Therapeutic vaccines for cancer: an overview of clinical trials

Active immunotherapy is emerging as an important addition to conventional cancer treatments, but many important questions remain. Optimal combinations of antigens, adjuvants and delivery vehicles need to be determined and effective strategies for overcoming tumour-associated immunosuppression ought to be developed. This Review provides an overview of new results from clinical studies of therapeutic cancer vaccines directed against tumour-associated antigens and discusses their implications for the use of active immunotherapy. The therapeutic potential of host-specific and tumour-specific immune responses is well recognized and, after many years, active immunotherapies directed at inducing or augmenting these responses are entering clinical practice. Antitumour immunization is a complex, multi-component task, and the optimal combinations of antigens, adjuvants, delivery vehicles and routes of administration are not yet identified. Active immunotherapy must also address the immunosuppressive and tolerogenic mechanisms deployed by tumours. This Review provides an overview of new results from clinical studies of therapeutic cancer vaccines directed against tumour-associated antigens and discusses their implications for the use of active immunotherapy.