INTERSEPT: an international, multicenter, placebo-controlled trial of monoclonal antibody to human tumor necrosis factor-alpha in patients with sepsis. International Sepsis Trial Study Group

Abstract

Objective: To determine the safety and efficacy of BAY x 1351, a murine monoclonal antibody to recombinant human tumor necrosis factor (TNF)-alpha, in patients with sepsis.

Design: An international, multicenter, prospective, placebo-controlled trial in patients with sepsis, stratified into shock/nonshock groups.

Setting: Forty acute clinical care facilities in 14 countries.

Patients: Of the 564 patients enrolled in the study, 553 patients received study drug or placebo.

Interventions: Patients received 15 mg/kg or 3 mg/kg of BAY x 1351, or placebo, as a single intravenous infusion.

Measurements and main results: The patients were well matched for severity of illness and for risk factors known to influence the outcome of sepsis. There was no difference in 28-day mortality rates between groups (placebo group 66 [39.5%] of 167;3 mg/kg group 57 [31.5%] of 181; 15 mg/kg group 87 [42.4%] of 205). Approximately 9 months after this study had begun, an interim safety examination of NORASEPT, a North American Sepsis Trial using the same monoclonal antibody, indicated that there was no benefit to patients in the nonshock group and further enrollment of these nonshock septic patients into INTERSEPT was stopped. The analysis therefore focused on the 420 patients in shock. The primary efficacy variable was the 28-day, all-cause mortality rate: placebo group 57 (42.9%) of 133; 3-mg/kg group 51 (36.7%) of 139; and 15-mg/kg group 66 (44.6%) of 148 (not significant). Two secondary efficacy variables were identified prospectively: shock reversal and frequency of organ failures. Life-table analysis showed that in patients who survived 28 days, there was a more rapid reversal of shock in both treatment groups compared with placebo (15-mg/kg group vs. placebo group log-rank statistic p = .007, 3-mg/kg group vs. placebo group p = .01). Similarly, in patients surviving 28 days, there was a significant delay in the time to the onset of first organ failure (log rank 15 mg/kg vs. placebo p = .03, 3 mg/kg vs. placebo p = .07), and more patients in the placebo group developed at least one organ failure: 15-mg/kg group 33 (40.2%) of 82; 3-mg/kg group 39 (44.3%) of 88; and placebo group 45 (59.2%) of 76 (15 mg/kg vs. placebo p = .03, 3 mg/kg vs. placebo p = .06). No significant adverse events were associated with the monoclonal antibody treatment.

Conclusions: INTERSEPT provides additional clinical data implicating TNF-alpha as an integral mediator of septic shock. The study suggested a possible role for anti-TNF antibody as adjunctive therapy, but this possibility requires confirmation by another clinical trial.