Disclosed is a method of treating melanoma in a mammal comprising administering (a) a therapeutically effective amount of an inhibitor of metabotropic glutamate receptor 1 (GRM1) and (b) a therapeutically effective amount of an inhibitor of at least one downstream signaling target of GRM1. Also disclosed are compositions and kits for treating melanoma comprising (a) a therapeutically effective amount of an inhibitor of GRM1 and (b) a therapeutically effective amount of an inhibitor of at least one downstream signaling target of GRM1.
