A drug used with trametinib to treat anaplastic thyroid cancer and non-small cell lung cancer that are advanced or have spread to other parts of the body. It is also used alone or with trametinib to treat certain types of melanoma. Dabrafenib mesylate is used in patients whose cancer has a mutated (changed) form of a gene called BRAF. It is also being studied in the treatment of other types of cancer. Dabrafenib mesylate blocks certain proteins made by the mutated BRAF gene, which may help keep cancer cells from growing and may kill them. It is a type of kinase inhibitor and a type of targeted therapy. Also called Tafinlar.