Cancer vaccines have long been a topic of debate, because cancer is an incredibly complex disease, making the creation of a vaccine–let alone one able to cover multiple cancers–seemingly impossible. But Stephen Johnston, the director of Arizona State University’s Center of Innovations in Medicine, is attempting the impossible. “If the chance is 10 percent that it might work,” Johnston, who is a scientist and inventor, told CNN, “I can’t see any reason why we shouldn’t take that chance.”
Johnston recently began a clinical trial, called the Vaccination Against Canine Cancer Study, to test out a cancer vaccine on hundreds of dogs in the United States; the trial will look into whether the vaccine is able to delay–or even prevent–an assortment of cancers in older dogs in fine shape. If this trial is a success, it could help Johnston and his team develop a similar vaccine for humans.
At first, Johnston set out to create and conduct a cancer vaccine trial in humans, but both the cost and approval process were grueling. By serendipity, perhaps, Johnston met Doug Thamm, a veterinarian and cancer survivor who’s the director of clinical research at the Flint Animal Cancer Center at Colorado State University. According to Thamm, cancer is the predominant cause of death in adult dogs, who spontaneously develop tumors as they get older, in a process similar to the way humans often develop cancer.
On a molecular level, many human and canine cancers are comparable as well, largely due to the fact that we live in the same environments. Furthermore, according to Thamm, dogs are very useful in a study like this because they have a shorter lifespan, so the research team can assess whether the vaccine is effective in three to five years instead of over a span of decades.
According to Johnston and Thamm, this is the largest interventional clinical trial ever performed in dogs. The canine-patients are first screened for health issues; half of those approved for the trial will receive a placebo, while the other half will receive the vaccine. Neither the vets nor the dogs’ owners will know which pups are receiving the vaccine and which aren’t, in order to prevent any bias from affecting the study’s results. The dogs will get four doses of the vaccine to start, then annual boosters for the study’s five years.
Thamm told CNN that there are three potential outcomes: that cancer will be delayed, appear at a lower incidence, or that the vaccine has no effect.
This model has actually worked in the past: the cancer drug known as Imbruvica was tested in dogs before it was fine tuned for humans.
However, even if the vaccine does work in canines, the team will have quite the battle achieving clearance to run a similar clinical trial in humans. This is because animal testing can be erratic, and the bulk of drugs that are tested in animals never get approved by the FDA to be used in humans because they’re considered ineffective or unsafe.