Sipuleucel-T for the treatment of metastatic prostate cancer: promise and challenges.

In the past 18 mo, three new life-prolonging therapies have been approved by the US. Food and Drug Administration for the treatment of men with metastatic castration-resistant prostate cancer (mCRPC), including sipuleucel-T, the first therapeutic vaccine approved for this disease. With very low toxicity and a demonstrable overall survival benefit, sipuleucel-T offers a promising new therapy and validates further investigation into other immunotherapy approaches for prostate cancer patients. However, questions about its mechanism of action, concerns about its cost, and its optimal sequencing in the prostate cancer treatment landscape may be limiting the adoption of sipuleucel-T. This review summarizes the state-of-the-science with respect to immunotherapy approaches for men with prostate cancer, provides information about the clinical development as well as the strengths and concerns associated with sipuleucel-T, and offers initial insights about where this promising treatment may best fit in the therapeutic landscape.