Phase 2 trial of eritoran tetrasodium (E5564), a toll-like receptor 4 antagonist, in patients with severe sepsis.

Abstract

Endotoxin is a potent stimulus of proinflammatory response and systemic coagulation in patients with severe sepsis. Endotoxin is a component of Gram-negative bacteria that triggers an innate immune response through Toll-like receptor 4 signaling pathways in myeloid cells. We evaluated safety and tolerability of two dose regimens of eritoran tetrasodium (E5564), a synthetic Toll-like receptor 4 antagonist, and explored whether it decreases 28-day mortality rate in subjects with severe sepsis. Prospective, randomized, double-blind, placebo-controlled, multicenter, ascending-dose phase II trial. Adult intensive care units in the United States and Canada. Three hundred adults within 12 hrs of recognition of severe sepsis, with Acute Physiology and Chronic Health Evaluation (APACHE) II-predicted risk of mortality between 20% and 80%. Intravenous eritoran tetrasodium (total dose of either 45 mg or 105 mg) or placebo administered every 12 hrs for 6 days. Prevalence of adverse events was similar among subjects treated with 45 mg or 105 mg of eritoran tetrasodium or with placebo. For modified intent-to-treat subjects, 28-day all-cause mortality rates were 26.6% (eritoran tetrasodium 105 mg), 32.0% (eritoran tetrasodium 45 mg), and 33.3% in the placebo group. Mortality rate in the eritoran tetrasodium 105-mg group was not significantly different from placebo (p = .335). In prespecified subgroups, subjects at highest risk of mortality by APACHE II score quartile had a trend toward lower mortality rate in the eritoran tetrasodium 105-mg group (33.3% vs. 56.3% placebo group, p = .105). A trend toward a higher mortality rate was observed in subjects in the lowest APACHE II score quartile for the eritoran 105-mg group (12.0% vs. 0.0% placebo group, p = .083). Eritoran tetrasodium treatment appears well tolerated. The observed trend toward a lower mortality rate at the 105-mg dose, in subjects with severe sepsis and high predicted risk of mortality, should be further investigated.