First Drug to Treat Cancer in Dogs Approved

The U.S. Food and Drug Administration announced the approval of Palladia (toceranib phosphate), the first drug developed specifically for the treatment of cancer in dogs.

Palladia is approved to treat canine cutaneous (skin-based) mast cell tumors, a type of cancer responsible for about 1 out of 5 cases of canine skin tumors. The drug is approved to treat the tumors with or without regional lymph node involvement.

All cancer drugs now used in veterinary medicine originally were developed for use in humans and are not approved for use in animals. Cancer treatments used in animals are used in an "extra-label" manner as allowed by the Animal Medicinal Drug Use Clarification Act of 1994.

"This cancer drug approval for dogs is an important step forward for veterinary medicine," said Bernadette Dunham, D.V.M., Ph.D., director of FDA's Center for Veterinary Medicine. "Prior to this approval, veterinarians had to rely on human oncology drugs, without knowledge of how safe or effective they would be for dogs. Today's approval offers dog owners, in consultation with their veterinarian, an option for treatment of their dog's cancer."

While canine mast cell tumors often appear small and insignificant, they can be a very serious form of cancer in dogs. Some mast cell tumors are easily removed without the development of any further problems, while others can lead to life threatening disease.
Palladia is a tyrosine kinase inhibitor and works in two ways: by killing tumor cells and by cutting off the blood supply to the tumor. In a clinical trial, Palladia showed a statistically significant difference in tumor shrinkage when compared with an inactive substance (placebo).

The most common side effects associated with Palladia are diarrhea, decrease or loss of appetite, lameness, weight loss, and blood in the stool.

Palladia is manufactured by Pfizer Animal Health Inc., New York City.