Merial, an animal health company, has received conditional approval from the U.S. Department of Agriculture for a vaccine that treats canine melanoma.

The vaccine also has potential for use in humans, according to researchers involved in the project.

The approval is the first by the federal government for a vaccine to treat cancer in either humans or animals, according to the company.

However, initial approval is only for use by specialists in veterinary oncology.

Merial developed the vaccine along with the Memorial Sloan-Kettering Cancer Center (MSKCC) and The Animal Medical Center (AMC) of New York. Merial, which had revenues of $2.2 billion in 2006, obtained rights to the vaccine.

Alan Houghton and Jedd Wolchok of the MSKCC developed the vaccine along with Philip Bergman of the AMC.

"Both humans and dogs develop this cancer in exactly the same way. The disease occurs spontaneously through an interaction of genes with the environment," explained Dr. Jedd D. Wolchok, an oncologist on the Clinical Immunology Service at Memorial Sloan-Kettering. "By conducting trials in humans and in animals that live in the same surroundings as humans, there can be a synergy that we hope will result in improved cancer treatment for all."

Canine melanoma often is fatal in one to five months for dogs receiving conventional treatment. Dogs receiving the vaccine in clinical trials demonstrated what Merical called “significantly longer life spans.” Additional testing and research will continue, the company said.