When dosed orally once daily at 5, 20, and 45 mg/kg to mice, BMS-935177 inhibits anti-KLH antibodies of the IgG isotype at day 14, with statistically significant reductions at all doses. In satellite mice from this study dosed with 6 at 5 mg/kg, the plasma concentration is maintained above the mouse whole blood BCR-stimulated CD69 IC50 value of 2 μM for only approximately 5 h. At once daily oral doses of 10, 20, and 30 mg/kg beginning on the day of primary immunization, BMS-935177 provides a clear dose-dependent reduction in both the severity and incidence of clinically evident disease in this rodent model of RA. At 10 mg/kg of BMS-935177, disease severity is reduced about 40% compared to vehicle treatment, and the percentage of animals showing any signs of disease is reduced by a third.