DRB1*11 allele expression and HER2 pre-existing immunity may predict benefit in breast cancer patients vaccinated with the HER2 modified AE37 peptide vaccine

Background Identification of immune biomarkers indicating potential clinical benefit from immunotherapies may contribute to the selection of the right patient for the right therapy. We have recently reported that HLA-DRB1*11 and HLA-A*24 alleles might serve as predictive factors for immunological and clinical responses to vaccination with AE37, the Ii-Key hybrid peptide of HER2776-790 (AE36) in prostate cancer patients. The purpose of this study was to investigate the predictive significance of DRB1*11 allele expression in relation to immunological and clinical response in breast cancer patients vaccinated with AE37 in a randomized Phase II clinical trial.