A GROWING ARSENAL OF IMMUNE-BASED CANCER TREATMENTS
CAR Ts are one way the immune system can be primed to battle the disease. Other treatments are also proving to be successful cancer fighters, while some new immunotherapies show promise against a variety of cancers.
■ CYTOKINE TREATMENTS
Immune cells secrete chemicals called cytokines, which help them fight infections and cancers. Several of these substances, including interleukin-2 and interferon, have been made into drugs and approved by the FDA for the treatment of melanoma, kidney cancer, and other cancers. While they are effective, their side effects can be severe, which has limited their use.
■ MONOCLONAL ANTIBODIES
The immune system also produces antibodies that fight infections. Researchers have learned to design custom-made antibodies in the lab that recognize targets on cancer cells. More
than a dozen of these so-called monoclonal antibodies have been approved by the FDA to help control a variety of different cancers, including certain forms of lymphoma, leukemia, and head, neck, colorectal, and breast cancers. Now widely used in cancer therapy, they are rapidly becoming a standard treatment.
■ CHECKPOINT INHIBITORS
To keep T cells from attacking healthy cells in the body, the immune system uses a team of molecular checkpoints that must be turned on or off to start an immune response. Some tumors turn off T cells to avoid immune attack. New drugs called checkpoint inhibitors prevent tumors from doing this. Checkpoint inhibitors have been
shown to help some patients with a variety of forms of cancer, including melanoma and lung, kidney, bladder, and head and neck cancers.
■ CANCER VACCINES
The goal of cancer vaccines is to boost the power of immune cells to recognize and destroy malignant cells already in the body. The human papillomavirus vaccine and the hepatitis B vaccine are already preventing forms of cervical cancer and liver cancer caused by viruses. And last year, the FDA approved sipuleucel-t, or Provenge, a vaccine that has been shown to extend the lives of some patients with prostate cancer. Vaccines for lung, breast, colorectal, and other cancers are currently in clinical trials.