FDA Approves 2 Drugs and Lab Test for Melanoma

The United States Food and Drug Administration (FDA) has approved two new drugs, Tafinlar (dabrafenib) and Mekinist (trametinib), for the treatment of advanced melanoma with specific genetic mutations. In addition, the FDA has approved a laboratory test used prior to therapy that determines whether the melanoma has the specific genetic mutations.

Melanoma is a type of skin cancer that is considered incurable once it spreads from its site of origin to other locations in the body. A significant portion of melanomas harbor very specific genetic mutations that are involved in uncontrollable growth and/or spread of cells.

As researchers progress in their understanding of genetics and its role in cancer, greater advancements of treatment that target specific sites or mutations of cancer continue through development.

“Advancements in our understanding of the biological pathways of a disease have allowed for the development of Tafinlar and Mekinist, the third and fourth drugs the FDA has approved for treating metastatic melanoma in the past two years,” said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research.

Tafinlar is referred to as a BRAF inhibitor. It is approved for treatment of patients with melanoma that is considered inoperable and expresses the BRAF V600E gene mutation.

Mekinist is referred to as a MEK inhibitor. It is also approved for the treatment of patients with melanoma that is considered inoperable and has the BRAF V600E or V600K mutations.

The agents have been approved as single agent treatment, not to be used in combination. Furthermore, the FDA approved a companion diagnostic test called the THxID BRAF test, to determine if the melanoma has the mutations necessary to respond to either Tafinlar or Mekinist. A sample of the cancer that has been removed is used for the diagnostic test.

The genetic mutations that are being tested for to determine eligibility for Tafinlar and Mekinist are responsible for abnormal patterns in biologic pathways, contributing in part to the continued growth of the cancer.

Both Tafinlar and Mekinist block parts of a biologic pathway in cancer cells caused by the genetic mutations BRAF V600E or V600K. Through blocking of the pathway, cancer growth and spread can be reduced.

Patients with advanced melanoma whose cancer is considered inoperable may wish to speak with their physician regarding their risks and benefits of undergoing genetic testing to determine if they are eligible for treatment with Tafinlar or Mekinist.

Reference: Food and Drug Administration. FDA Approves Two Drugs, Companion Diagnostic test for Advanced Skin Cancer. Press Release. May 29,2013