Treatment of Septic Shock with the Tumor Necrosis Factor Receptor:Fc Fusion Protein

BACKGROUND: A recombinant, soluble fusion protein that is a dimer of an extracellular portion of the human tumor necrosis factor (TNF) receptor and the Fc portion of IgG1 (TNFR:Fc) binds and neutralizes TNF-alpha and prevents death in animal models of bacteremia and endotoxemia. METHODS: To evaluate the safety and efficacy of TNFR:Fc in the treatment of septic shock, we conducted a randomized, double-blind, placebo-controlled, multicenter trial. A total of 141 patients were randomly assigned to receive either placebo or a single intravenous infusion of one of three doses of TNFR:Fc (0.15, 0.45, or 1.5 mg per kilogram of body weight). The primary end point was mortality from all causes at 28 days. RESULTS: There were 10 deaths among the 33 patients in the placebo group (30 percent mortality), 9 deaths among the 30 patients receiving the low dose of TNFR:Fc (30 percent mortality), 14 deaths among the 29 receiving the middle dose (48 percent mortality), and 26 deaths among the 49 receiving the high dose (53 percent mortality) (P = 0.02 for the dose-response relation). Baseline differences in the severity of illness did not account for the increased mortality in the groups receiving the higher doses of TNFR:Fc. CONCLUSIONS: In patients with septic shock, treatment with the TNFR:Fc fusion protein does not reduce mortality, and higher doses appear to be associated with increased mortality.