Immunotherapy represents an advance in the treatment of cancer

Our immune system has only one purpose: to protect against disease. However, some types of cancer can overwhelm our immune systems, and cancer cells can multiply despite our bodies’ best efforts. Fortunately, researchers have developed a new class of drugs called immunotherapy, which can help a silent immune system fight cancer.

Immunotherapy was featured in the journal Science as the biggest scientific breakthrough of 2013. We are at a tipping point “as long-overdue efforts to unleash the immune system against tumors are paying off” with a growing number of patient success stories, the editors said. Immunotherapy drugs work by stimulating certain parts of the immune system or by neutralizing signals from cancer cells that block the immune response.

The idea of ​​harnessing our immune systems to treat cancer dates back to the late 19th century when Dr. William Cooley, a New York surgeon, discovered that the tumors of some cancer patients shrink if the patient developed an infection after surgery. Cooley developed a method of inducing fever to stimulate an immune response, but his approach was abandoned when he took up radiotherapy.

Research on immunotherapy increased significantly in the mid to late twentieth century. After hundreds of clinical trials and many hours in the lab, researchers are beginning to identify the mechanisms that would make immunotherapy work. One of the biggest discoveries was the finding that certain molecules in T cells were turned off when they encountered cancer cells. Researchers have developed drugs to prevent these molecules from stopping and to keep the immune system working.

In 2011, the Food and Drug Administration approved the first “checkpoint inhibitor” immunotherapy drug, ipilimumab (Yervoy®), for advanced and metastatic melanoma. Other drugs work in a similar way, but they target different molecules. Pembrolizumab (Keytruda®) targets programmed death protein 1 (PD-1) found in T cells and was recently approved by the US Food and Drug Administration for the treatment of advanced melanoma and is being studied in other types of cancer. Nivolumab (Opdivo®) is effective for some patients with skin cancer, as well as for patients with kidney cancer and non-small cell lung cancer.

Checkpoint inhibitors are only one type of medication in a broad class of immunotherapies, which also include:

Cancer vaccines: Vaccines that are used to help prevent or treat cancer are injected substances that activate the immune response against certain diseases. Sipuleucel-T (Provenge®) is the only FDA-approved vaccine for the treatment of cancer, especially advanced prostate cancer that has stopped responding to hormone therapy. Gardasil®, Gardasil 9® and Cervarix® are preventive vaccines against cervical cancer.

Cytokines: These proteins are naturally found in our bodies in small amounts and act as messengers to send signals to the immune system. For example, a cytokine known as interleukin-2 is available through the drug Desleukin® (Proleukin®) in much greater amounts than our bodies can produce. The drug helps the body make supercharged immune cells that kill cancer. Aldesleucine is FDA approved for patients with metastatic kidney cancer and metastatic melanoma.

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