Metastatic malignant melanoma is the deadliest form of skin cancer. Now, for the first time in 13 years, the FDA has approved not one, but two, medicines for metastatic or unresectable malignant melanoma.
Vemurafenib (brand name Zelboraf) is unique among chemotherapeutic agents in two ways: it is a pill taken by mouth, and it is specifically for patients whose melanoma cells express a certain gene mutation called BRAF. Only about 50% of melanomas have this mutation which must be screened for using a FDA-approved test. In the first clinical study, 337 patients received Zelboraf, and 338 patients received standard intravenous chemotherapy (dacarbazine). There were 48% responders in the Zelboraf group compared to 6% responders in the dacarbazine group. There were 78 deaths in the Zelboraf group compared to 121 deaths in the dacarbazine group at the time of the analysis. There was a 4-month improvement in the survival without progression of cancer in the patients treated with Zelboraf. Two of the patients had a complete response.
Ipilimumab (brand name Yervoy) also gained FDA approval for improving the overall survival of patients with metastatic melanoma compared to a melanoma vaccine and dacarbazine. The long-term survival rates were higher at one, two, and three years. Ipilimumab is administered intravenously. It works by enhancing the response of the patient’s own immune cells against the cancer cells.
Both of these new agents can cause significant side effects. Zelboraf is associated with an increased incidence of squamous cell skin cancer, allergic rashes, and sensitivity to sunlight. All of these adverse reactions fall under the purview of the Dermatologist who manages the patient in collaboration with the Medical Oncologist. Yervoy can cause serious autoimmune inflammatory reactions in skin, intestines, liver, and pituitary gland which may lead to discontinuation of the drug. It is expected that investigators will perform additional clinical trials to evaluate these two new drugs in combination with other agents in an attempt to improve survival even more in patients with metastatic malignant melanoma.