Multiple-center, randomized, placebo-controlled, double-blind study of the nitric oxide synthase inhibitor 546C88: effect on survival in patients with septic shock.

OBJECTIVE: To assess the safety and efficacy of the nitric oxide synthase inhibitor 546C88 in patients with septic shock. The predefined primary efficacy objective was survival at day 28. DESIGN: Multiple-center, randomized, two-stage, double-blind, placebo-controlled, safety and efficacy study. SETTING: A total of 124 intensive care units in Europe, North America, South America, South Africa, and Australasia. PATIENTS: A total of 797 patients with septic shock diagnosed for <24 hrs. INTERVENTIONS: Patients with septic shock were allocated to receive 546C88 or placebo (5% dextrose) for up to 7 days (stage 1) or 14 days (stage 2) in addition to conventional therapy. Study drug was initiated at 0.05 mL.kg(-1).hr(-1) (2.5 mg.kg(-1).hr(-1) 546C88) and titrated up to a maximum rate of 0.4 mL.kg(-1).hr(-1) to maintain mean arterial pressure between 70 and 90 mm Hg while attempting to withdraw concurrent vasopressors. MEASUREMENTS AND MAIN RESULTS: Hemodynamic variables, organ function data, microbiological data, concomitant therapy, and adverse event data were recorded at baseline, throughout treatment, and at follow-up. The primary end point was day-28 survival. The trial was stopped early after review by the independent data safety monitoring board. Day-28 mortality was 59% (259/439) in the 546C88 group and 49% (174/358) in the placebo group (p <.001). The overall incidence of adverse events was similar in both groups, although a higher proportion of the events was considered possibly attributable to study drug in the 546C88 group. Most of the events accounting for the disparity between the groups were associated with the cardiovascular system (e.g., decreased cardiac output, pulmonary hypertension, systemic arterial hypertension, heart failure). The causes of death in the study were consistent with those expected in patients with septic shock, although there was a higher proportion of cardiovascular deaths and a lower incidence of deaths caused by multiple organ failure in the 546C88 group. CONCLUSIONS: In this study, the nonselective nitric oxide synthase inhibitor 546C88 increased mortality in patients with septic shock.

Open randomized phase II trial of an extracorporeal endotoxin adsorber in suspected Gram-negative sepsis.

OBJECTIVE: An initial phase II trial to investigate the safety and therapeutic effect of the endotoxin adsorber system EN 500 in septic patients suffering from presumed Gram-negative infection. DESIGN: Open, controlled, prospective, randomized, multiple-center, parallel-group clinical trial. SETTING: Intensive care units of 31 university-affiliated and community hospitals in Europe. PATIENTS: One hundred forty-five patients with a clinical diagnosis of severe sepsis or septic shock due to suspected Gram-negative infection. INTERVENTIONS: Patients were randomized to receive either standard therapy alone for sepsis (n = 76) or standard therapy plus extracorporeal endotoxin adsorption (n = 67) daily for the first 4 days following study entry. MEASUREMENTS AND MAIN RESULTS: The primary end point was the proportion of responders (defined as a decrease in Acute Physiology and Chronic Health Evaluation II score by > or =4 points from study entry to day 4). Secondary outcomes were the Sequential Organ Failure Assessment score and its components, length of intensive care unit stay, survival rate, and safety of the adsorber treatment. Patient characteristics at entry were well balanced between the two treatment groups, except for a higher Sequential Organ Failure Assessment score in the adsorber group. On all-subjects-treated analysis, 65% of the adsorber group were responders vs. 57% for the standard (p =.389). A planned interim analysis restricted further enrollment to patients with peritonitis, in whom a slightly higher proportion of responders was observed with the adsorber treatment (69%) vs. standard treatment (54%, p =.159). There were no differences in survival, but adsorption treatment in peritonitis patients was associated with trends toward a reduction in length of intensive care unit stay and a more rapid decline in plasma endotoxin concentrations. There was a significantly greater reduction in platelet count with the adsorber; however, this did not require extra treatment. CONCLUSIONS: The endotoxin adsorber system did not result in a significantly improved primary end point in patients with presumed Gram-negative sepsis. In patients with peritonitis, the adsorber treatment likewise did not result in significantly improved Acute Physiology and Chronic Health Evaluation II scores. There were no clinically important side effects. These results provide encouragement for further study of adsorber treatment in patients with high likelihood of Gram-negative sepsis (e.g., peritonitis).