Melanoma Vaccines: What We Know So FarJanuary 1st 2005
Vaccines are a promising but still experimental treatment for melanoma.They are intended to stimulate immune responses against melanomaand by so doing, increase resistance against and slow the progressionof this cancer. Key requirements for vaccines to be effectiveare that they contain antigens that can stimulate tumor-protective immuneresponses and that some of these antigens are present on thetumor to be treated. Unfortunately, these antigens are still not known.To circumvent this problem, polyvalent vaccines can be constructedcontaining a broad array of melanoma-associated antigens. Severalstrategies are available to construct such polyvalent vaccines; each hasadvantages and disadvantages. Clinical trials have shown that vaccinesare safe to use and have much less toxicity than current therapy formelanoma. Vaccines can stimulate both antibody and T-cell responsesagainst melanoma, with the type of response induced, its frequency,and its magnitude depending on the vaccine and the adjuvant agentused. A growing body of evidence suggests that vaccines can be clinicallyeffective. This evidence includes correlations between vaccineinducedantibody or T-cell responses and improved clinical outcome,clearance of melanoma markers from the circulation, improved survivalcompared to historical controls, and most convincingly, two randomizedtrials in which the recurrence-free survival of vaccine-treatedpatients was significantly longer than that of control groups.