Peptide-based cancer vaccines.

The characterization of tumor antigens recognized by T lymphocytes has provided the opportunity to immunize cancer patients with well-defined peptides. Differentiation and tumor-specific antigens are expressed in a significant proportion of patients with cancer. Pilot studies have involved many patients with melanoma. No major toxicity has been reported after peptide vaccination. The clinical efficacy of peptide vaccines is limited to a minority of patients and the response rate is less than 20%. Some regressions have been complete and long-lasting. The development of this approach, and that of other methods to deliver tumor antigens, depends on clinical empirism to improve the therapeutic efficacy of the vaccine as well as the accurate understanding of the immune mechanisms involved in vivo. Copyright 2002, Elsevier Science (USA). All rights reserved.