He had always been true to his breed, calm, friendly, inexplicable gifted at opening doors and drawers to explore the contents-all the more remarkable given he had lived in a kennel most of his life, or perhaps that was the reason. But he became agitated last year in the fall. He pawed his face and spit out kibble. Pollien looked inside his mouth and saw a brown spot on his gums. “I could tell he was in pain,” she says.
            A biopsy revealed the reason: Bodo had melanoma. The aggressively spreading cancer strikes an estimated 50,000 dogs annually in the United States. Veterinarians measure the survival time in months. About 8,100 people die each year from the disease, the National Cancer Institute says. No agency tracks canine melanoma deaths.
            Bodo underwent surgery to remove the growth and small part of his jaw, which gave Pollien pause. “I really worried about how it would affect his quality of life, but the doctor said he would live only five months without the surgery and possibly three years with it. Adding that to his 12 years today would equal the life span of a Pointer.”

 

Worth The Cost

           Then in a stroke of luck, if luck can be said in the same breath with cancer, Bodo was referred to BrightHeart Veterinary Centers hospital, which was conducting a clinical trial of the canine-melanoma vaccine. The novel treatment has been available since June 2007, only from veterinary oncologists at referral clinics, and at 26 of the 27 veterinary schools in the U.S. with teaching hospitals.

            Researchers hope the vaccine, which uses human DNA (a protein called tyrosinase in human and canine melanoma cancer cells), may someday have human application. Early trials resulted in dogs with melanoma living up to 13 months, compared to five months with conventional therapies, which include surgery and radiation, although many dogs are living far longer now.

            Pollien didn’t hesitate to go ahead with the series of four vaccinations for Bodo, despite the $2,576 expense. With surgery, treatment totaled more than $5,000.

“I never thought about not doing it,” she said. In addition, she learned that BrightHeart's chief medical officer, Philip J. Bergman DVM MS, was one of the oncologists instrumental in the vaccine's development. “It's amazing to have access to the top person,” Pollien said.
 

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Stretching Survival

            Bergman had long believed scientist needed to find a way to harness the immune system to combat “this incredibly horrible disease.” In 1999 at a dinner in New York City – when he was at the Animal Medical Center there – another guest, Jedd Wolchok MC, an oncologist at the renowned Memorial Sloan-Kettering Cancer Center, asked him if dogs get melanoma.

            “I remember it like it was yesterday,” Bergman said.

A partnership was born.

            Four months later, he began a clinical trial of the melanoma vaccine that Wolchok and Alan Houghton MD had developed at the center. Later, parallel trials at the cancer center and AMC refined the dosage and use, said Merial, the maker of today's commercial vaccine.

            “We're very, very pleased with it,” said Bergman, at BrightHeart's Katonah-Bedford Veterinary Center in New York. “Side effects we've seen – which I'm overjoyed with – have been that one in 20 dogs develop mild redness at the injection site, which is actually needle-free.”

Oncologists administer the vaccine trans-dermally, using a device from BioJect that uses a force of pressurized air. “It affords a greater level of immune response and seems to hurt a lot less than a needle,” Bergman says.

            Some results have been dramatic.

“Jake, one of the original patients, had Stage IV melanoma, typically with one to two months to live,” Bergman said. Jake survived for more than five years, and died of another disease. “When we did the postmortem, we found no evidence of melanoma.”

            Scientist that he is, Bergman earned a PhD in human cancer biology to bring state-of-the-art expertise to veterinary medicine. He’s careful to say the vaccine is not a panacea. “It needs to be used in conjunction with surgery and /or radiation.”

            He continues to research other vaccines to treat feline mammary cancer, canine lymphoma, and other tumors, with the goal of opening a path for their use in human medicine. “The murine - the mouse - model has too many pitfalls, including it's size compared to humans,” he says. “I would hope the grant-giving agencies begin to look at research using pets as models for people. These are my patients – my pets are my kids – and I hate to think of them as ‘models,’ but in the end it’s incredibly important that we help out pets and help people, too.”

            So far, 1,500 dogs have had the vaccine, said Bob Menardi DVM, technical marketing manager at Merial in Duluth, Ga. “It’s really heartwarming to hear the stories of dogs given death sentences who are now surviving.”
 

            The USDA’s one-year, conditional licensing of the vaccine ended in March of this year. It was the first time the government had approved a vaccine for cancer treatment in animals or humans. Merial plans to ask for an extension, Menardi said. “We are working very hard to gain full approval, but since we are measuring a long-term benefit-survival time, we know that it will take another year. We are committed to moving forward with the approval process.”

            Carolyn J Henry DVM, president of the American College of Veterinary Internal Medicine’s oncology specialty and president-elect of the Veterinary Cancer Society, lauds the years of collaboration between human and veterinary oncology that brought the vaccine to the market:

            “This brings a real-life example of what we as veterinary oncologists have been preaching for years, that comparative oncology-which incorporates naturally occurring cancer in companion animals rather than just rodent models-has the potential to accelerate the acquisition of new, clinically applicable knowledge and treatment options that will impact both people and pets with cancer.”

            It is too early, she said, to assess the effect on dogs receiving the vaccine at the University of Missouri College of Veterinary Medicine, where she is an associate professor. A Rottweiler named Grace is among those handling the vaccine well. “I think Grace sees her visits to the hospital as more of a social event than a medical appointment,” Henry said.

            Grace does like to work the crowd, owner Julia Robberson said. She’s a far different dog than when she appeared seven years ago at Robberson's cow-calf operation in Urbana, Mo. “She was malnourished and full of worms,” Robberson says. “Her mammary glands were full of milk. She had probably had had litter after litter.”

            Robberton and Donna Hugh, who also helps run the farm, drove the dog to neighbors, fruitlessly searching for an owner. “She must have been dumped. We brought her home and took her to the vet, and she turned out to be the sweetest dog God ever breathed life in,” Robberson said. “When a calf lost his mama, she took care of him, cleaned him up. I never saw anything like that.”

            In November, Grace began licking her foot, Hugh says. “I told her ‘Grace, cut it out. You’re driving me crazy.’ Then I looked at it, and she had this awful thing like an open sore on her pad.” It was melanoma. Surgeons at the University of Missouri amputated her left rear leg, as is standard procedure. Grace is still adjusting to it, but her sunny nature and hearty appetite prevail, Robberson said. “She’s getting better every day.”

            Bodo, the Wirehair, is too. Though he usually gives other dogs the laser-eye, he’s warmed up to a Lab-mix that Pollien is fostering. The dogs race around the yard and around the apple trees, chasing prey long-gone or imagined. The trees are budding now. Spring has come.