Vaccine therapy for patients with melanoma.

Investigation into the therapeutic use of vaccines in patients with metastatic melanoma is critically important because of the lack of effective conventional modalities. The most extensively studied melanoma vaccines in clinical trials are whole-cell preparations or cell lysates that contain multiple antigens capable of stimulating an immune response. Unfortunately, in the majority of studies, immune responses to these vaccines have not translated into a survival advantage. Advances in tumor cell immunology have led to the identification of candidate tumor cell antigens that can stimulate an immune response; this, in turn, has allowed for refinements in vaccine design. However, the exact tumor antigens that should be targeted with a specific vaccine are unknown. The univalent antigen vaccines, which have greater purity, ease of manufacturing, and reproducibility compared with polyvalent vaccines, may suffer from poorer efficacy due to immunoselection and appearance of antigen-negative clones within the tumor. Novel approaches to vaccine design using gene transfection with cytokines and dendritic cells are all promising. However, the induction of immune responses does not necessarily confer a therapeutic benefit. Therefore, these elegant newer strategies need to be studied in carefully designed clinical trials so that outcomes can be compared objectively with standard therapy. If survival is improved with these vaccine approaches, their ease of administration and lack of toxicity will firmly entrench active specific vaccine immunotherapy as a standard modality in the treatment of the melanoma patient.