(A) Schematic representation of the IL-23–specific human hypersialylated (α2,6) IgG1 antibody with the F241A mutation (IL-23–IgG1–F241A). (B and C) Clinical scores (mean ± SEM) (B) or area under the curve (AUC) of clinical scores (box-and-whiskers plot) (C) of joint inflammation in KBxN mice treated with PBS or the indicated doses of human IL-23–IgG1, IL-23–IgG1–F241A, or TNP-specific IgG1-F241A antibodies. Depicted is the combination of 2 independent experiments with n = 6–12 mice per group. For statistical analysis, an ordinary 1-way ANOVA and a Dunnett’s multiple-comparison test were used. ***P < 0.001, ****P < 0.0001. (D and E) Quantification of bone erosions (in mm²) (D) and of the number of TRAP⁺ osteoclasts (E) on the surface of bone erosions in histological samples of KBxN mice treated with PBS or the respective amounts of the IL-23–IgG1, IL-23–IgG1–F241A, or TNP-IgG1-F241A antibody. Shown are all data points and the mean ± SEM of the combination of 2 independent experiments (n = 5–6 mice per group). For statistical analysis, a 2-way ANOVA and a Tukey’s multiple comparisons test were used. ***P < 0.001, ****P < 0.0001. (F) Clinical scores of KBxN mice treated with the indicated amounts of IL-23–IgG1, IgG1-F241A-Fc, IL-23–IgG1 + IgG1-F241A-Fc, IL-23–IgG1–F241A, or PBS. Statistically significant differences against PBS treatment were identified by using a 2-way ANOVA and Šídák’s multiple-comparison test. Depicted is the mean ± SEM of the combination of 2 independent experiments (n = 5–10 mice per group). *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.