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Updated: Oct 22, 2026

Intravenous Endotoxin Challenge in Healthy Humans: An Experimental Platform to Investigate and Modulate Systemic Inflammation
Published on: May 16, 2016
The effect of the lipid A analog, E5531 on fever induced by endotoxin from Escherichia coli
1Formulation Research Laboratory, Kawashima, Eisai Co., Ltd., Gifu, Japan.
Abstract:
E5531 is a specific lipid A antagonist and is expected to be a drug for the treatment of septic shock. The LAL (limulus amebocyte lysate) activity and pyrogenicity of E5531 were determined. The LAL activity of E5531 is large and confirmed that E5531 had a high affinity to the lipopolysaccharide receptor. The pyrogenic activity of E5531 is weak and the pyrogenic profile of E5531 is different from that of USP (United States Pharmacopoeia) reference standard endotoxin (ETX). E5531 suppressed the pyrogenicity of ETX in rabbits, indicating that E5531 is expected to be useful for the treatment of fever induced by ETX.

