No evidence of cancer found in dog after novel vaccine therapy

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A new vaccination shows successful treatment of canine cancer after a golden retriever, Hunter, has no evidence of bone cancer after therapy. In early 2022, Hunter was diagnosed with osteosarcoma, a prognosis of 70% of patients not living longer than 12 months after developing the disease.¹ Osteosarcoma is the most common primary bone tumor in dogs, representing 85% to 98% of all bone tumors.^2,3 Appendicular osteosarcoma is the most common malignant primary canine bone tumor and is typically found in large to giant dog breeds. When treated by amputation or tumor removal alone, median survival times do not exceed 5 months, with the majority of dogs suffering from metastatic disease.⁴

After undergoing treatment from Yale researcher, Mark Mamula, PhD, Hunter now has no evidence of cancer. The vaccination treatment is a form of immunotherapy that is currently under review by the US Department of Agriculture. The vaccine has also been tested in clinical trials⁵ and has demonstrated promising results for the vaccine, showing its effectiveness in hundreds of dogs, including Hunter.^1,5

Mamula is currently a professor of medicine (rheumatology) at Yale School of Medicine and has been working on this research development for years. "Dogs, just like humans, get cancer spontaneously; they grow and metastasize and mutate, just like human cancers do,” said Mamula in a Yale university release.¹ “If we can provide some benefit, some relief — a pain-free life — that is the best outcome that we could ever have.”

Much like in humans, researchers have discovered that dogs with various cancers, such as colorectal cancer, breast cancer, and osteosarcoma, exhibit elevated levels of proteins called epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2). The typical treatment for humans with these cancers involves monoclonal antibodies, which are proteins that can attach to and influence EGFR and/or HER2 function. However, patients often build resistance to these antibodies, diminishing their effectiveness over time.¹

To create a new treatment approach, Mamula and his team took am innovative route. While monoclonal antibody treatments are derived from a single immune cell and target specific parts of EGFR/HER2 molecules, Mamula and his team aimed to trigger a polyclonal response. This means generating antibodies from multiple immune cells rather than just one, enabling them to bind to various parts of the EGFR/HER2 molecules instead of a single area. The goal is to reduce the likelihood of resistance development, theoretically enhancing the treatment's effectiveness.^1,5

The first clinical trial was conducted in 2016 and more trials are still ongoing at 10 locations in the US and Canada. Over 300 dogs have now been treated with the vaccine. The vaccine induces the production of antibodies capable of targeting and binding to tumors, which then disrupt the signaling pathways responsible for tumor growth. The research team currently reports a notable improvement in the 12-month survival rates of dogs with varying types of cancers, at approximately 35% to 60%. Additionally, many dogs undergoing the treatment experience tumor shrinkage.^1,5 While exploring the vaccine's effectiveness in humans through clinical trials is a potential future step, the current focus for Mamula is obtaining USDA approval for the vaccine's use in dogs and its broader distribution.

“I get many emails from grateful dog owners who had been told that their pets had weeks or months to live but who are now 2 or 3 years past their cancer diagnosis,” Mamula said. “It’s a program that’s not only valuable to me as a dog lover. Witnessing the happiness that successful therapies provide to families with dogs is incredibly rewarding.”¹

Hunter had his front limb amputated and after the vaccine treatment, he has been cancer free for 2 years. He used to work alongside his owner, Deana Hudgins, as a search-and-rescue dog, helping find victims of building collapses and other disasters. After his cancer diagnosis, he no longer performs those duties, but now, at 11-years-old, Hunter helps Hudgins train other dogs.¹

Mamula told Yale that once this vaccine is approved and available on the market, it will be free for working dogs like Hunter.

References

1. Locklear M. Novel cancer vaccine offers new hope for dogs — and those who love them. News release. Yale University. March 5, 2024. Accessed March 11, 2024. https://news.yale.edu/2024/03/05/novel-cancer-vaccine-offers-new-hope-dogs-and-those-who-love-them
2. Dernell W, Straw R, Withrow S. Tumors of the skeletal system. In: Withrow S, MacEwen E, eds. Small Animal Clinical Oncology. WB Saunders; 2001:378-417.
3. Liptak JM, Dernell WS, Ehrhart N, Withrow SJ. Canine appendicular osteosarcoma: diagnosis and palliative treatment. Compendium. 2004;26(3):172-183.
4. Boerman I, Selvarajah GT, Nielen M, Kirpensteijn J. Prognostic factors in canine appendicular osteosarcoma - a meta-analysis. BMC Vet Res. 2012 May 15;8:56. doi: 10.1186/1746-6148-8-56. PMID: 22587466; PMCID: PMC3482154.
5. Doyle HA, Gee RJ, Masters TD, et al. Vaccine-induced ErbB (EGFR/HER2)-specific immunity in spontaneous canine cancer. Transl Oncol. 2021;14(11):101205. doi:10.1016/j.tranon.2021.101205