Toceranib (INN[2]), sold under the brand name Palladia, is a receptor tyrosine kinase inhibitor that is used in the treatment of canine mast cell tumor also called mastocytoma.[3] It is the first medication developed specifically for the treatment of cancer in dogs.[4][5] It is used as its phosphate salt, toceranib phosphate. It was developed by SUGEN as SU11654,[6] a sister compound to sunitinib, which was later approved for human therapies. Toceranib is a tyrosine kinase inhibitor and works in two ways: by killing tumor cells and by cutting off the blood supply to the tumor.[4]