From bench to bedside: The use of the li-Key technology to improve helper peptides for clinical use in cancer vaccines.

2508 Background: Work involving peptide vaccines has shown that peptides containing MHC Class II epitopes, which elicit CD4+ T cell responses, may play a role in potentiating an immune response. The Ii-Key peptide (amino acids 77-80 of the immune-regulatory Ii protein), when covalently linked to an MHC Class II epitope, can induce conformational change in the epitope binding groove, increasing CD4+ T cell stimulation up to 250 fold. Here we present an update of results from clinical trials evaluating this novel technology in an adjuvant breast cancer vaccine targeting HER2/neu. Methods: We reviewed our trials investigating AE37, a hybrid peptide created by the addition of the Ii-Key peptide (LRMK) to AE36 (GVGSPYVSRLLGICL), an MHC Class II-binding peptide from the intracellular domain of the HER2 protein. We have completed a phase I study and are currently conducting a randomized phase II trial of the AE37 peptide + GM-CSF in the adjuvant treatment of disease-free breast cancer patients with any level of ...