The last decade has seen remarkable advances in the treatment of prostate cancer. Until 2010, only docetaxel had demonstrated the ability to improve the survival in metastatic castration-resistant prostate cancer (mCRPC). While effective, many men were reluctant to get treatment with docetaxel because of the perceived toxicity, thereby further limiting the benefit of the one available and effective therapy. Remarkably, within the last 8 years, the field has seen a multitude of therapies that demonstrate an ability to extend survival for men with prostate cancer. Abiraterone and enzalutamide demonstrated the importance of the androgen axis in propelling prostate cancer growth. Sipuleucel-T was immunotherapy's entry into the evolving prostate cancer armamentarium, as the therapeutic cancer vaccine established an ability to extend survival despite an apparent lack of short-term effect on progression-free survival and prostate-specific antigen (PSA). Radium-223 built on the palliative success of previous radiopharmaceuticals, but this alpha-emitting agent importantly had limited hematologic-related toxicity and was associated with a survival advantage, unlike its in-class predecessors. Cabazitaxel also emerged as a second-line chemotherapy option in patients who had already progressed on docetaxel.
Antineoplastic Agents/therapeutic use* ; Antineoplastic Agents, Immunological/therapeutic use* ; Humans ; Male ; Molecular Targeted Therapy ; Prostatic Neoplasms/drug therapy*

Despite impressive survival benefits with immunotherapy in patients with various solid tumors, the full potential of these agents in prostate cancer has yet to be realized. Sipuleucel-T demonstrated a survival benefit in this population, indicating that prostate cancer is an immunoresponsive disease; however, these results have not been matched by other agents. A large trial with ipilimumab in prostate cancer failed to meet its primary objective, and small trials with PD-1/PD-L1 inhibitors did not yield a significant improvement in overall response. However, several late-stage clinical trials are underway with other vaccines in prostate cancer. Reports of clinical benefit with immunotherapies, particularly when used in combination or a select population, have provided the framework to develop sound clinical trials. Understanding immunogenic modulation, antigen spread, biomarkers, and DNA-repair defects will also help mold future strategies. Through rational patient selection and evidence-based combination approaches, patients with prostate cancer may soon derive durable survival benefits with immunotherapies.
Animals ; Antineoplastic Agents, Immunological/therapeutic use* ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; B7-H1 Antigen/antagonists & inhibitors* ; Benzamides ; CTLA-4 Antigen/antagonists & inhibitors* ; Cancer Vaccines/therapeutic use* ; Humans ; Immunotherapy ; Ipilimumab/therapeutic use* ; Male ; Nitriles ; Phenylthiohydantoin/analogs & derivatives* ; Programmed Cell Death 1 Receptor/antagonists & inhibitors* ; Prostatic Neoplasms/drug therapy* ; Tissue Extracts/administration & dosage*