Cancer immunotherapy refers to treatments that can unleash the power of a patient’s immune system to fight cancer the way it fights infection.

Not all cancer immunotherapy treatments work in the same way. Some release the brakes on the natural cancer-fighting power of the immune system, some boost the killing power of the immune system and some help cancer-fighting immune cells find cancer cells.

Seeing is believing

The excitement surrounding cancer immunotherapy stems from the fact that several of these treatments have yielded remarkable and long-lasting responses for some patients with various types of cancer.

"Some immunotherapy treatments release the brakes on the natural cancer-fighting power of the immune system and some help cancer-fighting immune cells find cancer cells."

Cancer immunotherapy treatments that work by releasing brakes on cancer-fighting immune cells called T cells have proven particularly powerful against a number of types of cancer, including metastatic melanoma—a deadly form of skin cancer that historically has very poor outcomes, with most patients living less than a year after diagnosis of metastases. For example, 1 in 5 patients who receive ipilimumab (Yervoy), the first of these treatments to be approved by the FDA, survive for more than three years and the risk of death from melanoma for these patients is very low.

Moving forward

Among the arsenal of cancer immunotherapy treatments that boost the killing power of the immune system are a group referred to as chimeric antigen receptor T–cell therapies (CAR T–cell therapies). CAR T–cell therapy is a complex medical procedure in which T cells are harvested from a patient’s blood or bone marrow and genetically modified to target and then attack the patient’s cancer cells after they have been expanded in number and returned to the patient.

CAR T–cell therapy is showing particular promise for adults and children with acute lymphoblastic leukemia (ALL). Motivated by these early results, researchers are working to develop CAR T–cell therapies that will target other types of cancer.

Despite the progress so far, researchers are continually learning more about how the immune system functions. Thanks to their efforts, in the future, we can expect to see new cancer immunotherapies and novel ways to use those that already exist.