A MEK inhibitor is a chemical or drug that inhibits the mitogen-activated protein kinase enzymes MEK1 and MEK2. MEK1 and MEK2 have critical parts in tumorigenesis, cell production, and the elimination of cancerous cells.
The MEK inhibitor impacts a target that is downstream from Ras in the MAP kinase, or MAPK, pathway. These can be used to affect the MAPK/ERK pathway that is often active in certain types of cancers.
Blocking activity of the MEK protein may be an effective way to attack cancer tumors, specifically in non-small cell lung cancer (NSCLC), advanced melanoma, colorectal cancer, thyroid cancer, and ovarian cancer. MEK inhibitors have also demonstrated clinical activity in some patients with multiple myeloma, biliary cancer, and ocular melanoma.
Researchers are finding that some MEK inhibitors have a short half-life, meaning that they are cleared from the patient’s bloodstream very quickly, which can make it difficult to maintain enough of the drug within the circulation system to effectively slow down the cancer tumor growth. For this reason, additional MEK inhibitors are still being investigated. They have been approved by the US Food and Drug Administration for the treatment of BRAF-mutated melanoma, and other agents have been examined as possible MEK inhibitors.