Clinical trial will assess effectiveness of canine cancer vaccine

A new high-risk, high-reward clinical trial of a potential cancer vaccine has received a grant enabling the project to go forward.

The test subjects?

Healthy, middle-aged pet dogs that will continue to live their normal lives at home and receive biennial exams with a complete clinical pathology workup. 

The trial will assess the effectiveness of a new vaccine at preventing any type of cancer in dogs.

The research team eventually wants to test the vaccine in humans. However, they feel that first testing it in dogs has many advantages.

Cancer is the leading cause of death in pet dogs and their cancers are very similar to their human counterparts. In addition, the canine immune system responds to tumors and vaccines similarly to that of humans, but the course of tumor development in dogs is much shorter.

Scientist Stephen Johnston thinks they can evaluate the effectiveness of the vaccine in five years or less, versus the 15 to 20 years it would take in a human trial. The vaccine they are testing in dogs will be comparable to the one they would test in people.

“Our goal has always been, that if this is possible, we should at least try it,” said Johnston, who directs the Biodesign Center for Innovations in Medicine and is a professor in the School of Life Sciences at Arizona State University. He will lead the research.

Searching for a vaccine

It’s been widely held that cancers are unique, and therefore a general, vaccine would not be possible.

However, Johnston’s team has identified tumor antigens that are common to all cancers. These toxins are the key components of their vaccine.

The new drug — a multivalent frame-shift peptide, or FSP vaccine — was developed by Johnston and his team over the past 10 years. The vaccine already has been tested for efficacy in mice and shown to be safe in dogs.

“We have been working over 10 years to develop a vaccine that could potentially prevent any cancer,” said Luhui Shen, senior science director of the vaccine project. “Our next goal is to test the vaccine in owner-enrolled, healthy dogs. We are fairly confident that if the vaccine works in dogs, it could work in people.”

How the trial will work

The trial will be conducted under the direction of Douglas Thamm, director of clinical research at the Flint Animal Cancer Center at Colorado State University.

Dogs will be randomly chosen to receive either the vaccine or a placebo. Dogs receiving the latter are expected to develop cancer at normal rates. The experiment will determine whether the vaccine can prevent cancers.

Any owner whose dog develops cancer during the trial, in either the test or control group, will be given a credit toward medical expenses.

If successful, this trial would provide strong support for the concept of employing FSP vaccines to prevent cancer in its earliest stages, possibly leading to a canine cancer vaccine. It could eventually justify human clinical trials for both treatment and prevention.

Open Philanthropy to the rescue

The research is moving forward because the Open Philanthropy Project recently awarded it a multi-year grant of $6.4 million.

The trial will be the largest interventional canine clinical study ever conducted.

“We consider this a high-risk project with an unusual opportunity for high impact as it possibly reduces the incidence of cancer and cancer metastasis,” the Open Philanthropy Project grant announcement said.

“We believe cancer preventative vaccines have a higher expected value than curative cancer therapies, since an effective vaccine would likely be a less expensive way to provide decades of healthy life compared to current cancer therapies, which often only extend life for a few months or years. We also believe cancer vaccines would be tractable in developing countries, which have a high cancer burden.”

“Open Philanthropy was the only organization that responded to support our high-risk project, the biggest cancer intervention trial in dogs ever. I really admire them for that,” said Johnston.