Immunotherapy for prostate cancer works by helping a patient’s own immune system fight back against cancer cells. One immune therapy that has been approved by the FDA is a vaccine called sipuleucel-T (Provenge), which spurs a patient’s immune system to attack prostate cancer cells. The vaccine is tailored to match each patient’s own immune system using the following process:

1. Using a special machine, white blood cells are removed from the patient over the course of a few hours.
2. In the lab, the white blood cells are exposed to a protein from prostate cancer cells called prostatic acid phosphatase. This exposure trains the white blood cells to recognize prostate cancer cells.
3. The trained cells are infused back into the patient’s body. The infused cells help other immune system cells attack the prostate cancer.

While sipuleucel-T does not appear to reduce PSA levels or stop prostate cancer growth, it may increase survival in patients with metastatic castration-resistant cancer who show few or no symptoms.

Common side effects of the vaccine include fever, fatigue, chills, back and joint pain, headache and nausea. They are associated with the infusion period and usually only last for a few days.