Therapeutic vaccines for prostate cancer

Although androgen deprivation is the standard of care for advanced prostate cancer, patients with metastatic disease eventually progress to a castration-resistant state. The available options for secondary therapy are hormonal therapy and chemotherapy. Significant potential remains for the development of alternative approaches, which can improve survival with early treatment but do not cause the toxicities associated with chemotherapy. The field of immunotherapy for prostate cancer has recently made significant progress, and data from several clinical trials demonstrating the efficacy of this type of therapy have been reported. These reports include data from randomized controlled trials with sipuleucel-T (Dendreon Corp) and with PROSTVAC-VF-TRICOM (NCI/BN ImmunoTherapeutics Inc), both of which resulted in improvements in overall survival in patients with advanced prostate cancer. Although these results are encouraging, there are many unresolved questions regarding immunotherapy, including the best clinical setting for immunotherapy, the definition of relevant clinical and immunological endpoints, and the potential combination of immunotherapies with other treatments. This review discusses the most promising recent developments in vaccine therapy for prostate cancer, as well as the challenges remaining to be addressed.