The Department of Agriculture recently granted full licensure for a DNA vaccine to help extend survival time of dogs with oral melanoma.
Merial developed the new vaccine, Oncept, in partnership with the Memorial Sloan-Kettering Cancer Center and the Animal Medical Center of New York.
The vaccine uses a DNA plasmid containing a gene for the human version of tyrosinase, a protein present on melanoma cancer cells in humans and dogs. Following a dog's vaccination with Oncept, some of the dog's cells will produce the human version of tyrosinase. The dog's immune system reacts by attacking not only the foreign human version of tyrosinase but also the homologous canine version—and thus the melanoma.
In a study, 58 dogs with stage II or stage III oral melanoma received Oncept after local disease control through surgery. Dogs that received the vaccine had a significantly better survival time than the controls did.
Dr. Philip J. Bergman of BrightHeart Veterinary Centers and Sloan-Kettering collaborated with Jedd Wolchok, MD, of Sloan-Kettering on the research that led to the licensure of Oncept. Dr. Bergman said dogs with stage II or stage III oral melanoma have median survival times of five to six months or less when surgery is the sole treatment. He said, "Oncept is a welcome addition for dogs that have been diagnosed with this often fatal disease."
The USDA licensed the first DNA vaccine for use in the United States in 2005 for prevention of West Nile virus infection in horses.