research
The first dog enrolled in the pilot study in 2011 at
In July of 2012, Sasha, an American Bulldog, became the
UGA was a 7-year-old pit bull named Petsy. After Petsy
first of six dogs to receive the modified listeria vaccine.
suffered a seizure, a brain tumor was discovered. Surgery
All the dogs have her2/neu-positive osteosarcoma, a
removed part of the tumor, but could not get it all. So
requirement to be in the study, as the listeria is modified
immediately after surgery and for the following three
to include a her2/neu marker. The hope is that while the
days the investigational drug was infused directly into
dog’s immune cells attack the listeria virus, they will also
the tumor via catheters in a process called convection-
learn to recognize and subsequently attack cells that
enhanced delivery. Blood tests and neurologic tests
express the her2/neu marker. The marker distinguishes
demonstrated no toxic effects of the investigational drug.
cancer cells from healthy cells, making it possible for the
A follow-up MRI six weeks after surgery showed that the
immune system to target remaining cancer cells more
investigational drug was still present in the remaining
efficiently.
portion of the brain tumor. Another MRI five months after surgery showed that the tumor had shrunk markedly. In spring of 2013 (as this was being written), Petsy had remained seizure-free and in good health. Limited human trials have begun. The “one medicine” concept is also attacking another cancer – osteosarcoma. Unfortunately, osteosarcoma is fairly common in large-breed dogs, and in humans. In dogs, the intial occurrence is usually in a leg bone, and the cancer is so aggressive that amputation is the treatment of choice. But even when amputation is followed with chemotherapy, post-surgical survival averages only a year. There has been no improvement in
Of the six dogs, only one, which was given only a low dose of the vaccine, has developed lung metastases. Sasha and the other four dogs remain health and apparently cancer-free ten months later. Other researchers are acknowledging that testing cancer treatments in mice is largely unproductive because most of the treatments that work in the mice don’t have the same positive effects in people. But dogs, like people, actually suffer from the cancers, rather than being manipulated to manifest them artificially, plus dogs are much closer to humans in genetics, biology, and environment, providing a much more appropriate model.
this prognosis for decades. The cancer returns, attacking
Testing therapies in dogs can actually sort out those that
other bones or metastasizing to the lungs.
show real promise for dogs and humans. And due to the
Dr. Nicola Mason, of the University of Pennsylvania, working with the university’s School of Veterinary Medicine and Advaxis Inc., is conducting a small phase
difference in our lifespans, a treatment that keeps a dog cancer-free for two years may provide ten to fifteen years of good health to a human.
I study of a vaccine for canine osteosarcoma. Mason
The University of Penn study is still enrolling dogs, and
is unusually well-suited to pursue the one medicine
if safety and efficacy of the vaccine continues to be
concept, as she has a veterinary degree and a doctorage
demonstrated, a larger phase II clinical trial is scheduled
in immunology.
to start in fall 2013. c
Fanciers and breeders can help their breed (and perhaps even themselves or their loved ones) by using the genetic tests available for diseases that strike their breed, and providing samples or pedigrees to any of the applicable ongoing studies. Breed clubs can donate to the AKC Canine Health Foundation with a directive on what disease they would like investigated. The crossspecies dog-human research concept has already demonstrated notable successes and seems poised to provide many more.
164 CANADIAN DOG Fancier