Therapeutic Modalities: Immunotherapy
Harnessing the immune system’s ability to fight cancer holds significant promise for treating aggressive malignancies, particularly in preventing or controlling metastatic disease.
Since the introduction of the Oncept canine melanoma vaccine in 2007, which was the first USDA-licensed immunotherapeutic agent for dogs with stage II or III oral melanoma, the field of veterinary immunotherapy has seen notable advancements as well as challenges. Oncept marked a significant step forward, but both progress and setbacks have occurred in developing further immunotherapeutics. To date, options remain limited, and some immunotherapies have been discontinued because of safety concerns or lack of efficacy identified in larger studies.
One of the notable recent developments is gilvetmab, which targets the PD-1 pathway in dogs. It is the first conditionally licensed caninized anti-PD-1 monoclonal antibody in veterinary medicine. It is labeled for use in dogs with stage I, II, or III MCTs and stage II or III melanoma. Gilvetmab results in immune checkpoint inhibition by preventing the suppression of T cells and enabling them to recognize and kill tumor cells. This therapeutic approach is designed to boost the immune system’s response against cancer cells, essentially “unmasking” the cancer cells to allow the dog’s immune system to target and attack them. Currently, this immunotherapeutic agent is only available through veterinary oncologists.
In addition to monoclonal antibodies like gilvetmab, ongoing research is exploring other immunotherapeutic approaches, including cancer vaccines, checkpoint inhibitors, and adoptive T-cell therapies. These therapies aim to bolster the body’s immune response against cancer cells and provide new treatment options, particularly for cancers that are resistant to conventional therapies.
Combination therapy will be crucial in the success of immunotherapy. Just as in human oncology, the effectiveness of immunotherapy in veterinary medicine often hinges on its integration with other treatment modalities, such as surgery, radiation therapy, and chemotherapy. These combinations can significantly enhance outcomes, offering new hope for patients with difficult-to-treat cancers. As the field of veterinary immunotherapy continues to advance, ongoing clinical trials and research are critical for determining the most effective therapies and combinations.
The 2026 AAHA Oncology Guidelines for Dogs and Cats are generously supported by CareCredit, Hill’s Pet Nutrition, Merck Animal Health, and Zoetis.
