Toceranib Phophate

This medication was developed to address the mast cell tumor in dogs. Normal mast cells line the body’s interfaces with the outside world (skin, respiratory tract, etc.) and become bound by antibodies directed against invading parasites. When a mast cell coated with antibodies meets a parasitic protein, a reaction occurs whereby the mast cell “degranulates” which means it releases its stored inflammatory proteins. These inflammatory mediators help destroy the invader.

When mast cells become tumorous, they degranulate spontaneously creating inappropriate tissue inflammation. When mast cell tumors are malignant, they can spread through the body creating a highly inflammatory form of cancer. Mast cells tumor malignancy is commonly graded 1, 2, or 3, with 3 being the most highly invasive and malignant form.

Toceranib phosphate was developed for use against grade 2 and grade 3 mast cell tumors. Toceranib phosphate is what is called a “tyrosine kinase inhibitor.” It has two actions against the mast cell tumor: first it kills the tumor cells directly and second, it interferes with the tumor’s blood supply.