The lipid A antagonist E-5531 is the first agent that has been shown to block or ameliorate all the effects of bacterial lipopolysaccharide [LPS] endotoxin in a human endotoxin challenge model, according to study results presented at the 7th International IBC Conference on Sepsis [Washington DC, US; April 1997]. Treatment with E-5531 was one of 3 new methods of neutralising the effects of LPS in Gram-negative sepsis that were presented at the conference. The other approaches discussed were the use of the lipid A biosynthesis inhibitor L-573655 and its analogues, and the administration of reconstituted HDL-cholesterol for clearing LPS from the circulation. According to leading researchers in the field, blocking the effects of LPS may be the key to reducing mortality and morbidity rates in sepsis.