Cancer Immunotherapy/Biotherapy

This is one of the most exciting and changing fields in medicine, based on drugs that act on the body’s immune system. A number of newly developed treatments are now being tested with some success. 

One of the earliest forms immunotherapy (also known as biologic therapy) makes use of chemicals that occur naturally in the body. Protein hormones (called lymphokines) are chemicals occurring naturally in small quantities in the body. These lymphokines are produced by white cells (lymphocytes) when they come in contact with tumor cells, viruses, or other harmful substances. Lymphokines can be used to activate the immune system to kill some types of cancers, including melanoma and kidney cancer. One such lymphokine, called Interleukin-2 can markedly activate white blood cells to directly kill cancer cells. This agent, although it has numerous side effects, can produce long term remissions in 5-7% of patients with metastatic melanoma or kidney cancer.  Another lymphokine is interferon-alpha, which has been shown to be effective in decreasing the risk of melanoma recurrence after complete surgical excision of involved lymph glands. Other forms of immunotherapy that are currently experimental (in testing) include experimental melanoma and kidney cancer vaccines. These vaccines are intended to stimulate the immune system so that it reacts more strongly against a patient’s cancer cells, preventing cancer recurrence or slowing cancer progression. Also there are a number of monoclonal antibodies that are in clinical testing. Monoclonal antibodies directed against a molecule called CTLA-4 are showing promise in reactivating the immune system against melanoma and kidney cancer. There are additional new cancer treatments that are in clinical trials that are designed to activate the immune system to attack cancers, using other new and exciting approaches.