Effect of iptacopan (antifactor B), danicopan (antifactor D), eculizumab (anti-C5), ravulizumab (anti-C5), and AMY-101 (anti-C3) on C3 and C5b-9 deposition on the surface of Np, Hi, and Sp. A twofold dilution series of complement inhibitors was made with pooled plasma. Bacteria (Nm, Hi, and Sp) were incubated in 10% plasma for 30 minutes at 37°C, and binding of C3 and C5b-9 was determined by flow cytometry. Binding of C3 is represented in black and binding of C5b-9 is represented in red (mean ± standard error of the mean; Nm: n = 3 for all inhibitors, except for iptacopan C5b-9 (n = 2); Hi: n = 3 for iptacopan, danicopan, and eculizumab, and n = 4 for AMY-101 and ravulizumab; and Sp: n = 4 for AMY-101, n = 5 for iptacopan and danicopan, n = 7 for eculizumab and n = 6 for ravulizumab). The results were normalized to pooled plasma without inhibitors. IC50 values were determined using variable-slope, 4-parameter nonlinear regression analysis in GraphPad Prism.
