ObjectivesTo determine the safety and pharmacokinetics of a murine monoclonal antibody to E-selectin in patients with newly developed septic shock.DesignOpen-label, prospective, phase II pilot study with escalating doses of the antibody.SettingIntensive care unit of a 900-bed university hospital.PatientsNine patients who survived the first 24 hrs of septic shock.InterventionsIn addition to standard therapy, an intravenous bolus of a murine monoclonal antibody to E-selectin, CY1787, was given at doses of 0.1 mg/kg (n equals 3), 0.33 mg/kg (n equals 3), and 1.0 mg/kg (n equals 3).Measurements and Main ResultsCY1787 was well tolerated in all patients. Signs of shock resolved in all patients, and organ failure entirely reversed in eight patients. All patients survived the 28-day follow-up. Administration of CY1787 was associated with an early and brisk increase in Pao2/FIO2ratio (p less than .001), from 146 plus minus 38 mm Hg (19.5 plus minus 5.1 kPa) to 205 plus minus 45 mm Hg (27.3 plus minus 6.0 kPa) after 2 hrs, and 250 plus minus 58 mm Hg (33.3 plus minus 7.7 kPa) after 12 hrs. A doserelated effect of CY1787 was suggested by an earlier weaning from catecholamine therapy and a faster resolution of organ failure in the high-dose group. Development of antimouse antibodies was documented in eight patients.ConclusionsThis pilot study indicates that this antibody to E-selectin appears to be safe and may represent a promising form of therapy in septic shock.(Crit Care Med 1996; 24:229-233)