A cancer vaccine has shown efficacy in dogs, with implications for benefit in humans.
The most broadly known cancer vaccine available today is the human papillomavirus (HPV) 9-valent vaccine (Gardasil; Merck & Co), yet the HPV vaccine and others used in the fight against cancer do not prevent cancer. Instead, they prevent infectious diseases that can cause cancer; HPV, for example, has been linked to 6 different kinds of cancer and is the leading cause of cervical cancer.1
However, scientists have more recently been working on a vaccine targeting the prevention of the formation of cancer tumors. This new multicancer vaccine, developed by scientists at Calviri, focuses on RNA neoantigens, or molecules born of errors in RNA processing, and is currently being tested in a veterinary clinical trial. So far, the vaccine is working. What’s more, the positive data from studies in canines have already led to clinical trials in human participants.
How One Study and 800 Dogs Have Raised a Paw Against Cancer
There are currently more than 471 million canine pets globally.2 Just like people, our 4-legged family members can be struck by disease at any moment in their lifetimes. For dogs, the prevalence of disease is getting higher with each passing year; currently, 1 in 4 dogs will develop neoplasia, or abnormal tissue growths, at some point in their lives. Further, for dogs over the age of 10, there is a nearly 50% chance of being diagnosed with cancer—that’s almost the same rate of cancers as in humans. For this reason, researchers began developing a cancer vaccine for canines first.
Launched in 2019, the 5-year Vaccine Against Canine Cancer Study (VACCS) is the largest and most ambitious canine cancer vaccine study ever conducted and includes a clinical trial for Calviri’s cancer preventative vaccine. This clinical trial is different because it isn’t using lab dogs to test the efficacy and safety of potential drug candidates. Instead, just like in a human clinical trial, dogs must enroll—or rather be enrolled by willing pet parents—and qualify to participate through a series of health exams indicating no pre-existing cancer. The double-blind trial is split in half, with 400 dogs receiving the anti-cancer vaccine, which contains 31 antigens from 8 common canine cancers, and 400 dogs receiving a placebo.
In 2022, at the end of the study’s third year, an independent Data Safety Monitoring Board determined that there were no adverse events associated with the vaccine, and there’s sufficient positive clinical data to move forward to the next stage of study investigation: efficacy. Because we don’t know everything there is to know yet about cancer in canines, efficacy of the vaccine will be tested this year, as well as in years 4 and 5, to make sure that it’s effectively stopping cancer before it starts. Right now, all signs are pointing to the potential for efficacy in cancer prevention.
Transferring Veterinary Data into Human Data
Many pet owners are participating in VACCS program and the Calviri clinical trial because they hope, just as the scientists do, that information garnered from the canine clinical trial will inform the development of a pancancer preventative vaccine for humans. So far, researchers are learning a significant amount about the immunology of canine cancer. That matters not only in developing more accurate predictions and more viable treatments for canine cancer, but when translated across timescales, it will also help scientists better understand the immunology of cancer in humans.
Scientists and researchers are already putting that information to work for the development of preventative vaccines against cancer as well as therapeutic vaccines that, if successful, could replace outdated cancer treatments with a series of quick and simple injections. Right now, there are 3 vaccines our researchers are investigating: a therapeutic vaccine for dog hemangiosarcoma, a therapeutic vaccine for renal medullary carcinoma in humans, and a vaccine for the pediatric brain cancer neurofibromatosis in humans. These researchers understand that, for those who already have cancer or will be diagnosed before a preventative vaccine is available, early diagnosis remains critical. That’s why researchers are also working on improved diagnostics for multiple different types of cancers and have 3 diagnostics in phase 1 clinical trials right now: stage 1 breast cancer, stage 1 colorectal cancer, and ICI response and adverse events predictors for multiple cancers, including lung cancer.4
Today, cancer prevention and treatment are an underserved and unmet need, and where it currently exists it is financially out of reach for millions of people… and their dogs. Preventative pancancer vaccines are the key to saving billions of dollars, not only on veterinary health care, but on human health care too. Affordable therapeutics and preventative vaccines will be, and already are becoming, the gamechanger that could put an end to cancer once and for all. And that’s nothing to bark at.
About the Author
Stephen Albert Johnston, PhD, is the CEO at Calviri; director at Arizona State University Biodesign Institute’s Center for Innovations in Medicine; and professor at the Arizona State University School of Life Sciences.
Amy Carissa Oliver is an independent science researcher.