27 Feb Five-Year Trial Tests Universal Canine Cancer Vaccine
By Meghan Lepisto, University of Wisconsin School of Veterinary Medicine
Could the body’s own immune system be primed to prevent cancer through a quick vaccine? A clinical trial launched last fall aims to bring new clarity to this complex question.
“We’re testing a totally novel way of creating an anticancer immune response,” says David Vail, the Barbara A. Suran Chair in Comparative Oncology at the University of Wisconsin (UW) School of Veterinary Medicine.
The Vaccination Against Canine Cancer Study will evaluate a vaccine strategy for the prevention, rather than treatment, of cancer in dogs. With more than 800 patients enrolled as participants, it is the largest clinical trial conducted to date for canine cancer and across the history of veterinary medicine. The UW School of Veterinary Medicine is one of three participating institutions, together with Colorado State University and the University of California, Davis.
Cancer is the number one cause of illness and death in the aging dog population, with approximately one out of every three dogs affected and six million new cancer diagnoses made in dogs each year. If the trial is successful, it could provide both a new strategy to prevent a critical health concern in canine companions and justification for studying a similar approach in people.
Much like an influenza vaccine bolsters the body’s readiness to fight the flu, this preventative cancer vaccine follows the same principal.
Traditionally, vaccines work by introducing into the body a protein found on the surface of the virus that the vaccine is protecting against. The immune system sees the protein as a threat, establishes a memory of it, and then, if there is a later infection, recognizes that protein and is primed to react.
The anti-cancer vaccine targets approximately 30 abnormal proteins found on the surface of cancer cells. These proteins, a result of improperly coded RNA (so called frame-shift mutations), are generally only found in patients with cancer (both dogs and people) and are agnostic of cancer type. By injecting this cluster of proteins into healthy patients, along with a substance that stimulates an immune response, it’s theorized that the vaccine could
serve as a universal defender against cancer by “turning on” the immune system. Several cancers that are common to dogs are targeted, including lymphoma, osteosarcoma, hemangiosarcoma and mastocytomas.
Stephen Johnson, a professor at Arizona State University, developed the technology behind the vaccine.
The trial is slated to run over five years, with cancer-free, healthy dogs between the ages of six to 10 randomized to receive either a series of the investigational vaccine or placebo vaccines. Participating dogs will live at home and be checked two to three times yearly for five years after enrollment to monitor for the development of any cancers. This medical care will be covered by the study, which is funded by a $6 million grant from the Open Philanthropic Project. Information gleaned throughout the trial will advance scientists’ understanding of cancer, the immune system and how it responds.
The potential to preventively target numerous types of cancer with a single vaccine series would be a major paradigm shift in veterinary and human medicine, according to Vail. “The key is that you don’t have to personalize the vaccine to an individual, which is a very expensive proposition. This is more of a global vaccination.”
Initial trials of the vaccine in mice suggest that this strategy could be successful, but many in the scientific community remain unsure.
“Based on what we know right now about the immune system, there are several reasons why this vaccine shouldn’t work and there are several reasons why it could work,” says Vail. “With the possibility to prevent several cancer types before they develop, somebody absolutely needs to do the study.”