoplan achieved a statistically significant reduction in proteinuria of 68% (95% CI, 57.3 to 76.2; p < 0.0001) compared with placebo.[2][3] Activity adjustment in the histological index of glomerulopathy C3 was not significantly different between groups in 69 patients with evaluable kidney biopsies.[2] Pegcetacoplan did not increase the incidence of adverse events compared to placebo, there were no serious infections with encapsulated bacteria, or graft rejection or loss; one patient on pegcetacoplana died of coronavirus pneumonia.[2]