What are cancer treatment vaccines?

Cancer treatment vaccines are designed to treat cancers that have already developed rather than to prevent them in the first place. Cancer treatment vaccines contain cancer-associated antigens to enhance the immune system’s response to a patient’s tumor cells. The cancer-associated antigens can be proteins or another type of molecule found on the surface of or inside cancer cells that can stimulate B cells or killer T cells to attack them.

Some vaccines that are under development target antigens that are found on or in many types of cancer cells. These types of cancer vaccines are being tested in clinical trials in patients with a variety of cancers, including prostate, colorectal, lung, breast, and thyroid cancers. Other cancer vaccines target antigens that are unique to a specific cancer type (7-14). Still other vaccines are designed against an antigen specific to one patient’s tumor and need to be customized for each patient. The one cancer treatment vaccine that has received FDA approval, sipuleucel-T, is this type of vaccine.

Because of the limited toxicity seen with cancer vaccines, they are also being tested in clinical trials in combination with other forms of therapy, such as hormonal therapy, chemotherapy, radiation therapy, and targeted therapies.