[Show abstract][Hide abstract] ABSTRACT: We prepared and characterized golimumab, a human IgG1 tumor necrosis factor alpha (TNFalpha) antagonist monoclonal antibody chosen for clinical development based on its molecular properties. Golimumab was compared with infliximab, adalimumab and etanercept for affinity and in vitro TNFalpha neutralization. The affinity of golimumab for soluble human TNFalpha, as determined by surface plasmon resonance, was similar to that of etanercept (18 pM versus 11 pM), greater than that of infliximab (44 pM) and significantly greater than that of adalimumab (127 pM, p = 0.018). The concentration of golimumab necessary to neutralize TNFalpha-induced E-selectin expression on human endothelial cells by 50% was significantly less than those for infliximab (3.2-fold; p = 0.017) and adalimumab (3.3-fold; p = 0.008) and comparable to that for etanercept. The conformational stability of golimumab was greater than that of infliximab (primary melting temperature [Tm] 74.8 degrees C vs. 69.5 degrees C) as assessed by differential scanning calorimetry. In addition, golimumab showed minimal aggregation over the intended shelf life when formulated as a high concentration liquid product (100 mg/mL) for subcutaneous administration. In vivo, golimumab at doses of 1 and 10 mg/kg significantly delayed disease progression in a mouse model of human TNFalpha-induced arthritis when compared with untreated mice, while infliximab was effective only at 10 mg/kg. Golimumab also significantly reduced histological scores for arthritis severity and cartilage damage, as well as serum levels of pro-inflammatory cytokines and chemokines associated with arthritis. Thus, we have demonstrated that golimumab is a highly stable human monoclonal antibody with high affinity and capacity to neutralize human TNFalpha in vitro and in vivo.