June 3, 2009

NEW YORK -- The Food and Drug Administration approved today the nation's first drug developed specifically for the treatment of canine cancer.

Manufactured by Pfizer Animal Health Inc., based in New York City, the drug marketed as Palladia, or chemically known as toceranib phosphate, will hit the markets in early 2010.

"This cancer drug approval for dogs is an important step forward for veterinary medicine," Bernadette Dunham, D.V.M., Ph.D., director of FDA's Center for Veterinary Medicine, said in a released statement.

"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."

Current cancer drugs used in veterinary medicine are in fact not approved for use in animals, as they were originally designed for human use. But vets are allowed to administer human cancer medicine and other treatments under Federal law for controlled substances, per Animal Medicinal Drug Use Clarification Act of 1994.

Before Palladia's mainstream release, Pfizer plans to introduce Palladia to boarded specialists to expand the body of clinical experience with the United States' first canine cancer therapy.

"At the completion of a Palladia clinical study, approximately 60 percent of dogs had their tumors disappear, shrink or stop growing," said Cheryl London, who has helped Pfizer Animal Health's Veterinary Medicine Research & Development to develop Palladia since 2000.

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 the placebo.

The first-of-its-kind drug could vastly change the lives of dogs as cancer is the leading cause of death in canines, according to the Morris Animal Foundation. Additionally, Pfizer estimates 1.2 million new canine cases are reported in the U.S. annually.

Palladia tablet is indicated to treat Patnaik grade II or III recurrent cutaneous mast cell tumors with or without regional lymph node involvement. This type of cancer, the FDA reports, is responsible for one-out-of-five case of canine skin tumors.

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 approved to treat the tumors with or without regional lymph node involvement. Common side effects include diarrhea, decrease or loss of appetite, lameness, weight loss, and blood in the stool.

Click for more information on FDA's full study.

RTT News and Robin Wallace, Zootoo Pet News editor, contributed to this report.