International meeting on cancer vaccines: how can we enhance efficacy of therapeutic vaccines?

The major aims of the International Meeting on Cancer Vaccines were to review the state-of-the-art research on cancer vaccines, to compare different experimental approaches of therapeutic vaccination and to discuss critical issues and perspectives. The results from recent clinical trials in patients treated with different types of cancer vaccines were presented. Reasons for the limited response and possible modalities for enhancing efficacy of therapeutic vaccines were subjects of major discussion. A consensus was achieved on the need of combining cancer vaccines with other anticancer treatments. Of note, evidence stemming from studies in animal models pointed out new rationales for a selective combination of cancer vaccines with chemotherapy. In addition, some main presentations focused on new adjuvants (CpG oligonucleotides) and on the role of cytokines (i.e., type I IFN, interleukin 12, and interleukin 15) in promoting an antitumor immune response to vaccines. A considerable attention was given to regulatory T cells and to strategies for suppressing their function, thus enhancing vaccine efficacy. An entire session was devoted to the use of dendritic cells for the development of cancer vaccines. The results of clinical studies and the advantages of using new modalities for preparing dendritic cell-based vaccines were discussed.