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 begun to develop drugs that attack these changes. These targeted drugs work differently from standard chemotherapy drugs. Sometimes, they work when chemotherapy doesn’t. They can also have less severe side effects. Doctors are still learning the best way to use these drugs to treat melanoma.

Drugs that target changes in the BRAF gene

About half of all melanomas have changes (mutations) in the BRAF gene. These changes cause the gene to make an altered BRAF protein that signals the melanoma cells to grow and divide quickly. Drugs that target this protein are now available. If you have advanced melanoma, a biopsy sample of it might be tested to see if it contains a BRAF mutation. Drugs that target the BRAF protein are not likely to work in patients whose melanomas have a normal BRAF gene.

Vemurafenib (Zelboraf) is a drug that targets melanoma cells with the altered BRAF gene. It causes tumors to shrink in about half of the people whose metastatic melanoma has a BRAF gene change. It also prolongs the time before the tumors start growing again and helps some patients live longer, although the melanoma usually starts growing again eventually.

This drug is taken as a pill, twice a day. The most common side effects are joint pain, fatigue, hair loss, rash, itching, sensitivity to the sun, and nausea. Less common but serious side effects can occur, such as heart rhythm problems, liver problems, severe allergic reactions, and severe skin or eye problems.

Some people treated with vemurafenib develop new skin cancers called squamous cell carcinomas. These cancers are usually not serious and can be treated by removing them. Still, your doctor will want to check your skin often during treatment and for several months afterward. You should also let your doctor know right away if you notice any new growths or abnormal areas on your skin.

Other drugs that target changes in the BRAF gene are now being studied as well. Drugs that target different genes, such as MEK, have also shown early promise in clinical trials (see “What’s new in research and treatment of melanoma of the skin?”