E6020: a synthetic Toll-like receptor 4 agonist as a vaccine adjuvant

Expert Rev Vaccines. 2007 Oct;6(5):773-84. doi: 10.1586/14760584.6.5.773.


Safe and cost-effective adjuvants are a critical component to enhance the efficacy of subunit vaccines. Studies have demonstrated that modified natural lipid As derived from enterobacterial lipopolysaccharides, which are agonists of Toll-like receptor 4, are beneficial to vaccine performance. The synthetic phospholipid dimer, E6020, mimics the physicochemical and biological properties of many of the natural lipid As derived from gram-negative bacteria. Similar to its natural counterparts, E6020, which was discovered and developed by Eisai, agonizes Toll-like receptor 4, albeit in an attenuated fashion, eliciting an immunostimulatory response that is conducive to use as a vaccine adjuvant. The derivation of E6020, along with physicochemical properties and in vitro and in vivo studies of immunostimulation and adjuvant activity, are reviewed as a background to its imminent assessment in the clinic.

Publication types

  • Review

MeSH terms

  • Adjuvants, Immunologic / administration & dosage
  • Adjuvants, Immunologic / chemistry*
  • Animals
  • Humans
  • Phospholipids / administration & dosage
  • Phospholipids / chemistry*
  • Toll-Like Receptor 4 / administration & dosage
  • Toll-Like Receptor 4 / chemistry*
  • Vaccines / administration & dosage
  • Vaccines / chemistry*


  • Adjuvants, Immunologic
  • ER-804053
  • Phospholipids
  • TLR4 protein, human
  • Toll-Like Receptor 4
  • Vaccines