Types of Immunotherapy for Metastatic Melanoma
Melanoma is a type of cancer that originates in the cells that pigment your skin and form moles. Compared to other forms of skin cancer, melanoma is more likely to spread to different parts of the body. With the rates of melanoma increasing over the last 30 years, research continues to search for new ways to treat this serious disease.
When melanoma is caught early, it can often be removed surgically. Yet once it becomes metastatic, meaning it has travelled to distant lymph nodes and areas of the body, it’s harder to manage. Thankfully, immunotherapy is showing promise for treating patients with metastatic melanoma. Immunotherapy works by activating the body’s immune system to destroy cancer cells. There are a few types of immunotherapy that have been approved by the U.S. Food and Drug Administration (FDA) and are in current use, while others are still being studied in clinical trials. Each has a slightly different method of operation.
Cytokines are found naturally within your body. They are proteins that help cells communicate with each other when your immune system is working. Interferon-alpha and Interleukin-2 are two types of cytokines scientists have been able to replicate. For a small number of patients with metastatic melanoma, when cytokines are given at high doses, either through an IV or through an injection, the cancer shrinks.
Giving interferon or interleukin at high doses has the potential to cause significant side effects, including fever, chills, and fatigue. Some patients may need to be hospitalized during treatment for this reason.
Checkpoint inhibitors are proving to be an important type of immunotherapy. They are being used more frequently to treat metastatic melanoma because they’re often more effective and better tolerated than cytokines.
Cancer cells can grow and spread when the immune system does not recognize them as foreign, harmful cells. Checkpoint inhibitors give the immune system a boost, so it can attack the cancer cells. These drugs are given through an IV infusion every 2 to 3 weeks.
There are two classes of checkpoint inhibitors that are used for metastatic melanoma:
PD-1 inhibitors- Pembrolizumab (Keytruda) and nivolumab (Opdivo)
CTLA-4 inhibitors- Ipilimumab (Yervoy)
While many patients have experienced success with checkpoint inhibitors, side effects can still occur. The most common include rash, fatigue and diarrhea. Occasionally, the boosted immune system will harm other parts of the body, such as the kidneys or lungs, so patients need to be monitored carefully and must notify their doctors when any side effects occur.
New forms of immunotherapy are continuously being studied to determine the best modes of treatment for metastatic melanoma. These include:
Vaccines- Just as the vaccines you received as a child strengthened your immune system to protect you from getting a disease, new cancer vaccines are being developed to help your body fight an active disease.
New checkpoint inhibitors- Researchers are trying to target different parts of the immune system to see how to make the response most effective against cancer cells.
Tumor-infiltrating lymphocytes- These are white blood cells that are found within tumors and help to slow their growth. Scientists are trying to find ways to manipulate tumor-infiltrating lymphocytes so they can be given patients to help shrink melanoma tumors.
The future of immunotherapy looks bright. Not only are new types of immunotherapy being developed, but researchers are also studying how to combine various forms of immunotherapy or combine immunotherapy with chemotherapy and targeted therapy to improve effectiveness.
If you are a patient with metastatic melanoma, talk to your doctor about what options are appropriate for you. Your doctor can provide you with more information regarding the risks and benefits of immunotherapy, as well as discuss if you are a candidate for any current clinical trials.