PROSTVAC in Castration-Resistant Prostate Cancer

James L. Gulley, MD, PhD, Head, Clinical Trials Group,Deputy Laboratory Chief, National Cancer Institute (NCI), discusses how PROSTVAC works in patients with castration-resistant prostate cancer.

Gulley says the PROSTVAC vaccine was designed to generate an immune response directed against cells that produce prostate-specific antigens (PSA) in patients with prostate cancer. PROSTVAC is given to patients via a subcutaneous injection in the thigh or arm, Gulley says. This is different than an oncolytic virus, which is delivered to the patient via IV.

Once the vaccine is injected, Gulley says, the virus can infect multiple cells, including antigen-presenting cells and dendritic cells. After this, the vaccine then trains the T cells to recognize and attack any cells making PSA, creating a robust immune response, Gulley says. As the T cells learn how to kill the tumor; there can be an expansion of an immune response to kill other targets within the prostate cancer.

Clinical Pearls

• PROSTVAC was designed to generate an immune response against PSA in patients with prostate cancer
• PROSTVAC is given to patients via a subcutaneous injection in the thigh or arm
• Once PROSTVAC is injected, the virus trains the T cells to recognize and attack cells that make PSA
• Once the T cells learn how to kill the tumor, there can be an expansion of an immune response to kill other targets within the prostate cancer