June 3, 2009 -- The FDA has approved Palladia, the first drug developed specifically to treat cancer in dogs.
Palladia is approved to treat canine cutaneous (skin-based) mast cell tumors, a type of cancer responsible for about one in five cases of canine skin tumors. The drug is approved to treat those tumors, whether or not nearby lymph nodes are affected.
Until now, all cancer drugs used in veterinary medicine were originally developed for use in humans and haven't been approved by the FDA for use in animals. Cancer treatments used in animals are given 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," Bernadette Dunham, DVM, PhD, director of the FDA's Center for Veterinary Medicine, says in a news release.
Although 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, but others can lead to life-threatening disease.
Palladia, which is a type of prescription drug called a tyrosine kinase inhibitor, is given orally to dogs. It works in two ways: by killing tumor cells and by cutting off the blood supply to the tumor.
The FDA notes that in a clinical trial, Palladia was more likely than a placebo to shrink tumors.
The most common side effects associated with Palladia are diarrhea, decrease or loss of appetite, lameness, weight loss, and blood in the stool, according to the FDA. Life-threatening effects are rare but possible and early recognition is critical, states a news release from Palladia's maker, Pfizer Animal Health.
Palladia is not for human use and is only available in the U.S. Children should not come in contact with Palladia, and all people should avoid direct contact with broken or partially dissolved Palladia tablets or biological waste from dogs treated with Palladia, notes Pfizer Animal Health.