PURPOSE: To evaluate the safety, tolerability, pharmacokinetics, and efficacy of kukoamine B (KB), an alkaloid compound with high affinity for both lipopolysaccharide (LPS) and oligodeoxynucle-otides containing CpG motifs (CpG DNA), in patients with sepsis-induced organ failure. MATERIALS AND METHODS: This was a multicenter, randomized, double-blind, placebo-controlled phase IIa trial. Patients with sepsis-induced organ failure were randomized to receive either KB (0.06, 0.12, or 0.24 mg/kg) or placebo, every 8 h for 7 days. Primary endpoint was safety, and secondary endpoints included pharmacokinetic (PK) parameters, changes in inflammatory mediators' level, and prognostic parameters. RESULTS: Of 44 patients enrolled, adverse events occurred in 28 patients [n = 20, 66.7% (KB pooled); n = 8, 57.1% (placebo)], while treatment emergent adverse events were reported in 14 patients [n = 10, 33.3% (KB pooled); n = 4, 28.6% (placebo)]. Seven patients died at 28-day follow-up [n = 4, 13.3% (KB pooled); n = 3, 21.4% (placebo)], none was related to study drug. PK parameters suggested dose-dependent drug exposure and no drug accumulation. KB did not affect clinical outcomes such as DeltaSOFA score, vasopressor-free days or ventilator-free days. CONCLUSIONS: In patients with sepsis-induced organ failure, KB was safe and well tolerated. Further investigation is warranted. TRIAL REGISTRATION: http://ClinicalTrials.gov, NCT03237728. CI - Copyright (c) 2023. Published by Elsevier Inc.