A drug used with vemurafenib to treat melanoma that cannot be removed by surgery or has spread to other parts of the body. It is used in patients whose cancer has a mutated (changed) form of a cell protein called BRAF. It is also being studied in the treatment of other types of cancer. Cobimetinib blocks certain proteins, 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 Cotellic.