Immunotherapy for Prostate Cancer Enters Its Golden Age

In the United States, prostate cancer is the most frequent malignancy in men and ranks second in terms of mortality. Although recurrent or metastatic disease can be managed initially with androgen ablation, most patients eventually develop castration-resistant disease within a number of years, for which conventional treatments (eg, chemotherapy) provide only modest benefits. In the last few years, immunotherapy has emerged as an exciting therapeutic modality for advanced prostate cancer, and this field is evolving rapidly. Encouragingly, the US Food and Drug Administration (FDA) has recently approved two novel immunotherapy agents for patients with advanced cancer: the antigen presenting cell-based product sipuleucel-T and the anti-CTLA4 (cytotoxic T-lymphocyte antigen 4) antibody ipilimumab, based on improvements in overall survival in patients with castration-resistant prostate cancer and metastatic melanoma, respectively. Currently, a number of trials are investigating the role of various immunological approaches for the treatment of prostate cancer, many of them with early indications of success. As immunotherapy for prostate cancer enters its golden age, the challenge of the future will be to design rational combinations of immunotherapy agents with each other or with other standard prostate cancer treatments in an effort to improve patient outcomes further.