Purpose

Interest in the development of antimelanoma peptide vaccines has been renewed by the identification of specific epitopes recognized by tumor-infiltrating lymphocytes that mediate tumor regression after adoptive transfer. The human leukocyte antigen (HLA)-A2* 0201-restricted, nonmutated melanocyte differentiation antigen gp100 has multiple T-cell epitopes, of which three are recognized by most gp100-reactive tumor infiltrating lymphocytes. Synthetic peptides based on two of these epitopes, or modifications to improve HLA binding affinity, were used individually to vaccinate patients with metastatic melanoma. The purpose of this study was to evaluate the success of the vaccinations, as determined by the results of enzyme-linked immunospot (ELISPOT) tests of individual immune cells.