Targeted therapy is the use of medicines that target the parts of cancer cells that make them unlike normal cells. Targeted medicines for melanoma work on genes and proteins in melanoma cells. Targeted medicines are different from standard chemotherapy medicines. They can work when chemotherapy medicines don’t. And they have different side effects.
BRAF is a gene that’s part of body cells. About half of all melanomas have changes in the BRAF gene. These changes help the melanoma cancer cells grow. Some medicines can target this gene to help attack melanoma cancer. Before the medicines are used, a sample of melanoma tissue is tested for change in the BRAF gene. Melanoma cells that don’t have a change in the BRAF gene would not be helped by the targeted medicines.
Vemurafenib and dabrafenib are 2 medicines that target the BRAF gene. These are used to treat advanced melanomas that can’t be removed with surgery. They can often shrink tumors for at least several months. The medicine is taken daily as pills or capsules.
The most common side effects of these medicines include:
In some cases, these medicines can cause squamous cell carcinoma. This is a less serious type of skin cancer that can be easily treated with surgery. Less common but more serious side effects are also possible. Talk with your doctor about the risks and benefits of these medicines for you.
A protein in cells called MEK can interact with the BRAF protein to help melanoma cells grow. Trametinib is a medicine that targets the MEK proteins. This medicine is taken daily as a pill to help treat advanced melanomas. It is only helpful for people whose melanoma cells have BRAF gene changes. When used alone, this medicine does not shrink tumors as well as a BRAF inhibitor. But when used with a BRAF inhibitor, the 2 medicines may work better than either medicine alone. Also, combining the medicines may lower the risk getting other skin cancers when using a BRAF inhibitor.
The most common side effects of this medicine include:
Some other side effects are less common but can be more serious. Talk with your doctor about the risks and benefits of this medicine for you.
More targeted medicines being tested
Researchers continue to learn more about what makes melanoma cells different from other cells. They’re working to develop new medicines to target these differences. New medicines are being tested in clinical trials.
Researchers are also testing existing medicines to use for melanoma. A small number of melanomas have changes in the C-KIT gene that help them grow. This is most often the case for melanomas in areas such as the palms, soles of the feet, or inside the mouth. Several medicines that target C-KIT are already used to treat some other types of cancers. These medicines are now being tested in clinical trials to see if they can help treat melanomas.
If you’re interested in a medicine that is part of a clinical trial, talk with your health care provider. He or she can help you find out if a clinical trial would be right for you.
March 30, 2020
Alteri, Rick, MD, Foster, Sara, RN, MPH