Targeted therapy for melanoma skin cancer
As doctors have found some of the gene changes that make melanoma cells different from normal cells, they have created drugs that attack these changes. These targeted drugs work differently from standard chemo drugs. Sometimes, they work when chemo doesn’t. They can also have different side effects.
Drugs that target cells BRAF gene changes
About half of all melanomas have changes (mutations) in the BRAF gene. These changes cause the gene to make more of the BRAF protein, which tells the melanoma cells to grow and divide quickly. Drugs that target this and related proteins can be used in patients with advanced melanoma that has a BRAF mutation. These drugs are not likely to work in patients whose melanomas have a normal BRAF gene.
Some drugs attack the BRAF protein directly:
- Vemurafenib (Zelboraf)
- Dabrafenib (Tafinlar)
These drugs are taken as pills. Common side effects can include skin thickening, headache, fever, joint pain, fatigue, hair loss, and rash. Less common but more serious side effects can also occur. Some people treated with these drugs get new skin cancers called squamous cell carcinomas, which can be treated by removing them.
Some drugs target the MEK protein, which is related to the BRAF protein:
- Trametinib (Mekinist)
- Cobimetinib (Cotellic)
These drugs are also taken as pills. They do not seem to shrink as many melanomas as the BRAF drugs, but combining the 2 types of drugs seems to work better than using either type alone. Some side effects (such as getting other skin cancers) are actually less common with the combination. Common side effects of MEK inhibitors can include rash, diarrhea, nausea, swelling, and sensitivity to sunlight. Rare but serious side effects can also occur.
Drugs that target cells with C-KIT gene changes
A small portion of melanomas have changes in the C-KIT gene that help them grow. These changes are more common in melanomas that start in certain parts of the body:
- On the palms of the hands, soles of the feet, or under the nails (known as acral melanomas)
- Inside the mouth or other mucosal (wet) areas
- In parts of the body that get a lot of sun
Some targeted drugs, such as imatinib (Gleevec) and nilotinib (Tasigna), can affect cells with changes in C-KIT. If you have a melanoma that started in one of these places, your doctor may test your melanoma cells for changes in the C-KIT gene, which might mean that one of these drugs could be helpful.
Drugs that target other changes are now being studied as well (see “What’s new in melanoma skin cancer research?”)
Last Medical Review: 05/01/2015
Last Revised: 02/01/2016